eventespresso / event-espresso-core

core/db_models/EEM_Registration.model.php

Indentation +866 added lines, -866 removed lines

@@ -13,815 +13,815 @@ 
 class EEM_Registration extends EEM_Soft_Delete_Base
 {
 
-    /**
-     * @var EEM_Registration $_instance
-     */
-    protected static $_instance;
-
-    /**
-     * Keys are the status IDs for registrations (eg, RAP, RCN, etc), and the values
-     * are status codes (eg, approved, cancelled, etc)
-     *
-     * @var array
-     */
-    private static $_reg_status;
-
-    /**
-     * The value of REG_count for a primary registrant
-     */
-    const PRIMARY_REGISTRANT_COUNT = 1;
-
-    /**
-     * Status ID (STS_ID on esp_status table) to indicate an INCOMPLETE registration.
-     * Initial status for registrations when they are first created
-     * Payments are NOT allowed.
-     * Automatically toggled to whatever the default Event registration status is upon completion of the attendee
-     * information reg step NO space reserved. Registration is NOT active
-     */
-    const status_id_incomplete = 'RIC';
-
-    /**
-     * Status ID (STS_ID on esp_status table) to indicate an UNAPPROVED registration.
-     * Payments are NOT allowed.
-     * Event Admin must manually toggle STS_ID for it to change
-     * No space reserved.
-     * Registration is active
-     */
-    const status_id_not_approved = 'RNA';
-
-    /**
-     * Status ID (STS_ID on esp_status table) to indicate registration is PENDING_PAYMENT .
-     * Payments are allowed.
-     * STS_ID will automatically be toggled to RAP if payment is made in full by the attendee
-     * No space reserved.
-     * Registration is active
-     */
-    const status_id_pending_payment = 'RPP';
-
-    /**
-     * Status ID (STS_ID on esp_status table) to indicate registration is on the WAIT_LIST .
-     * Payments are allowed.
-     * STS_ID will automatically be toggled to RAP if payment is made in full by the attendee
-     * No space reserved.
-     * Registration is active
-     */
-    const status_id_wait_list = 'RWL';
-
-    /**
-     * Status ID (STS_ID on esp_status table) to indicate an APPROVED registration.
-     * the TXN may or may not be completed ( paid in full )
-     * Payments are allowed.
-     * A space IS reserved.
-     * Registration is active
-     */
-    const status_id_approved = 'RAP';
-
-    /**
-     * Status ID (STS_ID on esp_status table) to indicate a registration was CANCELLED by the attendee.
-     * Payments are NOT allowed.
-     * NO space reserved.
-     * Registration is NOT active
-     */
-    const status_id_cancelled = 'RCN';
-
-    /**
-     * Status ID (STS_ID on esp_status table) to indicate a registration was DECLINED by the Event Admin
-     * Payments are NOT allowed.
-     * No space reserved.
-     * Registration is NOT active
-     */
-    const status_id_declined = 'RDC';
-
-    /**
-     * @var TableAnalysis $table_analysis
-     */
-    protected $_table_analysis;
-
-
-    /**
-     *    private constructor to prevent direct creation
-     *
-     * @Constructor
-     * @access protected
-     * @param string $timezone string representing the timezone we want to set for returned Date Time Strings (and any
-     *                         incoming timezone data that gets saved). Note this just sends the timezone info to the
-     *                         date time model field objects.  Default is NULL (and will be assumed using the set
-     *                         timezone in the 'timezone_string' wp option)
-     * @throws EE_Error
-     */
-    protected function __construct($timezone = null)
-    {
-        $this->_table_analysis = EE_Registry::instance()->create('TableAnalysis', array(), true);
-        $this->singular_item = esc_html__('Registration', 'event_espresso');
-        $this->plural_item = esc_html__('Registrations', 'event_espresso');
-        $this->_tables = array(
-            'Registration' => new EE_Primary_Table('esp_registration', 'REG_ID'),
-        );
-        $this->_fields = array(
-            'Registration' => array(
-                'REG_ID' => new EE_Primary_Key_Int_Field(
-                    'REG_ID',
-                    esc_html__('Registration ID', 'event_espresso')
-                ),
-                'EVT_ID' => new EE_Foreign_Key_Int_Field(
-                    'EVT_ID',
-                    esc_html__('Event ID', 'event_espresso'),
-                    false,
-                    0,
-                    'Event'
-                ),
-                'ATT_ID' => new EE_Foreign_Key_Int_Field(
-                    'ATT_ID',
-                    esc_html__('Attendee ID', 'event_espresso'),
-                    false,
-                    0,
-                    'Attendee'
-                ),
-                'TXN_ID' => new EE_Foreign_Key_Int_Field(
-                    'TXN_ID',
-                    esc_html__('Transaction ID', 'event_espresso'),
-                    false,
-                    0,
-                    'Transaction'
-                ),
-                'TKT_ID' => new EE_Foreign_Key_Int_Field(
-                    'TKT_ID',
-                    esc_html__('Ticket ID', 'event_espresso'),
-                    false,
-                    0,
-                    'Ticket'
-                ),
-                'STS_ID' => new EE_Foreign_Key_String_Field(
-                    'STS_ID',
-                    esc_html__('Status ID', 'event_espresso'),
-                    false,
-                    EEM_Registration::status_id_incomplete,
-                    'Status'
-                ),
-                'REG_date' => new EE_Datetime_Field(
-                    'REG_date',
-                    esc_html__('Time registration occurred', 'event_espresso'),
-                    false,
-                    EE_Datetime_Field::now,
-                    $timezone
-                ),
-                'REG_final_price' => new EE_Money_Field(
-                    'REG_final_price',
-                    esc_html__('Registration\'s share of the transaction total', 'event_espresso'),
-                    false,
-                    0
-                ),
-                'REG_paid' => new EE_Money_Field(
-                    'REG_paid',
-                    esc_html__('Amount paid to date towards registration', 'event_espresso'),
-                    false,
-                    0
-                ),
-                'REG_session' => new EE_Plain_Text_Field(
-                    'REG_session',
-                    esc_html__('Session ID of registration', 'event_espresso'),
-                    false,
-                    ''
-                ),
-                'REG_code' => new EE_Plain_Text_Field(
-                    'REG_code',
-                    esc_html__('Unique Code for this registration', 'event_espresso'),
-                    false,
-                    ''
-                ),
-                'REG_url_link' => new EE_Plain_Text_Field(
-                    'REG_url_link',
-                    esc_html__('String to be used in URL for identifying registration', 'event_espresso'),
-                    false,
-                    ''
-                ),
-                'REG_count' => new EE_Integer_Field(
-                    'REG_count',
-                    esc_html__('Count of this registration in the group registration ', 'event_espresso'),
-                    true,
-                    1
-                ),
-                'REG_group_size' => new EE_Integer_Field(
-                    'REG_group_size',
-                    esc_html__('Number of registrations on this group', 'event_espresso'),
-                    false,
-                    1
-                ),
-                'REG_att_is_going' => new EE_Boolean_Field(
-                    'REG_att_is_going',
-                    esc_html__('Flag indicating the registrant plans on attending', 'event_espresso'),
-                    false,
-                    false
-                ),
-                'REG_deleted' => new EE_Trashed_Flag_Field(
-                    'REG_deleted',
-                    esc_html__('Flag indicating if registration has been archived or not.', 'event_espresso'),
-                    false,
-                    false
-                ),
-            ),
-        );
-        $this->_model_relations = array(
-            'Event' => new EE_Belongs_To_Relation(),
-            'Attendee' => new EE_Belongs_To_Relation(),
-            'Transaction' => new EE_Belongs_To_Relation(),
-            'Ticket' => new EE_Belongs_To_Relation(),
-            'Status' => new EE_Belongs_To_Relation(),
-            'Answer' => new EE_Has_Many_Relation(),
-            'Checkin' => new EE_Has_Many_Relation(),
-            'Registration_Payment' => new EE_Has_Many_Relation(),
-            'Payment' => new EE_HABTM_Relation('Registration_Payment'),
-            'Message' => new EE_Has_Many_Any_Relation(false)
-            // allow deletes even if there are messages in the queue related
-        );
-        $this->_model_chain_to_wp_user = 'Event';
-        parent::__construct($timezone);
-    }
-
-
-    /**
-     * a list of ALL valid registration statuses currently in use within the system
-     * generated by combining the filterable active and inactive reg status arrays
-     *
-     * @return array
-     */
-    public static function reg_statuses()
-    {
-        return array_unique(
-            array_merge(
-                EEM_Registration::active_reg_statuses(),
-                EEM_Registration::inactive_reg_statuses()
-            )
-        );
-    }
-
-
-    /**
-     * reg_statuses_that_allow_payment
-     * a filterable list of registration statuses that allow a registrant to make a payment
-     *
-     * @access public
-     * @return array
-     */
-    public static function reg_statuses_that_allow_payment()
-    {
-        return apply_filters(
-            'FHEE__EEM_Registration__reg_statuses_that_allow_payment',
-            array(
-                EEM_Registration::status_id_approved,
-                EEM_Registration::status_id_pending_payment,
-            )
-        );
-    }
-
-
-    /**
-     * active_reg_statuses
-     * a filterable list of registration statuses that are considered active
-     *
-     * @access public
-     * @return array
-     */
-    public static function active_reg_statuses()
-    {
-        return apply_filters(
-            'FHEE__EEM_Registration__active_reg_statuses',
-            array(
-                EEM_Registration::status_id_approved,
-                EEM_Registration::status_id_pending_payment,
-                EEM_Registration::status_id_wait_list,
-                EEM_Registration::status_id_not_approved,
-            )
-        );
-    }
-
-
-    /**
-     * inactive_reg_statuses
-     * a filterable list of registration statuses that are not considered active
-     *
-     * @access public
-     * @return array
-     */
-    public static function inactive_reg_statuses()
-    {
-        return apply_filters(
-            'FHEE__EEM_Registration__inactive_reg_statuses',
-            array(
-                EEM_Registration::status_id_incomplete,
-                EEM_Registration::status_id_cancelled,
-                EEM_Registration::status_id_declined,
-            )
-        );
-    }
-
-
-    /**
-     *    closed_reg_statuses
-     *    a filterable list of registration statuses that are considered "closed"
-     * meaning they should not be considered in any calculations involving monies owing
-     *
-     * @access public
-     * @return array
-     */
-    public static function closed_reg_statuses()
-    {
-        return apply_filters(
-            'FHEE__EEM_Registration__closed_reg_statuses',
-            array(
-                EEM_Registration::status_id_cancelled,
-                EEM_Registration::status_id_declined,
-                EEM_Registration::status_id_wait_list,
-            )
-        );
-    }
-
-
-    /**
-     *        get list of registration statuses
-     *
-     * @access public
-     * @param array $exclude The status ids to exclude from the returned results
-     * @param bool $translated If true will return the values as singular localized strings
-     * @return array
-     * @throws EE_Error
-     */
-    public static function reg_status_array($exclude = array(), $translated = false)
-    {
-        EEM_Registration::instance()->_get_registration_status_array($exclude);
-        return $translated
-            ? EEM_Status::instance()->localized_status(self::$_reg_status, false, 'sentence')
-            : self::$_reg_status;
-    }
-
-
-    /**
-     *    get list of registration statuses
-     *
-     * @access private
-     * @param array $exclude
-     * @return void
-     * @throws EE_Error
-     */
-    private function _get_registration_status_array($exclude = array())
-    {
-        // in the very rare circumstance that we are deleting a model's table's data
-        // and the table hasn't actually been created, this could have an error
-        /** @type WPDB $wpdb */
-        global $wpdb;
-        if ($this->_get_table_analysis()->tableExists($wpdb->prefix . 'esp_status')) {
-            $results = $wpdb->get_results(
-                "SELECT STS_ID, STS_code FROM {$wpdb->prefix}esp_status WHERE STS_type = 'registration'"
-            );
-            self::$_reg_status = array();
-            foreach ($results as $status) {
-                if (!in_array($status->STS_ID, $exclude, true)) {
-                    self::$_reg_status[ $status->STS_ID ] = $status->STS_code;
-                }
-            }
-        }
-    }
-
-
-    /**
-     * Gets the injected table analyzer, or throws an exception
-     *
-     * @return TableAnalysis
-     * @throws EE_Error
-     */
-    protected function _get_table_analysis()
-    {
-        if ($this->_table_analysis instanceof TableAnalysis) {
-            return $this->_table_analysis;
-        }
-        throw new EE_Error(
-            sprintf(
-                esc_html__('Table analysis class on class %1$s is not set properly.', 'event_espresso'),
-                get_class($this)
-            )
-        );
-    }
-
-
-    /**
-     * This returns a wpdb->results array of all registration date month and years matching the incoming query params
-     * and grouped by month and year.
-     *
-     * @param  array $where_params @see https://github.com/eventespresso/event-espresso-core/tree/master/docs/G--Model-System/model-query-params.md#0-where-conditions
-     * @return array
-     * @throws EE_Error
-     */
-    public function get_reg_months_and_years($where_params)
-    {
-        $query_params[0] = $where_params;
-        $query_params['group_by'] = array('reg_year', 'reg_month');
-        $query_params['order_by'] = array('REG_date' => 'DESC');
-        $columns_to_select = array(
-            'reg_year' => array('YEAR(REG_date)', '%s'),
-            'reg_month' => array('MONTHNAME(REG_date)', '%s'),
-        );
-        return $this->_get_all_wpdb_results($query_params, OBJECT, $columns_to_select);
-    }
-
-
-    /**
-     * retrieve ALL registrations for a particular Attendee from db
-     *
-     * @param int $ATT_ID
-     * @return EE_Base_Class[]|EE_Registration[]|null
-     * @throws EE_Error
-     */
-    public function get_all_registrations_for_attendee($ATT_ID = 0)
-    {
-        if (!$ATT_ID) {
-            return null;
-        }
-        return $this->get_all(array(array('ATT_ID' => $ATT_ID)));
-    }
-
-
-    /**
-     * Gets a registration given their REG_url_link. Yes, this should usually
-     * be passed via a GET parameter.
-     *
-     * @param string $REG_url_link
-     * @return EE_Base_Class|EE_Registration|null
-     * @throws EE_Error
-     */
-    public function get_registration_for_reg_url_link($REG_url_link)
-    {
-        if (!$REG_url_link) {
-            return null;
-        }
-        return $this->get_one(array(array('REG_url_link' => $REG_url_link)));
-    }
-
-
-    /**
-     *        retrieve registration for a specific transaction attendee from db
-     *
-     * @access        public
-     * @param    int $TXN_ID
-     * @param    int $ATT_ID
-     * @param    int $att_nmbr in case the ATT_ID is the same for multiple registrations (same details used) then the
-     *                         attendee number is required
-     * @return        mixed        array on success, FALSE on fail
-     * @throws EE_Error
-     */
-    public function get_registration_for_transaction_attendee($TXN_ID = 0, $ATT_ID = 0, $att_nmbr = 0)
-    {
-        return $this->get_one(array(
-            array(
-                'TXN_ID' => $TXN_ID,
-                'ATT_ID' => $ATT_ID,
-            ),
-            'limit' => array(min($att_nmbr - 1, 0), 1),
-        ));
-    }
-
-
-    /**
-     *        get the number of registrations per day  for the Registration Admin page Reports Tab.
-     *        (doesn't utilize models because it's a fairly specialized query)
-     *
-     * @access        public
-     * @param $period string which can be passed to php's strtotime function (eg "-1 month")
-     * @return stdClass[] with properties regDate and total
-     * @throws EE_Error
-     */
-    public function get_registrations_per_day_report($period = '-1 month')
-    {
-        $sql_date = $this->convert_datetime_for_query(
-            'REG_date',
-            date('Y-m-d H:i:s', strtotime($period)),
-            'Y-m-d H:i:s',
-            'UTC'
-        );
-        $where = array(
-            'REG_date' => array('>=', $sql_date),
-            'STS_ID' => array('!=', EEM_Registration::status_id_incomplete),
-        );
-        if (!EE_Registry::instance()->CAP->current_user_can('ee_read_others_registrations', 'reg_per_day_report')) {
-            $where['Event.EVT_wp_user'] = get_current_user_id();
-        }
-        $query_interval = EEH_DTT_Helper::get_sql_query_interval_for_offset($this->get_timezone(), 'REG_date');
-        $results = $this->_get_all_wpdb_results(
-            array(
-                $where,
-                'group_by' => 'regDate',
-                'order_by' => array('REG_date' => 'ASC'),
-            ),
-            OBJECT,
-            array(
-                'regDate' => array('DATE(' . $query_interval . ')', '%s'),
-                'total' => array('count(REG_ID)', '%d'),
-            )
-        );
-        return $results;
-    }
-
-
-    /**
-     * Get the number of registrations per day including the count of registrations for each Registration Status.
-     * Note: EEM_Registration::status_id_incomplete registrations are excluded from the results.
-     *
-     * @param string $period
-     * @return stdClass[] with properties Registration_REG_date and a column for each registration status as the STS_ID
-     * @throws EE_Error
-     *                    (i.e. RAP)
-     */
-    public function get_registrations_per_day_and_per_status_report($period = '-1 month')
-    {
-        global $wpdb;
-        $registration_table = $wpdb->prefix . 'esp_registration';
-        $event_table = $wpdb->posts;
-        $sql_date = date('Y-m-d H:i:s', strtotime($period));
-        // prepare the query interval for displaying offset
-        $query_interval = EEH_DTT_Helper::get_sql_query_interval_for_offset($this->get_timezone(), 'dates.REG_date');
-        // inner date query
-        $inner_date_query = "SELECT DISTINCT REG_date from {$registration_table} ";
-        $inner_where = ' WHERE';
-        // exclude events not authored by user if permissions in effect
-        if (!EE_Registry::instance()->CAP->current_user_can('ee_read_others_registrations', 'reg_per_event_report')) {
-            $inner_date_query .= "LEFT JOIN {$event_table} ON ID = EVT_ID";
-            $inner_where .= ' post_author = ' . get_current_user_id() . ' AND';
-        }
-        $inner_where .= " REG_date >= '{$sql_date}'";
-        $inner_date_query .= $inner_where;
-        // start main query
-        $select = "SELECT DATE({$query_interval}) as Registration_REG_date, ";
-        $join = '';
-        $join_parts = array();
-        $select_parts = array();
-        // loop through registration stati to do parts for each status.
-        foreach (EEM_Registration::reg_status_array() as $STS_ID => $STS_code) {
-            if ($STS_ID === EEM_Registration::status_id_incomplete) {
-                continue;
-            }
-            $select_parts[] = "COUNT({$STS_code}.REG_ID) as {$STS_ID}";
-            $join_parts[] = "{$registration_table} AS {$STS_code} ON {$STS_code}.REG_date = dates.REG_date AND {$STS_code}.STS_ID = '{$STS_ID}'";
-        }
-        // setup the selects
-        $select .= implode(', ', $select_parts);
-        $select .= " FROM ($inner_date_query) AS dates LEFT JOIN ";
-        // setup the joins
-        $join .= implode(' LEFT JOIN ', $join_parts);
-        // now let's put it all together
-        $query = $select . $join . ' GROUP BY Registration_REG_date';
-        // and execute it
-        return $wpdb->get_results($query, ARRAY_A);
-    }
-
-
-    /**
-     *        get the number of registrations per event  for the Registration Admin page Reports Tab
-     *
-     * @access        public
-     * @param $period string which can be passed to php's strtotime function (eg "-1 month")
-     * @return stdClass[] each with properties event_name, reg_limit, and total
-     * @throws EE_Error
-     */
-    public function get_registrations_per_event_report($period = '-1 month')
-    {
-        $date_sql = $this->convert_datetime_for_query(
-            'REG_date',
-            date('Y-m-d H:i:s', strtotime($period)),
-            'Y-m-d H:i:s',
-            'UTC'
-        );
-        $where = array(
-            'REG_date' => array('>=', $date_sql),
-            'STS_ID' => array('!=', EEM_Registration::status_id_incomplete),
-        );
-        if (!EE_Registry::instance()->CAP->current_user_can(
-            'ee_read_others_registrations',
-            'reg_per_event_report'
-        )
-        ) {
-            $where['Event.EVT_wp_user'] = get_current_user_id();
-        }
-        $results = $this->_get_all_wpdb_results(
-            array(
-            $where,
-            'group_by' => 'Event.EVT_name',
-            'order_by' => 'Event.EVT_name',
-            'limit' => array(0, 24),
-            ),
-            OBJECT,
-            array(
-                'event_name' => array('Event_CPT.post_title', '%s'),
-                'total' => array('COUNT(REG_ID)', '%s'),
-            )
-        );
-        return $results;
-    }
-
-
-    /**
-     * Get the number of registrations per event grouped by registration status.
-     * Note: EEM_Registration::status_id_incomplete registrations are excluded from the results.
-     *
-     * @param string $period
-     * @return stdClass[] with properties `Registration_Event` and a column for each registration status as the STS_ID
-     * @throws EE_Error
-     *                    (i.e. RAP)
-     */
-    public function get_registrations_per_event_and_per_status_report($period = '-1 month')
-    {
-        global $wpdb;
-        $registration_table = $wpdb->prefix . 'esp_registration';
-        $event_table = $wpdb->posts;
-        $sql_date = date('Y-m-d H:i:s', strtotime($period));
-        // inner date query
-        $inner_date_query = "SELECT DISTINCT EVT_ID, REG_date from $registration_table ";
-        $inner_where = ' WHERE';
-        // exclude events not authored by user if permissions in effect
-        if (!EE_Registry::instance()->CAP->current_user_can('ee_read_others_registrations', 'reg_per_event_report')) {
-            $inner_date_query .= "LEFT JOIN {$event_table} ON ID = EVT_ID";
-            $inner_where .= ' post_author = ' . get_current_user_id() . ' AND';
-        }
-        $inner_where .= " REG_date >= '{$sql_date}'";
-        $inner_date_query .= $inner_where;
-        // build main query
-        $select = 'SELECT Event.post_title as Registration_Event, ';
-        $join = '';
-        $join_parts = array();
-        $select_parts = array();
-        // loop through registration stati to do parts for each status.
-        foreach (EEM_Registration::reg_status_array() as $STS_ID => $STS_code) {
-            if ($STS_ID === EEM_Registration::status_id_incomplete) {
-                continue;
-            }
-            $select_parts[] = "COUNT({$STS_code}.REG_ID) as {$STS_ID}";
-            $join_parts[] = "{$registration_table} AS {$STS_code} ON {$STS_code}.EVT_ID = dates.EVT_ID AND {$STS_code}.STS_ID = '{$STS_ID}' AND {$STS_code}.REG_date = dates.REG_date";
-        }
-        // setup the selects
-        $select .= implode(', ', $select_parts);
-        $select .= " FROM ($inner_date_query) AS dates LEFT JOIN $event_table as Event ON Event.ID = dates.EVT_ID LEFT JOIN ";
-        // setup remaining joins
-        $join .= implode(' LEFT JOIN ', $join_parts);
-        // now put it all together
-        $query = $select . $join . ' GROUP BY Registration_Event';
-        // and execute
-        return $wpdb->get_results($query, ARRAY_A);
-    }
-
-
-    /**
-     * Returns the EE_Registration of the primary attendee on the transaction id provided
-     *
-     * @param int $TXN_ID
-     * @return EE_Base_Class|EE_Registration|null
-     * @throws EE_Error
-     */
-    public function get_primary_registration_for_transaction_ID($TXN_ID = 0)
-    {
-        if (!$TXN_ID) {
-            return null;
-        }
-        return $this->get_one(array(
-            array(
-                'TXN_ID' => $TXN_ID,
-                'REG_count' => EEM_Registration::PRIMARY_REGISTRANT_COUNT,
-            ),
-        ));
-    }
-
-
-    /**
-     *        get_event_registration_count
-     *
-     * @access public
-     * @param int $EVT_ID
-     * @param boolean $for_incomplete_payments
-     * @return int
-     * @throws EE_Error
-     */
-    public function get_event_registration_count($EVT_ID, $for_incomplete_payments = false)
-    {
-        // we only count approved registrations towards registration limits
-        $query_params = array(array('EVT_ID' => $EVT_ID, 'STS_ID' => self::status_id_approved));
-        if ($for_incomplete_payments) {
-            $query_params[0]['Transaction.STS_ID'] = array('!=', EEM_Transaction::complete_status_code);
-        }
-        return $this->count($query_params);
-    }
-
-
-    /**
-     * Deletes all registrations with no transactions. Note that this needs to be very efficient
-     * and so it uses wpdb directly
-     *
-     * @global WPDB $wpdb
-     * @return int number deleted
-     * @throws EE_Error
-     */
-    public function delete_registrations_with_no_transaction()
-    {
-        /** @type WPDB $wpdb */
-        global $wpdb;
-        return $wpdb->query(
-            'DELETE r FROM '
-            . $this->table()
-            . ' r LEFT JOIN '
-            . EEM_Transaction::instance()->table()
-            . ' t ON r.TXN_ID = t.TXN_ID WHERE t.TXN_ID IS NULL'
-        );
-    }
-
-
-    /**
-     *  Count registrations checked into (or out of) a datetime
-     *
-     * @param int $DTT_ID datetime ID
-     * @param boolean $checked_in whether to count registrations checked IN or OUT
-     * @return int
-     * @throws EE_Error
-     */
-    public function count_registrations_checked_into_datetime($DTT_ID, $checked_in = true)
-    {
-        global $wpdb;
-        // subquery to get latest checkin
-        $query = $wpdb->prepare(
-            'SELECT '
-            . 'COUNT( DISTINCT checkins.REG_ID ) '
-            . 'FROM ' . EEM_Checkin::instance()->table() . ' AS checkins INNER JOIN'
-            . '( SELECT '
-            . 'max( CHK_timestamp ) AS latest_checkin, '
-            . 'REG_ID AS REG_ID '
-            . 'FROM ' . EEM_Checkin::instance()->table() . ' '
-            . 'WHERE DTT_ID=%d '
-            . 'GROUP BY REG_ID'
-            . ') AS most_recent_checkin_per_reg '
-            . 'ON checkins.REG_ID=most_recent_checkin_per_reg.REG_ID '
-            . 'AND checkins.CHK_timestamp = most_recent_checkin_per_reg.latest_checkin '
-            . 'WHERE '
-            . 'checkins.CHK_in=%d',
-            $DTT_ID,
-            $checked_in
-        );
-        return (int) $wpdb->get_var($query);
-    }
-
-
-    /**
-     *  Count registrations checked into (or out of) an event.
-     *
-     * @param int $EVT_ID event ID
-     * @param boolean $checked_in whether to count registrations checked IN or OUT
-     * @return int
-     * @throws EE_Error
-     */
-    public function count_registrations_checked_into_event($EVT_ID, $checked_in = true)
-    {
-        global $wpdb;
-        // subquery to get latest checkin
-        $query = $wpdb->prepare(
-            'SELECT '
-            . 'COUNT( DISTINCT checkins.REG_ID ) '
-            . 'FROM ' . EEM_Checkin::instance()->table() . ' AS checkins INNER JOIN'
-            . '( SELECT '
-            . 'max( CHK_timestamp ) AS latest_checkin, '
-            . 'REG_ID AS REG_ID '
-            . 'FROM ' . EEM_Checkin::instance()->table() . ' AS c '
-            . 'INNER JOIN ' . EEM_Datetime::instance()->table() . ' AS d '
-            . 'ON c.DTT_ID=d.DTT_ID '
-            . 'WHERE d.EVT_ID=%d '
-            . 'GROUP BY REG_ID'
-            . ') AS most_recent_checkin_per_reg '
-            . 'ON checkins.REG_ID=most_recent_checkin_per_reg.REG_ID '
-            . 'AND checkins.CHK_timestamp = most_recent_checkin_per_reg.latest_checkin '
-            . 'WHERE '
-            . 'checkins.CHK_in=%d',
-            $EVT_ID,
-            $checked_in
-        );
-        return (int) $wpdb->get_var($query);
-    }
-
-
-    /**
-     * The purpose of this method is to retrieve an array of
-     * EE_Registration objects that represent the latest registration
-     * for each ATT_ID given in the function argument.
-     *
-     * @param array $attendee_ids
-     * @return EE_Base_Class[]|EE_Registration[]
-     * @throws EE_Error
-     */
-    public function get_latest_registration_for_each_of_given_contacts($attendee_ids = array())
-    {
-        // first do a native wp_query to get the latest REG_ID's matching these attendees.
-        global $wpdb;
-        $registration_table = $wpdb->prefix . 'esp_registration';
-        $attendee_table = $wpdb->posts;
-        $attendee_ids = is_array($attendee_ids)
-            ? array_map('absint', $attendee_ids)
-            : array((int) $attendee_ids);
-        $ATT_IDs = implode(',', $attendee_ids);
-        // first we do a query to get the registration ids
-        // (because a group by before order by causes the order by to be ignored.)
-        $registration_id_query = "
+	/**
+	 * @var EEM_Registration $_instance
+	 */
+	protected static $_instance;
+
+	/**
+	 * Keys are the status IDs for registrations (eg, RAP, RCN, etc), and the values
+	 * are status codes (eg, approved, cancelled, etc)
+	 *
+	 * @var array
+	 */
+	private static $_reg_status;
+
+	/**
+	 * The value of REG_count for a primary registrant
+	 */
+	const PRIMARY_REGISTRANT_COUNT = 1;
+
+	/**
+	 * Status ID (STS_ID on esp_status table) to indicate an INCOMPLETE registration.
+	 * Initial status for registrations when they are first created
+	 * Payments are NOT allowed.
+	 * Automatically toggled to whatever the default Event registration status is upon completion of the attendee
+	 * information reg step NO space reserved. Registration is NOT active
+	 */
+	const status_id_incomplete = 'RIC';
+
+	/**
+	 * Status ID (STS_ID on esp_status table) to indicate an UNAPPROVED registration.
+	 * Payments are NOT allowed.
+	 * Event Admin must manually toggle STS_ID for it to change
+	 * No space reserved.
+	 * Registration is active
+	 */
+	const status_id_not_approved = 'RNA';
+
+	/**
+	 * Status ID (STS_ID on esp_status table) to indicate registration is PENDING_PAYMENT .
+	 * Payments are allowed.
+	 * STS_ID will automatically be toggled to RAP if payment is made in full by the attendee
+	 * No space reserved.
+	 * Registration is active
+	 */
+	const status_id_pending_payment = 'RPP';
+
+	/**
+	 * Status ID (STS_ID on esp_status table) to indicate registration is on the WAIT_LIST .
+	 * Payments are allowed.
+	 * STS_ID will automatically be toggled to RAP if payment is made in full by the attendee
+	 * No space reserved.
+	 * Registration is active
+	 */
+	const status_id_wait_list = 'RWL';
+
+	/**
+	 * Status ID (STS_ID on esp_status table) to indicate an APPROVED registration.
+	 * the TXN may or may not be completed ( paid in full )
+	 * Payments are allowed.
+	 * A space IS reserved.
+	 * Registration is active
+	 */
+	const status_id_approved = 'RAP';
+
+	/**
+	 * Status ID (STS_ID on esp_status table) to indicate a registration was CANCELLED by the attendee.
+	 * Payments are NOT allowed.
+	 * NO space reserved.
+	 * Registration is NOT active
+	 */
+	const status_id_cancelled = 'RCN';
+
+	/**
+	 * Status ID (STS_ID on esp_status table) to indicate a registration was DECLINED by the Event Admin
+	 * Payments are NOT allowed.
+	 * No space reserved.
+	 * Registration is NOT active
+	 */
+	const status_id_declined = 'RDC';
+
+	/**
+	 * @var TableAnalysis $table_analysis
+	 */
+	protected $_table_analysis;
+
+
+	/**
+	 *    private constructor to prevent direct creation
+	 *
+	 * @Constructor
+	 * @access protected
+	 * @param string $timezone string representing the timezone we want to set for returned Date Time Strings (and any
+	 *                         incoming timezone data that gets saved). Note this just sends the timezone info to the
+	 *                         date time model field objects.  Default is NULL (and will be assumed using the set
+	 *                         timezone in the 'timezone_string' wp option)
+	 * @throws EE_Error
+	 */
+	protected function __construct($timezone = null)
+	{
+		$this->_table_analysis = EE_Registry::instance()->create('TableAnalysis', array(), true);
+		$this->singular_item = esc_html__('Registration', 'event_espresso');
+		$this->plural_item = esc_html__('Registrations', 'event_espresso');
+		$this->_tables = array(
+			'Registration' => new EE_Primary_Table('esp_registration', 'REG_ID'),
+		);
+		$this->_fields = array(
+			'Registration' => array(
+				'REG_ID' => new EE_Primary_Key_Int_Field(
+					'REG_ID',
+					esc_html__('Registration ID', 'event_espresso')
+				),
+				'EVT_ID' => new EE_Foreign_Key_Int_Field(
+					'EVT_ID',
+					esc_html__('Event ID', 'event_espresso'),
+					false,
+					0,
+					'Event'
+				),
+				'ATT_ID' => new EE_Foreign_Key_Int_Field(
+					'ATT_ID',
+					esc_html__('Attendee ID', 'event_espresso'),
+					false,
+					0,
+					'Attendee'
+				),
+				'TXN_ID' => new EE_Foreign_Key_Int_Field(
+					'TXN_ID',
+					esc_html__('Transaction ID', 'event_espresso'),
+					false,
+					0,
+					'Transaction'
+				),
+				'TKT_ID' => new EE_Foreign_Key_Int_Field(
+					'TKT_ID',
+					esc_html__('Ticket ID', 'event_espresso'),
+					false,
+					0,
+					'Ticket'
+				),
+				'STS_ID' => new EE_Foreign_Key_String_Field(
+					'STS_ID',
+					esc_html__('Status ID', 'event_espresso'),
+					false,
+					EEM_Registration::status_id_incomplete,
+					'Status'
+				),
+				'REG_date' => new EE_Datetime_Field(
+					'REG_date',
+					esc_html__('Time registration occurred', 'event_espresso'),
+					false,
+					EE_Datetime_Field::now,
+					$timezone
+				),
+				'REG_final_price' => new EE_Money_Field(
+					'REG_final_price',
+					esc_html__('Registration\'s share of the transaction total', 'event_espresso'),
+					false,
+					0
+				),
+				'REG_paid' => new EE_Money_Field(
+					'REG_paid',
+					esc_html__('Amount paid to date towards registration', 'event_espresso'),
+					false,
+					0
+				),
+				'REG_session' => new EE_Plain_Text_Field(
+					'REG_session',
+					esc_html__('Session ID of registration', 'event_espresso'),
+					false,
+					''
+				),
+				'REG_code' => new EE_Plain_Text_Field(
+					'REG_code',
+					esc_html__('Unique Code for this registration', 'event_espresso'),
+					false,
+					''
+				),
+				'REG_url_link' => new EE_Plain_Text_Field(
+					'REG_url_link',
+					esc_html__('String to be used in URL for identifying registration', 'event_espresso'),
+					false,
+					''
+				),
+				'REG_count' => new EE_Integer_Field(
+					'REG_count',
+					esc_html__('Count of this registration in the group registration ', 'event_espresso'),
+					true,
+					1
+				),
+				'REG_group_size' => new EE_Integer_Field(
+					'REG_group_size',
+					esc_html__('Number of registrations on this group', 'event_espresso'),
+					false,
+					1
+				),
+				'REG_att_is_going' => new EE_Boolean_Field(
+					'REG_att_is_going',
+					esc_html__('Flag indicating the registrant plans on attending', 'event_espresso'),
+					false,
+					false
+				),
+				'REG_deleted' => new EE_Trashed_Flag_Field(
+					'REG_deleted',
+					esc_html__('Flag indicating if registration has been archived or not.', 'event_espresso'),
+					false,
+					false
+				),
+			),
+		);
+		$this->_model_relations = array(
+			'Event' => new EE_Belongs_To_Relation(),
+			'Attendee' => new EE_Belongs_To_Relation(),
+			'Transaction' => new EE_Belongs_To_Relation(),
+			'Ticket' => new EE_Belongs_To_Relation(),
+			'Status' => new EE_Belongs_To_Relation(),
+			'Answer' => new EE_Has_Many_Relation(),
+			'Checkin' => new EE_Has_Many_Relation(),
+			'Registration_Payment' => new EE_Has_Many_Relation(),
+			'Payment' => new EE_HABTM_Relation('Registration_Payment'),
+			'Message' => new EE_Has_Many_Any_Relation(false)
+			// allow deletes even if there are messages in the queue related
+		);
+		$this->_model_chain_to_wp_user = 'Event';
+		parent::__construct($timezone);
+	}
+
+
+	/**
+	 * a list of ALL valid registration statuses currently in use within the system
+	 * generated by combining the filterable active and inactive reg status arrays
+	 *
+	 * @return array
+	 */
+	public static function reg_statuses()
+	{
+		return array_unique(
+			array_merge(
+				EEM_Registration::active_reg_statuses(),
+				EEM_Registration::inactive_reg_statuses()
+			)
+		);
+	}
+
+
+	/**
+	 * reg_statuses_that_allow_payment
+	 * a filterable list of registration statuses that allow a registrant to make a payment
+	 *
+	 * @access public
+	 * @return array
+	 */
+	public static function reg_statuses_that_allow_payment()
+	{
+		return apply_filters(
+			'FHEE__EEM_Registration__reg_statuses_that_allow_payment',
+			array(
+				EEM_Registration::status_id_approved,
+				EEM_Registration::status_id_pending_payment,
+			)
+		);
+	}
+
+
+	/**
+	 * active_reg_statuses
+	 * a filterable list of registration statuses that are considered active
+	 *
+	 * @access public
+	 * @return array
+	 */
+	public static function active_reg_statuses()
+	{
+		return apply_filters(
+			'FHEE__EEM_Registration__active_reg_statuses',
+			array(
+				EEM_Registration::status_id_approved,
+				EEM_Registration::status_id_pending_payment,
+				EEM_Registration::status_id_wait_list,
+				EEM_Registration::status_id_not_approved,
+			)
+		);
+	}
+
+
+	/**
+	 * inactive_reg_statuses
+	 * a filterable list of registration statuses that are not considered active
+	 *
+	 * @access public
+	 * @return array
+	 */
+	public static function inactive_reg_statuses()
+	{
+		return apply_filters(
+			'FHEE__EEM_Registration__inactive_reg_statuses',
+			array(
+				EEM_Registration::status_id_incomplete,
+				EEM_Registration::status_id_cancelled,
+				EEM_Registration::status_id_declined,
+			)
+		);
+	}
+
+
+	/**
+	 *    closed_reg_statuses
+	 *    a filterable list of registration statuses that are considered "closed"
+	 * meaning they should not be considered in any calculations involving monies owing
+	 *
+	 * @access public
+	 * @return array
+	 */
+	public static function closed_reg_statuses()
+	{
+		return apply_filters(
+			'FHEE__EEM_Registration__closed_reg_statuses',
+			array(
+				EEM_Registration::status_id_cancelled,
+				EEM_Registration::status_id_declined,
+				EEM_Registration::status_id_wait_list,
+			)
+		);
+	}
+
+
+	/**
+	 *        get list of registration statuses
+	 *
+	 * @access public
+	 * @param array $exclude The status ids to exclude from the returned results
+	 * @param bool $translated If true will return the values as singular localized strings
+	 * @return array
+	 * @throws EE_Error
+	 */
+	public static function reg_status_array($exclude = array(), $translated = false)
+	{
+		EEM_Registration::instance()->_get_registration_status_array($exclude);
+		return $translated
+			? EEM_Status::instance()->localized_status(self::$_reg_status, false, 'sentence')
+			: self::$_reg_status;
+	}
+
+
+	/**
+	 *    get list of registration statuses
+	 *
+	 * @access private
+	 * @param array $exclude
+	 * @return void
+	 * @throws EE_Error
+	 */
+	private function _get_registration_status_array($exclude = array())
+	{
+		// in the very rare circumstance that we are deleting a model's table's data
+		// and the table hasn't actually been created, this could have an error
+		/** @type WPDB $wpdb */
+		global $wpdb;
+		if ($this->_get_table_analysis()->tableExists($wpdb->prefix . 'esp_status')) {
+			$results = $wpdb->get_results(
+				"SELECT STS_ID, STS_code FROM {$wpdb->prefix}esp_status WHERE STS_type = 'registration'"
+			);
+			self::$_reg_status = array();
+			foreach ($results as $status) {
+				if (!in_array($status->STS_ID, $exclude, true)) {
+					self::$_reg_status[ $status->STS_ID ] = $status->STS_code;
+				}
+			}
+		}
+	}
+
+
+	/**
+	 * Gets the injected table analyzer, or throws an exception
+	 *
+	 * @return TableAnalysis
+	 * @throws EE_Error
+	 */
+	protected function _get_table_analysis()
+	{
+		if ($this->_table_analysis instanceof TableAnalysis) {
+			return $this->_table_analysis;
+		}
+		throw new EE_Error(
+			sprintf(
+				esc_html__('Table analysis class on class %1$s is not set properly.', 'event_espresso'),
+				get_class($this)
+			)
+		);
+	}
+
+
+	/**
+	 * This returns a wpdb->results array of all registration date month and years matching the incoming query params
+	 * and grouped by month and year.
+	 *
+	 * @param  array $where_params @see https://github.com/eventespresso/event-espresso-core/tree/master/docs/G--Model-System/model-query-params.md#0-where-conditions
+	 * @return array
+	 * @throws EE_Error
+	 */
+	public function get_reg_months_and_years($where_params)
+	{
+		$query_params[0] = $where_params;
+		$query_params['group_by'] = array('reg_year', 'reg_month');
+		$query_params['order_by'] = array('REG_date' => 'DESC');
+		$columns_to_select = array(
+			'reg_year' => array('YEAR(REG_date)', '%s'),
+			'reg_month' => array('MONTHNAME(REG_date)', '%s'),
+		);
+		return $this->_get_all_wpdb_results($query_params, OBJECT, $columns_to_select);
+	}
+
+
+	/**
+	 * retrieve ALL registrations for a particular Attendee from db
+	 *
+	 * @param int $ATT_ID
+	 * @return EE_Base_Class[]|EE_Registration[]|null
+	 * @throws EE_Error
+	 */
+	public function get_all_registrations_for_attendee($ATT_ID = 0)
+	{
+		if (!$ATT_ID) {
+			return null;
+		}
+		return $this->get_all(array(array('ATT_ID' => $ATT_ID)));
+	}
+
+
+	/**
+	 * Gets a registration given their REG_url_link. Yes, this should usually
+	 * be passed via a GET parameter.
+	 *
+	 * @param string $REG_url_link
+	 * @return EE_Base_Class|EE_Registration|null
+	 * @throws EE_Error
+	 */
+	public function get_registration_for_reg_url_link($REG_url_link)
+	{
+		if (!$REG_url_link) {
+			return null;
+		}
+		return $this->get_one(array(array('REG_url_link' => $REG_url_link)));
+	}
+
+
+	/**
+	 *        retrieve registration for a specific transaction attendee from db
+	 *
+	 * @access        public
+	 * @param    int $TXN_ID
+	 * @param    int $ATT_ID
+	 * @param    int $att_nmbr in case the ATT_ID is the same for multiple registrations (same details used) then the
+	 *                         attendee number is required
+	 * @return        mixed        array on success, FALSE on fail
+	 * @throws EE_Error
+	 */
+	public function get_registration_for_transaction_attendee($TXN_ID = 0, $ATT_ID = 0, $att_nmbr = 0)
+	{
+		return $this->get_one(array(
+			array(
+				'TXN_ID' => $TXN_ID,
+				'ATT_ID' => $ATT_ID,
+			),
+			'limit' => array(min($att_nmbr - 1, 0), 1),
+		));
+	}
+
+
+	/**
+	 *        get the number of registrations per day  for the Registration Admin page Reports Tab.
+	 *        (doesn't utilize models because it's a fairly specialized query)
+	 *
+	 * @access        public
+	 * @param $period string which can be passed to php's strtotime function (eg "-1 month")
+	 * @return stdClass[] with properties regDate and total
+	 * @throws EE_Error
+	 */
+	public function get_registrations_per_day_report($period = '-1 month')
+	{
+		$sql_date = $this->convert_datetime_for_query(
+			'REG_date',
+			date('Y-m-d H:i:s', strtotime($period)),
+			'Y-m-d H:i:s',
+			'UTC'
+		);
+		$where = array(
+			'REG_date' => array('>=', $sql_date),
+			'STS_ID' => array('!=', EEM_Registration::status_id_incomplete),
+		);
+		if (!EE_Registry::instance()->CAP->current_user_can('ee_read_others_registrations', 'reg_per_day_report')) {
+			$where['Event.EVT_wp_user'] = get_current_user_id();
+		}
+		$query_interval = EEH_DTT_Helper::get_sql_query_interval_for_offset($this->get_timezone(), 'REG_date');
+		$results = $this->_get_all_wpdb_results(
+			array(
+				$where,
+				'group_by' => 'regDate',
+				'order_by' => array('REG_date' => 'ASC'),
+			),
+			OBJECT,
+			array(
+				'regDate' => array('DATE(' . $query_interval . ')', '%s'),
+				'total' => array('count(REG_ID)', '%d'),
+			)
+		);
+		return $results;
+	}
+
+
+	/**
+	 * Get the number of registrations per day including the count of registrations for each Registration Status.
+	 * Note: EEM_Registration::status_id_incomplete registrations are excluded from the results.
+	 *
+	 * @param string $period
+	 * @return stdClass[] with properties Registration_REG_date and a column for each registration status as the STS_ID
+	 * @throws EE_Error
+	 *                    (i.e. RAP)
+	 */
+	public function get_registrations_per_day_and_per_status_report($period = '-1 month')
+	{
+		global $wpdb;
+		$registration_table = $wpdb->prefix . 'esp_registration';
+		$event_table = $wpdb->posts;
+		$sql_date = date('Y-m-d H:i:s', strtotime($period));
+		// prepare the query interval for displaying offset
+		$query_interval = EEH_DTT_Helper::get_sql_query_interval_for_offset($this->get_timezone(), 'dates.REG_date');
+		// inner date query
+		$inner_date_query = "SELECT DISTINCT REG_date from {$registration_table} ";
+		$inner_where = ' WHERE';
+		// exclude events not authored by user if permissions in effect
+		if (!EE_Registry::instance()->CAP->current_user_can('ee_read_others_registrations', 'reg_per_event_report')) {
+			$inner_date_query .= "LEFT JOIN {$event_table} ON ID = EVT_ID";
+			$inner_where .= ' post_author = ' . get_current_user_id() . ' AND';
+		}
+		$inner_where .= " REG_date >= '{$sql_date}'";
+		$inner_date_query .= $inner_where;
+		// start main query
+		$select = "SELECT DATE({$query_interval}) as Registration_REG_date, ";
+		$join = '';
+		$join_parts = array();
+		$select_parts = array();
+		// loop through registration stati to do parts for each status.
+		foreach (EEM_Registration::reg_status_array() as $STS_ID => $STS_code) {
+			if ($STS_ID === EEM_Registration::status_id_incomplete) {
+				continue;
+			}
+			$select_parts[] = "COUNT({$STS_code}.REG_ID) as {$STS_ID}";
+			$join_parts[] = "{$registration_table} AS {$STS_code} ON {$STS_code}.REG_date = dates.REG_date AND {$STS_code}.STS_ID = '{$STS_ID}'";
+		}
+		// setup the selects
+		$select .= implode(', ', $select_parts);
+		$select .= " FROM ($inner_date_query) AS dates LEFT JOIN ";
+		// setup the joins
+		$join .= implode(' LEFT JOIN ', $join_parts);
+		// now let's put it all together
+		$query = $select . $join . ' GROUP BY Registration_REG_date';
+		// and execute it
+		return $wpdb->get_results($query, ARRAY_A);
+	}
+
+
+	/**
+	 *        get the number of registrations per event  for the Registration Admin page Reports Tab
+	 *
+	 * @access        public
+	 * @param $period string which can be passed to php's strtotime function (eg "-1 month")
+	 * @return stdClass[] each with properties event_name, reg_limit, and total
+	 * @throws EE_Error
+	 */
+	public function get_registrations_per_event_report($period = '-1 month')
+	{
+		$date_sql = $this->convert_datetime_for_query(
+			'REG_date',
+			date('Y-m-d H:i:s', strtotime($period)),
+			'Y-m-d H:i:s',
+			'UTC'
+		);
+		$where = array(
+			'REG_date' => array('>=', $date_sql),
+			'STS_ID' => array('!=', EEM_Registration::status_id_incomplete),
+		);
+		if (!EE_Registry::instance()->CAP->current_user_can(
+			'ee_read_others_registrations',
+			'reg_per_event_report'
+		)
+		) {
+			$where['Event.EVT_wp_user'] = get_current_user_id();
+		}
+		$results = $this->_get_all_wpdb_results(
+			array(
+			$where,
+			'group_by' => 'Event.EVT_name',
+			'order_by' => 'Event.EVT_name',
+			'limit' => array(0, 24),
+			),
+			OBJECT,
+			array(
+				'event_name' => array('Event_CPT.post_title', '%s'),
+				'total' => array('COUNT(REG_ID)', '%s'),
+			)
+		);
+		return $results;
+	}
+
+
+	/**
+	 * Get the number of registrations per event grouped by registration status.
+	 * Note: EEM_Registration::status_id_incomplete registrations are excluded from the results.
+	 *
+	 * @param string $period
+	 * @return stdClass[] with properties `Registration_Event` and a column for each registration status as the STS_ID
+	 * @throws EE_Error
+	 *                    (i.e. RAP)
+	 */
+	public function get_registrations_per_event_and_per_status_report($period = '-1 month')
+	{
+		global $wpdb;
+		$registration_table = $wpdb->prefix . 'esp_registration';
+		$event_table = $wpdb->posts;
+		$sql_date = date('Y-m-d H:i:s', strtotime($period));
+		// inner date query
+		$inner_date_query = "SELECT DISTINCT EVT_ID, REG_date from $registration_table ";
+		$inner_where = ' WHERE';
+		// exclude events not authored by user if permissions in effect
+		if (!EE_Registry::instance()->CAP->current_user_can('ee_read_others_registrations', 'reg_per_event_report')) {
+			$inner_date_query .= "LEFT JOIN {$event_table} ON ID = EVT_ID";
+			$inner_where .= ' post_author = ' . get_current_user_id() . ' AND';
+		}
+		$inner_where .= " REG_date >= '{$sql_date}'";
+		$inner_date_query .= $inner_where;
+		// build main query
+		$select = 'SELECT Event.post_title as Registration_Event, ';
+		$join = '';
+		$join_parts = array();
+		$select_parts = array();
+		// loop through registration stati to do parts for each status.
+		foreach (EEM_Registration::reg_status_array() as $STS_ID => $STS_code) {
+			if ($STS_ID === EEM_Registration::status_id_incomplete) {
+				continue;
+			}
+			$select_parts[] = "COUNT({$STS_code}.REG_ID) as {$STS_ID}";
+			$join_parts[] = "{$registration_table} AS {$STS_code} ON {$STS_code}.EVT_ID = dates.EVT_ID AND {$STS_code}.STS_ID = '{$STS_ID}' AND {$STS_code}.REG_date = dates.REG_date";
+		}
+		// setup the selects
+		$select .= implode(', ', $select_parts);
+		$select .= " FROM ($inner_date_query) AS dates LEFT JOIN $event_table as Event ON Event.ID = dates.EVT_ID LEFT JOIN ";
+		// setup remaining joins
+		$join .= implode(' LEFT JOIN ', $join_parts);
+		// now put it all together
+		$query = $select . $join . ' GROUP BY Registration_Event';
+		// and execute
+		return $wpdb->get_results($query, ARRAY_A);
+	}
+
+
+	/**
+	 * Returns the EE_Registration of the primary attendee on the transaction id provided
+	 *
+	 * @param int $TXN_ID
+	 * @return EE_Base_Class|EE_Registration|null
+	 * @throws EE_Error
+	 */
+	public function get_primary_registration_for_transaction_ID($TXN_ID = 0)
+	{
+		if (!$TXN_ID) {
+			return null;
+		}
+		return $this->get_one(array(
+			array(
+				'TXN_ID' => $TXN_ID,
+				'REG_count' => EEM_Registration::PRIMARY_REGISTRANT_COUNT,
+			),
+		));
+	}
+
+
+	/**
+	 *        get_event_registration_count
+	 *
+	 * @access public
+	 * @param int $EVT_ID
+	 * @param boolean $for_incomplete_payments
+	 * @return int
+	 * @throws EE_Error
+	 */
+	public function get_event_registration_count($EVT_ID, $for_incomplete_payments = false)
+	{
+		// we only count approved registrations towards registration limits
+		$query_params = array(array('EVT_ID' => $EVT_ID, 'STS_ID' => self::status_id_approved));
+		if ($for_incomplete_payments) {
+			$query_params[0]['Transaction.STS_ID'] = array('!=', EEM_Transaction::complete_status_code);
+		}
+		return $this->count($query_params);
+	}
+
+
+	/**
+	 * Deletes all registrations with no transactions. Note that this needs to be very efficient
+	 * and so it uses wpdb directly
+	 *
+	 * @global WPDB $wpdb
+	 * @return int number deleted
+	 * @throws EE_Error
+	 */
+	public function delete_registrations_with_no_transaction()
+	{
+		/** @type WPDB $wpdb */
+		global $wpdb;
+		return $wpdb->query(
+			'DELETE r FROM '
+			. $this->table()
+			. ' r LEFT JOIN '
+			. EEM_Transaction::instance()->table()
+			. ' t ON r.TXN_ID = t.TXN_ID WHERE t.TXN_ID IS NULL'
+		);
+	}
+
+
+	/**
+	 *  Count registrations checked into (or out of) a datetime
+	 *
+	 * @param int $DTT_ID datetime ID
+	 * @param boolean $checked_in whether to count registrations checked IN or OUT
+	 * @return int
+	 * @throws EE_Error
+	 */
+	public function count_registrations_checked_into_datetime($DTT_ID, $checked_in = true)
+	{
+		global $wpdb;
+		// subquery to get latest checkin
+		$query = $wpdb->prepare(
+			'SELECT '
+			. 'COUNT( DISTINCT checkins.REG_ID ) '
+			. 'FROM ' . EEM_Checkin::instance()->table() . ' AS checkins INNER JOIN'
+			. '( SELECT '
+			. 'max( CHK_timestamp ) AS latest_checkin, '
+			. 'REG_ID AS REG_ID '
+			. 'FROM ' . EEM_Checkin::instance()->table() . ' '
+			. 'WHERE DTT_ID=%d '
+			. 'GROUP BY REG_ID'
+			. ') AS most_recent_checkin_per_reg '
+			. 'ON checkins.REG_ID=most_recent_checkin_per_reg.REG_ID '
+			. 'AND checkins.CHK_timestamp = most_recent_checkin_per_reg.latest_checkin '
+			. 'WHERE '
+			. 'checkins.CHK_in=%d',
+			$DTT_ID,
+			$checked_in
+		);
+		return (int) $wpdb->get_var($query);
+	}
+
+
+	/**
+	 *  Count registrations checked into (or out of) an event.
+	 *
+	 * @param int $EVT_ID event ID
+	 * @param boolean $checked_in whether to count registrations checked IN or OUT
+	 * @return int
+	 * @throws EE_Error
+	 */
+	public function count_registrations_checked_into_event($EVT_ID, $checked_in = true)
+	{
+		global $wpdb;
+		// subquery to get latest checkin
+		$query = $wpdb->prepare(
+			'SELECT '
+			. 'COUNT( DISTINCT checkins.REG_ID ) '
+			. 'FROM ' . EEM_Checkin::instance()->table() . ' AS checkins INNER JOIN'
+			. '( SELECT '
+			. 'max( CHK_timestamp ) AS latest_checkin, '
+			. 'REG_ID AS REG_ID '
+			. 'FROM ' . EEM_Checkin::instance()->table() . ' AS c '
+			. 'INNER JOIN ' . EEM_Datetime::instance()->table() . ' AS d '
+			. 'ON c.DTT_ID=d.DTT_ID '
+			. 'WHERE d.EVT_ID=%d '
+			. 'GROUP BY REG_ID'
+			. ') AS most_recent_checkin_per_reg '
+			. 'ON checkins.REG_ID=most_recent_checkin_per_reg.REG_ID '
+			. 'AND checkins.CHK_timestamp = most_recent_checkin_per_reg.latest_checkin '
+			. 'WHERE '
+			. 'checkins.CHK_in=%d',
+			$EVT_ID,
+			$checked_in
+		);
+		return (int) $wpdb->get_var($query);
+	}
+
+
+	/**
+	 * The purpose of this method is to retrieve an array of
+	 * EE_Registration objects that represent the latest registration
+	 * for each ATT_ID given in the function argument.
+	 *
+	 * @param array $attendee_ids
+	 * @return EE_Base_Class[]|EE_Registration[]
+	 * @throws EE_Error
+	 */
+	public function get_latest_registration_for_each_of_given_contacts($attendee_ids = array())
+	{
+		// first do a native wp_query to get the latest REG_ID's matching these attendees.
+		global $wpdb;
+		$registration_table = $wpdb->prefix . 'esp_registration';
+		$attendee_table = $wpdb->posts;
+		$attendee_ids = is_array($attendee_ids)
+			? array_map('absint', $attendee_ids)
+			: array((int) $attendee_ids);
+		$ATT_IDs = implode(',', $attendee_ids);
+		// first we do a query to get the registration ids
+		// (because a group by before order by causes the order by to be ignored.)
+		$registration_id_query = "
 			SELECT registrations.registration_ids as registration_id
 			FROM (
 				SELECT
@@ -835,61 +835,61 @@ 
 			  ) AS registrations
 			  GROUP BY registrations.attendee_ids
 		";
-        $registration_ids = $wpdb->get_results($registration_id_query, ARRAY_A);
-        if (empty($registration_ids)) {
-            return array();
-        }
-        $ids_for_model_query = array();
-        // let's flatten the ids so they can be used in the model query.
-        foreach ($registration_ids as $registration_id) {
-            if (isset($registration_id['registration_id'])) {
-                $ids_for_model_query[] = $registration_id['registration_id'];
-            }
-        }
-        // construct query
-        $_where = array(
-            'REG_ID' => array('IN', $ids_for_model_query),
-        );
-        return $this->get_all(array($_where));
-    }
-
-
-
-    /**
-     * returns a count of registrations for the supplied event having the status as specified
-     *
-     * @param int $EVT_ID
-     * @param array $statuses
-     * @return int
-     * @throws InvalidArgumentException
-     * @throws InvalidStatusException
-     * @throws EE_Error
-     */
-    public function event_reg_count_for_statuses($EVT_ID, $statuses = array())
-    {
-        $EVT_ID = absint($EVT_ID);
-        if (! $EVT_ID) {
-            throw new InvalidArgumentException(
-                esc_html__('An invalid Event ID was supplied.', 'event_espresso')
-            );
-        }
-        $statuses = is_array($statuses) ? $statuses : array($statuses);
-        $statuses = ! empty($statuses) ? $statuses : array(EEM_Registration::status_id_approved);
-        $valid_reg_statuses = EEM_Registration::reg_statuses();
-        foreach ($statuses as $status) {
-            if (! in_array($status, $valid_reg_statuses, true)) {
-                throw new InvalidStatusException($status, esc_html__('Registration', 'event_espresso'));
-            }
-        }
-        return $this->count(
-            array(
-                array(
-                    'EVT_ID' => $EVT_ID,
-                    'STS_ID' => array('IN', $statuses),
-                ),
-            ),
-            'REG_ID',
-            true
-        );
-    }
+		$registration_ids = $wpdb->get_results($registration_id_query, ARRAY_A);
+		if (empty($registration_ids)) {
+			return array();
+		}
+		$ids_for_model_query = array();
+		// let's flatten the ids so they can be used in the model query.
+		foreach ($registration_ids as $registration_id) {
+			if (isset($registration_id['registration_id'])) {
+				$ids_for_model_query[] = $registration_id['registration_id'];
+			}
+		}
+		// construct query
+		$_where = array(
+			'REG_ID' => array('IN', $ids_for_model_query),
+		);
+		return $this->get_all(array($_where));
+	}
+
+
+
+	/**
+	 * returns a count of registrations for the supplied event having the status as specified
+	 *
+	 * @param int $EVT_ID
+	 * @param array $statuses
+	 * @return int
+	 * @throws InvalidArgumentException
+	 * @throws InvalidStatusException
+	 * @throws EE_Error
+	 */
+	public function event_reg_count_for_statuses($EVT_ID, $statuses = array())
+	{
+		$EVT_ID = absint($EVT_ID);
+		if (! $EVT_ID) {
+			throw new InvalidArgumentException(
+				esc_html__('An invalid Event ID was supplied.', 'event_espresso')
+			);
+		}
+		$statuses = is_array($statuses) ? $statuses : array($statuses);
+		$statuses = ! empty($statuses) ? $statuses : array(EEM_Registration::status_id_approved);
+		$valid_reg_statuses = EEM_Registration::reg_statuses();
+		foreach ($statuses as $status) {
+			if (! in_array($status, $valid_reg_statuses, true)) {
+				throw new InvalidStatusException($status, esc_html__('Registration', 'event_espresso'));
+			}
+		}
+		return $this->count(
+			array(
+				array(
+					'EVT_ID' => $EVT_ID,
+					'STS_ID' => array('IN', $statuses),
+				),
+			),
+			'REG_ID',
+			true
+		);
+	}
 }

core/db_models/strategies/EE_Default_Where_Conditions.strategy.php

Indentation +140 added lines, -140 removed lines

@@ -3,7 +3,7 @@ 
 /**
  *
  * Class EE_Default_Where_Conditions
-  *
+ *
  * Strategy to be used for getting default where conditions for EEM_Base children.
  * Should be initialized and set on construction of model
  *
@@ -16,143 +16,143 @@ 
 class EE_Default_Where_Conditions
 {
 
-    /**
-     * This const can be used in EE_Default_Where_Conditions values, and at the time of querying it will be
-     * replaced with the current user's ID (because we don't want to use the current user's ID at time of
-     * initializing the models because it's too early)
-     */
-    const current_user_placeholder = '%$current_user_placeholder_should_be_replaced_automatically$%';
-
-    /**
-     * This const can be used in EE_Default_Where_Conditions where parameters as the name
-     * of the user field. When we are actually generating the where conditions it will be
-     * replaced with the model's wp user fieldname
-     */
-    const user_field_name_placeholder = '%$user_field_name_placeholder$%';
-
-    /**
-     * Model for which this strategy find default where conditions
-     * @var EEM_Base
-     */
-    protected $_model;
-
-    /**
-     * Where conditions specified on construction
-     * @var array
-     */
-    protected $_where_conditions_provided = array();
-
-    /**
-     * Custom where conditions. Model relation chains will be automatically added
-     * onto any field names
-     * @param array $custom_where_conditions
-     */
-    public function __construct($custom_where_conditions = array())
-    {
-        $this->_where_conditions_provided = $custom_where_conditions;
-    }
-
-
-
-    /**
-     * finalizes construction of the strategy for use in getting default where conditions
-     * for querying of the model.
-     * @param EEM_Base $model
-     */
-    public function _finalize_construct(EEM_Base $model)
-    {
-        $this->_model = $model;
-    }
-
-
-
-    /**
-     * Returns the where conditions explicitly passed in the constructor
-     * @return array
-     */
-    public function get_where_conditions_provided()
-    {
-        return $this->_where_conditions_provided;
-    }
-
-
-
-    /**
-     * Gets the where conditions to be added onto the query
-     * @param string $model_relation_chain
-     * @return array @see https://github.com/eventespresso/event-espresso-core/tree/master/docs/G--Model-System/model-query-params.md#0-where-conditions
-     */
-    public function get_default_where_conditions($model_relation_chain = '')
-    {
-        return $this->prepare_where_conditions_for_querying(array_merge($this->_get_default_where_conditions(), $this->get_where_conditions_provided()), $model_relation_chain);
-    }
-
-
-
-    /**
-     * Gets the default where conditions that are specific to this child of EE_Default_Where_Conditions.
-     * Adding model relation chains is handled by the public method get_default_where_conditions
-     * @return array
-     */
-    protected function _get_default_where_conditions()
-    {
-        return array();
-    }
-
-
-
-    /**
-     * Takes the default query parameters, and traverses them, adding the model relation chain
-     * onto them (intelligently doesn't do that to logic query params like NOT, OR, and AND)
-     * @param array $where_conditions
-     * @param string $model_relation_chain
-     * @return array
-     * @throws \EE_Error
-     */
-    public function prepare_where_conditions_for_querying($where_conditions, $model_relation_chain)
-    {
-        $where_conditions_with_model_relation_chain_prefixes = array();
-        if (! is_array($where_conditions)) {
-            $where_conditions = array();
-        }
-        foreach ($where_conditions as $key => $value) {
-            if (in_array($key, array( 'OR', 'AND', 'NOT' ))
-                || strpos($key, 'OR*') !== false
-                || strpos($key, 'AND*') !== false
-                || strpos($key, 'NOT*') !== false
-            ) {
-                $where_conditions_with_model_relation_chain_prefixes[ $key ] = $this->prepare_where_conditions_for_querying(
-                    $value,
-                    $model_relation_chain
-                );
-            } else {
-                if ($model_relation_chain != ''
-                    && $model_relation_chain[ strlen($model_relation_chain) - 1 ] != '.'
-                ) {
-                    $model_relation_chain = $model_relation_chain . ".";
-                }
-                // check for the current user id place holder, and if present change it
-                if ($value === self::current_user_placeholder) {
-                    $value = get_current_user_id();
-                }
-                // check for user field placeholder
-                if ($key == self::user_field_name_placeholder) {
-                    if (! $this->_model->wp_user_field_name()) {
-                        throw new EE_Error(
-                            sprintf(
-                                __(
-                                    'There is no foreign key to the WP_User model on model %s. Please either modify your default where conditions, add a _model_chain_to_wp_user onto the model, or a proper EE_WP_User_Field onto the model',
-                                    'event_espresso'
-                                ),
-                                $this->_model->get_this_model_name()
-                            )
-                        );
-                    }
-                    $key = $this->_model->wp_user_field_name();
-                }
-                $where_conditions_with_model_relation_chain_prefixes[ $model_relation_chain . $key ] = $value;
-            }
-        }
-        return $where_conditions_with_model_relation_chain_prefixes;
-    }
+	/**
+	 * This const can be used in EE_Default_Where_Conditions values, and at the time of querying it will be
+	 * replaced with the current user's ID (because we don't want to use the current user's ID at time of
+	 * initializing the models because it's too early)
+	 */
+	const current_user_placeholder = '%$current_user_placeholder_should_be_replaced_automatically$%';
+
+	/**
+	 * This const can be used in EE_Default_Where_Conditions where parameters as the name
+	 * of the user field. When we are actually generating the where conditions it will be
+	 * replaced with the model's wp user fieldname
+	 */
+	const user_field_name_placeholder = '%$user_field_name_placeholder$%';
+
+	/**
+	 * Model for which this strategy find default where conditions
+	 * @var EEM_Base
+	 */
+	protected $_model;
+
+	/**
+	 * Where conditions specified on construction
+	 * @var array
+	 */
+	protected $_where_conditions_provided = array();
+
+	/**
+	 * Custom where conditions. Model relation chains will be automatically added
+	 * onto any field names
+	 * @param array $custom_where_conditions
+	 */
+	public function __construct($custom_where_conditions = array())
+	{
+		$this->_where_conditions_provided = $custom_where_conditions;
+	}
+
+
+
+	/**
+	 * finalizes construction of the strategy for use in getting default where conditions
+	 * for querying of the model.
+	 * @param EEM_Base $model
+	 */
+	public function _finalize_construct(EEM_Base $model)
+	{
+		$this->_model = $model;
+	}
+
+
+
+	/**
+	 * Returns the where conditions explicitly passed in the constructor
+	 * @return array
+	 */
+	public function get_where_conditions_provided()
+	{
+		return $this->_where_conditions_provided;
+	}
+
+
+
+	/**
+	 * Gets the where conditions to be added onto the query
+	 * @param string $model_relation_chain
+	 * @return array @see https://github.com/eventespresso/event-espresso-core/tree/master/docs/G--Model-System/model-query-params.md#0-where-conditions
+	 */
+	public function get_default_where_conditions($model_relation_chain = '')
+	{
+		return $this->prepare_where_conditions_for_querying(array_merge($this->_get_default_where_conditions(), $this->get_where_conditions_provided()), $model_relation_chain);
+	}
+
+
+
+	/**
+	 * Gets the default where conditions that are specific to this child of EE_Default_Where_Conditions.
+	 * Adding model relation chains is handled by the public method get_default_where_conditions
+	 * @return array
+	 */
+	protected function _get_default_where_conditions()
+	{
+		return array();
+	}
+
+
+
+	/**
+	 * Takes the default query parameters, and traverses them, adding the model relation chain
+	 * onto them (intelligently doesn't do that to logic query params like NOT, OR, and AND)
+	 * @param array $where_conditions
+	 * @param string $model_relation_chain
+	 * @return array
+	 * @throws \EE_Error
+	 */
+	public function prepare_where_conditions_for_querying($where_conditions, $model_relation_chain)
+	{
+		$where_conditions_with_model_relation_chain_prefixes = array();
+		if (! is_array($where_conditions)) {
+			$where_conditions = array();
+		}
+		foreach ($where_conditions as $key => $value) {
+			if (in_array($key, array( 'OR', 'AND', 'NOT' ))
+				|| strpos($key, 'OR*') !== false
+				|| strpos($key, 'AND*') !== false
+				|| strpos($key, 'NOT*') !== false
+			) {
+				$where_conditions_with_model_relation_chain_prefixes[ $key ] = $this->prepare_where_conditions_for_querying(
+					$value,
+					$model_relation_chain
+				);
+			} else {
+				if ($model_relation_chain != ''
+					&& $model_relation_chain[ strlen($model_relation_chain) - 1 ] != '.'
+				) {
+					$model_relation_chain = $model_relation_chain . ".";
+				}
+				// check for the current user id place holder, and if present change it
+				if ($value === self::current_user_placeholder) {
+					$value = get_current_user_id();
+				}
+				// check for user field placeholder
+				if ($key == self::user_field_name_placeholder) {
+					if (! $this->_model->wp_user_field_name()) {
+						throw new EE_Error(
+							sprintf(
+								__(
+									'There is no foreign key to the WP_User model on model %s. Please either modify your default where conditions, add a _model_chain_to_wp_user onto the model, or a proper EE_WP_User_Field onto the model',
+									'event_espresso'
+								),
+								$this->_model->get_this_model_name()
+							)
+						);
+					}
+					$key = $this->_model->wp_user_field_name();
+				}
+				$where_conditions_with_model_relation_chain_prefixes[ $model_relation_chain . $key ] = $value;
+			}
+		}
+		return $where_conditions_with_model_relation_chain_prefixes;
+	}
 }

core/db_models/strategies/EE_Soft_Delete_Where_Conditions.strategy.php

Indentation +37 added lines, -37 removed lines

@@ -13,41 +13,41 @@
  */
 class EE_Soft_Delete_Where_Conditions extends EE_Default_Where_Conditions
 {
-    /**
-     * Strategy for setting default soft delete where conditions. This strategy will find
-     * the field of type 'EE_Trashed_Flag_Field', and add a condition that it be FALSE on all queries involving
-     * the model.
-     * If you want to override these default where conditions, you may explicitly in the query you send to the model.
-     * Eg,
-     *
-     */
-    public function __construct()
-    {
-    }
-    /**
-     * Gets the where default where conditions for a custom post type model
-     * @return array @see https://github.com/eventespresso/event-espresso-core/tree/master/docs/G--Model-System/model-query-params.md#0-where-conditions
-     */
-    protected function _get_default_where_conditions()
-    {
-        $trashed_field_name = $this->deleted_field_name();
-        return array(
-            $trashed_field_name => false
-        );
-    }
-    /**
-     * Searches for field on the model of type 'deleted_flag'. if it is found,
-     * returns it's name.
-     * @return string
-     * @throws EE_Error
-     */
-    private function deleted_field_name()
-    {
-        $field = $this->_model->get_a_field_of_type('EE_Trashed_Flag_Field');
-        if ($field) {
-            return $field->get_name();
-        } else {
-            throw new EE_Error(sprintf(__('We are trying to find the deleted flag field on %s, but none was found. Are you sure there is a field of type EE_Trashed_Flag_Field in %s constructor?', 'event_espresso'), get_class($this), get_class($this)));
-        }
-    }
+	/**
+	 * Strategy for setting default soft delete where conditions. This strategy will find
+	 * the field of type 'EE_Trashed_Flag_Field', and add a condition that it be FALSE on all queries involving
+	 * the model.
+	 * If you want to override these default where conditions, you may explicitly in the query you send to the model.
+	 * Eg,
+	 *
+	 */
+	public function __construct()
+	{
+	}
+	/**
+	 * Gets the where default where conditions for a custom post type model
+	 * @return array @see https://github.com/eventespresso/event-espresso-core/tree/master/docs/G--Model-System/model-query-params.md#0-where-conditions
+	 */
+	protected function _get_default_where_conditions()
+	{
+		$trashed_field_name = $this->deleted_field_name();
+		return array(
+			$trashed_field_name => false
+		);
+	}
+	/**
+	 * Searches for field on the model of type 'deleted_flag'. if it is found,
+	 * returns it's name.
+	 * @return string
+	 * @throws EE_Error
+	 */
+	private function deleted_field_name()
+	{
+		$field = $this->_model->get_a_field_of_type('EE_Trashed_Flag_Field');
+		if ($field) {
+			return $field->get_name();
+		} else {
+			throw new EE_Error(sprintf(__('We are trying to find the deleted flag field on %s, but none was found. Are you sure there is a field of type EE_Trashed_Flag_Field in %s constructor?', 'event_espresso'), get_class($this), get_class($this)));
+		}
+	}
 }

core/db_classes/EE_Base_Class.class.php

Indentation +3140 added lines, -3140 removed lines

@@ -13,3144 +13,3144 @@
 abstract class EE_Base_Class
 {
 
-    /**
-     * This is an array of the original properties and values provided during construction
-     * of this model object. (keys are model field names, values are their values).
-     * This list is important to remember so that when we are merging data from the db, we know
-     * which values to override and which to not override.
-     *
-     * @var array
-     */
-    protected $_props_n_values_provided_in_constructor;
-
-    /**
-     * Timezone
-     * This gets set by the "set_timezone()" method so that we know what timezone incoming strings|timestamps are in.
-     * This can also be used before a get to set what timezone you want strings coming out of the object to be in.  NOT
-     * all EE_Base_Class child classes use this property but any that use a EE_Datetime_Field data type will have
-     * access to it.
-     *
-     * @var string
-     */
-    protected $_timezone;
-
-    /**
-     * date format
-     * pattern or format for displaying dates
-     *
-     * @var string $_dt_frmt
-     */
-    protected $_dt_frmt;
-
-    /**
-     * time format
-     * pattern or format for displaying time
-     *
-     * @var string $_tm_frmt
-     */
-    protected $_tm_frmt;
-
-    /**
-     * This property is for holding a cached array of object properties indexed by property name as the key.
-     * The purpose of this is for setting a cache on properties that may have calculated values after a
-     * prepare_for_get.  That way the cache can be checked first and the calculated property returned instead of having
-     * to recalculate. Used by _set_cached_property() and _get_cached_property() methods.
-     *
-     * @var array
-     */
-    protected $_cached_properties = array();
-
-    /**
-     * An array containing keys of the related model, and values are either an array of related mode objects or a
-     * single
-     * related model object. see the model's _model_relations. The keys should match those specified. And if the
-     * relation is of type EE_Belongs_To (or one of its children), then there should only be ONE related model object,
-     * all others have an array)
-     *
-     * @var array
-     */
-    protected $_model_relations = array();
-
-    /**
-     * Array where keys are field names (see the model's _fields property) and values are their values. To see what
-     * their types should be, look at what that field object returns on its prepare_for_get and prepare_for_set methods)
-     *
-     * @var array
-     */
-    protected $_fields = array();
-
-    /**
-     * @var boolean indicating whether or not this model object is intended to ever be saved
-     * For example, we might create model objects intended to only be used for the duration
-     * of this request and to be thrown away, and if they were accidentally saved
-     * it would be a bug.
-     */
-    protected $_allow_persist = true;
-
-    /**
-     * @var boolean indicating whether or not this model object's properties have changed since construction
-     */
-    protected $_has_changes = false;
-
-    /**
-     * @var EEM_Base
-     */
-    protected $_model;
-
-    /**
-     * This is a cache of results from custom selections done on a query that constructs this entity. The only purpose
-     * for these values is for retrieval of the results, they are not further queryable and they are not persisted to
-     * the db.  They also do not automatically update if there are any changes to the data that produced their results.
-     * The format is a simple array of field_alias => field_value.  So for instance if a custom select was something
-     * like,  "Select COUNT(Registration.REG_ID) as Registration_Count ...", then the resulting value will be in this
-     * array as:
-     * array(
-     *  'Registration_Count' => 24
-     * );
-     * Note: if the custom select configuration for the query included a data type, the value will be in the data type
-     * provided for the query (@see EventEspresso\core\domain\values\model\CustomSelects::__construct phpdocs for more
-     * info)
-     *
-     * @var array
-     */
-    protected $custom_selection_results = array();
-
-
-    /**
-     * basic constructor for Event Espresso classes, performs any necessary initialization, and verifies it's children
-     * play nice
-     *
-     * @param array   $fieldValues                             where each key is a field (ie, array key in the 2nd
-     *                                                         layer of the model's _fields array, (eg, EVT_ID,
-     *                                                         TXN_amount, QST_name, etc) and values are their values
-     * @param boolean $bydb                                    a flag for setting if the class is instantiated by the
-     *                                                         corresponding db model or not.
-     * @param string  $timezone                                indicate what timezone you want any datetime fields to
-     *                                                         be in when instantiating a EE_Base_Class object.
-     * @param array   $date_formats                            An array of date formats to set on construct where first
-     *                                                         value is the date_format and second value is the time
-     *                                                         format.
-     * @throws InvalidArgumentException
-     * @throws InvalidInterfaceException
-     * @throws InvalidDataTypeException
-     * @throws EE_Error
-     * @throws ReflectionException
-     */
-    protected function __construct($fieldValues = array(), $bydb = false, $timezone = '', $date_formats = array())
-    {
-        $className = get_class($this);
-        do_action("AHEE__{$className}__construct", $this, $fieldValues);
-        $model = $this->get_model();
-        $model_fields = $model->field_settings(false);
-        // ensure $fieldValues is an array
-        $fieldValues = is_array($fieldValues) ? $fieldValues : array($fieldValues);
-        // verify client code has not passed any invalid field names
-        foreach ($fieldValues as $field_name => $field_value) {
-            if (! isset($model_fields[ $field_name ])) {
-                throw new EE_Error(
-                    sprintf(
-                        esc_html__(
-                            'Invalid field (%s) passed to constructor of %s. Allowed fields are :%s',
-                            'event_espresso'
-                        ),
-                        $field_name,
-                        get_class($this),
-                        implode(', ', array_keys($model_fields))
-                    )
-                );
-            }
-        }
-        $this->_timezone = EEH_DTT_Helper::get_valid_timezone_string($timezone);
-        if (! empty($date_formats) && is_array($date_formats)) {
-            list($this->_dt_frmt, $this->_tm_frmt) = $date_formats;
-        } else {
-            // set default formats for date and time
-            $this->_dt_frmt = (string) get_option('date_format', 'Y-m-d');
-            $this->_tm_frmt = (string) get_option('time_format', 'g:i a');
-        }
-        // if db model is instantiating
-        if ($bydb) {
-            // client code has indicated these field values are from the database
-            foreach ($model_fields as $fieldName => $field) {
-                $this->set_from_db(
-                    $fieldName,
-                    isset($fieldValues[ $fieldName ]) ? $fieldValues[ $fieldName ] : null
-                );
-            }
-        } else {
-            // we're constructing a brand
-            // new instance of the model object. Generally, this means we'll need to do more field validation
-            foreach ($model_fields as $fieldName => $field) {
-                $this->set(
-                    $fieldName,
-                    isset($fieldValues[ $fieldName ]) ? $fieldValues[ $fieldName ] : null,
-                    true
-                );
-            }
-        }
-        // remember what values were passed to this constructor
-        $this->_props_n_values_provided_in_constructor = $fieldValues;
-        // remember in entity mapper
-        if (! $bydb && $model->has_primary_key_field() && $this->ID()) {
-            $model->add_to_entity_map($this);
-        }
-        // setup all the relations
-        foreach ($model->relation_settings() as $relation_name => $relation_obj) {
-            if ($relation_obj instanceof EE_Belongs_To_Relation) {
-                $this->_model_relations[ $relation_name ] = null;
-            } else {
-                $this->_model_relations[ $relation_name ] = array();
-            }
-        }
-        /**
-         * Action done at the end of each model object construction
-         *
-         * @param EE_Base_Class $this the model object just created
-         */
-        do_action('AHEE__EE_Base_Class__construct__finished', $this);
-    }
-
-
-    /**
-     * Gets whether or not this model object is allowed to persist/be saved to the database.
-     *
-     * @return boolean
-     */
-    public function allow_persist()
-    {
-        return $this->_allow_persist;
-    }
-
-
-    /**
-     * Sets whether or not this model object should be allowed to be saved to the DB.
-     * Normally once this is set to FALSE you wouldn't set it back to TRUE, unless
-     * you got new information that somehow made you change your mind.
-     *
-     * @param boolean $allow_persist
-     * @return boolean
-     */
-    public function set_allow_persist($allow_persist)
-    {
-        return $this->_allow_persist = $allow_persist;
-    }
-
-
-    /**
-     * Gets the field's original value when this object was constructed during this request.
-     * This can be helpful when determining if a model object has changed or not
-     *
-     * @param string $field_name
-     * @return mixed|null
-     * @throws ReflectionException
-     * @throws InvalidArgumentException
-     * @throws InvalidInterfaceException
-     * @throws InvalidDataTypeException
-     * @throws EE_Error
-     */
-    public function get_original($field_name)
-    {
-        if (isset($this->_props_n_values_provided_in_constructor[ $field_name ])
-            && $field_settings = $this->get_model()->field_settings_for($field_name)
-        ) {
-            return $field_settings->prepare_for_get($this->_props_n_values_provided_in_constructor[ $field_name ]);
-        }
-        return null;
-    }
-
-
-    /**
-     * @param EE_Base_Class $obj
-     * @return string
-     */
-    public function get_class($obj)
-    {
-        return get_class($obj);
-    }
-
-
-    /**
-     * Overrides parent because parent expects old models.
-     * This also doesn't do any validation, and won't work for serialized arrays
-     *
-     * @param    string $field_name
-     * @param    mixed  $field_value
-     * @param bool      $use_default
-     * @throws InvalidArgumentException
-     * @throws InvalidInterfaceException
-     * @throws InvalidDataTypeException
-     * @throws EE_Error
-     * @throws ReflectionException
-     * @throws ReflectionException
-     * @throws ReflectionException
-     */
-    public function set($field_name, $field_value, $use_default = false)
-    {
-        // if not using default and nothing has changed, and object has already been setup (has ID),
-        // then don't do anything
-        if (! $use_default
-            && $this->_fields[ $field_name ] === $field_value
-            && $this->ID()
-        ) {
-            return;
-        }
-        $model = $this->get_model();
-        $this->_has_changes = true;
-        $field_obj = $model->field_settings_for($field_name);
-        if ($field_obj instanceof EE_Model_Field_Base) {
-            // if ( method_exists( $field_obj, 'set_timezone' )) {
-            if ($field_obj instanceof EE_Datetime_Field) {
-                $field_obj->set_timezone($this->_timezone);
-                $field_obj->set_date_format($this->_dt_frmt);
-                $field_obj->set_time_format($this->_tm_frmt);
-            }
-            $holder_of_value = $field_obj->prepare_for_set($field_value);
-            // should the value be null?
-            if (($field_value === null || $holder_of_value === null || $holder_of_value === '') && $use_default) {
-                $this->_fields[ $field_name ] = $field_obj->get_default_value();
-                /**
-                 * To save having to refactor all the models, if a default value is used for a
-                 * EE_Datetime_Field, and that value is not null nor is it a DateTime
-                 * object.  Then let's do a set again to ensure that it becomes a DateTime
-                 * object.
-                 *
-                 * @since 4.6.10+
-                 */
-                if ($field_obj instanceof EE_Datetime_Field
-                    && $this->_fields[ $field_name ] !== null
-                    && ! $this->_fields[ $field_name ] instanceof DateTime
-                ) {
-                    empty($this->_fields[ $field_name ])
-                        ? $this->set($field_name, time())
-                        : $this->set($field_name, $this->_fields[ $field_name ]);
-                }
-            } else {
-                $this->_fields[ $field_name ] = $holder_of_value;
-            }
-            // if we're not in the constructor...
-            // now check if what we set was a primary key
-            if (// note: props_n_values_provided_in_constructor is only set at the END of the constructor
-                $this->_props_n_values_provided_in_constructor
-                && $field_value
-                && $field_name === $model->primary_key_name()
-            ) {
-                // if so, we want all this object's fields to be filled either with
-                // what we've explicitly set on this model
-                // or what we have in the db
-                // echo "setting primary key!";
-                $fields_on_model = self::_get_model(get_class($this))->field_settings();
-                $obj_in_db = self::_get_model(get_class($this))->get_one_by_ID($field_value);
-                foreach ($fields_on_model as $field_obj) {
-                    if (! array_key_exists($field_obj->get_name(), $this->_props_n_values_provided_in_constructor)
-                        && $field_obj->get_name() !== $field_name
-                    ) {
-                        $this->set($field_obj->get_name(), $obj_in_db->get($field_obj->get_name()));
-                    }
-                }
-                // oh this model object has an ID? well make sure its in the entity mapper
-                $model->add_to_entity_map($this);
-            }
-            // let's unset any cache for this field_name from the $_cached_properties property.
-            $this->_clear_cached_property($field_name);
-        } else {
-            throw new EE_Error(
-                sprintf(
-                    esc_html__(
-                        'A valid EE_Model_Field_Base could not be found for the given field name: %s',
-                        'event_espresso'
-                    ),
-                    $field_name
-                )
-            );
-        }
-    }
-
-
-    /**
-     * Set custom select values for model.
-     *
-     * @param array $custom_select_values
-     */
-    public function setCustomSelectsValues(array $custom_select_values)
-    {
-        $this->custom_selection_results = $custom_select_values;
-    }
-
-
-    /**
-     * Returns the custom select value for the provided alias if its set.
-     * If not set, returns null.
-     *
-     * @param string $alias
-     * @return string|int|float|null
-     */
-    public function getCustomSelect($alias)
-    {
-        return isset($this->custom_selection_results[ $alias ])
-            ? $this->custom_selection_results[ $alias ]
-            : null;
-    }
-
-
-    /**
-     * This sets the field value on the db column if it exists for the given $column_name or
-     * saves it to EE_Extra_Meta if the given $column_name does not match a db column.
-     *
-     * @see EE_message::get_column_value for related documentation on the necessity of this method.
-     * @param string $field_name  Must be the exact column name.
-     * @param mixed  $field_value The value to set.
-     * @return int|bool @see EE_Base_Class::update_extra_meta() for return docs.
-     * @throws InvalidArgumentException
-     * @throws InvalidInterfaceException
-     * @throws InvalidDataTypeException
-     * @throws EE_Error
-     * @throws ReflectionException
-     */
-    public function set_field_or_extra_meta($field_name, $field_value)
-    {
-        if ($this->get_model()->has_field($field_name)) {
-            $this->set($field_name, $field_value);
-            return true;
-        }
-        // ensure this object is saved first so that extra meta can be properly related.
-        $this->save();
-        return $this->update_extra_meta($field_name, $field_value);
-    }
-
-
-    /**
-     * This retrieves the value of the db column set on this class or if that's not present
-     * it will attempt to retrieve from extra_meta if found.
-     * Example Usage:
-     * Via EE_Message child class:
-     * Due to the dynamic nature of the EE_messages system, EE_messengers will always have a "to",
-     * "from", "subject", and "content" field (as represented in the EE_Message schema), however they may
-     * also have additional main fields specific to the messenger.  The system accommodates those extra
-     * fields through the EE_Extra_Meta table.  This method allows for EE_messengers to retrieve the
-     * value for those extra fields dynamically via the EE_message object.
-     *
-     * @param  string $field_name expecting the fully qualified field name.
-     * @return mixed|null  value for the field if found.  null if not found.
-     * @throws ReflectionException
-     * @throws InvalidArgumentException
-     * @throws InvalidInterfaceException
-     * @throws InvalidDataTypeException
-     * @throws EE_Error
-     */
-    public function get_field_or_extra_meta($field_name)
-    {
-        if ($this->get_model()->has_field($field_name)) {
-            $column_value = $this->get($field_name);
-        } else {
-            // This isn't a column in the main table, let's see if it is in the extra meta.
-            $column_value = $this->get_extra_meta($field_name, true, null);
-        }
-        return $column_value;
-    }
-
-
-    /**
-     * See $_timezone property for description of what the timezone property is for.  This SETS the timezone internally
-     * for being able to reference what timezone we are running conversions on when converting TO the internal timezone
-     * (UTC Unix Timestamp) for the object OR when converting FROM the internal timezone (UTC Unix Timestamp). This is
-     * available to all child classes that may be using the EE_Datetime_Field for a field data type.
-     *
-     * @access public
-     * @param string $timezone A valid timezone string as described by @link http://www.php.net/manual/en/timezones.php
-     * @return void
-     * @throws InvalidArgumentException
-     * @throws InvalidInterfaceException
-     * @throws InvalidDataTypeException
-     * @throws EE_Error
-     * @throws ReflectionException
-     */
-    public function set_timezone($timezone = '')
-    {
-        $this->_timezone = EEH_DTT_Helper::get_valid_timezone_string($timezone);
-        // make sure we clear all cached properties because they won't be relevant now
-        $this->_clear_cached_properties();
-        // make sure we update field settings and the date for all EE_Datetime_Fields
-        $model_fields = $this->get_model()->field_settings(false);
-        foreach ($model_fields as $field_name => $field_obj) {
-            if ($field_obj instanceof EE_Datetime_Field) {
-                $field_obj->set_timezone($this->_timezone);
-                if (isset($this->_fields[ $field_name ]) && $this->_fields[ $field_name ] instanceof DateTime) {
-                    EEH_DTT_Helper::setTimezone($this->_fields[ $field_name ], new DateTimeZone($this->_timezone));
-                }
-            }
-        }
-    }
-
-
-    /**
-     * This just returns whatever is set for the current timezone.
-     *
-     * @access public
-     * @return string timezone string
-     */
-    public function get_timezone()
-    {
-        return $this->_timezone;
-    }
-
-
-    /**
-     * This sets the internal date format to what is sent in to be used as the new default for the class
-     * internally instead of wp set date format options
-     *
-     * @since 4.6
-     * @param string $format should be a format recognizable by PHP date() functions.
-     */
-    public function set_date_format($format)
-    {
-        $this->_dt_frmt = $format;
-        // clear cached_properties because they won't be relevant now.
-        $this->_clear_cached_properties();
-    }
-
-
-    /**
-     * This sets the internal time format string to what is sent in to be used as the new default for the
-     * class internally instead of wp set time format options.
-     *
-     * @since 4.6
-     * @param string $format should be a format recognizable by PHP date() functions.
-     */
-    public function set_time_format($format)
-    {
-        $this->_tm_frmt = $format;
-        // clear cached_properties because they won't be relevant now.
-        $this->_clear_cached_properties();
-    }
-
-
-    /**
-     * This returns the current internal set format for the date and time formats.
-     *
-     * @param bool $full           if true (default), then return the full format.  Otherwise will return an array
-     *                             where the first value is the date format and the second value is the time format.
-     * @return mixed string|array
-     */
-    public function get_format($full = true)
-    {
-        return $full ? $this->_dt_frmt . ' ' . $this->_tm_frmt : array($this->_dt_frmt, $this->_tm_frmt);
-    }
-
-
-    /**
-     * cache
-     * stores the passed model object on the current model object.
-     * In certain circumstances, we can use this cached model object instead of querying for another one entirely.
-     *
-     * @param string        $relationName    one of the keys in the _model_relations array on the model. Eg
-     *                                       'Registration' associated with this model object
-     * @param EE_Base_Class $object_to_cache that has a relation to this model object. (Eg, if this is a Transaction,
-     *                                       that could be a payment or a registration)
-     * @param null          $cache_id        a string or number that will be used as the key for any Belongs_To_Many
-     *                                       items which will be stored in an array on this object
-     * @throws ReflectionException
-     * @throws InvalidArgumentException
-     * @throws InvalidInterfaceException
-     * @throws InvalidDataTypeException
-     * @throws EE_Error
-     * @return mixed    index into cache, or just TRUE if the relation is of type Belongs_To (because there's only one
-     *                                       related thing, no array)
-     */
-    public function cache($relationName = '', $object_to_cache = null, $cache_id = null)
-    {
-        // its entirely possible that there IS no related object yet in which case there is nothing to cache.
-        if (! $object_to_cache instanceof EE_Base_Class) {
-            return false;
-        }
-        // also get "how" the object is related, or throw an error
-        if (! $relationship_to_model = $this->get_model()->related_settings_for($relationName)) {
-            throw new EE_Error(
-                sprintf(
-                    esc_html__('There is no relationship to %s on a %s. Cannot cache it', 'event_espresso'),
-                    $relationName,
-                    get_class($this)
-                )
-            );
-        }
-        // how many things are related ?
-        if ($relationship_to_model instanceof EE_Belongs_To_Relation) {
-            // if it's a "belongs to" relationship, then there's only one related model object
-            // eg, if this is a registration, there's only 1 attendee for it
-            // so for these model objects just set it to be cached
-            $this->_model_relations[ $relationName ] = $object_to_cache;
-            $return = true;
-        } else {
-            // otherwise, this is the "many" side of a one to many relationship,
-            // so we'll add the object to the array of related objects for that type.
-            // eg: if this is an event, there are many registrations for that event,
-            // so we cache the registrations in an array
-            if (! is_array($this->_model_relations[ $relationName ])) {
-                // if for some reason, the cached item is a model object,
-                // then stick that in the array, otherwise start with an empty array
-                $this->_model_relations[ $relationName ] = $this->_model_relations[ $relationName ]
-                                                           instanceof
-                                                           EE_Base_Class
-                    ? array($this->_model_relations[ $relationName ]) : array();
-            }
-            // first check for a cache_id which is normally empty
-            if (! empty($cache_id)) {
-                // if the cache_id exists, then it means we are purposely trying to cache this
-                // with a known key that can then be used to retrieve the object later on
-                $this->_model_relations[ $relationName ][ $cache_id ] = $object_to_cache;
-                $return = $cache_id;
-            } elseif ($object_to_cache->ID()) {
-                // OR the cached object originally came from the db, so let's just use it's PK for an ID
-                $this->_model_relations[ $relationName ][ $object_to_cache->ID() ] = $object_to_cache;
-                $return = $object_to_cache->ID();
-            } else {
-                // OR it's a new object with no ID, so just throw it in the array with an auto-incremented ID
-                $this->_model_relations[ $relationName ][] = $object_to_cache;
-                // move the internal pointer to the end of the array
-                end($this->_model_relations[ $relationName ]);
-                // and grab the key so that we can return it
-                $return = key($this->_model_relations[ $relationName ]);
-            }
-        }
-        return $return;
-    }
-
-
-    /**
-     * For adding an item to the cached_properties property.
-     *
-     * @access protected
-     * @param string      $fieldname the property item the corresponding value is for.
-     * @param mixed       $value     The value we are caching.
-     * @param string|null $cache_type
-     * @return void
-     * @throws ReflectionException
-     * @throws InvalidArgumentException
-     * @throws InvalidInterfaceException
-     * @throws InvalidDataTypeException
-     * @throws EE_Error
-     */
-    protected function _set_cached_property($fieldname, $value, $cache_type = null)
-    {
-        // first make sure this property exists
-        $this->get_model()->field_settings_for($fieldname);
-        $cache_type = empty($cache_type) ? 'standard' : $cache_type;
-        $this->_cached_properties[ $fieldname ][ $cache_type ] = $value;
-    }
-
-
-    /**
-     * This returns the value cached property if it exists OR the actual property value if the cache doesn't exist.
-     * This also SETS the cache if we return the actual property!
-     *
-     * @param string $fieldname        the name of the property we're trying to retrieve
-     * @param bool   $pretty
-     * @param string $extra_cache_ref  This allows the user to specify an extra cache ref for the given property
-     *                                 (in cases where the same property may be used for different outputs
-     *                                 - i.e. datetime, money etc.)
-     *                                 It can also accept certain pre-defined "schema" strings
-     *                                 to define how to output the property.
-     *                                 see the field's prepare_for_pretty_echoing for what strings can be used
-     * @return mixed                   whatever the value for the property is we're retrieving
-     * @throws ReflectionException
-     * @throws InvalidArgumentException
-     * @throws InvalidInterfaceException
-     * @throws InvalidDataTypeException
-     * @throws EE_Error
-     */
-    protected function _get_cached_property($fieldname, $pretty = false, $extra_cache_ref = null)
-    {
-        // verify the field exists
-        $model = $this->get_model();
-        $model->field_settings_for($fieldname);
-        $cache_type = $pretty ? 'pretty' : 'standard';
-        $cache_type .= ! empty($extra_cache_ref) ? '_' . $extra_cache_ref : '';
-        if (isset($this->_cached_properties[ $fieldname ][ $cache_type ])) {
-            return $this->_cached_properties[ $fieldname ][ $cache_type ];
-        }
-        $value = $this->_get_fresh_property($fieldname, $pretty, $extra_cache_ref);
-        $this->_set_cached_property($fieldname, $value, $cache_type);
-        return $value;
-    }
-
-
-    /**
-     * If the cache didn't fetch the needed item, this fetches it.
-     *
-     * @param string $fieldname
-     * @param bool   $pretty
-     * @param string $extra_cache_ref
-     * @return mixed
-     * @throws InvalidArgumentException
-     * @throws InvalidInterfaceException
-     * @throws InvalidDataTypeException
-     * @throws EE_Error
-     * @throws ReflectionException
-     */
-    protected function _get_fresh_property($fieldname, $pretty = false, $extra_cache_ref = null)
-    {
-        $field_obj = $this->get_model()->field_settings_for($fieldname);
-        // If this is an EE_Datetime_Field we need to make sure timezone, formats, and output are correct
-        if ($field_obj instanceof EE_Datetime_Field) {
-            $this->_prepare_datetime_field($field_obj, $pretty, $extra_cache_ref);
-        }
-        if (! isset($this->_fields[ $fieldname ])) {
-            $this->_fields[ $fieldname ] = null;
-        }
-        $value = $pretty
-            ? $field_obj->prepare_for_pretty_echoing($this->_fields[ $fieldname ], $extra_cache_ref)
-            : $field_obj->prepare_for_get($this->_fields[ $fieldname ]);
-        return $value;
-    }
-
-
-    /**
-     * set timezone, formats, and output for EE_Datetime_Field objects
-     *
-     * @param \EE_Datetime_Field $datetime_field
-     * @param bool               $pretty
-     * @param null               $date_or_time
-     * @return void
-     * @throws InvalidArgumentException
-     * @throws InvalidInterfaceException
-     * @throws InvalidDataTypeException
-     * @throws EE_Error
-     */
-    protected function _prepare_datetime_field(
-        EE_Datetime_Field $datetime_field,
-        $pretty = false,
-        $date_or_time = null
-    ) {
-        $datetime_field->set_timezone($this->_timezone);
-        $datetime_field->set_date_format($this->_dt_frmt, $pretty);
-        $datetime_field->set_time_format($this->_tm_frmt, $pretty);
-        // set the output returned
-        switch ($date_or_time) {
-            case 'D':
-                $datetime_field->set_date_time_output('date');
-                break;
-            case 'T':
-                $datetime_field->set_date_time_output('time');
-                break;
-            default:
-                $datetime_field->set_date_time_output();
-        }
-    }
-
-
-    /**
-     * This just takes care of clearing out the cached_properties
-     *
-     * @return void
-     */
-    protected function _clear_cached_properties()
-    {
-        $this->_cached_properties = array();
-    }
-
-
-    /**
-     * This just clears out ONE property if it exists in the cache
-     *
-     * @param  string $property_name the property to remove if it exists (from the _cached_properties array)
-     * @return void
-     */
-    protected function _clear_cached_property($property_name)
-    {
-        if (isset($this->_cached_properties[ $property_name ])) {
-            unset($this->_cached_properties[ $property_name ]);
-        }
-    }
-
-
-    /**
-     * Ensures that this related thing is a model object.
-     *
-     * @param mixed  $object_or_id EE_base_Class/int/string either a related model object, or its ID
-     * @param string $model_name   name of the related thing, eg 'Attendee',
-     * @return EE_Base_Class
-     * @throws ReflectionException
-     * @throws InvalidArgumentException
-     * @throws InvalidInterfaceException
-     * @throws InvalidDataTypeException
-     * @throws EE_Error
-     */
-    protected function ensure_related_thing_is_model_obj($object_or_id, $model_name)
-    {
-        $other_model_instance = self::_get_model_instance_with_name(
-            self::_get_model_classname($model_name),
-            $this->_timezone
-        );
-        return $other_model_instance->ensure_is_obj($object_or_id);
-    }
-
-
-    /**
-     * Forgets the cached model of the given relation Name. So the next time we request it,
-     * we will fetch it again from the database. (Handy if you know it's changed somehow).
-     * If a specific object is supplied, and the relationship to it is either a HasMany or HABTM,
-     * then only remove that one object from our cached array. Otherwise, clear the entire list
-     *
-     * @param string $relationName                         one of the keys in the _model_relations array on the model.
-     *                                                     Eg 'Registration'
-     * @param mixed  $object_to_remove_or_index_into_array or an index into the array of cached things, or NULL
-     *                                                     if you intend to use $clear_all = TRUE, or the relation only
-     *                                                     has 1 object anyways (ie, it's a BelongsToRelation)
-     * @param bool   $clear_all                            This flags clearing the entire cache relation property if
-     *                                                     this is HasMany or HABTM.
-     * @throws ReflectionException
-     * @throws InvalidArgumentException
-     * @throws InvalidInterfaceException
-     * @throws InvalidDataTypeException
-     * @throws EE_Error
-     * @return EE_Base_Class | boolean from which was cleared from the cache, or true if we requested to remove a
-     *                                                     relation from all
-     */
-    public function clear_cache($relationName, $object_to_remove_or_index_into_array = null, $clear_all = false)
-    {
-        $relationship_to_model = $this->get_model()->related_settings_for($relationName);
-        $index_in_cache = '';
-        if (! $relationship_to_model) {
-            throw new EE_Error(
-                sprintf(
-                    esc_html__('There is no relationship to %s on a %s. Cannot clear that cache', 'event_espresso'),
-                    $relationName,
-                    get_class($this)
-                )
-            );
-        }
-        if ($clear_all) {
-            $obj_removed = true;
-            $this->_model_relations[ $relationName ] = null;
-        } elseif ($relationship_to_model instanceof EE_Belongs_To_Relation) {
-            $obj_removed = $this->_model_relations[ $relationName ];
-            $this->_model_relations[ $relationName ] = null;
-        } else {
-            if ($object_to_remove_or_index_into_array instanceof EE_Base_Class
-                && $object_to_remove_or_index_into_array->ID()
-            ) {
-                $index_in_cache = $object_to_remove_or_index_into_array->ID();
-                if (is_array($this->_model_relations[ $relationName ])
-                    && ! isset($this->_model_relations[ $relationName ][ $index_in_cache ])
-                ) {
-                    $index_found_at = null;
-                    // find this object in the array even though it has a different key
-                    foreach ($this->_model_relations[ $relationName ] as $index => $obj) {
-                        /** @noinspection TypeUnsafeComparisonInspection */
-                        if ($obj instanceof EE_Base_Class
-                            && (
-                                $obj == $object_to_remove_or_index_into_array
-                                || $obj->ID() === $object_to_remove_or_index_into_array->ID()
-                            )
-                        ) {
-                            $index_found_at = $index;
-                            break;
-                        }
-                    }
-                    if ($index_found_at) {
-                        $index_in_cache = $index_found_at;
-                    } else {
-                        // it wasn't found. huh. well obviously it doesn't need to be removed from teh cache
-                        // if it wasn't in it to begin with. So we're done
-                        return $object_to_remove_or_index_into_array;
-                    }
-                }
-            } elseif ($object_to_remove_or_index_into_array instanceof EE_Base_Class) {
-                // so they provided a model object, but it's not yet saved to the DB... so let's go hunting for it!
-                foreach ($this->get_all_from_cache($relationName) as $index => $potentially_obj_we_want) {
-                    /** @noinspection TypeUnsafeComparisonInspection */
-                    if ($potentially_obj_we_want == $object_to_remove_or_index_into_array) {
-                        $index_in_cache = $index;
-                    }
-                }
-            } else {
-                $index_in_cache = $object_to_remove_or_index_into_array;
-            }
-            // supposedly we've found it. But it could just be that the client code
-            // provided a bad index/object
-            if (isset($this->_model_relations[ $relationName ][ $index_in_cache ])) {
-                $obj_removed = $this->_model_relations[ $relationName ][ $index_in_cache ];
-                unset($this->_model_relations[ $relationName ][ $index_in_cache ]);
-            } else {
-                // that thing was never cached anyways.
-                $obj_removed = null;
-            }
-        }
-        return $obj_removed;
-    }
-
-
-    /**
-     * update_cache_after_object_save
-     * Allows a cached item to have it's cache ID (within the array of cached items) reset using the new ID it has
-     * obtained after being saved to the db
-     *
-     * @param string        $relationName       - the type of object that is cached
-     * @param EE_Base_Class $newly_saved_object - the newly saved object to be re-cached
-     * @param string        $current_cache_id   - the ID that was used when originally caching the object
-     * @return boolean TRUE on success, FALSE on fail
-     * @throws ReflectionException
-     * @throws InvalidArgumentException
-     * @throws InvalidInterfaceException
-     * @throws InvalidDataTypeException
-     * @throws EE_Error
-     */
-    public function update_cache_after_object_save(
-        $relationName,
-        EE_Base_Class $newly_saved_object,
-        $current_cache_id = ''
-    ) {
-        // verify that incoming object is of the correct type
-        $obj_class = 'EE_' . $relationName;
-        if ($newly_saved_object instanceof $obj_class) {
-            /* @type EE_Base_Class $newly_saved_object */
-            // now get the type of relation
-            $relationship_to_model = $this->get_model()->related_settings_for($relationName);
-            // if this is a 1:1 relationship
-            if ($relationship_to_model instanceof EE_Belongs_To_Relation) {
-                // then just replace the cached object with the newly saved object
-                $this->_model_relations[ $relationName ] = $newly_saved_object;
-                return true;
-                // or if it's some kind of sordid feral polyamorous relationship...
-            }
-            if (is_array($this->_model_relations[ $relationName ])
-                && isset($this->_model_relations[ $relationName ][ $current_cache_id ])
-            ) {
-                // then remove the current cached item
-                unset($this->_model_relations[ $relationName ][ $current_cache_id ]);
-                // and cache the newly saved object using it's new ID
-                $this->_model_relations[ $relationName ][ $newly_saved_object->ID() ] = $newly_saved_object;
-                return true;
-            }
-        }
-        return false;
-    }
-
-
-    /**
-     * Fetches a single EE_Base_Class on that relation. (If the relation is of type
-     * BelongsTo, it will only ever have 1 object. However, other relations could have an array of objects)
-     *
-     * @param string $relationName
-     * @return EE_Base_Class
-     */
-    public function get_one_from_cache($relationName)
-    {
-        $cached_array_or_object = isset($this->_model_relations[ $relationName ])
-            ? $this->_model_relations[ $relationName ]
-            : null;
-        if (is_array($cached_array_or_object)) {
-            return array_shift($cached_array_or_object);
-        }
-        return $cached_array_or_object;
-    }
-
-
-    /**
-     * Fetches a single EE_Base_Class on that relation. (If the relation is of type
-     * BelongsTo, it will only ever have 1 object. However, other relations could have an array of objects)
-     *
-     * @param string $relationName
-     * @throws ReflectionException
-     * @throws InvalidArgumentException
-     * @throws InvalidInterfaceException
-     * @throws InvalidDataTypeException
-     * @throws EE_Error
-     * @return EE_Base_Class[] NOT necessarily indexed by primary keys
-     */
-    public function get_all_from_cache($relationName)
-    {
-        $objects = isset($this->_model_relations[ $relationName ]) ? $this->_model_relations[ $relationName ] : array();
-        // if the result is not an array, but exists, make it an array
-        $objects = is_array($objects) ? $objects : array($objects);
-        // bugfix for https://events.codebasehq.com/projects/event-espresso/tickets/7143
-        // basically, if this model object was stored in the session, and these cached model objects
-        // already have IDs, let's make sure they're in their model's entity mapper
-        // otherwise we will have duplicates next time we call
-        // EE_Registry::instance()->load_model( $relationName )->get_one_by_ID( $result->ID() );
-        $model = EE_Registry::instance()->load_model($relationName);
-        foreach ($objects as $model_object) {
-            if ($model instanceof EEM_Base && $model_object instanceof EE_Base_Class) {
-                // ensure its in the map if it has an ID; otherwise it will be added to the map when its saved
-                if ($model_object->ID()) {
-                    $model->add_to_entity_map($model_object);
-                }
-            } else {
-                throw new EE_Error(
-                    sprintf(
-                        esc_html__(
-                            'Error retrieving related model objects. Either $1%s is not a model or $2%s is not a model object',
-                            'event_espresso'
-                        ),
-                        $relationName,
-                        gettype($model_object)
-                    )
-                );
-            }
-        }
-        return $objects;
-    }
-
-
-    /**
-     * Returns the next x number of EE_Base_Class objects in sequence from this object as found in the database
-     * matching the given query conditions.
-     *
-     * @param null  $field_to_order_by  What field is being used as the reference point.
-     * @param int   $limit              How many objects to return.
-     * @param array $query_params       Any additional conditions on the query.
-     * @param null  $columns_to_select  If left null, then an array of EE_Base_Class objects is returned, otherwise
-     *                                  you can indicate just the columns you want returned
-     * @return array|EE_Base_Class[]
-     * @throws ReflectionException
-     * @throws InvalidArgumentException
-     * @throws InvalidInterfaceException
-     * @throws InvalidDataTypeException
-     * @throws EE_Error
-     */
-    public function next_x($field_to_order_by = null, $limit = 1, $query_params = array(), $columns_to_select = null)
-    {
-        $model = $this->get_model();
-        $field = empty($field_to_order_by) && $model->has_primary_key_field()
-            ? $model->get_primary_key_field()->get_name()
-            : $field_to_order_by;
-        $current_value = ! empty($field) ? $this->get($field) : null;
-        if (empty($field) || empty($current_value)) {
-            return array();
-        }
-        return $model->next_x($current_value, $field, $limit, $query_params, $columns_to_select);
-    }
-
-
-    /**
-     * Returns the previous x number of EE_Base_Class objects in sequence from this object as found in the database
-     * matching the given query conditions.
-     *
-     * @param null  $field_to_order_by  What field is being used as the reference point.
-     * @param int   $limit              How many objects to return.
-     * @param array $query_params       Any additional conditions on the query.
-     * @param null  $columns_to_select  If left null, then an array of EE_Base_Class objects is returned, otherwise
-     *                                  you can indicate just the columns you want returned
-     * @return array|EE_Base_Class[]
-     * @throws ReflectionException
-     * @throws InvalidArgumentException
-     * @throws InvalidInterfaceException
-     * @throws InvalidDataTypeException
-     * @throws EE_Error
-     */
-    public function previous_x(
-        $field_to_order_by = null,
-        $limit = 1,
-        $query_params = array(),
-        $columns_to_select = null
-    ) {
-        $model = $this->get_model();
-        $field = empty($field_to_order_by) && $model->has_primary_key_field()
-            ? $model->get_primary_key_field()->get_name()
-            : $field_to_order_by;
-        $current_value = ! empty($field) ? $this->get($field) : null;
-        if (empty($field) || empty($current_value)) {
-            return array();
-        }
-        return $model->previous_x($current_value, $field, $limit, $query_params, $columns_to_select);
-    }
-
-
-    /**
-     * Returns the next EE_Base_Class object in sequence from this object as found in the database
-     * matching the given query conditions.
-     *
-     * @param null  $field_to_order_by  What field is being used as the reference point.
-     * @param array $query_params       Any additional conditions on the query.
-     * @param null  $columns_to_select  If left null, then an array of EE_Base_Class objects is returned, otherwise
-     *                                  you can indicate just the columns you want returned
-     * @return array|EE_Base_Class
-     * @throws ReflectionException
-     * @throws InvalidArgumentException
-     * @throws InvalidInterfaceException
-     * @throws InvalidDataTypeException
-     * @throws EE_Error
-     */
-    public function next($field_to_order_by = null, $query_params = array(), $columns_to_select = null)
-    {
-        $model = $this->get_model();
-        $field = empty($field_to_order_by) && $model->has_primary_key_field()
-            ? $model->get_primary_key_field()->get_name()
-            : $field_to_order_by;
-        $current_value = ! empty($field) ? $this->get($field) : null;
-        if (empty($field) || empty($current_value)) {
-            return array();
-        }
-        return $model->next($current_value, $field, $query_params, $columns_to_select);
-    }
-
-
-    /**
-     * Returns the previous EE_Base_Class object in sequence from this object as found in the database
-     * matching the given query conditions.
-     *
-     * @param null  $field_to_order_by  What field is being used as the reference point.
-     * @param array $query_params       Any additional conditions on the query.
-     * @param null  $columns_to_select  If left null, then an EE_Base_Class object is returned, otherwise
-     *                                  you can indicate just the column you want returned
-     * @return array|EE_Base_Class
-     * @throws ReflectionException
-     * @throws InvalidArgumentException
-     * @throws InvalidInterfaceException
-     * @throws InvalidDataTypeException
-     * @throws EE_Error
-     */
-    public function previous($field_to_order_by = null, $query_params = array(), $columns_to_select = null)
-    {
-        $model = $this->get_model();
-        $field = empty($field_to_order_by) && $model->has_primary_key_field()
-            ? $model->get_primary_key_field()->get_name()
-            : $field_to_order_by;
-        $current_value = ! empty($field) ? $this->get($field) : null;
-        if (empty($field) || empty($current_value)) {
-            return array();
-        }
-        return $model->previous($current_value, $field, $query_params, $columns_to_select);
-    }
-
-
-    /**
-     * Overrides parent because parent expects old models.
-     * This also doesn't do any validation, and won't work for serialized arrays
-     *
-     * @param string $field_name
-     * @param mixed  $field_value_from_db
-     * @throws ReflectionException
-     * @throws InvalidArgumentException
-     * @throws InvalidInterfaceException
-     * @throws InvalidDataTypeException
-     * @throws EE_Error
-     */
-    public function set_from_db($field_name, $field_value_from_db)
-    {
-        $field_obj = $this->get_model()->field_settings_for($field_name);
-        if ($field_obj instanceof EE_Model_Field_Base) {
-            // you would think the DB has no NULLs for non-null label fields right? wrong!
-            // eg, a CPT model object could have an entry in the posts table, but no
-            // entry in the meta table. Meaning that all its columns in the meta table
-            // are null! yikes! so when we find one like that, use defaults for its meta columns
-            if ($field_value_from_db === null) {
-                if ($field_obj->is_nullable()) {
-                    // if the field allows nulls, then let it be null
-                    $field_value = null;
-                } else {
-                    $field_value = $field_obj->get_default_value();
-                }
-            } else {
-                $field_value = $field_obj->prepare_for_set_from_db($field_value_from_db);
-            }
-            $this->_fields[ $field_name ] = $field_value;
-            $this->_clear_cached_property($field_name);
-        }
-    }
-
-
-    /**
-     * verifies that the specified field is of the correct type
-     *
-     * @param string $field_name
-     * @param string $extra_cache_ref This allows the user to specify an extra cache ref for the given property
-     *                                (in cases where the same property may be used for different outputs
-     *                                - i.e. datetime, money etc.)
-     * @return mixed
-     * @throws ReflectionException
-     * @throws InvalidArgumentException
-     * @throws InvalidInterfaceException
-     * @throws InvalidDataTypeException
-     * @throws EE_Error
-     */
-    public function get($field_name, $extra_cache_ref = null)
-    {
-        return $this->_get_cached_property($field_name, false, $extra_cache_ref);
-    }
-
-
-    /**
-     * This method simply returns the RAW unprocessed value for the given property in this class
-     *
-     * @param  string $field_name A valid fieldname
-     * @return mixed              Whatever the raw value stored on the property is.
-     * @throws ReflectionException
-     * @throws InvalidArgumentException
-     * @throws InvalidInterfaceException
-     * @throws InvalidDataTypeException
-     * @throws EE_Error if fieldSettings is misconfigured or the field doesn't exist.
-     */
-    public function get_raw($field_name)
-    {
-        $field_settings = $this->get_model()->field_settings_for($field_name);
-        return $field_settings instanceof EE_Datetime_Field && $this->_fields[ $field_name ] instanceof DateTime
-            ? $this->_fields[ $field_name ]->format('U')
-            : $this->_fields[ $field_name ];
-    }
-
-
-    /**
-     * This is used to return the internal DateTime object used for a field that is a
-     * EE_Datetime_Field.
-     *
-     * @param string $field_name               The field name retrieving the DateTime object.
-     * @return mixed null | false | DateTime  If the requested field is NOT a EE_Datetime_Field then
-     * @throws EE_Error an error is set and false returned.  If the field IS an
-     *                                         EE_Datetime_Field and but the field value is null, then
-     *                                         just null is returned (because that indicates that likely
-     *                                         this field is nullable).
-     * @throws InvalidArgumentException
-     * @throws InvalidDataTypeException
-     * @throws InvalidInterfaceException
-     * @throws ReflectionException
-     */
-    public function get_DateTime_object($field_name)
-    {
-        $field_settings = $this->get_model()->field_settings_for($field_name);
-        if (! $field_settings instanceof EE_Datetime_Field) {
-            EE_Error::add_error(
-                sprintf(
-                    esc_html__(
-                        'The field %s is not an EE_Datetime_Field field.  There is no DateTime object stored on this field type.',
-                        'event_espresso'
-                    ),
-                    $field_name
-                ),
-                __FILE__,
-                __FUNCTION__,
-                __LINE__
-            );
-            return false;
-        }
-        return isset($this->_fields[ $field_name ]) && $this->_fields[ $field_name ] instanceof DateTime
-            ? clone $this->_fields[ $field_name ]
-            : null;
-    }
-
-
-    /**
-     * To be used in template to immediately echo out the value, and format it for output.
-     * Eg, should call stripslashes and whatnot before echoing
-     *
-     * @param string $field_name      the name of the field as it appears in the DB
-     * @param string $extra_cache_ref This allows the user to specify an extra cache ref for the given property
-     *                                (in cases where the same property may be used for different outputs
-     *                                - i.e. datetime, money etc.)
-     * @return void
-     * @throws ReflectionException
-     * @throws InvalidArgumentException
-     * @throws InvalidInterfaceException
-     * @throws InvalidDataTypeException
-     * @throws EE_Error
-     */
-    public function e($field_name, $extra_cache_ref = null)
-    {
-        echo $this->get_pretty($field_name, $extra_cache_ref);
-    }
-
-
-    /**
-     * Exactly like e(), echoes out the field, but sets its schema to 'form_input', so that it
-     * can be easily used as the value of form input.
-     *
-     * @param string $field_name
-     * @return void
-     * @throws ReflectionException
-     * @throws InvalidArgumentException
-     * @throws InvalidInterfaceException
-     * @throws InvalidDataTypeException
-     * @throws EE_Error
-     */
-    public function f($field_name)
-    {
-        $this->e($field_name, 'form_input');
-    }
-
-
-    /**
-     * Same as `f()` but just returns the value instead of echoing it
-     *
-     * @param string $field_name
-     * @return string
-     * @throws ReflectionException
-     * @throws InvalidArgumentException
-     * @throws InvalidInterfaceException
-     * @throws InvalidDataTypeException
-     * @throws EE_Error
-     */
-    public function get_f($field_name)
-    {
-        return (string) $this->get_pretty($field_name, 'form_input');
-    }
-
-
-    /**
-     * Gets a pretty view of the field's value. $extra_cache_ref can specify different formats for this.
-     * The $extra_cache_ref will be passed to the model field's prepare_for_pretty_echoing, so consult the field's class
-     * to see what options are available.
-     *
-     * @param string $field_name
-     * @param string $extra_cache_ref This allows the user to specify an extra cache ref for the given property
-     *                                (in cases where the same property may be used for different outputs
-     *                                - i.e. datetime, money etc.)
-     * @return mixed
-     * @throws ReflectionException
-     * @throws InvalidArgumentException
-     * @throws InvalidInterfaceException
-     * @throws InvalidDataTypeException
-     * @throws EE_Error
-     */
-    public function get_pretty($field_name, $extra_cache_ref = null)
-    {
-        return $this->_get_cached_property($field_name, true, $extra_cache_ref);
-    }
-
-
-    /**
-     * This simply returns the datetime for the given field name
-     * Note: this protected function is called by the wrapper get_date or get_time or get_datetime functions
-     * (and the equivalent e_date, e_time, e_datetime).
-     *
-     * @access   protected
-     * @param string   $field_name   Field on the instantiated EE_Base_Class child object
-     * @param string   $dt_frmt      valid datetime format used for date
-     *                               (if '' then we just use the default on the field,
-     *                               if NULL we use the last-used format)
-     * @param string   $tm_frmt      Same as above except this is for time format
-     * @param string   $date_or_time if NULL then both are returned, otherwise "D" = only date and "T" = only time.
-     * @param  boolean $echo         Whether the dtt is echoing using pretty echoing or just returned using vanilla get
-     * @return string|bool|EE_Error string on success, FALSE on fail, or EE_Error Exception is thrown
-     *                               if field is not a valid dtt field, or void if echoing
-     * @throws ReflectionException
-     * @throws InvalidArgumentException
-     * @throws InvalidInterfaceException
-     * @throws InvalidDataTypeException
-     * @throws EE_Error
-     */
-    protected function _get_datetime($field_name, $dt_frmt = '', $tm_frmt = '', $date_or_time = '', $echo = false)
-    {
-        // clear cached property
-        $this->_clear_cached_property($field_name);
-        // reset format properties because they are used in get()
-        $this->_dt_frmt = $dt_frmt !== '' ? $dt_frmt : $this->_dt_frmt;
-        $this->_tm_frmt = $tm_frmt !== '' ? $tm_frmt : $this->_tm_frmt;
-        if ($echo) {
-            $this->e($field_name, $date_or_time);
-            return '';
-        }
-        return $this->get($field_name, $date_or_time);
-    }
-
-
-    /**
-     * below are wrapper functions for the various datetime outputs that can be obtained for JUST returning the date
-     * portion of a datetime value. (note the only difference between get_ and e_ is one returns the value and the
-     * other echoes the pretty value for dtt)
-     *
-     * @param  string $field_name name of model object datetime field holding the value
-     * @param  string $format     format for the date returned (if NULL we use default in dt_frmt property)
-     * @return string            datetime value formatted
-     * @throws ReflectionException
-     * @throws InvalidArgumentException
-     * @throws InvalidInterfaceException
-     * @throws InvalidDataTypeException
-     * @throws EE_Error
-     */
-    public function get_date($field_name, $format = '')
-    {
-        return $this->_get_datetime($field_name, $format, null, 'D');
-    }
-
-
-    /**
-     * @param        $field_name
-     * @param string $format
-     * @throws ReflectionException
-     * @throws InvalidArgumentException
-     * @throws InvalidInterfaceException
-     * @throws InvalidDataTypeException
-     * @throws EE_Error
-     */
-    public function e_date($field_name, $format = '')
-    {
-        $this->_get_datetime($field_name, $format, null, 'D', true);
-    }
-
-
-    /**
-     * below are wrapper functions for the various datetime outputs that can be obtained for JUST returning the time
-     * portion of a datetime value. (note the only difference between get_ and e_ is one returns the value and the
-     * other echoes the pretty value for dtt)
-     *
-     * @param  string $field_name name of model object datetime field holding the value
-     * @param  string $format     format for the time returned ( if NULL we use default in tm_frmt property)
-     * @return string             datetime value formatted
-     * @throws ReflectionException
-     * @throws InvalidArgumentException
-     * @throws InvalidInterfaceException
-     * @throws InvalidDataTypeException
-     * @throws EE_Error
-     */
-    public function get_time($field_name, $format = '')
-    {
-        return $this->_get_datetime($field_name, null, $format, 'T');
-    }
-
-
-    /**
-     * @param        $field_name
-     * @param string $format
-     * @throws ReflectionException
-     * @throws InvalidArgumentException
-     * @throws InvalidInterfaceException
-     * @throws InvalidDataTypeException
-     * @throws EE_Error
-     */
-    public function e_time($field_name, $format = '')
-    {
-        $this->_get_datetime($field_name, null, $format, 'T', true);
-    }
-
-
-    /**
-     * below are wrapper functions for the various datetime outputs that can be obtained for returning the date AND
-     * time portion of a datetime value. (note the only difference between get_ and e_ is one returns the value and the
-     * other echoes the pretty value for dtt)
-     *
-     * @param  string $field_name name of model object datetime field holding the value
-     * @param  string $dt_frmt    format for the date returned (if NULL we use default in dt_frmt property)
-     * @param  string $tm_frmt    format for the time returned (if NULL we use default in tm_frmt property)
-     * @return string             datetime value formatted
-     * @throws ReflectionException
-     * @throws InvalidArgumentException
-     * @throws InvalidInterfaceException
-     * @throws InvalidDataTypeException
-     * @throws EE_Error
-     */
-    public function get_datetime($field_name, $dt_frmt = '', $tm_frmt = '')
-    {
-        return $this->_get_datetime($field_name, $dt_frmt, $tm_frmt);
-    }
-
-
-    /**
-     * @param string $field_name
-     * @param string $dt_frmt
-     * @param string $tm_frmt
-     * @throws ReflectionException
-     * @throws InvalidArgumentException
-     * @throws InvalidInterfaceException
-     * @throws InvalidDataTypeException
-     * @throws EE_Error
-     */
-    public function e_datetime($field_name, $dt_frmt = '', $tm_frmt = '')
-    {
-        $this->_get_datetime($field_name, $dt_frmt, $tm_frmt, null, true);
-    }
-
-
-    /**
-     * Get the i8ln value for a date using the WordPress @see date_i18n function.
-     *
-     * @param string $field_name The EE_Datetime_Field reference for the date being retrieved.
-     * @param string $format     PHP valid date/time string format.  If none is provided then the internal set format
-     *                           on the object will be used.
-     * @return string Date and time string in set locale or false if no field exists for the given
-     * @throws ReflectionException
-     * @throws InvalidArgumentException
-     * @throws InvalidInterfaceException
-     * @throws InvalidDataTypeException
-     * @throws EE_Error
-     *                           field name.
-     */
-    public function get_i18n_datetime($field_name, $format = '')
-    {
-        $format = empty($format) ? $this->_dt_frmt . ' ' . $this->_tm_frmt : $format;
-        return date_i18n(
-            $format,
-            EEH_DTT_Helper::get_timestamp_with_offset(
-                $this->get_raw($field_name),
-                $this->_timezone
-            )
-        );
-    }
-
-
-    /**
-     * This method validates whether the given field name is a valid field on the model object as well as it is of a
-     * type EE_Datetime_Field.  On success there will be returned the field settings.  On fail an EE_Error exception is
-     * thrown.
-     *
-     * @param  string $field_name The field name being checked
-     * @throws ReflectionException
-     * @throws InvalidArgumentException
-     * @throws InvalidInterfaceException
-     * @throws InvalidDataTypeException
-     * @throws EE_Error
-     * @return EE_Datetime_Field
-     */
-    protected function _get_dtt_field_settings($field_name)
-    {
-        $field = $this->get_model()->field_settings_for($field_name);
-        // check if field is dtt
-        if ($field instanceof EE_Datetime_Field) {
-            return $field;
-        }
-        throw new EE_Error(
-            sprintf(
-                esc_html__(
-                    'The field name "%s" has been requested for the EE_Base_Class datetime functions and it is not a valid EE_Datetime_Field.  Please check the spelling of the field and make sure it has been setup as a EE_Datetime_Field in the %s model constructor',
-                    'event_espresso'
-                ),
-                $field_name,
-                self::_get_model_classname(get_class($this))
-            )
-        );
-    }
-
-
-
-
-    /**
-     * NOTE ABOUT BELOW:
-     * These convenience date and time setters are for setting date and time independently.  In other words you might
-     * want to change the time on a datetime_field but leave the date the same (or vice versa). IF on the other hand
-     * you want to set both date and time at the same time, you can just use the models default set($fieldname,$value)
-     * method and make sure you send the entire datetime value for setting.
-     */
-    /**
-     * sets the time on a datetime property
-     *
-     * @access protected
-     * @param string|Datetime $time      a valid time string for php datetime functions (or DateTime object)
-     * @param string          $fieldname the name of the field the time is being set on (must match a EE_Datetime_Field)
-     * @throws ReflectionException
-     * @throws InvalidArgumentException
-     * @throws InvalidInterfaceException
-     * @throws InvalidDataTypeException
-     * @throws EE_Error
-     */
-    protected function _set_time_for($time, $fieldname)
-    {
-        $this->_set_date_time('T', $time, $fieldname);
-    }
-
-
-    /**
-     * sets the date on a datetime property
-     *
-     * @access protected
-     * @param string|DateTime $date      a valid date string for php datetime functions ( or DateTime object)
-     * @param string          $fieldname the name of the field the date is being set on (must match a EE_Datetime_Field)
-     * @throws ReflectionException
-     * @throws InvalidArgumentException
-     * @throws InvalidInterfaceException
-     * @throws InvalidDataTypeException
-     * @throws EE_Error
-     */
-    protected function _set_date_for($date, $fieldname)
-    {
-        $this->_set_date_time('D', $date, $fieldname);
-    }
-
-
-    /**
-     * This takes care of setting a date or time independently on a given model object property. This method also
-     * verifies that the given fieldname matches a model object property and is for a EE_Datetime_Field field
-     *
-     * @access protected
-     * @param string          $what           "T" for time, 'B' for both, 'D' for Date.
-     * @param string|DateTime $datetime_value A valid Date or Time string (or DateTime object)
-     * @param string          $fieldname      the name of the field the date OR time is being set on (must match a
-     *                                        EE_Datetime_Field property)
-     * @throws ReflectionException
-     * @throws InvalidArgumentException
-     * @throws InvalidInterfaceException
-     * @throws InvalidDataTypeException
-     * @throws EE_Error
-     */
-    protected function _set_date_time($what = 'T', $datetime_value, $fieldname)
-    {
-        $field = $this->_get_dtt_field_settings($fieldname);
-        $field->set_timezone($this->_timezone);
-        $field->set_date_format($this->_dt_frmt);
-        $field->set_time_format($this->_tm_frmt);
-        switch ($what) {
-            case 'T':
-                $this->_fields[ $fieldname ] = $field->prepare_for_set_with_new_time(
-                    $datetime_value,
-                    $this->_fields[ $fieldname ]
-                );
-                break;
-            case 'D':
-                $this->_fields[ $fieldname ] = $field->prepare_for_set_with_new_date(
-                    $datetime_value,
-                    $this->_fields[ $fieldname ]
-                );
-                break;
-            case 'B':
-                $this->_fields[ $fieldname ] = $field->prepare_for_set($datetime_value);
-                break;
-        }
-        $this->_clear_cached_property($fieldname);
-    }
-
-
-    /**
-     * This will return a timestamp for the website timezone but ONLY when the current website timezone is different
-     * than the timezone set for the website. NOTE, this currently only works well with methods that return values.  If
-     * you use it with methods that echo values the $_timestamp property may not get reset to its original value and
-     * that could lead to some unexpected results!
-     *
-     * @access public
-     * @param string $field_name               This is the name of the field on the object that contains the date/time
-     *                                         value being returned.
-     * @param string $callback                 must match a valid method in this class (defaults to get_datetime)
-     * @param mixed (array|string) $args       This is the arguments that will be passed to the callback.
-     * @param string $prepend                  You can include something to prepend on the timestamp
-     * @param string $append                   You can include something to append on the timestamp
-     * @throws ReflectionException
-     * @throws InvalidArgumentException
-     * @throws InvalidInterfaceException
-     * @throws InvalidDataTypeException
-     * @throws EE_Error
-     * @return string timestamp
-     */
-    public function display_in_my_timezone(
-        $field_name,
-        $callback = 'get_datetime',
-        $args = null,
-        $prepend = '',
-        $append = ''
-    ) {
-        $timezone = EEH_DTT_Helper::get_timezone();
-        if ($timezone === $this->_timezone) {
-            return '';
-        }
-        $original_timezone = $this->_timezone;
-        $this->set_timezone($timezone);
-        $fn = (array) $field_name;
-        $args = array_merge($fn, (array) $args);
-        if (! method_exists($this, $callback)) {
-            throw new EE_Error(
-                sprintf(
-                    esc_html__(
-                        'The method named "%s" given as the callback param in "display_in_my_timezone" does not exist.  Please check your spelling',
-                        'event_espresso'
-                    ),
-                    $callback
-                )
-            );
-        }
-        $args = (array) $args;
-        $return = $prepend . call_user_func_array(array($this, $callback), $args) . $append;
-        $this->set_timezone($original_timezone);
-        return $return;
-    }
-
-
-    /**
-     * Deletes this model object.
-     * This calls the `EE_Base_Class::_delete` method.  Child classes wishing to change default behaviour should
-     * override
-     * `EE_Base_Class::_delete` NOT this class.
-     *
-     * @return boolean | int
-     * @throws ReflectionException
-     * @throws InvalidArgumentException
-     * @throws InvalidInterfaceException
-     * @throws InvalidDataTypeException
-     * @throws EE_Error
-     */
-    public function delete()
-    {
-        /**
-         * Called just before the `EE_Base_Class::_delete` method call.
-         * Note:
-         * `EE_Base_Class::_delete` might be overridden by child classes so any client code hooking into these actions
-         * should be aware that `_delete` may not always result in a permanent delete.
-         * For example, `EE_Soft_Delete_Base_Class::_delete`
-         * soft deletes (trash) the object and does not permanently delete it.
-         *
-         * @param EE_Base_Class $model_object about to be 'deleted'
-         */
-        do_action('AHEE__EE_Base_Class__delete__before', $this);
-        $result = $this->_delete();
-        /**
-         * Called just after the `EE_Base_Class::_delete` method call.
-         * Note:
-         * `EE_Base_Class::_delete` might be overridden by child classes so any client code hooking into these actions
-         * should be aware that `_delete` may not always result in a permanent delete.
-         * For example `EE_Soft_Base_Class::_delete`
-         * soft deletes (trash) the object and does not permanently delete it.
-         *
-         * @param EE_Base_Class $model_object that was just 'deleted'
-         * @param boolean       $result
-         */
-        do_action('AHEE__EE_Base_Class__delete__end', $this, $result);
-        return $result;
-    }
-
-
-    /**
-     * Calls the specific delete method for the instantiated class.
-     * This method is called by the public `EE_Base_Class::delete` method.  Any child classes desiring to override
-     * default functionality for "delete" (which is to call `permanently_delete`) should override this method NOT
-     * `EE_Base_Class::delete`
-     *
-     * @return bool|int
-     * @throws ReflectionException
-     * @throws InvalidArgumentException
-     * @throws InvalidInterfaceException
-     * @throws InvalidDataTypeException
-     * @throws EE_Error
-     */
-    protected function _delete()
-    {
-        return $this->delete_permanently();
-    }
-
-
-    /**
-     * Deletes this model object permanently from db
-     * (but keep in mind related models may block the delete and return an error)
-     *
-     * @return bool | int
-     * @throws ReflectionException
-     * @throws InvalidArgumentException
-     * @throws InvalidInterfaceException
-     * @throws InvalidDataTypeException
-     * @throws EE_Error
-     */
-    public function delete_permanently()
-    {
-        /**
-         * Called just before HARD deleting a model object
-         *
-         * @param EE_Base_Class $model_object about to be 'deleted'
-         */
-        do_action('AHEE__EE_Base_Class__delete_permanently__before', $this);
-        $model = $this->get_model();
-        $result = $model->delete_permanently_by_ID($this->ID());
-        $this->refresh_cache_of_related_objects();
-        /**
-         * Called just after HARD deleting a model object
-         *
-         * @param EE_Base_Class $model_object that was just 'deleted'
-         * @param boolean       $result
-         */
-        do_action('AHEE__EE_Base_Class__delete_permanently__end', $this, $result);
-        return $result;
-    }
-
-
-    /**
-     * When this model object is deleted, it may still be cached on related model objects. This clears the cache of
-     * related model objects
-     *
-     * @throws ReflectionException
-     * @throws InvalidArgumentException
-     * @throws InvalidInterfaceException
-     * @throws InvalidDataTypeException
-     * @throws EE_Error
-     */
-    public function refresh_cache_of_related_objects()
-    {
-        $model = $this->get_model();
-        foreach ($model->relation_settings() as $relation_name => $relation_obj) {
-            if (! empty($this->_model_relations[ $relation_name ])) {
-                $related_objects = $this->_model_relations[ $relation_name ];
-                if ($relation_obj instanceof EE_Belongs_To_Relation) {
-                    // this relation only stores a single model object, not an array
-                    // but let's make it consistent
-                    $related_objects = array($related_objects);
-                }
-                foreach ($related_objects as $related_object) {
-                    // only refresh their cache if they're in memory
-                    if ($related_object instanceof EE_Base_Class) {
-                        $related_object->clear_cache(
-                            $model->get_this_model_name(),
-                            $this
-                        );
-                    }
-                }
-            }
-        }
-    }
-
-
-    /**
-     *        Saves this object to the database. An array may be supplied to set some values on this
-     * object just before saving.
-     *
-     * @access public
-     * @param array $set_cols_n_values keys are field names, values are their new values,
-     *                                 if provided during the save() method (often client code will change the fields'
-     *                                 values before calling save)
-     * @throws InvalidArgumentException
-     * @throws InvalidInterfaceException
-     * @throws InvalidDataTypeException
-     * @throws EE_Error
-     * @return int , 1 on a successful update, the ID of the new entry on insert; 0 on failure or if the model object
-     *                                 isn't allowed to persist (as determined by EE_Base_Class::allow_persist())
-     * @throws ReflectionException
-     * @throws ReflectionException
-     * @throws ReflectionException
-     */
-    public function save($set_cols_n_values = array())
-    {
-        $model = $this->get_model();
-        /**
-         * Filters the fields we're about to save on the model object
-         *
-         * @param array         $set_cols_n_values
-         * @param EE_Base_Class $model_object
-         */
-        $set_cols_n_values = (array) apply_filters(
-            'FHEE__EE_Base_Class__save__set_cols_n_values',
-            $set_cols_n_values,
-            $this
-        );
-        // set attributes as provided in $set_cols_n_values
-        foreach ($set_cols_n_values as $column => $value) {
-            $this->set($column, $value);
-        }
-        // no changes ? then don't do anything
-        if (! $this->_has_changes && $this->ID() && $model->get_primary_key_field()->is_auto_increment()) {
-            return 0;
-        }
-        /**
-         * Saving a model object.
-         * Before we perform a save, this action is fired.
-         *
-         * @param EE_Base_Class $model_object the model object about to be saved.
-         */
-        do_action('AHEE__EE_Base_Class__save__begin', $this);
-        if (! $this->allow_persist()) {
-            return 0;
-        }
-        // now get current attribute values
-        $save_cols_n_values = $this->_fields;
-        // if the object already has an ID, update it. Otherwise, insert it
-        // also: change the assumption about values passed to the model NOT being prepare dby the model object.
-        // They have been
-        $old_assumption_concerning_value_preparation = $model
-            ->get_assumption_concerning_values_already_prepared_by_model_object();
-        $model->assume_values_already_prepared_by_model_object(true);
-        // does this model have an autoincrement PK?
-        if ($model->has_primary_key_field()) {
-            if ($model->get_primary_key_field()->is_auto_increment()) {
-                // ok check if it's set, if so: update; if not, insert
-                if (! empty($save_cols_n_values[ $model->primary_key_name() ])) {
-                    $results = $model->update_by_ID($save_cols_n_values, $this->ID());
-                } else {
-                    unset($save_cols_n_values[ $model->primary_key_name() ]);
-                    $results = $model->insert($save_cols_n_values);
-                    if ($results) {
-                        // if successful, set the primary key
-                        // but don't use the normal SET method, because it will check if
-                        // an item with the same ID exists in the mapper & db, then
-                        // will find it in the db (because we just added it) and THAT object
-                        // will get added to the mapper before we can add this one!
-                        // but if we just avoid using the SET method, all that headache can be avoided
-                        $pk_field_name = $model->primary_key_name();
-                        $this->_fields[ $pk_field_name ] = $results;
-                        $this->_clear_cached_property($pk_field_name);
-                        $model->add_to_entity_map($this);
-                        $this->_update_cached_related_model_objs_fks();
-                    }
-                }
-            } else {// PK is NOT auto-increment
-                // so check if one like it already exists in the db
-                if ($model->exists_by_ID($this->ID())) {
-                    if (WP_DEBUG && ! $this->in_entity_map()) {
-                        throw new EE_Error(
-                            sprintf(
-                                esc_html__(
-                                    'Using a model object %1$s that is NOT in the entity map, can lead to unexpected errors. You should either: %4$s 1. Put it in the entity mapper by calling %2$s %4$s 2. Discard this model object and use what is in the entity mapper %4$s 3. Fetch from the database using %3$s',
-                                    'event_espresso'
-                                ),
-                                get_class($this),
-                                get_class($model) . '::instance()->add_to_entity_map()',
-                                get_class($model) . '::instance()->get_one_by_ID()',
-                                '<br />'
-                            )
-                        );
-                    }
-                    $results = $model->update_by_ID($save_cols_n_values, $this->ID());
-                } else {
-                    $results = $model->insert($save_cols_n_values);
-                    $this->_update_cached_related_model_objs_fks();
-                }
-            }
-        } else {// there is NO primary key
-            $already_in_db = false;
-            foreach ($model->unique_indexes() as $index) {
-                $uniqueness_where_params = array_intersect_key($save_cols_n_values, $index->fields());
-                if ($model->exists(array($uniqueness_where_params))) {
-                    $already_in_db = true;
-                }
-            }
-            if ($already_in_db) {
-                $combined_pk_fields_n_values = array_intersect_key(
-                    $save_cols_n_values,
-                    $model->get_combined_primary_key_fields()
-                );
-                $results = $model->update(
-                    $save_cols_n_values,
-                    $combined_pk_fields_n_values
-                );
-            } else {
-                $results = $model->insert($save_cols_n_values);
-            }
-        }
-        // restore the old assumption about values being prepared by the model object
-        $model->assume_values_already_prepared_by_model_object(
-            $old_assumption_concerning_value_preparation
-        );
-        /**
-         * After saving the model object this action is called
-         *
-         * @param EE_Base_Class $model_object which was just saved
-         * @param boolean|int   $results      if it were updated, TRUE or FALSE; if it were newly inserted
-         *                                    the new ID (or 0 if an error occurred and it wasn't updated)
-         */
-        do_action('AHEE__EE_Base_Class__save__end', $this, $results);
-        $this->_has_changes = false;
-        return $results;
-    }
-
-
-    /**
-     * Updates the foreign key on related models objects pointing to this to have this model object's ID
-     * as their foreign key.  If the cached related model objects already exist in the db, saves them (so that the DB
-     * is consistent) Especially useful in case we JUST added this model object ot the database and we want to let its
-     * cached relations with foreign keys to it know about that change. Eg: we've created a transaction but haven't
-     * saved it to the db. We also create a registration and don't save it to the DB, but we DO cache it on the
-     * transaction. Now, when we save the transaction, the registration's TXN_ID will be automatically updated, whether
-     * or not they exist in the DB (if they do, their DB records will be automatically updated)
-     *
-     * @return void
-     * @throws ReflectionException
-     * @throws InvalidArgumentException
-     * @throws InvalidInterfaceException
-     * @throws InvalidDataTypeException
-     * @throws EE_Error
-     */
-    protected function _update_cached_related_model_objs_fks()
-    {
-        $model = $this->get_model();
-        foreach ($model->relation_settings() as $relation_name => $relation_obj) {
-            if ($relation_obj instanceof EE_Has_Many_Relation) {
-                foreach ($this->get_all_from_cache($relation_name) as $related_model_obj_in_cache) {
-                    $fk_to_this = $related_model_obj_in_cache->get_model()->get_foreign_key_to(
-                        $model->get_this_model_name()
-                    );
-                    $related_model_obj_in_cache->set($fk_to_this->get_name(), $this->ID());
-                    if ($related_model_obj_in_cache->ID()) {
-                        $related_model_obj_in_cache->save();
-                    }
-                }
-            }
-        }
-    }
-
-
-    /**
-     * Saves this model object and its NEW cached relations to the database.
-     * (Meaning, for now, IT DOES NOT WORK if the cached items already exist in the DB.
-     * In order for that to work, we would need to mark model objects as dirty/clean...
-     * because otherwise, there's a potential for infinite looping of saving
-     * Saves the cached related model objects, and ensures the relation between them
-     * and this object and properly setup
-     *
-     * @return int ID of new model object on save; 0 on failure+
-     * @throws ReflectionException
-     * @throws InvalidArgumentException
-     * @throws InvalidInterfaceException
-     * @throws InvalidDataTypeException
-     * @throws EE_Error
-     */
-    public function save_new_cached_related_model_objs()
-    {
-        // make sure this has been saved
-        if (! $this->ID()) {
-            $id = $this->save();
-        } else {
-            $id = $this->ID();
-        }
-        // now save all the NEW cached model objects  (ie they don't exist in the DB)
-        foreach ($this->get_model()->relation_settings() as $relationName => $relationObj) {
-            if ($this->_model_relations[ $relationName ]) {
-                // is this a relation where we should expect just ONE related object (ie, EE_Belongs_To_relation)
-                // or MANY related objects (ie, EE_HABTM_Relation or EE_Has_Many_Relation)?
-                /* @var $related_model_obj EE_Base_Class */
-                if ($relationObj instanceof EE_Belongs_To_Relation) {
-                    // add a relation to that relation type (which saves the appropriate thing in the process)
-                    // but ONLY if it DOES NOT exist in the DB
-                    $related_model_obj = $this->_model_relations[ $relationName ];
-                    // if( ! $related_model_obj->ID()){
-                    $this->_add_relation_to($related_model_obj, $relationName);
-                    $related_model_obj->save_new_cached_related_model_objs();
-                    // }
-                } else {
-                    foreach ($this->_model_relations[ $relationName ] as $related_model_obj) {
-                        // add a relation to that relation type (which saves the appropriate thing in the process)
-                        // but ONLY if it DOES NOT exist in the DB
-                        // if( ! $related_model_obj->ID()){
-                        $this->_add_relation_to($related_model_obj, $relationName);
-                        $related_model_obj->save_new_cached_related_model_objs();
-                        // }
-                    }
-                }
-            }
-        }
-        return $id;
-    }
-
-
-    /**
-     * for getting a model while instantiated.
-     *
-     * @return EEM_Base | EEM_CPT_Base
-     * @throws ReflectionException
-     * @throws InvalidArgumentException
-     * @throws InvalidInterfaceException
-     * @throws InvalidDataTypeException
-     * @throws EE_Error
-     */
-    public function get_model()
-    {
-        if (! $this->_model) {
-            $modelName = self::_get_model_classname(get_class($this));
-            $this->_model = self::_get_model_instance_with_name($modelName, $this->_timezone);
-        } else {
-            $this->_model->set_timezone($this->_timezone);
-        }
-        return $this->_model;
-    }
-
-
-    /**
-     * @param $props_n_values
-     * @param $classname
-     * @return mixed bool|EE_Base_Class|EEM_CPT_Base
-     * @throws ReflectionException
-     * @throws InvalidArgumentException
-     * @throws InvalidInterfaceException
-     * @throws InvalidDataTypeException
-     * @throws EE_Error
-     */
-    protected static function _get_object_from_entity_mapper($props_n_values, $classname)
-    {
-        // TODO: will not work for Term_Relationships because they have no PK!
-        $primary_id_ref = self::_get_primary_key_name($classname);
-        if (array_key_exists($primary_id_ref, $props_n_values)
-            && ! empty($props_n_values[ $primary_id_ref ])
-        ) {
-            $id = $props_n_values[ $primary_id_ref ];
-            return self::_get_model($classname)->get_from_entity_map($id);
-        }
-        return false;
-    }
-
-
-    /**
-     * This is called by child static "new_instance" method and we'll check to see if there is an existing db entry for
-     * the primary key (if present in incoming values). If there is a key in the incoming array that matches the
-     * primary key for the model AND it is not null, then we check the db. If there's a an object we return it.  If not
-     * we return false.
-     *
-     * @param  array  $props_n_values   incoming array of properties and their values
-     * @param  string $classname        the classname of the child class
-     * @param null    $timezone
-     * @param array   $date_formats     incoming date_formats in an array where the first value is the
-     *                                  date_format and the second value is the time format
-     * @return mixed (EE_Base_Class|bool)
-     * @throws InvalidArgumentException
-     * @throws InvalidInterfaceException
-     * @throws InvalidDataTypeException
-     * @throws EE_Error
-     * @throws ReflectionException
-     * @throws ReflectionException
-     * @throws ReflectionException
-     */
-    protected static function _check_for_object($props_n_values, $classname, $timezone = null, $date_formats = array())
-    {
-        $existing = null;
-        $model = self::_get_model($classname, $timezone);
-        if ($model->has_primary_key_field()) {
-            $primary_id_ref = self::_get_primary_key_name($classname);
-            if (array_key_exists($primary_id_ref, $props_n_values)
-                && ! empty($props_n_values[ $primary_id_ref ])
-            ) {
-                $existing = $model->get_one_by_ID(
-                    $props_n_values[ $primary_id_ref ]
-                );
-            }
-        } elseif ($model->has_all_combined_primary_key_fields($props_n_values)) {
-            // no primary key on this model, but there's still a matching item in the DB
-            $existing = self::_get_model($classname, $timezone)->get_one_by_ID(
-                self::_get_model($classname, $timezone)
-                    ->get_index_primary_key_string($props_n_values)
-            );
-        }
-        if ($existing) {
-            // set date formats if present before setting values
-            if (! empty($date_formats) && is_array($date_formats)) {
-                $existing->set_date_format($date_formats[0]);
-                $existing->set_time_format($date_formats[1]);
-            } else {
-                // set default formats for date and time
-                $existing->set_date_format(get_option('date_format'));
-                $existing->set_time_format(get_option('time_format'));
-            }
-            foreach ($props_n_values as $property => $field_value) {
-                $existing->set($property, $field_value);
-            }
-            return $existing;
-        }
-        return false;
-    }
-
-
-    /**
-     * Gets the EEM_*_Model for this class
-     *
-     * @access public now, as this is more convenient
-     * @param      $classname
-     * @param null $timezone
-     * @throws ReflectionException
-     * @throws InvalidArgumentException
-     * @throws InvalidInterfaceException
-     * @throws InvalidDataTypeException
-     * @throws EE_Error
-     * @return EEM_Base
-     */
-    protected static function _get_model($classname, $timezone = null)
-    {
-        // find model for this class
-        if (! $classname) {
-            throw new EE_Error(
-                sprintf(
-                    esc_html__(
-                        'What were you thinking calling _get_model(%s)?? You need to specify the class name',
-                        'event_espresso'
-                    ),
-                    $classname
-                )
-            );
-        }
-        $modelName = self::_get_model_classname($classname);
-        return self::_get_model_instance_with_name($modelName, $timezone);
-    }
-
-
-    /**
-     * Gets the model instance (eg instance of EEM_Attendee) given its classname (eg EE_Attendee)
-     *
-     * @param string $model_classname
-     * @param null   $timezone
-     * @return EEM_Base
-     * @throws ReflectionException
-     * @throws InvalidArgumentException
-     * @throws InvalidInterfaceException
-     * @throws InvalidDataTypeException
-     * @throws EE_Error
-     */
-    protected static function _get_model_instance_with_name($model_classname, $timezone = null)
-    {
-        $model_classname = str_replace('EEM_', '', $model_classname);
-        $model = EE_Registry::instance()->load_model($model_classname);
-        $model->set_timezone($timezone);
-        return $model;
-    }
-
-
-    /**
-     * If a model name is provided (eg Registration), gets the model classname for that model.
-     * Also works if a model class's classname is provided (eg EE_Registration).
-     *
-     * @param null $model_name
-     * @return string like EEM_Attendee
-     */
-    private static function _get_model_classname($model_name = null)
-    {
-        if (strpos($model_name, 'EE_') === 0) {
-            $model_classname = str_replace('EE_', 'EEM_', $model_name);
-        } else {
-            $model_classname = 'EEM_' . $model_name;
-        }
-        return $model_classname;
-    }
-
-
-    /**
-     * returns the name of the primary key attribute
-     *
-     * @param null $classname
-     * @throws ReflectionException
-     * @throws InvalidArgumentException
-     * @throws InvalidInterfaceException
-     * @throws InvalidDataTypeException
-     * @throws EE_Error
-     * @return string
-     */
-    protected static function _get_primary_key_name($classname = null)
-    {
-        if (! $classname) {
-            throw new EE_Error(
-                sprintf(
-                    esc_html__('What were you thinking calling _get_primary_key_name(%s)', 'event_espresso'),
-                    $classname
-                )
-            );
-        }
-        return self::_get_model($classname)->get_primary_key_field()->get_name();
-    }
-
-
-    /**
-     * Gets the value of the primary key.
-     * If the object hasn't yet been saved, it should be whatever the model field's default was
-     * (eg, if this were the EE_Event class, look at the primary key field on EEM_Event and see what its default value
-     * is. Usually defaults for integer primary keys are 0; string primary keys are usually NULL).
-     *
-     * @return mixed, if the primary key is of type INT it'll be an int. Otherwise it could be a string
-     * @throws ReflectionException
-     * @throws InvalidArgumentException
-     * @throws InvalidInterfaceException
-     * @throws InvalidDataTypeException
-     * @throws EE_Error
-     */
-    public function ID()
-    {
-        $model = $this->get_model();
-        // now that we know the name of the variable, use a variable variable to get its value and return its
-        if ($model->has_primary_key_field()) {
-            return $this->_fields[ $model->primary_key_name() ];
-        }
-        return $model->get_index_primary_key_string($this->_fields);
-    }
-
-
-    /**
-     * Adds a relationship to the specified EE_Base_Class object, given the relationship's name. Eg, if the current
-     * model is related to a group of events, the $relationName should be 'Event', and should be a key in the EE
-     * Model's $_model_relations array. If this model object doesn't exist in the DB, just caches the related thing
-     *
-     * @param mixed  $otherObjectModelObjectOrID       EE_Base_Class or the ID of the other object
-     * @param string $relationName                     eg 'Events','Question',etc.
-     *                                                 an attendee to a group, you also want to specify which role they
-     *                                                 will have in that group. So you would use this parameter to
-     *                                                 specify array('role-column-name'=>'role-id')
-     * @param array  $extra_join_model_fields_n_values You can optionally include an array of key=>value pairs that
-     *                                                 allow you to further constrict the relation to being added.
-     *                                                 However, keep in mind that the columns (keys) given must match a
-     *                                                 column on the JOIN table and currently only the HABTM models
-     *                                                 accept these additional conditions.  Also remember that if an
-     *                                                 exact match isn't found for these extra cols/val pairs, then a
-     *                                                 NEW row is created in the join table.
-     * @param null   $cache_id
-     * @throws ReflectionException
-     * @throws InvalidArgumentException
-     * @throws InvalidInterfaceException
-     * @throws InvalidDataTypeException
-     * @throws EE_Error
-     * @return EE_Base_Class the object the relation was added to
-     */
-    public function _add_relation_to(
-        $otherObjectModelObjectOrID,
-        $relationName,
-        $extra_join_model_fields_n_values = array(),
-        $cache_id = null
-    ) {
-        $model = $this->get_model();
-        // if this thing exists in the DB, save the relation to the DB
-        if ($this->ID()) {
-            $otherObject = $model->add_relationship_to(
-                $this,
-                $otherObjectModelObjectOrID,
-                $relationName,
-                $extra_join_model_fields_n_values
-            );
-            // clear cache so future get_many_related and get_first_related() return new results.
-            $this->clear_cache($relationName, $otherObject, true);
-            if ($otherObject instanceof EE_Base_Class) {
-                $otherObject->clear_cache($model->get_this_model_name(), $this);
-            }
-        } else {
-            // this thing doesn't exist in the DB,  so just cache it
-            if (! $otherObjectModelObjectOrID instanceof EE_Base_Class) {
-                throw new EE_Error(
-                    sprintf(
-                        esc_html__(
-                            'Before a model object is saved to the database, calls to _add_relation_to must be passed an actual object, not just an ID. You provided %s as the model object to a %s',
-                            'event_espresso'
-                        ),
-                        $otherObjectModelObjectOrID,
-                        get_class($this)
-                    )
-                );
-            }
-            $otherObject = $otherObjectModelObjectOrID;
-            $this->cache($relationName, $otherObjectModelObjectOrID, $cache_id);
-        }
-        if ($otherObject instanceof EE_Base_Class) {
-            // fix the reciprocal relation too
-            if ($otherObject->ID()) {
-                // its saved so assumed relations exist in the DB, so we can just
-                // clear the cache so future queries use the updated info in the DB
-                $otherObject->clear_cache(
-                    $model->get_this_model_name(),
-                    null,
-                    true
-                );
-            } else {
-                // it's not saved, so it caches relations like this
-                $otherObject->cache($model->get_this_model_name(), $this);
-            }
-        }
-        return $otherObject;
-    }
-
-
-    /**
-     * Removes a relationship to the specified EE_Base_Class object, given the relationships' name. Eg, if the current
-     * model is related to a group of events, the $relationName should be 'Events', and should be a key in the EE
-     * Model's $_model_relations array. If this model object doesn't exist in the DB, just removes the related thing
-     * from the cache
-     *
-     * @param mixed  $otherObjectModelObjectOrID
-     *                EE_Base_Class or the ID of the other object, OR an array key into the cache if this isn't saved
-     *                to the DB yet
-     * @param string $relationName
-     * @param array  $where_query
-     *                You can optionally include an array of key=>value pairs that allow you to further constrict the
-     *                relation to being added. However, keep in mind that the columns (keys) given must match a column
-     *                on the JOIN table and currently only the HABTM models accept these additional conditions. Also
-     *                remember that if an exact match isn't found for these extra cols/val pairs, then a NEW row is
-     *                created in the join table.
-     * @return EE_Base_Class the relation was removed from
-     * @throws ReflectionException
-     * @throws InvalidArgumentException
-     * @throws InvalidInterfaceException
-     * @throws InvalidDataTypeException
-     * @throws EE_Error
-     */
-    public function _remove_relation_to($otherObjectModelObjectOrID, $relationName, $where_query = array())
-    {
-        if ($this->ID()) {
-            // if this exists in the DB, save the relation change to the DB too
-            $otherObject = $this->get_model()->remove_relationship_to(
-                $this,
-                $otherObjectModelObjectOrID,
-                $relationName,
-                $where_query
-            );
-            $this->clear_cache(
-                $relationName,
-                $otherObject
-            );
-        } else {
-            // this doesn't exist in the DB, just remove it from the cache
-            $otherObject = $this->clear_cache(
-                $relationName,
-                $otherObjectModelObjectOrID
-            );
-        }
-        if ($otherObject instanceof EE_Base_Class) {
-            $otherObject->clear_cache(
-                $this->get_model()->get_this_model_name(),
-                $this
-            );
-        }
-        return $otherObject;
-    }
-
-
-    /**
-     * Removes ALL the related things for the $relationName.
-     *
-     * @param string $relationName
-     * @param array  $where_query_params @see https://github.com/eventespresso/event-espresso-core/tree/master/docs/G--Model-System/model-query-params.md#0-where-conditions
-     * @return EE_Base_Class
-     * @throws ReflectionException
-     * @throws InvalidArgumentException
-     * @throws InvalidInterfaceException
-     * @throws InvalidDataTypeException
-     * @throws EE_Error
-     */
-    public function _remove_relations($relationName, $where_query_params = array())
-    {
-        if ($this->ID()) {
-            // if this exists in the DB, save the relation change to the DB too
-            $otherObjects = $this->get_model()->remove_relations(
-                $this,
-                $relationName,
-                $where_query_params
-            );
-            $this->clear_cache(
-                $relationName,
-                null,
-                true
-            );
-        } else {
-            // this doesn't exist in the DB, just remove it from the cache
-            $otherObjects = $this->clear_cache(
-                $relationName,
-                null,
-                true
-            );
-        }
-        if (is_array($otherObjects)) {
-            foreach ($otherObjects as $otherObject) {
-                $otherObject->clear_cache(
-                    $this->get_model()->get_this_model_name(),
-                    $this
-                );
-            }
-        }
-        return $otherObjects;
-    }
-
-
-    /**
-     * Gets all the related model objects of the specified type. Eg, if the current class if
-     * EE_Event, you could call $this->get_many_related('Registration') to get an array of all the
-     * EE_Registration objects which related to this event. Note: by default, we remove the "default query params"
-     * because we want to get even deleted items etc.
-     *
-     * @param string $relationName key in the model's _model_relations array
-     * @param array  $query_params @see https://github.com/eventespresso/event-espresso-core/tree/master/docs/G--Model-System/model-query-params.md#0-where-conditions
-     * @return EE_Base_Class[]     Results not necessarily indexed by IDs, because some results might not have primary
-     *                             keys or might not be saved yet. Consider using EEM_Base::get_IDs() on these
-     *                             results if you want IDs
-     * @throws ReflectionException
-     * @throws InvalidArgumentException
-     * @throws InvalidInterfaceException
-     * @throws InvalidDataTypeException
-     * @throws EE_Error
-     */
-    public function get_many_related($relationName, $query_params = array())
-    {
-        if ($this->ID()) {
-            // this exists in the DB, so get the related things from either the cache or the DB
-            // if there are query parameters, forget about caching the related model objects.
-            if ($query_params) {
-                $related_model_objects = $this->get_model()->get_all_related(
-                    $this,
-                    $relationName,
-                    $query_params
-                );
-            } else {
-                // did we already cache the result of this query?
-                $cached_results = $this->get_all_from_cache($relationName);
-                if (! $cached_results) {
-                    $related_model_objects = $this->get_model()->get_all_related(
-                        $this,
-                        $relationName,
-                        $query_params
-                    );
-                    // if no query parameters were passed, then we got all the related model objects
-                    // for that relation. We can cache them then.
-                    foreach ($related_model_objects as $related_model_object) {
-                        $this->cache($relationName, $related_model_object);
-                    }
-                } else {
-                    $related_model_objects = $cached_results;
-                }
-            }
-        } else {
-            // this doesn't exist in the DB, so just get the related things from the cache
-            $related_model_objects = $this->get_all_from_cache($relationName);
-        }
-        return $related_model_objects;
-    }
-
-
-    /**
-     * Instead of getting the related model objects, simply counts them. Ignores default_where_conditions by default,
-     * unless otherwise specified in the $query_params
-     *
-     * @param string $relation_name  model_name like 'Event', or 'Registration'
-     * @param array  $query_params   @see https://github.com/eventespresso/event-espresso-core/tree/master/docs/G--Model-System/model-query-params.md
-     * @param string $field_to_count name of field to count by. By default, uses primary key
-     * @param bool   $distinct       if we want to only count the distinct values for the column then you can trigger
-     *                               that by the setting $distinct to TRUE;
-     * @return int
-     * @throws ReflectionException
-     * @throws InvalidArgumentException
-     * @throws InvalidInterfaceException
-     * @throws InvalidDataTypeException
-     * @throws EE_Error
-     */
-    public function count_related($relation_name, $query_params = array(), $field_to_count = null, $distinct = false)
-    {
-        return $this->get_model()->count_related(
-            $this,
-            $relation_name,
-            $query_params,
-            $field_to_count,
-            $distinct
-        );
-    }
-
-
-    /**
-     * Instead of getting the related model objects, simply sums up the values of the specified field.
-     * Note: ignores default_where_conditions by default, unless otherwise specified in the $query_params
-     *
-     * @param string $relation_name model_name like 'Event', or 'Registration'
-     * @param array  $query_params  @see https://github.com/eventespresso/event-espresso-core/tree/master/docs/G--Model-System/model-query-params.md
-     * @param string $field_to_sum  name of field to count by.
-     *                              By default, uses primary key
-     *                              (which doesn't make much sense, so you should probably change it)
-     * @return int
-     * @throws ReflectionException
-     * @throws InvalidArgumentException
-     * @throws InvalidInterfaceException
-     * @throws InvalidDataTypeException
-     * @throws EE_Error
-     */
-    public function sum_related($relation_name, $query_params = array(), $field_to_sum = null)
-    {
-        return $this->get_model()->sum_related(
-            $this,
-            $relation_name,
-            $query_params,
-            $field_to_sum
-        );
-    }
-
-
-    /**
-     * Gets the first (ie, one) related model object of the specified type.
-     *
-     * @param string $relationName key in the model's _model_relations array
-     * @param array  $query_params @see https://github.com/eventespresso/event-espresso-core/tree/master/docs/G--Model-System/model-query-params.md
-     * @return EE_Base_Class (not an array, a single object)
-     * @throws ReflectionException
-     * @throws InvalidArgumentException
-     * @throws InvalidInterfaceException
-     * @throws InvalidDataTypeException
-     * @throws EE_Error
-     */
-    public function get_first_related($relationName, $query_params = array())
-    {
-        $model = $this->get_model();
-        if ($this->ID()) {// this exists in the DB, get from the cache OR the DB
-            // if they've provided some query parameters, don't bother trying to cache the result
-            // also make sure we're not caching the result of get_first_related
-            // on a relation which should have an array of objects (because the cache might have an array of objects)
-            if ($query_params
-                || ! $model->related_settings_for($relationName)
-                     instanceof
-                     EE_Belongs_To_Relation
-            ) {
-                $related_model_object = $model->get_first_related(
-                    $this,
-                    $relationName,
-                    $query_params
-                );
-            } else {
-                // first, check if we've already cached the result of this query
-                $cached_result = $this->get_one_from_cache($relationName);
-                if (! $cached_result) {
-                    $related_model_object = $model->get_first_related(
-                        $this,
-                        $relationName,
-                        $query_params
-                    );
-                    $this->cache($relationName, $related_model_object);
-                } else {
-                    $related_model_object = $cached_result;
-                }
-            }
-        } else {
-            $related_model_object = null;
-            // this doesn't exist in the Db,
-            // but maybe the relation is of type belongs to, and so the related thing might
-            if ($model->related_settings_for($relationName) instanceof EE_Belongs_To_Relation) {
-                $related_model_object = $model->get_first_related(
-                    $this,
-                    $relationName,
-                    $query_params
-                );
-            }
-            // this doesn't exist in the DB and apparently the thing it belongs to doesn't either,
-            // just get what's cached on this object
-            if (! $related_model_object) {
-                $related_model_object = $this->get_one_from_cache($relationName);
-            }
-        }
-        return $related_model_object;
-    }
-
-
-    /**
-     * Does a delete on all related objects of type $relationName and removes
-     * the current model object's relation to them. If they can't be deleted (because
-     * of blocking related model objects) does nothing. If the related model objects are
-     * soft-deletable, they will be soft-deleted regardless of related blocking model objects.
-     * If this model object doesn't exist yet in the DB, just removes its related things
-     *
-     * @param string $relationName
-     * @param array  $query_params @see https://github.com/eventespresso/event-espresso-core/tree/master/docs/G--Model-System/model-query-params.md
-     * @return int how many deleted
-     * @throws ReflectionException
-     * @throws InvalidArgumentException
-     * @throws InvalidInterfaceException
-     * @throws InvalidDataTypeException
-     * @throws EE_Error
-     */
-    public function delete_related($relationName, $query_params = array())
-    {
-        if ($this->ID()) {
-            $count = $this->get_model()->delete_related(
-                $this,
-                $relationName,
-                $query_params
-            );
-        } else {
-            $count = count($this->get_all_from_cache($relationName));
-            $this->clear_cache($relationName, null, true);
-        }
-        return $count;
-    }
-
-
-    /**
-     * Does a hard delete (ie, removes the DB row) on all related objects of type $relationName and removes
-     * the current model object's relation to them. If they can't be deleted (because
-     * of blocking related model objects) just does a soft delete on it instead, if possible.
-     * If the related thing isn't a soft-deletable model object, this function is identical
-     * to delete_related(). If this model object doesn't exist in the DB, just remove its related things
-     *
-     * @param string $relationName
-     * @param array  $query_params @see https://github.com/eventespresso/event-espresso-core/tree/master/docs/G--Model-System/model-query-params.md
-     * @return int how many deleted (including those soft deleted)
-     * @throws ReflectionException
-     * @throws InvalidArgumentException
-     * @throws InvalidInterfaceException
-     * @throws InvalidDataTypeException
-     * @throws EE_Error
-     */
-    public function delete_related_permanently($relationName, $query_params = array())
-    {
-        if ($this->ID()) {
-            $count = $this->get_model()->delete_related_permanently(
-                $this,
-                $relationName,
-                $query_params
-            );
-        } else {
-            $count = count($this->get_all_from_cache($relationName));
-        }
-        $this->clear_cache($relationName, null, true);
-        return $count;
-    }
-
-
-    /**
-     * is_set
-     * Just a simple utility function children can use for checking if property exists
-     *
-     * @access  public
-     * @param  string $field_name property to check
-     * @return bool                              TRUE if existing,FALSE if not.
-     */
-    public function is_set($field_name)
-    {
-        return isset($this->_fields[ $field_name ]);
-    }
-
-
-    /**
-     * Just a simple utility function children can use for checking if property (or properties) exists and throwing an
-     * EE_Error exception if they don't
-     *
-     * @param  mixed (string|array) $properties properties to check
-     * @throws EE_Error
-     * @return bool                              TRUE if existing, throw EE_Error if not.
-     */
-    protected function _property_exists($properties)
-    {
-        foreach ((array) $properties as $property_name) {
-            // first make sure this property exists
-            if (! $this->_fields[ $property_name ]) {
-                throw new EE_Error(
-                    sprintf(
-                        esc_html__(
-                            'Trying to retrieve a non-existent property (%s).  Double check the spelling please',
-                            'event_espresso'
-                        ),
-                        $property_name
-                    )
-                );
-            }
-        }
-        return true;
-    }
-
-
-    /**
-     * This simply returns an array of model fields for this object
-     *
-     * @return array
-     * @throws ReflectionException
-     * @throws InvalidArgumentException
-     * @throws InvalidInterfaceException
-     * @throws InvalidDataTypeException
-     * @throws EE_Error
-     */
-    public function model_field_array()
-    {
-        $fields = $this->get_model()->field_settings(false);
-        $properties = array();
-        // remove prepended underscore
-        foreach ($fields as $field_name => $settings) {
-            $properties[ $field_name ] = $this->get($field_name);
-        }
-        return $properties;
-    }
-
-
-    /**
-     * Very handy general function to allow for plugins to extend any child of EE_Base_Class.
-     * If a method is called on a child of EE_Base_Class that doesn't exist, this function is called
-     * (http://www.garfieldtech.com/blog/php-magic-call) and passed the method's name and arguments.
-     * Instead of requiring a plugin to extend the EE_Base_Class
-     * (which works fine is there's only 1 plugin, but when will that happen?)
-     * they can add a hook onto 'filters_hook_espresso__{className}__{methodName}'
-     * (eg, filters_hook_espresso__EE_Answer__my_great_function)
-     * and accepts 2 arguments: the object on which the function was called,
-     * and an array of the original arguments passed to the function.
-     * Whatever their callback function returns will be returned by this function.
-     * Example: in functions.php (or in a plugin):
-     *      add_filter('FHEE__EE_Answer__my_callback','my_callback',10,3);
-     *      function my_callback($previousReturnValue,EE_Base_Class $object,$argsArray){
-     *          $returnString= "you called my_callback! and passed args:".implode(",",$argsArray);
-     *          return $previousReturnValue.$returnString;
-     *      }
-     * require('EE_Answer.class.php');
-     * $answer= EE_Answer::new_instance(array('REG_ID' => 2,'QST_ID' => 3,'ANS_value' => The answer is 42'));
-     * echo $answer->my_callback('monkeys',100);
-     * //will output "you called my_callback! and passed args:monkeys,100"
-     *
-     * @param string $methodName name of method which was called on a child of EE_Base_Class, but which
-     * @param array  $args       array of original arguments passed to the function
-     * @throws EE_Error
-     * @return mixed whatever the plugin which calls add_filter decides
-     */
-    public function __call($methodName, $args)
-    {
-        $className = get_class($this);
-        $tagName = "FHEE__{$className}__{$methodName}";
-        if (! has_filter($tagName)) {
-            throw new EE_Error(
-                sprintf(
-                    esc_html__(
-                        "Method %s on class %s does not exist! You can create one with the following code in functions.php or in a plugin: add_filter('%s','my_callback',10,3);function my_callback(\$previousReturnValue,EE_Base_Class \$object, \$argsArray){/*function body*/return \$whatever;}",
-                        'event_espresso'
-                    ),
-                    $methodName,
-                    $className,
-                    $tagName
-                )
-            );
-        }
-        return apply_filters($tagName, null, $this, $args);
-    }
-
-
-    /**
-     * Similar to insert_post_meta, adds a record in the Extra_Meta model's table with the given key and value.
-     * A $previous_value can be specified in case there are many meta rows with the same key
-     *
-     * @param string $meta_key
-     * @param mixed  $meta_value
-     * @param mixed  $previous_value
-     * @return bool|int # of records updated (or BOOLEAN if we actually ended up inserting the extra meta row)
-     *                  NOTE: if the values haven't changed, returns 0
-     * @throws InvalidArgumentException
-     * @throws InvalidInterfaceException
-     * @throws InvalidDataTypeException
-     * @throws EE_Error
-     * @throws ReflectionException
-     */
-    public function update_extra_meta($meta_key, $meta_value, $previous_value = null)
-    {
-        $query_params = array(
-            array(
-                'EXM_key'  => $meta_key,
-                'OBJ_ID'   => $this->ID(),
-                'EXM_type' => $this->get_model()->get_this_model_name(),
-            ),
-        );
-        if ($previous_value !== null) {
-            $query_params[0]['EXM_value'] = $meta_value;
-        }
-        $existing_rows_like_that = EEM_Extra_Meta::instance()->get_all($query_params);
-        if (! $existing_rows_like_that) {
-            return $this->add_extra_meta($meta_key, $meta_value);
-        }
-        foreach ($existing_rows_like_that as $existing_row) {
-            $existing_row->save(array('EXM_value' => $meta_value));
-        }
-        return count($existing_rows_like_that);
-    }
-
-
-    /**
-     * Adds a new extra meta record. If $unique is set to TRUE, we'll first double-check
-     * no other extra meta for this model object have the same key. Returns TRUE if the
-     * extra meta row was entered, false if not
-     *
-     * @param string  $meta_key
-     * @param mixed   $meta_value
-     * @param boolean $unique
-     * @return boolean
-     * @throws InvalidArgumentException
-     * @throws InvalidInterfaceException
-     * @throws InvalidDataTypeException
-     * @throws EE_Error
-     * @throws ReflectionException
-     * @throws ReflectionException
-     */
-    public function add_extra_meta($meta_key, $meta_value, $unique = false)
-    {
-        if ($unique) {
-            $existing_extra_meta = EEM_Extra_Meta::instance()->get_one(
-                array(
-                    array(
-                        'EXM_key'  => $meta_key,
-                        'OBJ_ID'   => $this->ID(),
-                        'EXM_type' => $this->get_model()->get_this_model_name(),
-                    ),
-                )
-            );
-            if ($existing_extra_meta) {
-                return false;
-            }
-        }
-        $new_extra_meta = EE_Extra_Meta::new_instance(
-            array(
-                'EXM_key'   => $meta_key,
-                'EXM_value' => $meta_value,
-                'OBJ_ID'    => $this->ID(),
-                'EXM_type'  => $this->get_model()->get_this_model_name(),
-            )
-        );
-        $new_extra_meta->save();
-        return true;
-    }
-
-
-    /**
-     * Deletes all the extra meta rows for this record as specified by key. If $meta_value
-     * is specified, only deletes extra meta records with that value.
-     *
-     * @param string $meta_key
-     * @param mixed  $meta_value
-     * @return int number of extra meta rows deleted
-     * @throws InvalidArgumentException
-     * @throws InvalidInterfaceException
-     * @throws InvalidDataTypeException
-     * @throws EE_Error
-     * @throws ReflectionException
-     */
-    public function delete_extra_meta($meta_key, $meta_value = null)
-    {
-        $query_params = array(
-            array(
-                'EXM_key'  => $meta_key,
-                'OBJ_ID'   => $this->ID(),
-                'EXM_type' => $this->get_model()->get_this_model_name(),
-            ),
-        );
-        if ($meta_value !== null) {
-            $query_params[0]['EXM_value'] = $meta_value;
-        }
-        return EEM_Extra_Meta::instance()->delete($query_params);
-    }
-
-
-    /**
-     * Gets the extra meta with the given meta key. If you specify "single" we just return 1, otherwise
-     * an array of everything found. Requires that this model actually have a relation of type EE_Has_Many_Any_Relation.
-     * You can specify $default is case you haven't found the extra meta
-     *
-     * @param string  $meta_key
-     * @param boolean $single
-     * @param mixed   $default if we don't find anything, what should we return?
-     * @return mixed single value if $single; array if ! $single
-     * @throws ReflectionException
-     * @throws InvalidArgumentException
-     * @throws InvalidInterfaceException
-     * @throws InvalidDataTypeException
-     * @throws EE_Error
-     */
-    public function get_extra_meta($meta_key, $single = false, $default = null)
-    {
-        if ($single) {
-            $result = $this->get_first_related(
-                'Extra_Meta',
-                array(array('EXM_key' => $meta_key))
-            );
-            if ($result instanceof EE_Extra_Meta) {
-                return $result->value();
-            }
-        } else {
-            $results = $this->get_many_related(
-                'Extra_Meta',
-                array(array('EXM_key' => $meta_key))
-            );
-            if ($results) {
-                $values = array();
-                foreach ($results as $result) {
-                    if ($result instanceof EE_Extra_Meta) {
-                        $values[ $result->ID() ] = $result->value();
-                    }
-                }
-                return $values;
-            }
-        }
-        // if nothing discovered yet return default.
-        return apply_filters(
-            'FHEE__EE_Base_Class__get_extra_meta__default_value',
-            $default,
-            $meta_key,
-            $single,
-            $this
-        );
-    }
-
-
-    /**
-     * Returns a simple array of all the extra meta associated with this model object.
-     * If $one_of_each_key is true (Default), it will be an array of simple key-value pairs, keys being the
-     * extra meta's key, and teh value being its value. However, if there are duplicate extra meta rows with
-     * the same key, only one will be used. (eg array('foo'=>'bar','monkey'=>123))
-     * If $one_of_each_key is false, it will return an array with the top-level keys being
-     * the extra meta keys, but their values are also arrays, which have the extra-meta's ID as their sub-key, and
-     * finally the extra meta's value as each sub-value. (eg
-     * array('foo'=>array(1=>'bar',2=>'bill'),'monkey'=>array(3=>123)))
-     *
-     * @param boolean $one_of_each_key
-     * @return array
-     * @throws ReflectionException
-     * @throws InvalidArgumentException
-     * @throws InvalidInterfaceException
-     * @throws InvalidDataTypeException
-     * @throws EE_Error
-     */
-    public function all_extra_meta_array($one_of_each_key = true)
-    {
-        $return_array = array();
-        if ($one_of_each_key) {
-            $extra_meta_objs = $this->get_many_related(
-                'Extra_Meta',
-                array('group_by' => 'EXM_key')
-            );
-            foreach ($extra_meta_objs as $extra_meta_obj) {
-                if ($extra_meta_obj instanceof EE_Extra_Meta) {
-                    $return_array[ $extra_meta_obj->key() ] = $extra_meta_obj->value();
-                }
-            }
-        } else {
-            $extra_meta_objs = $this->get_many_related('Extra_Meta');
-            foreach ($extra_meta_objs as $extra_meta_obj) {
-                if ($extra_meta_obj instanceof EE_Extra_Meta) {
-                    if (! isset($return_array[ $extra_meta_obj->key() ])) {
-                        $return_array[ $extra_meta_obj->key() ] = array();
-                    }
-                    $return_array[ $extra_meta_obj->key() ][ $extra_meta_obj->ID() ] = $extra_meta_obj->value();
-                }
-            }
-        }
-        return $return_array;
-    }
-
-
-    /**
-     * Gets a pretty nice displayable nice for this model object. Often overridden
-     *
-     * @return string
-     * @throws ReflectionException
-     * @throws InvalidArgumentException
-     * @throws InvalidInterfaceException
-     * @throws InvalidDataTypeException
-     * @throws EE_Error
-     */
-    public function name()
-    {
-        // find a field that's not a text field
-        $field_we_can_use = $this->get_model()->get_a_field_of_type('EE_Text_Field_Base');
-        if ($field_we_can_use) {
-            return $this->get($field_we_can_use->get_name());
-        }
-        $first_few_properties = $this->model_field_array();
-        $first_few_properties = array_slice($first_few_properties, 0, 3);
-        $name_parts = array();
-        foreach ($first_few_properties as $name => $value) {
-            $name_parts[] = "$name:$value";
-        }
-        return implode(',', $name_parts);
-    }
-
-
-    /**
-     * in_entity_map
-     * Checks if this model object has been proven to already be in the entity map
-     *
-     * @return boolean
-     * @throws ReflectionException
-     * @throws InvalidArgumentException
-     * @throws InvalidInterfaceException
-     * @throws InvalidDataTypeException
-     * @throws EE_Error
-     */
-    public function in_entity_map()
-    {
-        // well, if we looked, did we find it in the entity map?
-        return $this->ID() && $this->get_model()->get_from_entity_map($this->ID()) === $this;
-    }
-
-
-    /**
-     * refresh_from_db
-     * Makes sure the fields and values on this model object are in-sync with what's in the database.
-     *
-     * @throws ReflectionException
-     * @throws InvalidArgumentException
-     * @throws InvalidInterfaceException
-     * @throws InvalidDataTypeException
-     * @throws EE_Error if this model object isn't in the entity mapper (because then you should
-     * just use what's in the entity mapper and refresh it) and WP_DEBUG is TRUE
-     */
-    public function refresh_from_db()
-    {
-        if ($this->ID() && $this->in_entity_map()) {
-            $this->get_model()->refresh_entity_map_from_db($this->ID());
-        } else {
-            // if it doesn't have ID, you shouldn't be asking to refresh it from teh database (because its not in the database)
-            // if it has an ID but it's not in the map, and you're asking me to refresh it
-            // that's kinda dangerous. You should just use what's in the entity map, or add this to the entity map if there's
-            // absolutely nothing in it for this ID
-            if (WP_DEBUG) {
-                throw new EE_Error(
-                    sprintf(
-                        esc_html__(
-                            'Trying to refresh a model object with ID "%1$s" that\'s not in the entity map? First off: you should put it in the entity map by calling %2$s. Second off, if you want what\'s in the database right now, you should just call %3$s yourself and discard this model object.',
-                            'event_espresso'
-                        ),
-                        $this->ID(),
-                        get_class($this->get_model()) . '::instance()->add_to_entity_map()',
-                        get_class($this->get_model()) . '::instance()->refresh_entity_map()'
-                    )
-                );
-            }
-        }
-    }
-
-
-    /**
-     * Because some other plugins, like Advanced Cron Manager, expect all objects to have this method
-     * (probably a bad assumption they have made, oh well)
-     *
-     * @return string
-     */
-    public function __toString()
-    {
-        try {
-            return sprintf('%s (%s)', $this->name(), $this->ID());
-        } catch (Exception $e) {
-            EE_Error::add_error($e->getMessage(), __FILE__, __FUNCTION__, __LINE__);
-            return '';
-        }
-    }
-
-
-    /**
-     * Clear related model objects if they're already in the DB, because otherwise when we
-     * UN-serialize this model object we'll need to be careful to add them to the entity map.
-     * This means if we have made changes to those related model objects, and want to unserialize
-     * the this model object on a subsequent request, changes to those related model objects will be lost.
-     * Instead, those related model objects should be directly serialized and stored.
-     * Eg, the following won't work:
-     * $reg = EEM_Registration::instance()->get_one_by_ID( 123 );
-     * $att = $reg->attendee();
-     * $att->set( 'ATT_fname', 'Dirk' );
-     * update_option( 'my_option', serialize( $reg ) );
-     * //END REQUEST
-     * //START NEXT REQUEST
-     * $reg = get_option( 'my_option' );
-     * $reg->attendee()->save();
-     * And would need to be replace with:
-     * $reg = EEM_Registration::instance()->get_one_by_ID( 123 );
-     * $att = $reg->attendee();
-     * $att->set( 'ATT_fname', 'Dirk' );
-     * update_option( 'my_option', serialize( $reg ) );
-     * //END REQUEST
-     * //START NEXT REQUEST
-     * $att = get_option( 'my_option' );
-     * $att->save();
-     *
-     * @return array
-     * @throws ReflectionException
-     * @throws InvalidArgumentException
-     * @throws InvalidInterfaceException
-     * @throws InvalidDataTypeException
-     * @throws EE_Error
-     */
-    public function __sleep()
-    {
-        $model = $this->get_model();
-        foreach ($model->relation_settings() as $relation_name => $relation_obj) {
-            if ($relation_obj instanceof EE_Belongs_To_Relation) {
-                $classname = 'EE_' . $model->get_this_model_name();
-                if ($this->get_one_from_cache($relation_name) instanceof $classname
-                    && $this->get_one_from_cache($relation_name)->ID()
-                ) {
-                    $this->clear_cache(
-                        $relation_name,
-                        $this->get_one_from_cache($relation_name)->ID()
-                    );
-                }
-            }
-        }
-        $this->_props_n_values_provided_in_constructor = array();
-        $properties_to_serialize = get_object_vars($this);
-        // don't serialize the model. It's big and that risks recursion
-        unset($properties_to_serialize['_model']);
-        return array_keys($properties_to_serialize);
-    }
-
-
-    /**
-     * restore _props_n_values_provided_in_constructor
-     * PLZ NOTE: this will reset the array to whatever fields values were present prior to serialization,
-     * and therefore should NOT be used to determine if state change has occurred since initial construction.
-     * At best, you would only be able to detect if state change has occurred during THIS request.
-     */
-    public function __wakeup()
-    {
-        $this->_props_n_values_provided_in_constructor = $this->_fields;
-    }
-
-
-    /**
-     * Usage of this magic method is to ensure any internally cached references to object instances that must remain
-     * distinct with the clone host instance are also cloned.
-     */
-    public function __clone()
-    {
-        // handle DateTimes (this is handled in here because there's no one specific child class that uses datetimes).
-        foreach ($this->_fields as $field => $value) {
-            if ($value instanceof DateTime) {
-                $this->_fields[ $field ] = clone $value;
-            }
-        }
-    }
+	/**
+	 * This is an array of the original properties and values provided during construction
+	 * of this model object. (keys are model field names, values are their values).
+	 * This list is important to remember so that when we are merging data from the db, we know
+	 * which values to override and which to not override.
+	 *
+	 * @var array
+	 */
+	protected $_props_n_values_provided_in_constructor;
+
+	/**
+	 * Timezone
+	 * This gets set by the "set_timezone()" method so that we know what timezone incoming strings|timestamps are in.
+	 * This can also be used before a get to set what timezone you want strings coming out of the object to be in.  NOT
+	 * all EE_Base_Class child classes use this property but any that use a EE_Datetime_Field data type will have
+	 * access to it.
+	 *
+	 * @var string
+	 */
+	protected $_timezone;
+
+	/**
+	 * date format
+	 * pattern or format for displaying dates
+	 *
+	 * @var string $_dt_frmt
+	 */
+	protected $_dt_frmt;
+
+	/**
+	 * time format
+	 * pattern or format for displaying time
+	 *
+	 * @var string $_tm_frmt
+	 */
+	protected $_tm_frmt;
+
+	/**
+	 * This property is for holding a cached array of object properties indexed by property name as the key.
+	 * The purpose of this is for setting a cache on properties that may have calculated values after a
+	 * prepare_for_get.  That way the cache can be checked first and the calculated property returned instead of having
+	 * to recalculate. Used by _set_cached_property() and _get_cached_property() methods.
+	 *
+	 * @var array
+	 */
+	protected $_cached_properties = array();
+
+	/**
+	 * An array containing keys of the related model, and values are either an array of related mode objects or a
+	 * single
+	 * related model object. see the model's _model_relations. The keys should match those specified. And if the
+	 * relation is of type EE_Belongs_To (or one of its children), then there should only be ONE related model object,
+	 * all others have an array)
+	 *
+	 * @var array
+	 */
+	protected $_model_relations = array();
+
+	/**
+	 * Array where keys are field names (see the model's _fields property) and values are their values. To see what
+	 * their types should be, look at what that field object returns on its prepare_for_get and prepare_for_set methods)
+	 *
+	 * @var array
+	 */
+	protected $_fields = array();
+
+	/**
+	 * @var boolean indicating whether or not this model object is intended to ever be saved
+	 * For example, we might create model objects intended to only be used for the duration
+	 * of this request and to be thrown away, and if they were accidentally saved
+	 * it would be a bug.
+	 */
+	protected $_allow_persist = true;
+
+	/**
+	 * @var boolean indicating whether or not this model object's properties have changed since construction
+	 */
+	protected $_has_changes = false;
+
+	/**
+	 * @var EEM_Base
+	 */
+	protected $_model;
+
+	/**
+	 * This is a cache of results from custom selections done on a query that constructs this entity. The only purpose
+	 * for these values is for retrieval of the results, they are not further queryable and they are not persisted to
+	 * the db.  They also do not automatically update if there are any changes to the data that produced their results.
+	 * The format is a simple array of field_alias => field_value.  So for instance if a custom select was something
+	 * like,  "Select COUNT(Registration.REG_ID) as Registration_Count ...", then the resulting value will be in this
+	 * array as:
+	 * array(
+	 *  'Registration_Count' => 24
+	 * );
+	 * Note: if the custom select configuration for the query included a data type, the value will be in the data type
+	 * provided for the query (@see EventEspresso\core\domain\values\model\CustomSelects::__construct phpdocs for more
+	 * info)
+	 *
+	 * @var array
+	 */
+	protected $custom_selection_results = array();
+
+
+	/**
+	 * basic constructor for Event Espresso classes, performs any necessary initialization, and verifies it's children
+	 * play nice
+	 *
+	 * @param array   $fieldValues                             where each key is a field (ie, array key in the 2nd
+	 *                                                         layer of the model's _fields array, (eg, EVT_ID,
+	 *                                                         TXN_amount, QST_name, etc) and values are their values
+	 * @param boolean $bydb                                    a flag for setting if the class is instantiated by the
+	 *                                                         corresponding db model or not.
+	 * @param string  $timezone                                indicate what timezone you want any datetime fields to
+	 *                                                         be in when instantiating a EE_Base_Class object.
+	 * @param array   $date_formats                            An array of date formats to set on construct where first
+	 *                                                         value is the date_format and second value is the time
+	 *                                                         format.
+	 * @throws InvalidArgumentException
+	 * @throws InvalidInterfaceException
+	 * @throws InvalidDataTypeException
+	 * @throws EE_Error
+	 * @throws ReflectionException
+	 */
+	protected function __construct($fieldValues = array(), $bydb = false, $timezone = '', $date_formats = array())
+	{
+		$className = get_class($this);
+		do_action("AHEE__{$className}__construct", $this, $fieldValues);
+		$model = $this->get_model();
+		$model_fields = $model->field_settings(false);
+		// ensure $fieldValues is an array
+		$fieldValues = is_array($fieldValues) ? $fieldValues : array($fieldValues);
+		// verify client code has not passed any invalid field names
+		foreach ($fieldValues as $field_name => $field_value) {
+			if (! isset($model_fields[ $field_name ])) {
+				throw new EE_Error(
+					sprintf(
+						esc_html__(
+							'Invalid field (%s) passed to constructor of %s. Allowed fields are :%s',
+							'event_espresso'
+						),
+						$field_name,
+						get_class($this),
+						implode(', ', array_keys($model_fields))
+					)
+				);
+			}
+		}
+		$this->_timezone = EEH_DTT_Helper::get_valid_timezone_string($timezone);
+		if (! empty($date_formats) && is_array($date_formats)) {
+			list($this->_dt_frmt, $this->_tm_frmt) = $date_formats;
+		} else {
+			// set default formats for date and time
+			$this->_dt_frmt = (string) get_option('date_format', 'Y-m-d');
+			$this->_tm_frmt = (string) get_option('time_format', 'g:i a');
+		}
+		// if db model is instantiating
+		if ($bydb) {
+			// client code has indicated these field values are from the database
+			foreach ($model_fields as $fieldName => $field) {
+				$this->set_from_db(
+					$fieldName,
+					isset($fieldValues[ $fieldName ]) ? $fieldValues[ $fieldName ] : null
+				);
+			}
+		} else {
+			// we're constructing a brand
+			// new instance of the model object. Generally, this means we'll need to do more field validation
+			foreach ($model_fields as $fieldName => $field) {
+				$this->set(
+					$fieldName,
+					isset($fieldValues[ $fieldName ]) ? $fieldValues[ $fieldName ] : null,
+					true
+				);
+			}
+		}
+		// remember what values were passed to this constructor
+		$this->_props_n_values_provided_in_constructor = $fieldValues;
+		// remember in entity mapper
+		if (! $bydb && $model->has_primary_key_field() && $this->ID()) {
+			$model->add_to_entity_map($this);
+		}
+		// setup all the relations
+		foreach ($model->relation_settings() as $relation_name => $relation_obj) {
+			if ($relation_obj instanceof EE_Belongs_To_Relation) {
+				$this->_model_relations[ $relation_name ] = null;
+			} else {
+				$this->_model_relations[ $relation_name ] = array();
+			}
+		}
+		/**
+		 * Action done at the end of each model object construction
+		 *
+		 * @param EE_Base_Class $this the model object just created
+		 */
+		do_action('AHEE__EE_Base_Class__construct__finished', $this);
+	}
+
+
+	/**
+	 * Gets whether or not this model object is allowed to persist/be saved to the database.
+	 *
+	 * @return boolean
+	 */
+	public function allow_persist()
+	{
+		return $this->_allow_persist;
+	}
+
+
+	/**
+	 * Sets whether or not this model object should be allowed to be saved to the DB.
+	 * Normally once this is set to FALSE you wouldn't set it back to TRUE, unless
+	 * you got new information that somehow made you change your mind.
+	 *
+	 * @param boolean $allow_persist
+	 * @return boolean
+	 */
+	public function set_allow_persist($allow_persist)
+	{
+		return $this->_allow_persist = $allow_persist;
+	}
+
+
+	/**
+	 * Gets the field's original value when this object was constructed during this request.
+	 * This can be helpful when determining if a model object has changed or not
+	 *
+	 * @param string $field_name
+	 * @return mixed|null
+	 * @throws ReflectionException
+	 * @throws InvalidArgumentException
+	 * @throws InvalidInterfaceException
+	 * @throws InvalidDataTypeException
+	 * @throws EE_Error
+	 */
+	public function get_original($field_name)
+	{
+		if (isset($this->_props_n_values_provided_in_constructor[ $field_name ])
+			&& $field_settings = $this->get_model()->field_settings_for($field_name)
+		) {
+			return $field_settings->prepare_for_get($this->_props_n_values_provided_in_constructor[ $field_name ]);
+		}
+		return null;
+	}
+
+
+	/**
+	 * @param EE_Base_Class $obj
+	 * @return string
+	 */
+	public function get_class($obj)
+	{
+		return get_class($obj);
+	}
+
+
+	/**
+	 * Overrides parent because parent expects old models.
+	 * This also doesn't do any validation, and won't work for serialized arrays
+	 *
+	 * @param    string $field_name
+	 * @param    mixed  $field_value
+	 * @param bool      $use_default
+	 * @throws InvalidArgumentException
+	 * @throws InvalidInterfaceException
+	 * @throws InvalidDataTypeException
+	 * @throws EE_Error
+	 * @throws ReflectionException
+	 * @throws ReflectionException
+	 * @throws ReflectionException
+	 */
+	public function set($field_name, $field_value, $use_default = false)
+	{
+		// if not using default and nothing has changed, and object has already been setup (has ID),
+		// then don't do anything
+		if (! $use_default
+			&& $this->_fields[ $field_name ] === $field_value
+			&& $this->ID()
+		) {
+			return;
+		}
+		$model = $this->get_model();
+		$this->_has_changes = true;
+		$field_obj = $model->field_settings_for($field_name);
+		if ($field_obj instanceof EE_Model_Field_Base) {
+			// if ( method_exists( $field_obj, 'set_timezone' )) {
+			if ($field_obj instanceof EE_Datetime_Field) {
+				$field_obj->set_timezone($this->_timezone);
+				$field_obj->set_date_format($this->_dt_frmt);
+				$field_obj->set_time_format($this->_tm_frmt);
+			}
+			$holder_of_value = $field_obj->prepare_for_set($field_value);
+			// should the value be null?
+			if (($field_value === null || $holder_of_value === null || $holder_of_value === '') && $use_default) {
+				$this->_fields[ $field_name ] = $field_obj->get_default_value();
+				/**
+				 * To save having to refactor all the models, if a default value is used for a
+				 * EE_Datetime_Field, and that value is not null nor is it a DateTime
+				 * object.  Then let's do a set again to ensure that it becomes a DateTime
+				 * object.
+				 *
+				 * @since 4.6.10+
+				 */
+				if ($field_obj instanceof EE_Datetime_Field
+					&& $this->_fields[ $field_name ] !== null
+					&& ! $this->_fields[ $field_name ] instanceof DateTime
+				) {
+					empty($this->_fields[ $field_name ])
+						? $this->set($field_name, time())
+						: $this->set($field_name, $this->_fields[ $field_name ]);
+				}
+			} else {
+				$this->_fields[ $field_name ] = $holder_of_value;
+			}
+			// if we're not in the constructor...
+			// now check if what we set was a primary key
+			if (// note: props_n_values_provided_in_constructor is only set at the END of the constructor
+				$this->_props_n_values_provided_in_constructor
+				&& $field_value
+				&& $field_name === $model->primary_key_name()
+			) {
+				// if so, we want all this object's fields to be filled either with
+				// what we've explicitly set on this model
+				// or what we have in the db
+				// echo "setting primary key!";
+				$fields_on_model = self::_get_model(get_class($this))->field_settings();
+				$obj_in_db = self::_get_model(get_class($this))->get_one_by_ID($field_value);
+				foreach ($fields_on_model as $field_obj) {
+					if (! array_key_exists($field_obj->get_name(), $this->_props_n_values_provided_in_constructor)
+						&& $field_obj->get_name() !== $field_name
+					) {
+						$this->set($field_obj->get_name(), $obj_in_db->get($field_obj->get_name()));
+					}
+				}
+				// oh this model object has an ID? well make sure its in the entity mapper
+				$model->add_to_entity_map($this);
+			}
+			// let's unset any cache for this field_name from the $_cached_properties property.
+			$this->_clear_cached_property($field_name);
+		} else {
+			throw new EE_Error(
+				sprintf(
+					esc_html__(
+						'A valid EE_Model_Field_Base could not be found for the given field name: %s',
+						'event_espresso'
+					),
+					$field_name
+				)
+			);
+		}
+	}
+
+
+	/**
+	 * Set custom select values for model.
+	 *
+	 * @param array $custom_select_values
+	 */
+	public function setCustomSelectsValues(array $custom_select_values)
+	{
+		$this->custom_selection_results = $custom_select_values;
+	}
+
+
+	/**
+	 * Returns the custom select value for the provided alias if its set.
+	 * If not set, returns null.
+	 *
+	 * @param string $alias
+	 * @return string|int|float|null
+	 */
+	public function getCustomSelect($alias)
+	{
+		return isset($this->custom_selection_results[ $alias ])
+			? $this->custom_selection_results[ $alias ]
+			: null;
+	}
+
+
+	/**
+	 * This sets the field value on the db column if it exists for the given $column_name or
+	 * saves it to EE_Extra_Meta if the given $column_name does not match a db column.
+	 *
+	 * @see EE_message::get_column_value for related documentation on the necessity of this method.
+	 * @param string $field_name  Must be the exact column name.
+	 * @param mixed  $field_value The value to set.
+	 * @return int|bool @see EE_Base_Class::update_extra_meta() for return docs.
+	 * @throws InvalidArgumentException
+	 * @throws InvalidInterfaceException
+	 * @throws InvalidDataTypeException
+	 * @throws EE_Error
+	 * @throws ReflectionException
+	 */
+	public function set_field_or_extra_meta($field_name, $field_value)
+	{
+		if ($this->get_model()->has_field($field_name)) {
+			$this->set($field_name, $field_value);
+			return true;
+		}
+		// ensure this object is saved first so that extra meta can be properly related.
+		$this->save();
+		return $this->update_extra_meta($field_name, $field_value);
+	}
+
+
+	/**
+	 * This retrieves the value of the db column set on this class or if that's not present
+	 * it will attempt to retrieve from extra_meta if found.
+	 * Example Usage:
+	 * Via EE_Message child class:
+	 * Due to the dynamic nature of the EE_messages system, EE_messengers will always have a "to",
+	 * "from", "subject", and "content" field (as represented in the EE_Message schema), however they may
+	 * also have additional main fields specific to the messenger.  The system accommodates those extra
+	 * fields through the EE_Extra_Meta table.  This method allows for EE_messengers to retrieve the
+	 * value for those extra fields dynamically via the EE_message object.
+	 *
+	 * @param  string $field_name expecting the fully qualified field name.
+	 * @return mixed|null  value for the field if found.  null if not found.
+	 * @throws ReflectionException
+	 * @throws InvalidArgumentException
+	 * @throws InvalidInterfaceException
+	 * @throws InvalidDataTypeException
+	 * @throws EE_Error
+	 */
+	public function get_field_or_extra_meta($field_name)
+	{
+		if ($this->get_model()->has_field($field_name)) {
+			$column_value = $this->get($field_name);
+		} else {
+			// This isn't a column in the main table, let's see if it is in the extra meta.
+			$column_value = $this->get_extra_meta($field_name, true, null);
+		}
+		return $column_value;
+	}
+
+
+	/**
+	 * See $_timezone property for description of what the timezone property is for.  This SETS the timezone internally
+	 * for being able to reference what timezone we are running conversions on when converting TO the internal timezone
+	 * (UTC Unix Timestamp) for the object OR when converting FROM the internal timezone (UTC Unix Timestamp). This is
+	 * available to all child classes that may be using the EE_Datetime_Field for a field data type.
+	 *
+	 * @access public
+	 * @param string $timezone A valid timezone string as described by @link http://www.php.net/manual/en/timezones.php
+	 * @return void
+	 * @throws InvalidArgumentException
+	 * @throws InvalidInterfaceException
+	 * @throws InvalidDataTypeException
+	 * @throws EE_Error
+	 * @throws ReflectionException
+	 */
+	public function set_timezone($timezone = '')
+	{
+		$this->_timezone = EEH_DTT_Helper::get_valid_timezone_string($timezone);
+		// make sure we clear all cached properties because they won't be relevant now
+		$this->_clear_cached_properties();
+		// make sure we update field settings and the date for all EE_Datetime_Fields
+		$model_fields = $this->get_model()->field_settings(false);
+		foreach ($model_fields as $field_name => $field_obj) {
+			if ($field_obj instanceof EE_Datetime_Field) {
+				$field_obj->set_timezone($this->_timezone);
+				if (isset($this->_fields[ $field_name ]) && $this->_fields[ $field_name ] instanceof DateTime) {
+					EEH_DTT_Helper::setTimezone($this->_fields[ $field_name ], new DateTimeZone($this->_timezone));
+				}
+			}
+		}
+	}
+
+
+	/**
+	 * This just returns whatever is set for the current timezone.
+	 *
+	 * @access public
+	 * @return string timezone string
+	 */
+	public function get_timezone()
+	{
+		return $this->_timezone;
+	}
+
+
+	/**
+	 * This sets the internal date format to what is sent in to be used as the new default for the class
+	 * internally instead of wp set date format options
+	 *
+	 * @since 4.6
+	 * @param string $format should be a format recognizable by PHP date() functions.
+	 */
+	public function set_date_format($format)
+	{
+		$this->_dt_frmt = $format;
+		// clear cached_properties because they won't be relevant now.
+		$this->_clear_cached_properties();
+	}
+
+
+	/**
+	 * This sets the internal time format string to what is sent in to be used as the new default for the
+	 * class internally instead of wp set time format options.
+	 *
+	 * @since 4.6
+	 * @param string $format should be a format recognizable by PHP date() functions.
+	 */
+	public function set_time_format($format)
+	{
+		$this->_tm_frmt = $format;
+		// clear cached_properties because they won't be relevant now.
+		$this->_clear_cached_properties();
+	}
+
+
+	/**
+	 * This returns the current internal set format for the date and time formats.
+	 *
+	 * @param bool $full           if true (default), then return the full format.  Otherwise will return an array
+	 *                             where the first value is the date format and the second value is the time format.
+	 * @return mixed string|array
+	 */
+	public function get_format($full = true)
+	{
+		return $full ? $this->_dt_frmt . ' ' . $this->_tm_frmt : array($this->_dt_frmt, $this->_tm_frmt);
+	}
+
+
+	/**
+	 * cache
+	 * stores the passed model object on the current model object.
+	 * In certain circumstances, we can use this cached model object instead of querying for another one entirely.
+	 *
+	 * @param string        $relationName    one of the keys in the _model_relations array on the model. Eg
+	 *                                       'Registration' associated with this model object
+	 * @param EE_Base_Class $object_to_cache that has a relation to this model object. (Eg, if this is a Transaction,
+	 *                                       that could be a payment or a registration)
+	 * @param null          $cache_id        a string or number that will be used as the key for any Belongs_To_Many
+	 *                                       items which will be stored in an array on this object
+	 * @throws ReflectionException
+	 * @throws InvalidArgumentException
+	 * @throws InvalidInterfaceException
+	 * @throws InvalidDataTypeException
+	 * @throws EE_Error
+	 * @return mixed    index into cache, or just TRUE if the relation is of type Belongs_To (because there's only one
+	 *                                       related thing, no array)
+	 */
+	public function cache($relationName = '', $object_to_cache = null, $cache_id = null)
+	{
+		// its entirely possible that there IS no related object yet in which case there is nothing to cache.
+		if (! $object_to_cache instanceof EE_Base_Class) {
+			return false;
+		}
+		// also get "how" the object is related, or throw an error
+		if (! $relationship_to_model = $this->get_model()->related_settings_for($relationName)) {
+			throw new EE_Error(
+				sprintf(
+					esc_html__('There is no relationship to %s on a %s. Cannot cache it', 'event_espresso'),
+					$relationName,
+					get_class($this)
+				)
+			);
+		}
+		// how many things are related ?
+		if ($relationship_to_model instanceof EE_Belongs_To_Relation) {
+			// if it's a "belongs to" relationship, then there's only one related model object
+			// eg, if this is a registration, there's only 1 attendee for it
+			// so for these model objects just set it to be cached
+			$this->_model_relations[ $relationName ] = $object_to_cache;
+			$return = true;
+		} else {
+			// otherwise, this is the "many" side of a one to many relationship,
+			// so we'll add the object to the array of related objects for that type.
+			// eg: if this is an event, there are many registrations for that event,
+			// so we cache the registrations in an array
+			if (! is_array($this->_model_relations[ $relationName ])) {
+				// if for some reason, the cached item is a model object,
+				// then stick that in the array, otherwise start with an empty array
+				$this->_model_relations[ $relationName ] = $this->_model_relations[ $relationName ]
+														   instanceof
+														   EE_Base_Class
+					? array($this->_model_relations[ $relationName ]) : array();
+			}
+			// first check for a cache_id which is normally empty
+			if (! empty($cache_id)) {
+				// if the cache_id exists, then it means we are purposely trying to cache this
+				// with a known key that can then be used to retrieve the object later on
+				$this->_model_relations[ $relationName ][ $cache_id ] = $object_to_cache;
+				$return = $cache_id;
+			} elseif ($object_to_cache->ID()) {
+				// OR the cached object originally came from the db, so let's just use it's PK for an ID
+				$this->_model_relations[ $relationName ][ $object_to_cache->ID() ] = $object_to_cache;
+				$return = $object_to_cache->ID();
+			} else {
+				// OR it's a new object with no ID, so just throw it in the array with an auto-incremented ID
+				$this->_model_relations[ $relationName ][] = $object_to_cache;
+				// move the internal pointer to the end of the array
+				end($this->_model_relations[ $relationName ]);
+				// and grab the key so that we can return it
+				$return = key($this->_model_relations[ $relationName ]);
+			}
+		}
+		return $return;
+	}
+
+
+	/**
+	 * For adding an item to the cached_properties property.
+	 *
+	 * @access protected
+	 * @param string      $fieldname the property item the corresponding value is for.
+	 * @param mixed       $value     The value we are caching.
+	 * @param string|null $cache_type
+	 * @return void
+	 * @throws ReflectionException
+	 * @throws InvalidArgumentException
+	 * @throws InvalidInterfaceException
+	 * @throws InvalidDataTypeException
+	 * @throws EE_Error
+	 */
+	protected function _set_cached_property($fieldname, $value, $cache_type = null)
+	{
+		// first make sure this property exists
+		$this->get_model()->field_settings_for($fieldname);
+		$cache_type = empty($cache_type) ? 'standard' : $cache_type;
+		$this->_cached_properties[ $fieldname ][ $cache_type ] = $value;
+	}
+
+
+	/**
+	 * This returns the value cached property if it exists OR the actual property value if the cache doesn't exist.
+	 * This also SETS the cache if we return the actual property!
+	 *
+	 * @param string $fieldname        the name of the property we're trying to retrieve
+	 * @param bool   $pretty
+	 * @param string $extra_cache_ref  This allows the user to specify an extra cache ref for the given property
+	 *                                 (in cases where the same property may be used for different outputs
+	 *                                 - i.e. datetime, money etc.)
+	 *                                 It can also accept certain pre-defined "schema" strings
+	 *                                 to define how to output the property.
+	 *                                 see the field's prepare_for_pretty_echoing for what strings can be used
+	 * @return mixed                   whatever the value for the property is we're retrieving
+	 * @throws ReflectionException
+	 * @throws InvalidArgumentException
+	 * @throws InvalidInterfaceException
+	 * @throws InvalidDataTypeException
+	 * @throws EE_Error
+	 */
+	protected function _get_cached_property($fieldname, $pretty = false, $extra_cache_ref = null)
+	{
+		// verify the field exists
+		$model = $this->get_model();
+		$model->field_settings_for($fieldname);
+		$cache_type = $pretty ? 'pretty' : 'standard';
+		$cache_type .= ! empty($extra_cache_ref) ? '_' . $extra_cache_ref : '';
+		if (isset($this->_cached_properties[ $fieldname ][ $cache_type ])) {
+			return $this->_cached_properties[ $fieldname ][ $cache_type ];
+		}
+		$value = $this->_get_fresh_property($fieldname, $pretty, $extra_cache_ref);
+		$this->_set_cached_property($fieldname, $value, $cache_type);
+		return $value;
+	}
+
+
+	/**
+	 * If the cache didn't fetch the needed item, this fetches it.
+	 *
+	 * @param string $fieldname
+	 * @param bool   $pretty
+	 * @param string $extra_cache_ref
+	 * @return mixed
+	 * @throws InvalidArgumentException
+	 * @throws InvalidInterfaceException
+	 * @throws InvalidDataTypeException
+	 * @throws EE_Error
+	 * @throws ReflectionException
+	 */
+	protected function _get_fresh_property($fieldname, $pretty = false, $extra_cache_ref = null)
+	{
+		$field_obj = $this->get_model()->field_settings_for($fieldname);
+		// If this is an EE_Datetime_Field we need to make sure timezone, formats, and output are correct
+		if ($field_obj instanceof EE_Datetime_Field) {
+			$this->_prepare_datetime_field($field_obj, $pretty, $extra_cache_ref);
+		}
+		if (! isset($this->_fields[ $fieldname ])) {
+			$this->_fields[ $fieldname ] = null;
+		}
+		$value = $pretty
+			? $field_obj->prepare_for_pretty_echoing($this->_fields[ $fieldname ], $extra_cache_ref)
+			: $field_obj->prepare_for_get($this->_fields[ $fieldname ]);
+		return $value;
+	}
+
+
+	/**
+	 * set timezone, formats, and output for EE_Datetime_Field objects
+	 *
+	 * @param \EE_Datetime_Field $datetime_field
+	 * @param bool               $pretty
+	 * @param null               $date_or_time
+	 * @return void
+	 * @throws InvalidArgumentException
+	 * @throws InvalidInterfaceException
+	 * @throws InvalidDataTypeException
+	 * @throws EE_Error
+	 */
+	protected function _prepare_datetime_field(
+		EE_Datetime_Field $datetime_field,
+		$pretty = false,
+		$date_or_time = null
+	) {
+		$datetime_field->set_timezone($this->_timezone);
+		$datetime_field->set_date_format($this->_dt_frmt, $pretty);
+		$datetime_field->set_time_format($this->_tm_frmt, $pretty);
+		// set the output returned
+		switch ($date_or_time) {
+			case 'D':
+				$datetime_field->set_date_time_output('date');
+				break;
+			case 'T':
+				$datetime_field->set_date_time_output('time');
+				break;
+			default:
+				$datetime_field->set_date_time_output();
+		}
+	}
+
+
+	/**
+	 * This just takes care of clearing out the cached_properties
+	 *
+	 * @return void
+	 */
+	protected function _clear_cached_properties()
+	{
+		$this->_cached_properties = array();
+	}
+
+
+	/**
+	 * This just clears out ONE property if it exists in the cache
+	 *
+	 * @param  string $property_name the property to remove if it exists (from the _cached_properties array)
+	 * @return void
+	 */
+	protected function _clear_cached_property($property_name)
+	{
+		if (isset($this->_cached_properties[ $property_name ])) {
+			unset($this->_cached_properties[ $property_name ]);
+		}
+	}
+
+
+	/**
+	 * Ensures that this related thing is a model object.
+	 *
+	 * @param mixed  $object_or_id EE_base_Class/int/string either a related model object, or its ID
+	 * @param string $model_name   name of the related thing, eg 'Attendee',
+	 * @return EE_Base_Class
+	 * @throws ReflectionException
+	 * @throws InvalidArgumentException
+	 * @throws InvalidInterfaceException
+	 * @throws InvalidDataTypeException
+	 * @throws EE_Error
+	 */
+	protected function ensure_related_thing_is_model_obj($object_or_id, $model_name)
+	{
+		$other_model_instance = self::_get_model_instance_with_name(
+			self::_get_model_classname($model_name),
+			$this->_timezone
+		);
+		return $other_model_instance->ensure_is_obj($object_or_id);
+	}
+
+
+	/**
+	 * Forgets the cached model of the given relation Name. So the next time we request it,
+	 * we will fetch it again from the database. (Handy if you know it's changed somehow).
+	 * If a specific object is supplied, and the relationship to it is either a HasMany or HABTM,
+	 * then only remove that one object from our cached array. Otherwise, clear the entire list
+	 *
+	 * @param string $relationName                         one of the keys in the _model_relations array on the model.
+	 *                                                     Eg 'Registration'
+	 * @param mixed  $object_to_remove_or_index_into_array or an index into the array of cached things, or NULL
+	 *                                                     if you intend to use $clear_all = TRUE, or the relation only
+	 *                                                     has 1 object anyways (ie, it's a BelongsToRelation)
+	 * @param bool   $clear_all                            This flags clearing the entire cache relation property if
+	 *                                                     this is HasMany or HABTM.
+	 * @throws ReflectionException
+	 * @throws InvalidArgumentException
+	 * @throws InvalidInterfaceException
+	 * @throws InvalidDataTypeException
+	 * @throws EE_Error
+	 * @return EE_Base_Class | boolean from which was cleared from the cache, or true if we requested to remove a
+	 *                                                     relation from all
+	 */
+	public function clear_cache($relationName, $object_to_remove_or_index_into_array = null, $clear_all = false)
+	{
+		$relationship_to_model = $this->get_model()->related_settings_for($relationName);
+		$index_in_cache = '';
+		if (! $relationship_to_model) {
+			throw new EE_Error(
+				sprintf(
+					esc_html__('There is no relationship to %s on a %s. Cannot clear that cache', 'event_espresso'),
+					$relationName,
+					get_class($this)
+				)
+			);
+		}
+		if ($clear_all) {
+			$obj_removed = true;
+			$this->_model_relations[ $relationName ] = null;
+		} elseif ($relationship_to_model instanceof EE_Belongs_To_Relation) {
+			$obj_removed = $this->_model_relations[ $relationName ];
+			$this->_model_relations[ $relationName ] = null;
+		} else {
+			if ($object_to_remove_or_index_into_array instanceof EE_Base_Class
+				&& $object_to_remove_or_index_into_array->ID()
+			) {
+				$index_in_cache = $object_to_remove_or_index_into_array->ID();
+				if (is_array($this->_model_relations[ $relationName ])
+					&& ! isset($this->_model_relations[ $relationName ][ $index_in_cache ])
+				) {
+					$index_found_at = null;
+					// find this object in the array even though it has a different key
+					foreach ($this->_model_relations[ $relationName ] as $index => $obj) {
+						/** @noinspection TypeUnsafeComparisonInspection */
+						if ($obj instanceof EE_Base_Class
+							&& (
+								$obj == $object_to_remove_or_index_into_array
+								|| $obj->ID() === $object_to_remove_or_index_into_array->ID()
+							)
+						) {
+							$index_found_at = $index;
+							break;
+						}
+					}
+					if ($index_found_at) {
+						$index_in_cache = $index_found_at;
+					} else {
+						// it wasn't found. huh. well obviously it doesn't need to be removed from teh cache
+						// if it wasn't in it to begin with. So we're done
+						return $object_to_remove_or_index_into_array;
+					}
+				}
+			} elseif ($object_to_remove_or_index_into_array instanceof EE_Base_Class) {
+				// so they provided a model object, but it's not yet saved to the DB... so let's go hunting for it!
+				foreach ($this->get_all_from_cache($relationName) as $index => $potentially_obj_we_want) {
+					/** @noinspection TypeUnsafeComparisonInspection */
+					if ($potentially_obj_we_want == $object_to_remove_or_index_into_array) {
+						$index_in_cache = $index;
+					}
+				}
+			} else {
+				$index_in_cache = $object_to_remove_or_index_into_array;
+			}
+			// supposedly we've found it. But it could just be that the client code
+			// provided a bad index/object
+			if (isset($this->_model_relations[ $relationName ][ $index_in_cache ])) {
+				$obj_removed = $this->_model_relations[ $relationName ][ $index_in_cache ];
+				unset($this->_model_relations[ $relationName ][ $index_in_cache ]);
+			} else {
+				// that thing was never cached anyways.
+				$obj_removed = null;
+			}
+		}
+		return $obj_removed;
+	}
+
+
+	/**
+	 * update_cache_after_object_save
+	 * Allows a cached item to have it's cache ID (within the array of cached items) reset using the new ID it has
+	 * obtained after being saved to the db
+	 *
+	 * @param string        $relationName       - the type of object that is cached
+	 * @param EE_Base_Class $newly_saved_object - the newly saved object to be re-cached
+	 * @param string        $current_cache_id   - the ID that was used when originally caching the object
+	 * @return boolean TRUE on success, FALSE on fail
+	 * @throws ReflectionException
+	 * @throws InvalidArgumentException
+	 * @throws InvalidInterfaceException
+	 * @throws InvalidDataTypeException
+	 * @throws EE_Error
+	 */
+	public function update_cache_after_object_save(
+		$relationName,
+		EE_Base_Class $newly_saved_object,
+		$current_cache_id = ''
+	) {
+		// verify that incoming object is of the correct type
+		$obj_class = 'EE_' . $relationName;
+		if ($newly_saved_object instanceof $obj_class) {
+			/* @type EE_Base_Class $newly_saved_object */
+			// now get the type of relation
+			$relationship_to_model = $this->get_model()->related_settings_for($relationName);
+			// if this is a 1:1 relationship
+			if ($relationship_to_model instanceof EE_Belongs_To_Relation) {
+				// then just replace the cached object with the newly saved object
+				$this->_model_relations[ $relationName ] = $newly_saved_object;
+				return true;
+				// or if it's some kind of sordid feral polyamorous relationship...
+			}
+			if (is_array($this->_model_relations[ $relationName ])
+				&& isset($this->_model_relations[ $relationName ][ $current_cache_id ])
+			) {
+				// then remove the current cached item
+				unset($this->_model_relations[ $relationName ][ $current_cache_id ]);
+				// and cache the newly saved object using it's new ID
+				$this->_model_relations[ $relationName ][ $newly_saved_object->ID() ] = $newly_saved_object;
+				return true;
+			}
+		}
+		return false;
+	}
+
+
+	/**
+	 * Fetches a single EE_Base_Class on that relation. (If the relation is of type
+	 * BelongsTo, it will only ever have 1 object. However, other relations could have an array of objects)
+	 *
+	 * @param string $relationName
+	 * @return EE_Base_Class
+	 */
+	public function get_one_from_cache($relationName)
+	{
+		$cached_array_or_object = isset($this->_model_relations[ $relationName ])
+			? $this->_model_relations[ $relationName ]
+			: null;
+		if (is_array($cached_array_or_object)) {
+			return array_shift($cached_array_or_object);
+		}
+		return $cached_array_or_object;
+	}
+
+
+	/**
+	 * Fetches a single EE_Base_Class on that relation. (If the relation is of type
+	 * BelongsTo, it will only ever have 1 object. However, other relations could have an array of objects)
+	 *
+	 * @param string $relationName
+	 * @throws ReflectionException
+	 * @throws InvalidArgumentException
+	 * @throws InvalidInterfaceException
+	 * @throws InvalidDataTypeException
+	 * @throws EE_Error
+	 * @return EE_Base_Class[] NOT necessarily indexed by primary keys
+	 */
+	public function get_all_from_cache($relationName)
+	{
+		$objects = isset($this->_model_relations[ $relationName ]) ? $this->_model_relations[ $relationName ] : array();
+		// if the result is not an array, but exists, make it an array
+		$objects = is_array($objects) ? $objects : array($objects);
+		// bugfix for https://events.codebasehq.com/projects/event-espresso/tickets/7143
+		// basically, if this model object was stored in the session, and these cached model objects
+		// already have IDs, let's make sure they're in their model's entity mapper
+		// otherwise we will have duplicates next time we call
+		// EE_Registry::instance()->load_model( $relationName )->get_one_by_ID( $result->ID() );
+		$model = EE_Registry::instance()->load_model($relationName);
+		foreach ($objects as $model_object) {
+			if ($model instanceof EEM_Base && $model_object instanceof EE_Base_Class) {
+				// ensure its in the map if it has an ID; otherwise it will be added to the map when its saved
+				if ($model_object->ID()) {
+					$model->add_to_entity_map($model_object);
+				}
+			} else {
+				throw new EE_Error(
+					sprintf(
+						esc_html__(
+							'Error retrieving related model objects. Either $1%s is not a model or $2%s is not a model object',
+							'event_espresso'
+						),
+						$relationName,
+						gettype($model_object)
+					)
+				);
+			}
+		}
+		return $objects;
+	}
+
+
+	/**
+	 * Returns the next x number of EE_Base_Class objects in sequence from this object as found in the database
+	 * matching the given query conditions.
+	 *
+	 * @param null  $field_to_order_by  What field is being used as the reference point.
+	 * @param int   $limit              How many objects to return.
+	 * @param array $query_params       Any additional conditions on the query.
+	 * @param null  $columns_to_select  If left null, then an array of EE_Base_Class objects is returned, otherwise
+	 *                                  you can indicate just the columns you want returned
+	 * @return array|EE_Base_Class[]
+	 * @throws ReflectionException
+	 * @throws InvalidArgumentException
+	 * @throws InvalidInterfaceException
+	 * @throws InvalidDataTypeException
+	 * @throws EE_Error
+	 */
+	public function next_x($field_to_order_by = null, $limit = 1, $query_params = array(), $columns_to_select = null)
+	{
+		$model = $this->get_model();
+		$field = empty($field_to_order_by) && $model->has_primary_key_field()
+			? $model->get_primary_key_field()->get_name()
+			: $field_to_order_by;
+		$current_value = ! empty($field) ? $this->get($field) : null;
+		if (empty($field) || empty($current_value)) {
+			return array();
+		}
+		return $model->next_x($current_value, $field, $limit, $query_params, $columns_to_select);
+	}
+
+
+	/**
+	 * Returns the previous x number of EE_Base_Class objects in sequence from this object as found in the database
+	 * matching the given query conditions.
+	 *
+	 * @param null  $field_to_order_by  What field is being used as the reference point.
+	 * @param int   $limit              How many objects to return.
+	 * @param array $query_params       Any additional conditions on the query.
+	 * @param null  $columns_to_select  If left null, then an array of EE_Base_Class objects is returned, otherwise
+	 *                                  you can indicate just the columns you want returned
+	 * @return array|EE_Base_Class[]
+	 * @throws ReflectionException
+	 * @throws InvalidArgumentException
+	 * @throws InvalidInterfaceException
+	 * @throws InvalidDataTypeException
+	 * @throws EE_Error
+	 */
+	public function previous_x(
+		$field_to_order_by = null,
+		$limit = 1,
+		$query_params = array(),
+		$columns_to_select = null
+	) {
+		$model = $this->get_model();
+		$field = empty($field_to_order_by) && $model->has_primary_key_field()
+			? $model->get_primary_key_field()->get_name()
+			: $field_to_order_by;
+		$current_value = ! empty($field) ? $this->get($field) : null;
+		if (empty($field) || empty($current_value)) {
+			return array();
+		}
+		return $model->previous_x($current_value, $field, $limit, $query_params, $columns_to_select);
+	}
+
+
+	/**
+	 * Returns the next EE_Base_Class object in sequence from this object as found in the database
+	 * matching the given query conditions.
+	 *
+	 * @param null  $field_to_order_by  What field is being used as the reference point.
+	 * @param array $query_params       Any additional conditions on the query.
+	 * @param null  $columns_to_select  If left null, then an array of EE_Base_Class objects is returned, otherwise
+	 *                                  you can indicate just the columns you want returned
+	 * @return array|EE_Base_Class
+	 * @throws ReflectionException
+	 * @throws InvalidArgumentException
+	 * @throws InvalidInterfaceException
+	 * @throws InvalidDataTypeException
+	 * @throws EE_Error
+	 */
+	public function next($field_to_order_by = null, $query_params = array(), $columns_to_select = null)
+	{
+		$model = $this->get_model();
+		$field = empty($field_to_order_by) && $model->has_primary_key_field()
+			? $model->get_primary_key_field()->get_name()
+			: $field_to_order_by;
+		$current_value = ! empty($field) ? $this->get($field) : null;
+		if (empty($field) || empty($current_value)) {
+			return array();
+		}
+		return $model->next($current_value, $field, $query_params, $columns_to_select);
+	}
+
+
+	/**
+	 * Returns the previous EE_Base_Class object in sequence from this object as found in the database
+	 * matching the given query conditions.
+	 *
+	 * @param null  $field_to_order_by  What field is being used as the reference point.
+	 * @param array $query_params       Any additional conditions on the query.
+	 * @param null  $columns_to_select  If left null, then an EE_Base_Class object is returned, otherwise
+	 *                                  you can indicate just the column you want returned
+	 * @return array|EE_Base_Class
+	 * @throws ReflectionException
+	 * @throws InvalidArgumentException
+	 * @throws InvalidInterfaceException
+	 * @throws InvalidDataTypeException
+	 * @throws EE_Error
+	 */
+	public function previous($field_to_order_by = null, $query_params = array(), $columns_to_select = null)
+	{
+		$model = $this->get_model();
+		$field = empty($field_to_order_by) && $model->has_primary_key_field()
+			? $model->get_primary_key_field()->get_name()
+			: $field_to_order_by;
+		$current_value = ! empty($field) ? $this->get($field) : null;
+		if (empty($field) || empty($current_value)) {
+			return array();
+		}
+		return $model->previous($current_value, $field, $query_params, $columns_to_select);
+	}
+
+
+	/**
+	 * Overrides parent because parent expects old models.
+	 * This also doesn't do any validation, and won't work for serialized arrays
+	 *
+	 * @param string $field_name
+	 * @param mixed  $field_value_from_db
+	 * @throws ReflectionException
+	 * @throws InvalidArgumentException
+	 * @throws InvalidInterfaceException
+	 * @throws InvalidDataTypeException
+	 * @throws EE_Error
+	 */
+	public function set_from_db($field_name, $field_value_from_db)
+	{
+		$field_obj = $this->get_model()->field_settings_for($field_name);
+		if ($field_obj instanceof EE_Model_Field_Base) {
+			// you would think the DB has no NULLs for non-null label fields right? wrong!
+			// eg, a CPT model object could have an entry in the posts table, but no
+			// entry in the meta table. Meaning that all its columns in the meta table
+			// are null! yikes! so when we find one like that, use defaults for its meta columns
+			if ($field_value_from_db === null) {
+				if ($field_obj->is_nullable()) {
+					// if the field allows nulls, then let it be null
+					$field_value = null;
+				} else {
+					$field_value = $field_obj->get_default_value();
+				}
+			} else {
+				$field_value = $field_obj->prepare_for_set_from_db($field_value_from_db);
+			}
+			$this->_fields[ $field_name ] = $field_value;
+			$this->_clear_cached_property($field_name);
+		}
+	}
+
+
+	/**
+	 * verifies that the specified field is of the correct type
+	 *
+	 * @param string $field_name
+	 * @param string $extra_cache_ref This allows the user to specify an extra cache ref for the given property
+	 *                                (in cases where the same property may be used for different outputs
+	 *                                - i.e. datetime, money etc.)
+	 * @return mixed
+	 * @throws ReflectionException
+	 * @throws InvalidArgumentException
+	 * @throws InvalidInterfaceException
+	 * @throws InvalidDataTypeException
+	 * @throws EE_Error
+	 */
+	public function get($field_name, $extra_cache_ref = null)
+	{
+		return $this->_get_cached_property($field_name, false, $extra_cache_ref);
+	}
+
+
+	/**
+	 * This method simply returns the RAW unprocessed value for the given property in this class
+	 *
+	 * @param  string $field_name A valid fieldname
+	 * @return mixed              Whatever the raw value stored on the property is.
+	 * @throws ReflectionException
+	 * @throws InvalidArgumentException
+	 * @throws InvalidInterfaceException
+	 * @throws InvalidDataTypeException
+	 * @throws EE_Error if fieldSettings is misconfigured or the field doesn't exist.
+	 */
+	public function get_raw($field_name)
+	{
+		$field_settings = $this->get_model()->field_settings_for($field_name);
+		return $field_settings instanceof EE_Datetime_Field && $this->_fields[ $field_name ] instanceof DateTime
+			? $this->_fields[ $field_name ]->format('U')
+			: $this->_fields[ $field_name ];
+	}
+
+
+	/**
+	 * This is used to return the internal DateTime object used for a field that is a
+	 * EE_Datetime_Field.
+	 *
+	 * @param string $field_name               The field name retrieving the DateTime object.
+	 * @return mixed null | false | DateTime  If the requested field is NOT a EE_Datetime_Field then
+	 * @throws EE_Error an error is set and false returned.  If the field IS an
+	 *                                         EE_Datetime_Field and but the field value is null, then
+	 *                                         just null is returned (because that indicates that likely
+	 *                                         this field is nullable).
+	 * @throws InvalidArgumentException
+	 * @throws InvalidDataTypeException
+	 * @throws InvalidInterfaceException
+	 * @throws ReflectionException
+	 */
+	public function get_DateTime_object($field_name)
+	{
+		$field_settings = $this->get_model()->field_settings_for($field_name);
+		if (! $field_settings instanceof EE_Datetime_Field) {
+			EE_Error::add_error(
+				sprintf(
+					esc_html__(
+						'The field %s is not an EE_Datetime_Field field.  There is no DateTime object stored on this field type.',
+						'event_espresso'
+					),
+					$field_name
+				),
+				__FILE__,
+				__FUNCTION__,
+				__LINE__
+			);
+			return false;
+		}
+		return isset($this->_fields[ $field_name ]) && $this->_fields[ $field_name ] instanceof DateTime
+			? clone $this->_fields[ $field_name ]
+			: null;
+	}
+
+
+	/**
+	 * To be used in template to immediately echo out the value, and format it for output.
+	 * Eg, should call stripslashes and whatnot before echoing
+	 *
+	 * @param string $field_name      the name of the field as it appears in the DB
+	 * @param string $extra_cache_ref This allows the user to specify an extra cache ref for the given property
+	 *                                (in cases where the same property may be used for different outputs
+	 *                                - i.e. datetime, money etc.)
+	 * @return void
+	 * @throws ReflectionException
+	 * @throws InvalidArgumentException
+	 * @throws InvalidInterfaceException
+	 * @throws InvalidDataTypeException
+	 * @throws EE_Error
+	 */
+	public function e($field_name, $extra_cache_ref = null)
+	{
+		echo $this->get_pretty($field_name, $extra_cache_ref);
+	}
+
+
+	/**
+	 * Exactly like e(), echoes out the field, but sets its schema to 'form_input', so that it
+	 * can be easily used as the value of form input.
+	 *
+	 * @param string $field_name
+	 * @return void
+	 * @throws ReflectionException
+	 * @throws InvalidArgumentException
+	 * @throws InvalidInterfaceException
+	 * @throws InvalidDataTypeException
+	 * @throws EE_Error
+	 */
+	public function f($field_name)
+	{
+		$this->e($field_name, 'form_input');
+	}
+
+
+	/**
+	 * Same as `f()` but just returns the value instead of echoing it
+	 *
+	 * @param string $field_name
+	 * @return string
+	 * @throws ReflectionException
+	 * @throws InvalidArgumentException
+	 * @throws InvalidInterfaceException
+	 * @throws InvalidDataTypeException
+	 * @throws EE_Error
+	 */
+	public function get_f($field_name)
+	{
+		return (string) $this->get_pretty($field_name, 'form_input');
+	}
+
+
+	/**
+	 * Gets a pretty view of the field's value. $extra_cache_ref can specify different formats for this.
+	 * The $extra_cache_ref will be passed to the model field's prepare_for_pretty_echoing, so consult the field's class
+	 * to see what options are available.
+	 *
+	 * @param string $field_name
+	 * @param string $extra_cache_ref This allows the user to specify an extra cache ref for the given property
+	 *                                (in cases where the same property may be used for different outputs
+	 *                                - i.e. datetime, money etc.)
+	 * @return mixed
+	 * @throws ReflectionException
+	 * @throws InvalidArgumentException
+	 * @throws InvalidInterfaceException
+	 * @throws InvalidDataTypeException
+	 * @throws EE_Error
+	 */
+	public function get_pretty($field_name, $extra_cache_ref = null)
+	{
+		return $this->_get_cached_property($field_name, true, $extra_cache_ref);
+	}
+
+
+	/**
+	 * This simply returns the datetime for the given field name
+	 * Note: this protected function is called by the wrapper get_date or get_time or get_datetime functions
+	 * (and the equivalent e_date, e_time, e_datetime).
+	 *
+	 * @access   protected
+	 * @param string   $field_name   Field on the instantiated EE_Base_Class child object
+	 * @param string   $dt_frmt      valid datetime format used for date
+	 *                               (if '' then we just use the default on the field,
+	 *                               if NULL we use the last-used format)
+	 * @param string   $tm_frmt      Same as above except this is for time format
+	 * @param string   $date_or_time if NULL then both are returned, otherwise "D" = only date and "T" = only time.
+	 * @param  boolean $echo         Whether the dtt is echoing using pretty echoing or just returned using vanilla get
+	 * @return string|bool|EE_Error string on success, FALSE on fail, or EE_Error Exception is thrown
+	 *                               if field is not a valid dtt field, or void if echoing
+	 * @throws ReflectionException
+	 * @throws InvalidArgumentException
+	 * @throws InvalidInterfaceException
+	 * @throws InvalidDataTypeException
+	 * @throws EE_Error
+	 */
+	protected function _get_datetime($field_name, $dt_frmt = '', $tm_frmt = '', $date_or_time = '', $echo = false)
+	{
+		// clear cached property
+		$this->_clear_cached_property($field_name);
+		// reset format properties because they are used in get()
+		$this->_dt_frmt = $dt_frmt !== '' ? $dt_frmt : $this->_dt_frmt;
+		$this->_tm_frmt = $tm_frmt !== '' ? $tm_frmt : $this->_tm_frmt;
+		if ($echo) {
+			$this->e($field_name, $date_or_time);
+			return '';
+		}
+		return $this->get($field_name, $date_or_time);
+	}
+
+
+	/**
+	 * below are wrapper functions for the various datetime outputs that can be obtained for JUST returning the date
+	 * portion of a datetime value. (note the only difference between get_ and e_ is one returns the value and the
+	 * other echoes the pretty value for dtt)
+	 *
+	 * @param  string $field_name name of model object datetime field holding the value
+	 * @param  string $format     format for the date returned (if NULL we use default in dt_frmt property)
+	 * @return string            datetime value formatted
+	 * @throws ReflectionException
+	 * @throws InvalidArgumentException
+	 * @throws InvalidInterfaceException
+	 * @throws InvalidDataTypeException
+	 * @throws EE_Error
+	 */
+	public function get_date($field_name, $format = '')
+	{
+		return $this->_get_datetime($field_name, $format, null, 'D');
+	}
+
+
+	/**
+	 * @param        $field_name
+	 * @param string $format
+	 * @throws ReflectionException
+	 * @throws InvalidArgumentException
+	 * @throws InvalidInterfaceException
+	 * @throws InvalidDataTypeException
+	 * @throws EE_Error
+	 */
+	public function e_date($field_name, $format = '')
+	{
+		$this->_get_datetime($field_name, $format, null, 'D', true);
+	}
+
+
+	/**
+	 * below are wrapper functions for the various datetime outputs that can be obtained for JUST returning the time
+	 * portion of a datetime value. (note the only difference between get_ and e_ is one returns the value and the
+	 * other echoes the pretty value for dtt)
+	 *
+	 * @param  string $field_name name of model object datetime field holding the value
+	 * @param  string $format     format for the time returned ( if NULL we use default in tm_frmt property)
+	 * @return string             datetime value formatted
+	 * @throws ReflectionException
+	 * @throws InvalidArgumentException
+	 * @throws InvalidInterfaceException
+	 * @throws InvalidDataTypeException
+	 * @throws EE_Error
+	 */
+	public function get_time($field_name, $format = '')
+	{
+		return $this->_get_datetime($field_name, null, $format, 'T');
+	}
+
+
+	/**
+	 * @param        $field_name
+	 * @param string $format
+	 * @throws ReflectionException
+	 * @throws InvalidArgumentException
+	 * @throws InvalidInterfaceException
+	 * @throws InvalidDataTypeException
+	 * @throws EE_Error
+	 */
+	public function e_time($field_name, $format = '')
+	{
+		$this->_get_datetime($field_name, null, $format, 'T', true);
+	}
+
+
+	/**
+	 * below are wrapper functions for the various datetime outputs that can be obtained for returning the date AND
+	 * time portion of a datetime value. (note the only difference between get_ and e_ is one returns the value and the
+	 * other echoes the pretty value for dtt)
+	 *
+	 * @param  string $field_name name of model object datetime field holding the value
+	 * @param  string $dt_frmt    format for the date returned (if NULL we use default in dt_frmt property)
+	 * @param  string $tm_frmt    format for the time returned (if NULL we use default in tm_frmt property)
+	 * @return string             datetime value formatted
+	 * @throws ReflectionException
+	 * @throws InvalidArgumentException
+	 * @throws InvalidInterfaceException
+	 * @throws InvalidDataTypeException
+	 * @throws EE_Error
+	 */
+	public function get_datetime($field_name, $dt_frmt = '', $tm_frmt = '')
+	{
+		return $this->_get_datetime($field_name, $dt_frmt, $tm_frmt);
+	}
+
+
+	/**
+	 * @param string $field_name
+	 * @param string $dt_frmt
+	 * @param string $tm_frmt
+	 * @throws ReflectionException
+	 * @throws InvalidArgumentException
+	 * @throws InvalidInterfaceException
+	 * @throws InvalidDataTypeException
+	 * @throws EE_Error
+	 */
+	public function e_datetime($field_name, $dt_frmt = '', $tm_frmt = '')
+	{
+		$this->_get_datetime($field_name, $dt_frmt, $tm_frmt, null, true);
+	}
+
+
+	/**
+	 * Get the i8ln value for a date using the WordPress @see date_i18n function.
+	 *
+	 * @param string $field_name The EE_Datetime_Field reference for the date being retrieved.
+	 * @param string $format     PHP valid date/time string format.  If none is provided then the internal set format
+	 *                           on the object will be used.
+	 * @return string Date and time string in set locale or false if no field exists for the given
+	 * @throws ReflectionException
+	 * @throws InvalidArgumentException
+	 * @throws InvalidInterfaceException
+	 * @throws InvalidDataTypeException
+	 * @throws EE_Error
+	 *                           field name.
+	 */
+	public function get_i18n_datetime($field_name, $format = '')
+	{
+		$format = empty($format) ? $this->_dt_frmt . ' ' . $this->_tm_frmt : $format;
+		return date_i18n(
+			$format,
+			EEH_DTT_Helper::get_timestamp_with_offset(
+				$this->get_raw($field_name),
+				$this->_timezone
+			)
+		);
+	}
+
+
+	/**
+	 * This method validates whether the given field name is a valid field on the model object as well as it is of a
+	 * type EE_Datetime_Field.  On success there will be returned the field settings.  On fail an EE_Error exception is
+	 * thrown.
+	 *
+	 * @param  string $field_name The field name being checked
+	 * @throws ReflectionException
+	 * @throws InvalidArgumentException
+	 * @throws InvalidInterfaceException
+	 * @throws InvalidDataTypeException
+	 * @throws EE_Error
+	 * @return EE_Datetime_Field
+	 */
+	protected function _get_dtt_field_settings($field_name)
+	{
+		$field = $this->get_model()->field_settings_for($field_name);
+		// check if field is dtt
+		if ($field instanceof EE_Datetime_Field) {
+			return $field;
+		}
+		throw new EE_Error(
+			sprintf(
+				esc_html__(
+					'The field name "%s" has been requested for the EE_Base_Class datetime functions and it is not a valid EE_Datetime_Field.  Please check the spelling of the field and make sure it has been setup as a EE_Datetime_Field in the %s model constructor',
+					'event_espresso'
+				),
+				$field_name,
+				self::_get_model_classname(get_class($this))
+			)
+		);
+	}
+
+
+
+
+	/**
+	 * NOTE ABOUT BELOW:
+	 * These convenience date and time setters are for setting date and time independently.  In other words you might
+	 * want to change the time on a datetime_field but leave the date the same (or vice versa). IF on the other hand
+	 * you want to set both date and time at the same time, you can just use the models default set($fieldname,$value)
+	 * method and make sure you send the entire datetime value for setting.
+	 */
+	/**
+	 * sets the time on a datetime property
+	 *
+	 * @access protected
+	 * @param string|Datetime $time      a valid time string for php datetime functions (or DateTime object)
+	 * @param string          $fieldname the name of the field the time is being set on (must match a EE_Datetime_Field)
+	 * @throws ReflectionException
+	 * @throws InvalidArgumentException
+	 * @throws InvalidInterfaceException
+	 * @throws InvalidDataTypeException
+	 * @throws EE_Error
+	 */
+	protected function _set_time_for($time, $fieldname)
+	{
+		$this->_set_date_time('T', $time, $fieldname);
+	}
+
+
+	/**
+	 * sets the date on a datetime property
+	 *
+	 * @access protected
+	 * @param string|DateTime $date      a valid date string for php datetime functions ( or DateTime object)
+	 * @param string          $fieldname the name of the field the date is being set on (must match a EE_Datetime_Field)
+	 * @throws ReflectionException
+	 * @throws InvalidArgumentException
+	 * @throws InvalidInterfaceException
+	 * @throws InvalidDataTypeException
+	 * @throws EE_Error
+	 */
+	protected function _set_date_for($date, $fieldname)
+	{
+		$this->_set_date_time('D', $date, $fieldname);
+	}
+
+
+	/**
+	 * This takes care of setting a date or time independently on a given model object property. This method also
+	 * verifies that the given fieldname matches a model object property and is for a EE_Datetime_Field field
+	 *
+	 * @access protected
+	 * @param string          $what           "T" for time, 'B' for both, 'D' for Date.
+	 * @param string|DateTime $datetime_value A valid Date or Time string (or DateTime object)
+	 * @param string          $fieldname      the name of the field the date OR time is being set on (must match a
+	 *                                        EE_Datetime_Field property)
+	 * @throws ReflectionException
+	 * @throws InvalidArgumentException
+	 * @throws InvalidInterfaceException
+	 * @throws InvalidDataTypeException
+	 * @throws EE_Error
+	 */
+	protected function _set_date_time($what = 'T', $datetime_value, $fieldname)
+	{
+		$field = $this->_get_dtt_field_settings($fieldname);
+		$field->set_timezone($this->_timezone);
+		$field->set_date_format($this->_dt_frmt);
+		$field->set_time_format($this->_tm_frmt);
+		switch ($what) {
+			case 'T':
+				$this->_fields[ $fieldname ] = $field->prepare_for_set_with_new_time(
+					$datetime_value,
+					$this->_fields[ $fieldname ]
+				);
+				break;
+			case 'D':
+				$this->_fields[ $fieldname ] = $field->prepare_for_set_with_new_date(
+					$datetime_value,
+					$this->_fields[ $fieldname ]
+				);
+				break;
+			case 'B':
+				$this->_fields[ $fieldname ] = $field->prepare_for_set($datetime_value);
+				break;
+		}
+		$this->_clear_cached_property($fieldname);
+	}
+
+
+	/**
+	 * This will return a timestamp for the website timezone but ONLY when the current website timezone is different
+	 * than the timezone set for the website. NOTE, this currently only works well with methods that return values.  If
+	 * you use it with methods that echo values the $_timestamp property may not get reset to its original value and
+	 * that could lead to some unexpected results!
+	 *
+	 * @access public
+	 * @param string $field_name               This is the name of the field on the object that contains the date/time
+	 *                                         value being returned.
+	 * @param string $callback                 must match a valid method in this class (defaults to get_datetime)
+	 * @param mixed (array|string) $args       This is the arguments that will be passed to the callback.
+	 * @param string $prepend                  You can include something to prepend on the timestamp
+	 * @param string $append                   You can include something to append on the timestamp
+	 * @throws ReflectionException
+	 * @throws InvalidArgumentException
+	 * @throws InvalidInterfaceException
+	 * @throws InvalidDataTypeException
+	 * @throws EE_Error
+	 * @return string timestamp
+	 */
+	public function display_in_my_timezone(
+		$field_name,
+		$callback = 'get_datetime',
+		$args = null,
+		$prepend = '',
+		$append = ''
+	) {
+		$timezone = EEH_DTT_Helper::get_timezone();
+		if ($timezone === $this->_timezone) {
+			return '';
+		}
+		$original_timezone = $this->_timezone;
+		$this->set_timezone($timezone);
+		$fn = (array) $field_name;
+		$args = array_merge($fn, (array) $args);
+		if (! method_exists($this, $callback)) {
+			throw new EE_Error(
+				sprintf(
+					esc_html__(
+						'The method named "%s" given as the callback param in "display_in_my_timezone" does not exist.  Please check your spelling',
+						'event_espresso'
+					),
+					$callback
+				)
+			);
+		}
+		$args = (array) $args;
+		$return = $prepend . call_user_func_array(array($this, $callback), $args) . $append;
+		$this->set_timezone($original_timezone);
+		return $return;
+	}
+
+
+	/**
+	 * Deletes this model object.
+	 * This calls the `EE_Base_Class::_delete` method.  Child classes wishing to change default behaviour should
+	 * override
+	 * `EE_Base_Class::_delete` NOT this class.
+	 *
+	 * @return boolean | int
+	 * @throws ReflectionException
+	 * @throws InvalidArgumentException
+	 * @throws InvalidInterfaceException
+	 * @throws InvalidDataTypeException
+	 * @throws EE_Error
+	 */
+	public function delete()
+	{
+		/**
+		 * Called just before the `EE_Base_Class::_delete` method call.
+		 * Note:
+		 * `EE_Base_Class::_delete` might be overridden by child classes so any client code hooking into these actions
+		 * should be aware that `_delete` may not always result in a permanent delete.
+		 * For example, `EE_Soft_Delete_Base_Class::_delete`
+		 * soft deletes (trash) the object and does not permanently delete it.
+		 *
+		 * @param EE_Base_Class $model_object about to be 'deleted'
+		 */
+		do_action('AHEE__EE_Base_Class__delete__before', $this);
+		$result = $this->_delete();
+		/**
+		 * Called just after the `EE_Base_Class::_delete` method call.
+		 * Note:
+		 * `EE_Base_Class::_delete` might be overridden by child classes so any client code hooking into these actions
+		 * should be aware that `_delete` may not always result in a permanent delete.
+		 * For example `EE_Soft_Base_Class::_delete`
+		 * soft deletes (trash) the object and does not permanently delete it.
+		 *
+		 * @param EE_Base_Class $model_object that was just 'deleted'
+		 * @param boolean       $result
+		 */
+		do_action('AHEE__EE_Base_Class__delete__end', $this, $result);
+		return $result;
+	}
+
+
+	/**
+	 * Calls the specific delete method for the instantiated class.
+	 * This method is called by the public `EE_Base_Class::delete` method.  Any child classes desiring to override
+	 * default functionality for "delete" (which is to call `permanently_delete`) should override this method NOT
+	 * `EE_Base_Class::delete`
+	 *
+	 * @return bool|int
+	 * @throws ReflectionException
+	 * @throws InvalidArgumentException
+	 * @throws InvalidInterfaceException
+	 * @throws InvalidDataTypeException
+	 * @throws EE_Error
+	 */
+	protected function _delete()
+	{
+		return $this->delete_permanently();
+	}
+
+
+	/**
+	 * Deletes this model object permanently from db
+	 * (but keep in mind related models may block the delete and return an error)
+	 *
+	 * @return bool | int
+	 * @throws ReflectionException
+	 * @throws InvalidArgumentException
+	 * @throws InvalidInterfaceException
+	 * @throws InvalidDataTypeException
+	 * @throws EE_Error
+	 */
+	public function delete_permanently()
+	{
+		/**
+		 * Called just before HARD deleting a model object
+		 *
+		 * @param EE_Base_Class $model_object about to be 'deleted'
+		 */
+		do_action('AHEE__EE_Base_Class__delete_permanently__before', $this);
+		$model = $this->get_model();
+		$result = $model->delete_permanently_by_ID($this->ID());
+		$this->refresh_cache_of_related_objects();
+		/**
+		 * Called just after HARD deleting a model object
+		 *
+		 * @param EE_Base_Class $model_object that was just 'deleted'
+		 * @param boolean       $result
+		 */
+		do_action('AHEE__EE_Base_Class__delete_permanently__end', $this, $result);
+		return $result;
+	}
+
+
+	/**
+	 * When this model object is deleted, it may still be cached on related model objects. This clears the cache of
+	 * related model objects
+	 *
+	 * @throws ReflectionException
+	 * @throws InvalidArgumentException
+	 * @throws InvalidInterfaceException
+	 * @throws InvalidDataTypeException
+	 * @throws EE_Error
+	 */
+	public function refresh_cache_of_related_objects()
+	{
+		$model = $this->get_model();
+		foreach ($model->relation_settings() as $relation_name => $relation_obj) {
+			if (! empty($this->_model_relations[ $relation_name ])) {
+				$related_objects = $this->_model_relations[ $relation_name ];
+				if ($relation_obj instanceof EE_Belongs_To_Relation) {
+					// this relation only stores a single model object, not an array
+					// but let's make it consistent
+					$related_objects = array($related_objects);
+				}
+				foreach ($related_objects as $related_object) {
+					// only refresh their cache if they're in memory
+					if ($related_object instanceof EE_Base_Class) {
+						$related_object->clear_cache(
+							$model->get_this_model_name(),
+							$this
+						);
+					}
+				}
+			}
+		}
+	}
+
+
+	/**
+	 *        Saves this object to the database. An array may be supplied to set some values on this
+	 * object just before saving.
+	 *
+	 * @access public
+	 * @param array $set_cols_n_values keys are field names, values are their new values,
+	 *                                 if provided during the save() method (often client code will change the fields'
+	 *                                 values before calling save)
+	 * @throws InvalidArgumentException
+	 * @throws InvalidInterfaceException
+	 * @throws InvalidDataTypeException
+	 * @throws EE_Error
+	 * @return int , 1 on a successful update, the ID of the new entry on insert; 0 on failure or if the model object
+	 *                                 isn't allowed to persist (as determined by EE_Base_Class::allow_persist())
+	 * @throws ReflectionException
+	 * @throws ReflectionException
+	 * @throws ReflectionException
+	 */
+	public function save($set_cols_n_values = array())
+	{
+		$model = $this->get_model();
+		/**
+		 * Filters the fields we're about to save on the model object
+		 *
+		 * @param array         $set_cols_n_values
+		 * @param EE_Base_Class $model_object
+		 */
+		$set_cols_n_values = (array) apply_filters(
+			'FHEE__EE_Base_Class__save__set_cols_n_values',
+			$set_cols_n_values,
+			$this
+		);
+		// set attributes as provided in $set_cols_n_values
+		foreach ($set_cols_n_values as $column => $value) {
+			$this->set($column, $value);
+		}
+		// no changes ? then don't do anything
+		if (! $this->_has_changes && $this->ID() && $model->get_primary_key_field()->is_auto_increment()) {
+			return 0;
+		}
+		/**
+		 * Saving a model object.
+		 * Before we perform a save, this action is fired.
+		 *
+		 * @param EE_Base_Class $model_object the model object about to be saved.
+		 */
+		do_action('AHEE__EE_Base_Class__save__begin', $this);
+		if (! $this->allow_persist()) {
+			return 0;
+		}
+		// now get current attribute values
+		$save_cols_n_values = $this->_fields;
+		// if the object already has an ID, update it. Otherwise, insert it
+		// also: change the assumption about values passed to the model NOT being prepare dby the model object.
+		// They have been
+		$old_assumption_concerning_value_preparation = $model
+			->get_assumption_concerning_values_already_prepared_by_model_object();
+		$model->assume_values_already_prepared_by_model_object(true);
+		// does this model have an autoincrement PK?
+		if ($model->has_primary_key_field()) {
+			if ($model->get_primary_key_field()->is_auto_increment()) {
+				// ok check if it's set, if so: update; if not, insert
+				if (! empty($save_cols_n_values[ $model->primary_key_name() ])) {
+					$results = $model->update_by_ID($save_cols_n_values, $this->ID());
+				} else {
+					unset($save_cols_n_values[ $model->primary_key_name() ]);
+					$results = $model->insert($save_cols_n_values);
+					if ($results) {
+						// if successful, set the primary key
+						// but don't use the normal SET method, because it will check if
+						// an item with the same ID exists in the mapper & db, then
+						// will find it in the db (because we just added it) and THAT object
+						// will get added to the mapper before we can add this one!
+						// but if we just avoid using the SET method, all that headache can be avoided
+						$pk_field_name = $model->primary_key_name();
+						$this->_fields[ $pk_field_name ] = $results;
+						$this->_clear_cached_property($pk_field_name);
+						$model->add_to_entity_map($this);
+						$this->_update_cached_related_model_objs_fks();
+					}
+				}
+			} else {// PK is NOT auto-increment
+				// so check if one like it already exists in the db
+				if ($model->exists_by_ID($this->ID())) {
+					if (WP_DEBUG && ! $this->in_entity_map()) {
+						throw new EE_Error(
+							sprintf(
+								esc_html__(
+									'Using a model object %1$s that is NOT in the entity map, can lead to unexpected errors. You should either: %4$s 1. Put it in the entity mapper by calling %2$s %4$s 2. Discard this model object and use what is in the entity mapper %4$s 3. Fetch from the database using %3$s',
+									'event_espresso'
+								),
+								get_class($this),
+								get_class($model) . '::instance()->add_to_entity_map()',
+								get_class($model) . '::instance()->get_one_by_ID()',
+								'<br />'
+							)
+						);
+					}
+					$results = $model->update_by_ID($save_cols_n_values, $this->ID());
+				} else {
+					$results = $model->insert($save_cols_n_values);
+					$this->_update_cached_related_model_objs_fks();
+				}
+			}
+		} else {// there is NO primary key
+			$already_in_db = false;
+			foreach ($model->unique_indexes() as $index) {
+				$uniqueness_where_params = array_intersect_key($save_cols_n_values, $index->fields());
+				if ($model->exists(array($uniqueness_where_params))) {
+					$already_in_db = true;
+				}
+			}
+			if ($already_in_db) {
+				$combined_pk_fields_n_values = array_intersect_key(
+					$save_cols_n_values,
+					$model->get_combined_primary_key_fields()
+				);
+				$results = $model->update(
+					$save_cols_n_values,
+					$combined_pk_fields_n_values
+				);
+			} else {
+				$results = $model->insert($save_cols_n_values);
+			}
+		}
+		// restore the old assumption about values being prepared by the model object
+		$model->assume_values_already_prepared_by_model_object(
+			$old_assumption_concerning_value_preparation
+		);
+		/**
+		 * After saving the model object this action is called
+		 *
+		 * @param EE_Base_Class $model_object which was just saved
+		 * @param boolean|int   $results      if it were updated, TRUE or FALSE; if it were newly inserted
+		 *                                    the new ID (or 0 if an error occurred and it wasn't updated)
+		 */
+		do_action('AHEE__EE_Base_Class__save__end', $this, $results);
+		$this->_has_changes = false;
+		return $results;
+	}
+
+
+	/**
+	 * Updates the foreign key on related models objects pointing to this to have this model object's ID
+	 * as their foreign key.  If the cached related model objects already exist in the db, saves them (so that the DB
+	 * is consistent) Especially useful in case we JUST added this model object ot the database and we want to let its
+	 * cached relations with foreign keys to it know about that change. Eg: we've created a transaction but haven't
+	 * saved it to the db. We also create a registration and don't save it to the DB, but we DO cache it on the
+	 * transaction. Now, when we save the transaction, the registration's TXN_ID will be automatically updated, whether
+	 * or not they exist in the DB (if they do, their DB records will be automatically updated)
+	 *
+	 * @return void
+	 * @throws ReflectionException
+	 * @throws InvalidArgumentException
+	 * @throws InvalidInterfaceException
+	 * @throws InvalidDataTypeException
+	 * @throws EE_Error
+	 */
+	protected function _update_cached_related_model_objs_fks()
+	{
+		$model = $this->get_model();
+		foreach ($model->relation_settings() as $relation_name => $relation_obj) {
+			if ($relation_obj instanceof EE_Has_Many_Relation) {
+				foreach ($this->get_all_from_cache($relation_name) as $related_model_obj_in_cache) {
+					$fk_to_this = $related_model_obj_in_cache->get_model()->get_foreign_key_to(
+						$model->get_this_model_name()
+					);
+					$related_model_obj_in_cache->set($fk_to_this->get_name(), $this->ID());
+					if ($related_model_obj_in_cache->ID()) {
+						$related_model_obj_in_cache->save();
+					}
+				}
+			}
+		}
+	}
+
+
+	/**
+	 * Saves this model object and its NEW cached relations to the database.
+	 * (Meaning, for now, IT DOES NOT WORK if the cached items already exist in the DB.
+	 * In order for that to work, we would need to mark model objects as dirty/clean...
+	 * because otherwise, there's a potential for infinite looping of saving
+	 * Saves the cached related model objects, and ensures the relation between them
+	 * and this object and properly setup
+	 *
+	 * @return int ID of new model object on save; 0 on failure+
+	 * @throws ReflectionException
+	 * @throws InvalidArgumentException
+	 * @throws InvalidInterfaceException
+	 * @throws InvalidDataTypeException
+	 * @throws EE_Error
+	 */
+	public function save_new_cached_related_model_objs()
+	{
+		// make sure this has been saved
+		if (! $this->ID()) {
+			$id = $this->save();
+		} else {
+			$id = $this->ID();
+		}
+		// now save all the NEW cached model objects  (ie they don't exist in the DB)
+		foreach ($this->get_model()->relation_settings() as $relationName => $relationObj) {
+			if ($this->_model_relations[ $relationName ]) {
+				// is this a relation where we should expect just ONE related object (ie, EE_Belongs_To_relation)
+				// or MANY related objects (ie, EE_HABTM_Relation or EE_Has_Many_Relation)?
+				/* @var $related_model_obj EE_Base_Class */
+				if ($relationObj instanceof EE_Belongs_To_Relation) {
+					// add a relation to that relation type (which saves the appropriate thing in the process)
+					// but ONLY if it DOES NOT exist in the DB
+					$related_model_obj = $this->_model_relations[ $relationName ];
+					// if( ! $related_model_obj->ID()){
+					$this->_add_relation_to($related_model_obj, $relationName);
+					$related_model_obj->save_new_cached_related_model_objs();
+					// }
+				} else {
+					foreach ($this->_model_relations[ $relationName ] as $related_model_obj) {
+						// add a relation to that relation type (which saves the appropriate thing in the process)
+						// but ONLY if it DOES NOT exist in the DB
+						// if( ! $related_model_obj->ID()){
+						$this->_add_relation_to($related_model_obj, $relationName);
+						$related_model_obj->save_new_cached_related_model_objs();
+						// }
+					}
+				}
+			}
+		}
+		return $id;
+	}
+
+
+	/**
+	 * for getting a model while instantiated.
+	 *
+	 * @return EEM_Base | EEM_CPT_Base
+	 * @throws ReflectionException
+	 * @throws InvalidArgumentException
+	 * @throws InvalidInterfaceException
+	 * @throws InvalidDataTypeException
+	 * @throws EE_Error
+	 */
+	public function get_model()
+	{
+		if (! $this->_model) {
+			$modelName = self::_get_model_classname(get_class($this));
+			$this->_model = self::_get_model_instance_with_name($modelName, $this->_timezone);
+		} else {
+			$this->_model->set_timezone($this->_timezone);
+		}
+		return $this->_model;
+	}
+
+
+	/**
+	 * @param $props_n_values
+	 * @param $classname
+	 * @return mixed bool|EE_Base_Class|EEM_CPT_Base
+	 * @throws ReflectionException
+	 * @throws InvalidArgumentException
+	 * @throws InvalidInterfaceException
+	 * @throws InvalidDataTypeException
+	 * @throws EE_Error
+	 */
+	protected static function _get_object_from_entity_mapper($props_n_values, $classname)
+	{
+		// TODO: will not work for Term_Relationships because they have no PK!
+		$primary_id_ref = self::_get_primary_key_name($classname);
+		if (array_key_exists($primary_id_ref, $props_n_values)
+			&& ! empty($props_n_values[ $primary_id_ref ])
+		) {
+			$id = $props_n_values[ $primary_id_ref ];
+			return self::_get_model($classname)->get_from_entity_map($id);
+		}
+		return false;
+	}
+
+
+	/**
+	 * This is called by child static "new_instance" method and we'll check to see if there is an existing db entry for
+	 * the primary key (if present in incoming values). If there is a key in the incoming array that matches the
+	 * primary key for the model AND it is not null, then we check the db. If there's a an object we return it.  If not
+	 * we return false.
+	 *
+	 * @param  array  $props_n_values   incoming array of properties and their values
+	 * @param  string $classname        the classname of the child class
+	 * @param null    $timezone
+	 * @param array   $date_formats     incoming date_formats in an array where the first value is the
+	 *                                  date_format and the second value is the time format
+	 * @return mixed (EE_Base_Class|bool)
+	 * @throws InvalidArgumentException
+	 * @throws InvalidInterfaceException
+	 * @throws InvalidDataTypeException
+	 * @throws EE_Error
+	 * @throws ReflectionException
+	 * @throws ReflectionException
+	 * @throws ReflectionException
+	 */
+	protected static function _check_for_object($props_n_values, $classname, $timezone = null, $date_formats = array())
+	{
+		$existing = null;
+		$model = self::_get_model($classname, $timezone);
+		if ($model->has_primary_key_field()) {
+			$primary_id_ref = self::_get_primary_key_name($classname);
+			if (array_key_exists($primary_id_ref, $props_n_values)
+				&& ! empty($props_n_values[ $primary_id_ref ])
+			) {
+				$existing = $model->get_one_by_ID(
+					$props_n_values[ $primary_id_ref ]
+				);
+			}
+		} elseif ($model->has_all_combined_primary_key_fields($props_n_values)) {
+			// no primary key on this model, but there's still a matching item in the DB
+			$existing = self::_get_model($classname, $timezone)->get_one_by_ID(
+				self::_get_model($classname, $timezone)
+					->get_index_primary_key_string($props_n_values)
+			);
+		}
+		if ($existing) {
+			// set date formats if present before setting values
+			if (! empty($date_formats) && is_array($date_formats)) {
+				$existing->set_date_format($date_formats[0]);
+				$existing->set_time_format($date_formats[1]);
+			} else {
+				// set default formats for date and time
+				$existing->set_date_format(get_option('date_format'));
+				$existing->set_time_format(get_option('time_format'));
+			}
+			foreach ($props_n_values as $property => $field_value) {
+				$existing->set($property, $field_value);
+			}
+			return $existing;
+		}
+		return false;
+	}
+
+
+	/**
+	 * Gets the EEM_*_Model for this class
+	 *
+	 * @access public now, as this is more convenient
+	 * @param      $classname
+	 * @param null $timezone
+	 * @throws ReflectionException
+	 * @throws InvalidArgumentException
+	 * @throws InvalidInterfaceException
+	 * @throws InvalidDataTypeException
+	 * @throws EE_Error
+	 * @return EEM_Base
+	 */
+	protected static function _get_model($classname, $timezone = null)
+	{
+		// find model for this class
+		if (! $classname) {
+			throw new EE_Error(
+				sprintf(
+					esc_html__(
+						'What were you thinking calling _get_model(%s)?? You need to specify the class name',
+						'event_espresso'
+					),
+					$classname
+				)
+			);
+		}
+		$modelName = self::_get_model_classname($classname);
+		return self::_get_model_instance_with_name($modelName, $timezone);
+	}
+
+
+	/**
+	 * Gets the model instance (eg instance of EEM_Attendee) given its classname (eg EE_Attendee)
+	 *
+	 * @param string $model_classname
+	 * @param null   $timezone
+	 * @return EEM_Base
+	 * @throws ReflectionException
+	 * @throws InvalidArgumentException
+	 * @throws InvalidInterfaceException
+	 * @throws InvalidDataTypeException
+	 * @throws EE_Error
+	 */
+	protected static function _get_model_instance_with_name($model_classname, $timezone = null)
+	{
+		$model_classname = str_replace('EEM_', '', $model_classname);
+		$model = EE_Registry::instance()->load_model($model_classname);
+		$model->set_timezone($timezone);
+		return $model;
+	}
+
+
+	/**
+	 * If a model name is provided (eg Registration), gets the model classname for that model.
+	 * Also works if a model class's classname is provided (eg EE_Registration).
+	 *
+	 * @param null $model_name
+	 * @return string like EEM_Attendee
+	 */
+	private static function _get_model_classname($model_name = null)
+	{
+		if (strpos($model_name, 'EE_') === 0) {
+			$model_classname = str_replace('EE_', 'EEM_', $model_name);
+		} else {
+			$model_classname = 'EEM_' . $model_name;
+		}
+		return $model_classname;
+	}
+
+
+	/**
+	 * returns the name of the primary key attribute
+	 *
+	 * @param null $classname
+	 * @throws ReflectionException
+	 * @throws InvalidArgumentException
+	 * @throws InvalidInterfaceException
+	 * @throws InvalidDataTypeException
+	 * @throws EE_Error
+	 * @return string
+	 */
+	protected static function _get_primary_key_name($classname = null)
+	{
+		if (! $classname) {
+			throw new EE_Error(
+				sprintf(
+					esc_html__('What were you thinking calling _get_primary_key_name(%s)', 'event_espresso'),
+					$classname
+				)
+			);
+		}
+		return self::_get_model($classname)->get_primary_key_field()->get_name();
+	}
+
+
+	/**
+	 * Gets the value of the primary key.
+	 * If the object hasn't yet been saved, it should be whatever the model field's default was
+	 * (eg, if this were the EE_Event class, look at the primary key field on EEM_Event and see what its default value
+	 * is. Usually defaults for integer primary keys are 0; string primary keys are usually NULL).
+	 *
+	 * @return mixed, if the primary key is of type INT it'll be an int. Otherwise it could be a string
+	 * @throws ReflectionException
+	 * @throws InvalidArgumentException
+	 * @throws InvalidInterfaceException
+	 * @throws InvalidDataTypeException
+	 * @throws EE_Error
+	 */
+	public function ID()
+	{
+		$model = $this->get_model();
+		// now that we know the name of the variable, use a variable variable to get its value and return its
+		if ($model->has_primary_key_field()) {
+			return $this->_fields[ $model->primary_key_name() ];
+		}
+		return $model->get_index_primary_key_string($this->_fields);
+	}
+
+
+	/**
+	 * Adds a relationship to the specified EE_Base_Class object, given the relationship's name. Eg, if the current
+	 * model is related to a group of events, the $relationName should be 'Event', and should be a key in the EE
+	 * Model's $_model_relations array. If this model object doesn't exist in the DB, just caches the related thing
+	 *
+	 * @param mixed  $otherObjectModelObjectOrID       EE_Base_Class or the ID of the other object
+	 * @param string $relationName                     eg 'Events','Question',etc.
+	 *                                                 an attendee to a group, you also want to specify which role they
+	 *                                                 will have in that group. So you would use this parameter to
+	 *                                                 specify array('role-column-name'=>'role-id')
+	 * @param array  $extra_join_model_fields_n_values You can optionally include an array of key=>value pairs that
+	 *                                                 allow you to further constrict the relation to being added.
+	 *                                                 However, keep in mind that the columns (keys) given must match a
+	 *                                                 column on the JOIN table and currently only the HABTM models
+	 *                                                 accept these additional conditions.  Also remember that if an
+	 *                                                 exact match isn't found for these extra cols/val pairs, then a
+	 *                                                 NEW row is created in the join table.
+	 * @param null   $cache_id
+	 * @throws ReflectionException
+	 * @throws InvalidArgumentException
+	 * @throws InvalidInterfaceException
+	 * @throws InvalidDataTypeException
+	 * @throws EE_Error
+	 * @return EE_Base_Class the object the relation was added to
+	 */
+	public function _add_relation_to(
+		$otherObjectModelObjectOrID,
+		$relationName,
+		$extra_join_model_fields_n_values = array(),
+		$cache_id = null
+	) {
+		$model = $this->get_model();
+		// if this thing exists in the DB, save the relation to the DB
+		if ($this->ID()) {
+			$otherObject = $model->add_relationship_to(
+				$this,
+				$otherObjectModelObjectOrID,
+				$relationName,
+				$extra_join_model_fields_n_values
+			);
+			// clear cache so future get_many_related and get_first_related() return new results.
+			$this->clear_cache($relationName, $otherObject, true);
+			if ($otherObject instanceof EE_Base_Class) {
+				$otherObject->clear_cache($model->get_this_model_name(), $this);
+			}
+		} else {
+			// this thing doesn't exist in the DB,  so just cache it
+			if (! $otherObjectModelObjectOrID instanceof EE_Base_Class) {
+				throw new EE_Error(
+					sprintf(
+						esc_html__(
+							'Before a model object is saved to the database, calls to _add_relation_to must be passed an actual object, not just an ID. You provided %s as the model object to a %s',
+							'event_espresso'
+						),
+						$otherObjectModelObjectOrID,
+						get_class($this)
+					)
+				);
+			}
+			$otherObject = $otherObjectModelObjectOrID;
+			$this->cache($relationName, $otherObjectModelObjectOrID, $cache_id);
+		}
+		if ($otherObject instanceof EE_Base_Class) {
+			// fix the reciprocal relation too
+			if ($otherObject->ID()) {
+				// its saved so assumed relations exist in the DB, so we can just
+				// clear the cache so future queries use the updated info in the DB
+				$otherObject->clear_cache(
+					$model->get_this_model_name(),
+					null,
+					true
+				);
+			} else {
+				// it's not saved, so it caches relations like this
+				$otherObject->cache($model->get_this_model_name(), $this);
+			}
+		}
+		return $otherObject;
+	}
+
+
+	/**
+	 * Removes a relationship to the specified EE_Base_Class object, given the relationships' name. Eg, if the current
+	 * model is related to a group of events, the $relationName should be 'Events', and should be a key in the EE
+	 * Model's $_model_relations array. If this model object doesn't exist in the DB, just removes the related thing
+	 * from the cache
+	 *
+	 * @param mixed  $otherObjectModelObjectOrID
+	 *                EE_Base_Class or the ID of the other object, OR an array key into the cache if this isn't saved
+	 *                to the DB yet
+	 * @param string $relationName
+	 * @param array  $where_query
+	 *                You can optionally include an array of key=>value pairs that allow you to further constrict the
+	 *                relation to being added. However, keep in mind that the columns (keys) given must match a column
+	 *                on the JOIN table and currently only the HABTM models accept these additional conditions. Also
+	 *                remember that if an exact match isn't found for these extra cols/val pairs, then a NEW row is
+	 *                created in the join table.
+	 * @return EE_Base_Class the relation was removed from
+	 * @throws ReflectionException
+	 * @throws InvalidArgumentException
+	 * @throws InvalidInterfaceException
+	 * @throws InvalidDataTypeException
+	 * @throws EE_Error
+	 */
+	public function _remove_relation_to($otherObjectModelObjectOrID, $relationName, $where_query = array())
+	{
+		if ($this->ID()) {
+			// if this exists in the DB, save the relation change to the DB too
+			$otherObject = $this->get_model()->remove_relationship_to(
+				$this,
+				$otherObjectModelObjectOrID,
+				$relationName,
+				$where_query
+			);
+			$this->clear_cache(
+				$relationName,
+				$otherObject
+			);
+		} else {
+			// this doesn't exist in the DB, just remove it from the cache
+			$otherObject = $this->clear_cache(
+				$relationName,
+				$otherObjectModelObjectOrID
+			);
+		}
+		if ($otherObject instanceof EE_Base_Class) {
+			$otherObject->clear_cache(
+				$this->get_model()->get_this_model_name(),
+				$this
+			);
+		}
+		return $otherObject;
+	}
+
+
+	/**
+	 * Removes ALL the related things for the $relationName.
+	 *
+	 * @param string $relationName
+	 * @param array  $where_query_params @see https://github.com/eventespresso/event-espresso-core/tree/master/docs/G--Model-System/model-query-params.md#0-where-conditions
+	 * @return EE_Base_Class
+	 * @throws ReflectionException
+	 * @throws InvalidArgumentException
+	 * @throws InvalidInterfaceException
+	 * @throws InvalidDataTypeException
+	 * @throws EE_Error
+	 */
+	public function _remove_relations($relationName, $where_query_params = array())
+	{
+		if ($this->ID()) {
+			// if this exists in the DB, save the relation change to the DB too
+			$otherObjects = $this->get_model()->remove_relations(
+				$this,
+				$relationName,
+				$where_query_params
+			);
+			$this->clear_cache(
+				$relationName,
+				null,
+				true
+			);
+		} else {
+			// this doesn't exist in the DB, just remove it from the cache
+			$otherObjects = $this->clear_cache(
+				$relationName,
+				null,
+				true
+			);
+		}
+		if (is_array($otherObjects)) {
+			foreach ($otherObjects as $otherObject) {
+				$otherObject->clear_cache(
+					$this->get_model()->get_this_model_name(),
+					$this
+				);
+			}
+		}
+		return $otherObjects;
+	}
+
+
+	/**
+	 * Gets all the related model objects of the specified type. Eg, if the current class if
+	 * EE_Event, you could call $this->get_many_related('Registration') to get an array of all the
+	 * EE_Registration objects which related to this event. Note: by default, we remove the "default query params"
+	 * because we want to get even deleted items etc.
+	 *
+	 * @param string $relationName key in the model's _model_relations array
+	 * @param array  $query_params @see https://github.com/eventespresso/event-espresso-core/tree/master/docs/G--Model-System/model-query-params.md#0-where-conditions
+	 * @return EE_Base_Class[]     Results not necessarily indexed by IDs, because some results might not have primary
+	 *                             keys or might not be saved yet. Consider using EEM_Base::get_IDs() on these
+	 *                             results if you want IDs
+	 * @throws ReflectionException
+	 * @throws InvalidArgumentException
+	 * @throws InvalidInterfaceException
+	 * @throws InvalidDataTypeException
+	 * @throws EE_Error
+	 */
+	public function get_many_related($relationName, $query_params = array())
+	{
+		if ($this->ID()) {
+			// this exists in the DB, so get the related things from either the cache or the DB
+			// if there are query parameters, forget about caching the related model objects.
+			if ($query_params) {
+				$related_model_objects = $this->get_model()->get_all_related(
+					$this,
+					$relationName,
+					$query_params
+				);
+			} else {
+				// did we already cache the result of this query?
+				$cached_results = $this->get_all_from_cache($relationName);
+				if (! $cached_results) {
+					$related_model_objects = $this->get_model()->get_all_related(
+						$this,
+						$relationName,
+						$query_params
+					);
+					// if no query parameters were passed, then we got all the related model objects
+					// for that relation. We can cache them then.
+					foreach ($related_model_objects as $related_model_object) {
+						$this->cache($relationName, $related_model_object);
+					}
+				} else {
+					$related_model_objects = $cached_results;
+				}
+			}
+		} else {
+			// this doesn't exist in the DB, so just get the related things from the cache
+			$related_model_objects = $this->get_all_from_cache($relationName);
+		}
+		return $related_model_objects;
+	}
+
+
+	/**
+	 * Instead of getting the related model objects, simply counts them. Ignores default_where_conditions by default,
+	 * unless otherwise specified in the $query_params
+	 *
+	 * @param string $relation_name  model_name like 'Event', or 'Registration'
+	 * @param array  $query_params   @see https://github.com/eventespresso/event-espresso-core/tree/master/docs/G--Model-System/model-query-params.md
+	 * @param string $field_to_count name of field to count by. By default, uses primary key
+	 * @param bool   $distinct       if we want to only count the distinct values for the column then you can trigger
+	 *                               that by the setting $distinct to TRUE;
+	 * @return int
+	 * @throws ReflectionException
+	 * @throws InvalidArgumentException
+	 * @throws InvalidInterfaceException
+	 * @throws InvalidDataTypeException
+	 * @throws EE_Error
+	 */
+	public function count_related($relation_name, $query_params = array(), $field_to_count = null, $distinct = false)
+	{
+		return $this->get_model()->count_related(
+			$this,
+			$relation_name,
+			$query_params,
+			$field_to_count,
+			$distinct
+		);
+	}
+
+
+	/**
+	 * Instead of getting the related model objects, simply sums up the values of the specified field.
+	 * Note: ignores default_where_conditions by default, unless otherwise specified in the $query_params
+	 *
+	 * @param string $relation_name model_name like 'Event', or 'Registration'
+	 * @param array  $query_params  @see https://github.com/eventespresso/event-espresso-core/tree/master/docs/G--Model-System/model-query-params.md
+	 * @param string $field_to_sum  name of field to count by.
+	 *                              By default, uses primary key
+	 *                              (which doesn't make much sense, so you should probably change it)
+	 * @return int
+	 * @throws ReflectionException
+	 * @throws InvalidArgumentException
+	 * @throws InvalidInterfaceException
+	 * @throws InvalidDataTypeException
+	 * @throws EE_Error
+	 */
+	public function sum_related($relation_name, $query_params = array(), $field_to_sum = null)
+	{
+		return $this->get_model()->sum_related(
+			$this,
+			$relation_name,
+			$query_params,
+			$field_to_sum
+		);
+	}
+
+
+	/**
+	 * Gets the first (ie, one) related model object of the specified type.
+	 *
+	 * @param string $relationName key in the model's _model_relations array
+	 * @param array  $query_params @see https://github.com/eventespresso/event-espresso-core/tree/master/docs/G--Model-System/model-query-params.md
+	 * @return EE_Base_Class (not an array, a single object)
+	 * @throws ReflectionException
+	 * @throws InvalidArgumentException
+	 * @throws InvalidInterfaceException
+	 * @throws InvalidDataTypeException
+	 * @throws EE_Error
+	 */
+	public function get_first_related($relationName, $query_params = array())
+	{
+		$model = $this->get_model();
+		if ($this->ID()) {// this exists in the DB, get from the cache OR the DB
+			// if they've provided some query parameters, don't bother trying to cache the result
+			// also make sure we're not caching the result of get_first_related
+			// on a relation which should have an array of objects (because the cache might have an array of objects)
+			if ($query_params
+				|| ! $model->related_settings_for($relationName)
+					 instanceof
+					 EE_Belongs_To_Relation
+			) {
+				$related_model_object = $model->get_first_related(
+					$this,
+					$relationName,
+					$query_params
+				);
+			} else {
+				// first, check if we've already cached the result of this query
+				$cached_result = $this->get_one_from_cache($relationName);
+				if (! $cached_result) {
+					$related_model_object = $model->get_first_related(
+						$this,
+						$relationName,
+						$query_params
+					);
+					$this->cache($relationName, $related_model_object);
+				} else {
+					$related_model_object = $cached_result;
+				}
+			}
+		} else {
+			$related_model_object = null;
+			// this doesn't exist in the Db,
+			// but maybe the relation is of type belongs to, and so the related thing might
+			if ($model->related_settings_for($relationName) instanceof EE_Belongs_To_Relation) {
+				$related_model_object = $model->get_first_related(
+					$this,
+					$relationName,
+					$query_params
+				);
+			}
+			// this doesn't exist in the DB and apparently the thing it belongs to doesn't either,
+			// just get what's cached on this object
+			if (! $related_model_object) {
+				$related_model_object = $this->get_one_from_cache($relationName);
+			}
+		}
+		return $related_model_object;
+	}
+
+
+	/**
+	 * Does a delete on all related objects of type $relationName and removes
+	 * the current model object's relation to them. If they can't be deleted (because
+	 * of blocking related model objects) does nothing. If the related model objects are
+	 * soft-deletable, they will be soft-deleted regardless of related blocking model objects.
+	 * If this model object doesn't exist yet in the DB, just removes its related things
+	 *
+	 * @param string $relationName
+	 * @param array  $query_params @see https://github.com/eventespresso/event-espresso-core/tree/master/docs/G--Model-System/model-query-params.md
+	 * @return int how many deleted
+	 * @throws ReflectionException
+	 * @throws InvalidArgumentException
+	 * @throws InvalidInterfaceException
+	 * @throws InvalidDataTypeException
+	 * @throws EE_Error
+	 */
+	public function delete_related($relationName, $query_params = array())
+	{
+		if ($this->ID()) {
+			$count = $this->get_model()->delete_related(
+				$this,
+				$relationName,
+				$query_params
+			);
+		} else {
+			$count = count($this->get_all_from_cache($relationName));
+			$this->clear_cache($relationName, null, true);
+		}
+		return $count;
+	}
+
+
+	/**
+	 * Does a hard delete (ie, removes the DB row) on all related objects of type $relationName and removes
+	 * the current model object's relation to them. If they can't be deleted (because
+	 * of blocking related model objects) just does a soft delete on it instead, if possible.
+	 * If the related thing isn't a soft-deletable model object, this function is identical
+	 * to delete_related(). If this model object doesn't exist in the DB, just remove its related things
+	 *
+	 * @param string $relationName
+	 * @param array  $query_params @see https://github.com/eventespresso/event-espresso-core/tree/master/docs/G--Model-System/model-query-params.md
+	 * @return int how many deleted (including those soft deleted)
+	 * @throws ReflectionException
+	 * @throws InvalidArgumentException
+	 * @throws InvalidInterfaceException
+	 * @throws InvalidDataTypeException
+	 * @throws EE_Error
+	 */
+	public function delete_related_permanently($relationName, $query_params = array())
+	{
+		if ($this->ID()) {
+			$count = $this->get_model()->delete_related_permanently(
+				$this,
+				$relationName,
+				$query_params
+			);
+		} else {
+			$count = count($this->get_all_from_cache($relationName));
+		}
+		$this->clear_cache($relationName, null, true);
+		return $count;
+	}
+
+
+	/**
+	 * is_set
+	 * Just a simple utility function children can use for checking if property exists
+	 *
+	 * @access  public
+	 * @param  string $field_name property to check
+	 * @return bool                              TRUE if existing,FALSE if not.
+	 */
+	public function is_set($field_name)
+	{
+		return isset($this->_fields[ $field_name ]);
+	}
+
+
+	/**
+	 * Just a simple utility function children can use for checking if property (or properties) exists and throwing an
+	 * EE_Error exception if they don't
+	 *
+	 * @param  mixed (string|array) $properties properties to check
+	 * @throws EE_Error
+	 * @return bool                              TRUE if existing, throw EE_Error if not.
+	 */
+	protected function _property_exists($properties)
+	{
+		foreach ((array) $properties as $property_name) {
+			// first make sure this property exists
+			if (! $this->_fields[ $property_name ]) {
+				throw new EE_Error(
+					sprintf(
+						esc_html__(
+							'Trying to retrieve a non-existent property (%s).  Double check the spelling please',
+							'event_espresso'
+						),
+						$property_name
+					)
+				);
+			}
+		}
+		return true;
+	}
+
+
+	/**
+	 * This simply returns an array of model fields for this object
+	 *
+	 * @return array
+	 * @throws ReflectionException
+	 * @throws InvalidArgumentException
+	 * @throws InvalidInterfaceException
+	 * @throws InvalidDataTypeException
+	 * @throws EE_Error
+	 */
+	public function model_field_array()
+	{
+		$fields = $this->get_model()->field_settings(false);
+		$properties = array();
+		// remove prepended underscore
+		foreach ($fields as $field_name => $settings) {
+			$properties[ $field_name ] = $this->get($field_name);
+		}
+		return $properties;
+	}
+
+
+	/**
+	 * Very handy general function to allow for plugins to extend any child of EE_Base_Class.
+	 * If a method is called on a child of EE_Base_Class that doesn't exist, this function is called
+	 * (http://www.garfieldtech.com/blog/php-magic-call) and passed the method's name and arguments.
+	 * Instead of requiring a plugin to extend the EE_Base_Class
+	 * (which works fine is there's only 1 plugin, but when will that happen?)
+	 * they can add a hook onto 'filters_hook_espresso__{className}__{methodName}'
+	 * (eg, filters_hook_espresso__EE_Answer__my_great_function)
+	 * and accepts 2 arguments: the object on which the function was called,
+	 * and an array of the original arguments passed to the function.
+	 * Whatever their callback function returns will be returned by this function.
+	 * Example: in functions.php (or in a plugin):
+	 *      add_filter('FHEE__EE_Answer__my_callback','my_callback',10,3);
+	 *      function my_callback($previousReturnValue,EE_Base_Class $object,$argsArray){
+	 *          $returnString= "you called my_callback! and passed args:".implode(",",$argsArray);
+	 *          return $previousReturnValue.$returnString;
+	 *      }
+	 * require('EE_Answer.class.php');
+	 * $answer= EE_Answer::new_instance(array('REG_ID' => 2,'QST_ID' => 3,'ANS_value' => The answer is 42'));
+	 * echo $answer->my_callback('monkeys',100);
+	 * //will output "you called my_callback! and passed args:monkeys,100"
+	 *
+	 * @param string $methodName name of method which was called on a child of EE_Base_Class, but which
+	 * @param array  $args       array of original arguments passed to the function
+	 * @throws EE_Error
+	 * @return mixed whatever the plugin which calls add_filter decides
+	 */
+	public function __call($methodName, $args)
+	{
+		$className = get_class($this);
+		$tagName = "FHEE__{$className}__{$methodName}";
+		if (! has_filter($tagName)) {
+			throw new EE_Error(
+				sprintf(
+					esc_html__(
+						"Method %s on class %s does not exist! You can create one with the following code in functions.php or in a plugin: add_filter('%s','my_callback',10,3);function my_callback(\$previousReturnValue,EE_Base_Class \$object, \$argsArray){/*function body*/return \$whatever;}",
+						'event_espresso'
+					),
+					$methodName,
+					$className,
+					$tagName
+				)
+			);
+		}
+		return apply_filters($tagName, null, $this, $args);
+	}
+
+
+	/**
+	 * Similar to insert_post_meta, adds a record in the Extra_Meta model's table with the given key and value.
+	 * A $previous_value can be specified in case there are many meta rows with the same key
+	 *
+	 * @param string $meta_key
+	 * @param mixed  $meta_value
+	 * @param mixed  $previous_value
+	 * @return bool|int # of records updated (or BOOLEAN if we actually ended up inserting the extra meta row)
+	 *                  NOTE: if the values haven't changed, returns 0
+	 * @throws InvalidArgumentException
+	 * @throws InvalidInterfaceException
+	 * @throws InvalidDataTypeException
+	 * @throws EE_Error
+	 * @throws ReflectionException
+	 */
+	public function update_extra_meta($meta_key, $meta_value, $previous_value = null)
+	{
+		$query_params = array(
+			array(
+				'EXM_key'  => $meta_key,
+				'OBJ_ID'   => $this->ID(),
+				'EXM_type' => $this->get_model()->get_this_model_name(),
+			),
+		);
+		if ($previous_value !== null) {
+			$query_params[0]['EXM_value'] = $meta_value;
+		}
+		$existing_rows_like_that = EEM_Extra_Meta::instance()->get_all($query_params);
+		if (! $existing_rows_like_that) {
+			return $this->add_extra_meta($meta_key, $meta_value);
+		}
+		foreach ($existing_rows_like_that as $existing_row) {
+			$existing_row->save(array('EXM_value' => $meta_value));
+		}
+		return count($existing_rows_like_that);
+	}
+
+
+	/**
+	 * Adds a new extra meta record. If $unique is set to TRUE, we'll first double-check
+	 * no other extra meta for this model object have the same key. Returns TRUE if the
+	 * extra meta row was entered, false if not
+	 *
+	 * @param string  $meta_key
+	 * @param mixed   $meta_value
+	 * @param boolean $unique
+	 * @return boolean
+	 * @throws InvalidArgumentException
+	 * @throws InvalidInterfaceException
+	 * @throws InvalidDataTypeException
+	 * @throws EE_Error
+	 * @throws ReflectionException
+	 * @throws ReflectionException
+	 */
+	public function add_extra_meta($meta_key, $meta_value, $unique = false)
+	{
+		if ($unique) {
+			$existing_extra_meta = EEM_Extra_Meta::instance()->get_one(
+				array(
+					array(
+						'EXM_key'  => $meta_key,
+						'OBJ_ID'   => $this->ID(),
+						'EXM_type' => $this->get_model()->get_this_model_name(),
+					),
+				)
+			);
+			if ($existing_extra_meta) {
+				return false;
+			}
+		}
+		$new_extra_meta = EE_Extra_Meta::new_instance(
+			array(
+				'EXM_key'   => $meta_key,
+				'EXM_value' => $meta_value,
+				'OBJ_ID'    => $this->ID(),
+				'EXM_type'  => $this->get_model()->get_this_model_name(),
+			)
+		);
+		$new_extra_meta->save();
+		return true;
+	}
+
+
+	/**
+	 * Deletes all the extra meta rows for this record as specified by key. If $meta_value
+	 * is specified, only deletes extra meta records with that value.
+	 *
+	 * @param string $meta_key
+	 * @param mixed  $meta_value
+	 * @return int number of extra meta rows deleted
+	 * @throws InvalidArgumentException
+	 * @throws InvalidInterfaceException
+	 * @throws InvalidDataTypeException
+	 * @throws EE_Error
+	 * @throws ReflectionException
+	 */
+	public function delete_extra_meta($meta_key, $meta_value = null)
+	{
+		$query_params = array(
+			array(
+				'EXM_key'  => $meta_key,
+				'OBJ_ID'   => $this->ID(),
+				'EXM_type' => $this->get_model()->get_this_model_name(),
+			),
+		);
+		if ($meta_value !== null) {
+			$query_params[0]['EXM_value'] = $meta_value;
+		}
+		return EEM_Extra_Meta::instance()->delete($query_params);
+	}
+
+
+	/**
+	 * Gets the extra meta with the given meta key. If you specify "single" we just return 1, otherwise
+	 * an array of everything found. Requires that this model actually have a relation of type EE_Has_Many_Any_Relation.
+	 * You can specify $default is case you haven't found the extra meta
+	 *
+	 * @param string  $meta_key
+	 * @param boolean $single
+	 * @param mixed   $default if we don't find anything, what should we return?
+	 * @return mixed single value if $single; array if ! $single
+	 * @throws ReflectionException
+	 * @throws InvalidArgumentException
+	 * @throws InvalidInterfaceException
+	 * @throws InvalidDataTypeException
+	 * @throws EE_Error
+	 */
+	public function get_extra_meta($meta_key, $single = false, $default = null)
+	{
+		if ($single) {
+			$result = $this->get_first_related(
+				'Extra_Meta',
+				array(array('EXM_key' => $meta_key))
+			);
+			if ($result instanceof EE_Extra_Meta) {
+				return $result->value();
+			}
+		} else {
+			$results = $this->get_many_related(
+				'Extra_Meta',
+				array(array('EXM_key' => $meta_key))
+			);
+			if ($results) {
+				$values = array();
+				foreach ($results as $result) {
+					if ($result instanceof EE_Extra_Meta) {
+						$values[ $result->ID() ] = $result->value();
+					}
+				}
+				return $values;
+			}
+		}
+		// if nothing discovered yet return default.
+		return apply_filters(
+			'FHEE__EE_Base_Class__get_extra_meta__default_value',
+			$default,
+			$meta_key,
+			$single,
+			$this
+		);
+	}
+
+
+	/**
+	 * Returns a simple array of all the extra meta associated with this model object.
+	 * If $one_of_each_key is true (Default), it will be an array of simple key-value pairs, keys being the
+	 * extra meta's key, and teh value being its value. However, if there are duplicate extra meta rows with
+	 * the same key, only one will be used. (eg array('foo'=>'bar','monkey'=>123))
+	 * If $one_of_each_key is false, it will return an array with the top-level keys being
+	 * the extra meta keys, but their values are also arrays, which have the extra-meta's ID as their sub-key, and
+	 * finally the extra meta's value as each sub-value. (eg
+	 * array('foo'=>array(1=>'bar',2=>'bill'),'monkey'=>array(3=>123)))
+	 *
+	 * @param boolean $one_of_each_key
+	 * @return array
+	 * @throws ReflectionException
+	 * @throws InvalidArgumentException
+	 * @throws InvalidInterfaceException
+	 * @throws InvalidDataTypeException
+	 * @throws EE_Error
+	 */
+	public function all_extra_meta_array($one_of_each_key = true)
+	{
+		$return_array = array();
+		if ($one_of_each_key) {
+			$extra_meta_objs = $this->get_many_related(
+				'Extra_Meta',
+				array('group_by' => 'EXM_key')
+			);
+			foreach ($extra_meta_objs as $extra_meta_obj) {
+				if ($extra_meta_obj instanceof EE_Extra_Meta) {
+					$return_array[ $extra_meta_obj->key() ] = $extra_meta_obj->value();
+				}
+			}
+		} else {
+			$extra_meta_objs = $this->get_many_related('Extra_Meta');
+			foreach ($extra_meta_objs as $extra_meta_obj) {
+				if ($extra_meta_obj instanceof EE_Extra_Meta) {
+					if (! isset($return_array[ $extra_meta_obj->key() ])) {
+						$return_array[ $extra_meta_obj->key() ] = array();
+					}
+					$return_array[ $extra_meta_obj->key() ][ $extra_meta_obj->ID() ] = $extra_meta_obj->value();
+				}
+			}
+		}
+		return $return_array;
+	}
+
+
+	/**
+	 * Gets a pretty nice displayable nice for this model object. Often overridden
+	 *
+	 * @return string
+	 * @throws ReflectionException
+	 * @throws InvalidArgumentException
+	 * @throws InvalidInterfaceException
+	 * @throws InvalidDataTypeException
+	 * @throws EE_Error
+	 */
+	public function name()
+	{
+		// find a field that's not a text field
+		$field_we_can_use = $this->get_model()->get_a_field_of_type('EE_Text_Field_Base');
+		if ($field_we_can_use) {
+			return $this->get($field_we_can_use->get_name());
+		}
+		$first_few_properties = $this->model_field_array();
+		$first_few_properties = array_slice($first_few_properties, 0, 3);
+		$name_parts = array();
+		foreach ($first_few_properties as $name => $value) {
+			$name_parts[] = "$name:$value";
+		}
+		return implode(',', $name_parts);
+	}
+
+
+	/**
+	 * in_entity_map
+	 * Checks if this model object has been proven to already be in the entity map
+	 *
+	 * @return boolean
+	 * @throws ReflectionException
+	 * @throws InvalidArgumentException
+	 * @throws InvalidInterfaceException
+	 * @throws InvalidDataTypeException
+	 * @throws EE_Error
+	 */
+	public function in_entity_map()
+	{
+		// well, if we looked, did we find it in the entity map?
+		return $this->ID() && $this->get_model()->get_from_entity_map($this->ID()) === $this;
+	}
+
+
+	/**
+	 * refresh_from_db
+	 * Makes sure the fields and values on this model object are in-sync with what's in the database.
+	 *
+	 * @throws ReflectionException
+	 * @throws InvalidArgumentException
+	 * @throws InvalidInterfaceException
+	 * @throws InvalidDataTypeException
+	 * @throws EE_Error if this model object isn't in the entity mapper (because then you should
+	 * just use what's in the entity mapper and refresh it) and WP_DEBUG is TRUE
+	 */
+	public function refresh_from_db()
+	{
+		if ($this->ID() && $this->in_entity_map()) {
+			$this->get_model()->refresh_entity_map_from_db($this->ID());
+		} else {
+			// if it doesn't have ID, you shouldn't be asking to refresh it from teh database (because its not in the database)
+			// if it has an ID but it's not in the map, and you're asking me to refresh it
+			// that's kinda dangerous. You should just use what's in the entity map, or add this to the entity map if there's
+			// absolutely nothing in it for this ID
+			if (WP_DEBUG) {
+				throw new EE_Error(
+					sprintf(
+						esc_html__(
+							'Trying to refresh a model object with ID "%1$s" that\'s not in the entity map? First off: you should put it in the entity map by calling %2$s. Second off, if you want what\'s in the database right now, you should just call %3$s yourself and discard this model object.',
+							'event_espresso'
+						),
+						$this->ID(),
+						get_class($this->get_model()) . '::instance()->add_to_entity_map()',
+						get_class($this->get_model()) . '::instance()->refresh_entity_map()'
+					)
+				);
+			}
+		}
+	}
+
+
+	/**
+	 * Because some other plugins, like Advanced Cron Manager, expect all objects to have this method
+	 * (probably a bad assumption they have made, oh well)
+	 *
+	 * @return string
+	 */
+	public function __toString()
+	{
+		try {
+			return sprintf('%s (%s)', $this->name(), $this->ID());
+		} catch (Exception $e) {
+			EE_Error::add_error($e->getMessage(), __FILE__, __FUNCTION__, __LINE__);
+			return '';
+		}
+	}
+
+
+	/**
+	 * Clear related model objects if they're already in the DB, because otherwise when we
+	 * UN-serialize this model object we'll need to be careful to add them to the entity map.
+	 * This means if we have made changes to those related model objects, and want to unserialize
+	 * the this model object on a subsequent request, changes to those related model objects will be lost.
+	 * Instead, those related model objects should be directly serialized and stored.
+	 * Eg, the following won't work:
+	 * $reg = EEM_Registration::instance()->get_one_by_ID( 123 );
+	 * $att = $reg->attendee();
+	 * $att->set( 'ATT_fname', 'Dirk' );
+	 * update_option( 'my_option', serialize( $reg ) );
+	 * //END REQUEST
+	 * //START NEXT REQUEST
+	 * $reg = get_option( 'my_option' );
+	 * $reg->attendee()->save();
+	 * And would need to be replace with:
+	 * $reg = EEM_Registration::instance()->get_one_by_ID( 123 );
+	 * $att = $reg->attendee();
+	 * $att->set( 'ATT_fname', 'Dirk' );
+	 * update_option( 'my_option', serialize( $reg ) );
+	 * //END REQUEST
+	 * //START NEXT REQUEST
+	 * $att = get_option( 'my_option' );
+	 * $att->save();
+	 *
+	 * @return array
+	 * @throws ReflectionException
+	 * @throws InvalidArgumentException
+	 * @throws InvalidInterfaceException
+	 * @throws InvalidDataTypeException
+	 * @throws EE_Error
+	 */
+	public function __sleep()
+	{
+		$model = $this->get_model();
+		foreach ($model->relation_settings() as $relation_name => $relation_obj) {
+			if ($relation_obj instanceof EE_Belongs_To_Relation) {
+				$classname = 'EE_' . $model->get_this_model_name();
+				if ($this->get_one_from_cache($relation_name) instanceof $classname
+					&& $this->get_one_from_cache($relation_name)->ID()
+				) {
+					$this->clear_cache(
+						$relation_name,
+						$this->get_one_from_cache($relation_name)->ID()
+					);
+				}
+			}
+		}
+		$this->_props_n_values_provided_in_constructor = array();
+		$properties_to_serialize = get_object_vars($this);
+		// don't serialize the model. It's big and that risks recursion
+		unset($properties_to_serialize['_model']);
+		return array_keys($properties_to_serialize);
+	}
+
+
+	/**
+	 * restore _props_n_values_provided_in_constructor
+	 * PLZ NOTE: this will reset the array to whatever fields values were present prior to serialization,
+	 * and therefore should NOT be used to determine if state change has occurred since initial construction.
+	 * At best, you would only be able to detect if state change has occurred during THIS request.
+	 */
+	public function __wakeup()
+	{
+		$this->_props_n_values_provided_in_constructor = $this->_fields;
+	}
+
+
+	/**
+	 * Usage of this magic method is to ensure any internally cached references to object instances that must remain
+	 * distinct with the clone host instance are also cloned.
+	 */
+	public function __clone()
+	{
+		// handle DateTimes (this is handled in here because there's no one specific child class that uses datetimes).
+		foreach ($this->_fields as $field => $value) {
+			if ($value instanceof DateTime) {
+				$this->_fields[ $field ] = clone $value;
+			}
+		}
+	}
 }

core/db_classes/EE_Message_Template_Group.class.php

Indentation +483 added lines, -483 removed lines

@@ -13,487 +13,487 @@
 class EE_Message_Template_Group extends EE_Soft_Delete_Base_Class
 {
 
-    /**
-     * Extra Meta key prefix for whether a given context for this message tmeplate group is active or not.
-     */
-    const ACTIVE_CONTEXT_RECORD_META_KEY_PREFIX = 'active_context_';
-
-    /**
-     * @param array  $props_n_values
-     * @param string $timezone
-     * @return EE_Message_Template_Group|mixed
-     * @throws EE_Error
-     */
-    public static function new_instance($props_n_values = array(), $timezone = '')
-    {
-        $has_object = parent::_check_for_object($props_n_values, __CLASS__, $timezone);
-        return $has_object ? $has_object : new self($props_n_values, false, $timezone);
-    }
-
-
-    /**
-     * @param array  $props_n_values
-     * @param string $timezone
-     * @return EE_Message_Template_Group
-     */
-    public static function new_instance_from_db($props_n_values = array(), $timezone = '')
-    {
-        return new self($props_n_values, true, $timezone);
-    }
-
-
-    /**
-     * @param bool $message_type
-     * @throws EE_Error
-     */
-    public function set_message_type($message_type = false)
-    {
-        if (! $message_type) {
-            throw new EE_Error(esc_html__('Missing required value for the message_type parameter', 'event_espresso'));
-        }
-        $this->set('MTP_message_type', $message_type);
-    }
-
-
-    /**
-     * @param bool $messenger
-     * @throws EE_Error
-     */
-    public function set_messenger($messenger = false)
-    {
-        if (! $messenger) {
-            throw new EE_Error(esc_html__('Missing required value for the messenger parameter', 'event_espresso'));
-        }
-        $this->set('MTP_messenger', $messenger);
-    }
-
-
-    /**
-     * @param bool $GRP_ID
-     * @throws EE_Error
-     */
-    public function set_group_template_id($GRP_ID = false)
-    {
-        if (! $GRP_ID) {
-            throw new EE_Error(
-                esc_html__(
-                    'Missing required value for the message template group id',
-                    'event_espresso'
-                )
-            );
-        }
-        $this->set('GRP_ID', $GRP_ID);
-    }
-
-
-    /**
-     * get Group ID
-     *
-     * @access public
-     * @return int
-     * @throws EE_Error
-     */
-    public function GRP_ID()
-    {
-        return $this->get('GRP_ID');
-    }
-
-
-    /**
-     * get User ID
-     *
-     * @access public
-     * @return int
-     * @throws EE_Error
-     */
-    public function user()
-    {
-        $user_id = $this->get('MTP_user_id');
-        return empty($user_id) ? get_current_user_id() : $user_id;
-    }
-
-
-    /**
-     * Wrapper for the user function() (preserve backward compat)
-     *
-     * @since  4.5.0
-     * @return int
-     * @throws EE_Error
-     */
-    public function wp_user()
-    {
-        return $this->user();
-    }
-
-
-    /**
-     * This simply returns a count of all related events to this message template group
-     *
-     * @return int
-     */
-    public function count_events()
-    {
-        return $this->count_related('Event');
-    }
-
-
-    /**
-     * returns the name saved in the db for this template
-     *
-     * @return string
-     * @throws EE_Error
-     */
-    public function name()
-    {
-        return $this->get('MTP_name');
-    }
-
-
-    /**
-     * Returns the description saved in the db for this template group
-     *
-     * @return string
-     * @throws EE_Error
-     */
-    public function description()
-    {
-        return $this->get('MTP_description');
-    }
-
-
-    /**
-     * returns all related EE_Message_Template objects
-     *
-     * @param  array $query_params @see https://github.com/eventespresso/event-espresso-core/tree/master/docs/G--Model-System/model-query-params.md
-     * @return EE_Message_Template[]
-     * @throws EE_Error
-     */
-    public function message_templates($query_params = array())
-    {
-        return $this->get_many_related('Message_Template', $query_params);
-    }
-
-
-    /**
-     * get Message Messenger
-     *
-     * @access public
-     * @return string
-     * @throws EE_Error
-     */
-    public function messenger()
-    {
-        return $this->get('MTP_messenger');
-    }
-
-
-    /**
-     * get Message Messenger OBJECT
-     * If an attempt to get the corresponding messenger object fails, then we set this message
-     * template group to inactive, and save to db.  Then return null so client code can handle
-     * appropriately.
-     *
-     * @return EE_messenger
-     * @throws EE_Error
-     */
-    public function messenger_obj()
-    {
-        $messenger = $this->messenger();
-        try {
-            $messenger = EEH_MSG_Template::messenger_obj($messenger);
-        } catch (EE_Error $e) {
-            // if an exception was thrown then let's deactivate this message template group because it means there is no
-            // class for this messenger in this group.
-            $this->set('MTP_is_active', false);
-            $this->save();
-            return null;
-        }
-        return $messenger;
-    }
-
-
-    /**
-     * get Message Type
-     *
-     * @access public
-     * @return string
-     * @throws EE_Error
-     */
-    public function message_type()
-    {
-        return $this->get('MTP_message_type');
-    }
-
-
-    /**
-     * get Message type OBJECT
-     * If an attempt to get the corresponding message type object fails, then we set this message
-     * template group to inactive, and save to db.  Then return null so client code can handle
-     * appropriately.
-     *
-     * @throws EE_Error
-     * @return EE_message_type|false if exception thrown.
-     */
-    public function message_type_obj()
-    {
-        $message_type = $this->message_type();
-        try {
-            $message_type = EEH_MSG_Template::message_type_obj($message_type);
-        } catch (EE_Error $e) {
-            // if an exception was thrown then let's deactivate this message template group because it means there is no
-            // class for the message type in this group.
-            $this->set('MTP_is_active', false);
-            $this->save();
-            return null;
-        }
-        return $message_type;
-    }
-
-
-    /**
-     * @return array
-     * @throws EE_Error
-     */
-    public function contexts_config()
-    {
-        return $this->message_type_obj()->get_contexts();
-    }
-
-
-    /**
-     * This returns the context_label for contexts as set in the message type object
-     * Note this is an array with singular and plural keys
-     *
-     * @access public
-     * @return array labels for "context"
-     * @throws EE_Error
-     */
-    public function context_label()
-    {
-        $obj = $this->message_type_obj();
-        return $obj->get_context_label();
-    }
-
-
-    /**
-     * This returns an array of EE_Message_Template objects indexed by context and field.
-     *
-     * @return array ()
-     * @throws EE_Error
-     */
-    public function context_templates()
-    {
-        $mtps_arr = array();
-        $mtps = $this->get_many_related('Message_Template');
-        if (empty($mtps)) {
-            return array();
-        }
-        // note contexts could have CHECKBOX fields per context. So we return the objects indexed by context AND field.
-        foreach ($mtps as $mtp) {
-            $mtps_arr[ $mtp->get('MTP_context') ][ $mtp->get('MTP_template_field') ] = $mtp;
-        }
-        return $mtps_arr;
-    }
-
-
-    /**
-     * this returns if the template group this template belongs to is global
-     *
-     * @return bool true if it is, false if it isn't
-     * @throws EE_Error
-     */
-    public function is_global()
-    {
-        return $this->get('MTP_is_global');
-    }
-
-
-    /**
-     * this returns if the template group this template belongs to is active (i.e. turned "on" or not)
-     *
-     * @return bool true if it is, false if it isn't
-     * @throws EE_Error
-     */
-    public function is_active()
-    {
-        return $this->get('MTP_is_active');
-    }
-
-
-    /**
-     * This will return an array of shortcodes => labels from the messenger and message_type objects associated with
-     * this template.
-     *
-     * @since 4.3.0
-     * @uses  EEH_MSG_Template::get_shortcodes()
-     * @param string $context what context we're going to return shortcodes for
-     * @param array  $fields  what fields we're returning valid shortcodes for.  If empty then we assume all fields are
-     *                        to be returned.
-     * @param bool   $merged  If TRUE then we don't return shortcodes indexed by field but instead an array of the
-     *                        unique shortcodes for all the given (or all) fields.
-     * @return mixed (array|bool) an array of shortcodes in the format array( '[shortcode] => 'label') OR FALSE if no
-     *                        shortcodes found.
-     * @throws EE_Error
-     */
-    public function get_shortcodes($context, $fields = array(), $merged = false)
-    {
-        $messenger = $this->messenger();
-        $message_type = $this->message_type();
-        return EEH_MSG_Template::get_shortcodes($message_type, $messenger, $fields, $context, $merged);
-    }
-
-
-    /**
-     * This just gets the template pack name assigned to this message template group.  If it's not set, then we just
-     * use the default template pack.
-     *
-     * @since 4.5.0
-     * @return string
-     * @throws EE_Error
-     */
-    public function get_template_pack_name()
-    {
-        return $this->get_extra_meta('MTP_template_pack', true, 'default');
-    }
-
-
-    /**
-     * This returns the specific template pack object referenced by the template pack name attached to this message
-     * template group.  If no template pack is assigned then the default template pack is retrieved.
-     *
-     * @since 4.5.0
-     * @return EE_Messages_Template_Pack
-     * @throws EE_Error
-     * @throws InvalidArgumentException
-     * @throws ReflectionException
-     * @throws \EventEspresso\core\exceptions\InvalidDataTypeException
-     * @throws \EventEspresso\core\exceptions\InvalidInterfaceException
-     */
-    public function get_template_pack()
-    {
-        $pack_name = $this->get_template_pack_name();
-        EE_Registry::instance()->load_helper('MSG_Template');
-        return EEH_MSG_Template::get_template_pack($pack_name);
-    }
-
-
-    /**
-     * This retrieves the template variation assigned to this message template group.  If it's not set, then we just
-     * use the default template variation.
-     *
-     * @since 4.5.0
-     * @return string
-     * @throws EE_Error
-     */
-    public function get_template_pack_variation()
-    {
-        return $this->get_extra_meta('MTP_variation', true, 'default');
-    }
-
-
-    /**
-     * This just sets the template pack name attached to this message template group.
-     *
-     * @since 4.5.0
-     * @param string $template_pack_name What message template pack is assigned.
-     * @return int
-     * @throws EE_Error
-     */
-    public function set_template_pack_name($template_pack_name)
-    {
-        return $this->update_extra_meta('MTP_template_pack', $template_pack_name);
-    }
-
-
-    /**
-     * This just sets the template pack variation attached to this message template group.
-     *
-     * @since 4.5.0
-     * @param string $variation What variation is being set on the message template group.
-     * @return int
-     * @throws EE_Error
-     */
-    public function set_template_pack_variation($variation)
-    {
-        return $this->update_extra_meta('MTP_variation', $variation);
-    }
-
-
-    /**
-     * Deactivates the given context.
-     *
-     * @param $context
-     * @return bool|int
-     * @throws EE_Error
-     * @throws InvalidIdentifierException
-     */
-    public function deactivate_context($context)
-    {
-        $this->validate_context($context);
-        return $this->update_extra_meta(self::ACTIVE_CONTEXT_RECORD_META_KEY_PREFIX . $context, false);
-    }
-
-
-    /**
-     * Activates the given context.
-     *
-     * @param $context
-     * @return bool|int
-     * @throws EE_Error
-     * @throws InvalidIdentifierException
-     */
-    public function activate_context($context)
-    {
-        $this->validate_context($context);
-        return $this->update_extra_meta(self::ACTIVE_CONTEXT_RECORD_META_KEY_PREFIX . $context, true);
-    }
-
-
-    /**
-     * Returns whether the context is active or not.
-     * Note, this will default to true if the extra meta record doesn't exist.
-     * Also, this does NOT account for whether the "To" field is empty or not. Some messengers may allow the "To" field
-     * to be empty (@see EE_Messenger::allow_empty_to_field()) so an empty "To" field is not always an indicator of
-     * whether a context is "active" or not.
-     *
-     * @param $context
-     * @return bool
-     * @throws EE_Error
-     * @throws InvalidIdentifierException
-     */
-    public function is_context_active($context)
-    {
-        $this->validate_context($context);
-        return filter_var(
-            $this->get_extra_meta(self::ACTIVE_CONTEXT_RECORD_META_KEY_PREFIX . $context, true, true),
-            FILTER_VALIDATE_BOOLEAN
-        );
-    }
-
-
-    /**
-     * Validates the incoming context to verify it matches a registered context for the related message type.
-     *
-     * @param string $context
-     * @throws EE_Error
-     * @throws InvalidIdentifierException
-     */
-    public function validate_context($context)
-    {
-        $contexts = $this->contexts_config();
-        if (! isset($contexts[ $context ])) {
-            throw new InvalidIdentifierException(
-                '',
-                '',
-                sprintf(
-                    esc_html__(
-                        'An invalid string identifying a context was provided.  "%1$s" was received, and one of "%2$s" was expected.',
-                        'event_espresso'
-                    ),
-                    $context,
-                    implode(',', array_keys($contexts))
-                )
-            );
-        }
-    }
+	/**
+	 * Extra Meta key prefix for whether a given context for this message tmeplate group is active or not.
+	 */
+	const ACTIVE_CONTEXT_RECORD_META_KEY_PREFIX = 'active_context_';
+
+	/**
+	 * @param array  $props_n_values
+	 * @param string $timezone
+	 * @return EE_Message_Template_Group|mixed
+	 * @throws EE_Error
+	 */
+	public static function new_instance($props_n_values = array(), $timezone = '')
+	{
+		$has_object = parent::_check_for_object($props_n_values, __CLASS__, $timezone);
+		return $has_object ? $has_object : new self($props_n_values, false, $timezone);
+	}
+
+
+	/**
+	 * @param array  $props_n_values
+	 * @param string $timezone
+	 * @return EE_Message_Template_Group
+	 */
+	public static function new_instance_from_db($props_n_values = array(), $timezone = '')
+	{
+		return new self($props_n_values, true, $timezone);
+	}
+
+
+	/**
+	 * @param bool $message_type
+	 * @throws EE_Error
+	 */
+	public function set_message_type($message_type = false)
+	{
+		if (! $message_type) {
+			throw new EE_Error(esc_html__('Missing required value for the message_type parameter', 'event_espresso'));
+		}
+		$this->set('MTP_message_type', $message_type);
+	}
+
+
+	/**
+	 * @param bool $messenger
+	 * @throws EE_Error
+	 */
+	public function set_messenger($messenger = false)
+	{
+		if (! $messenger) {
+			throw new EE_Error(esc_html__('Missing required value for the messenger parameter', 'event_espresso'));
+		}
+		$this->set('MTP_messenger', $messenger);
+	}
+
+
+	/**
+	 * @param bool $GRP_ID
+	 * @throws EE_Error
+	 */
+	public function set_group_template_id($GRP_ID = false)
+	{
+		if (! $GRP_ID) {
+			throw new EE_Error(
+				esc_html__(
+					'Missing required value for the message template group id',
+					'event_espresso'
+				)
+			);
+		}
+		$this->set('GRP_ID', $GRP_ID);
+	}
+
+
+	/**
+	 * get Group ID
+	 *
+	 * @access public
+	 * @return int
+	 * @throws EE_Error
+	 */
+	public function GRP_ID()
+	{
+		return $this->get('GRP_ID');
+	}
+
+
+	/**
+	 * get User ID
+	 *
+	 * @access public
+	 * @return int
+	 * @throws EE_Error
+	 */
+	public function user()
+	{
+		$user_id = $this->get('MTP_user_id');
+		return empty($user_id) ? get_current_user_id() : $user_id;
+	}
+
+
+	/**
+	 * Wrapper for the user function() (preserve backward compat)
+	 *
+	 * @since  4.5.0
+	 * @return int
+	 * @throws EE_Error
+	 */
+	public function wp_user()
+	{
+		return $this->user();
+	}
+
+
+	/**
+	 * This simply returns a count of all related events to this message template group
+	 *
+	 * @return int
+	 */
+	public function count_events()
+	{
+		return $this->count_related('Event');
+	}
+
+
+	/**
+	 * returns the name saved in the db for this template
+	 *
+	 * @return string
+	 * @throws EE_Error
+	 */
+	public function name()
+	{
+		return $this->get('MTP_name');
+	}
+
+
+	/**
+	 * Returns the description saved in the db for this template group
+	 *
+	 * @return string
+	 * @throws EE_Error
+	 */
+	public function description()
+	{
+		return $this->get('MTP_description');
+	}
+
+
+	/**
+	 * returns all related EE_Message_Template objects
+	 *
+	 * @param  array $query_params @see https://github.com/eventespresso/event-espresso-core/tree/master/docs/G--Model-System/model-query-params.md
+	 * @return EE_Message_Template[]
+	 * @throws EE_Error
+	 */
+	public function message_templates($query_params = array())
+	{
+		return $this->get_many_related('Message_Template', $query_params);
+	}
+
+
+	/**
+	 * get Message Messenger
+	 *
+	 * @access public
+	 * @return string
+	 * @throws EE_Error
+	 */
+	public function messenger()
+	{
+		return $this->get('MTP_messenger');
+	}
+
+
+	/**
+	 * get Message Messenger OBJECT
+	 * If an attempt to get the corresponding messenger object fails, then we set this message
+	 * template group to inactive, and save to db.  Then return null so client code can handle
+	 * appropriately.
+	 *
+	 * @return EE_messenger
+	 * @throws EE_Error
+	 */
+	public function messenger_obj()
+	{
+		$messenger = $this->messenger();
+		try {
+			$messenger = EEH_MSG_Template::messenger_obj($messenger);
+		} catch (EE_Error $e) {
+			// if an exception was thrown then let's deactivate this message template group because it means there is no
+			// class for this messenger in this group.
+			$this->set('MTP_is_active', false);
+			$this->save();
+			return null;
+		}
+		return $messenger;
+	}
+
+
+	/**
+	 * get Message Type
+	 *
+	 * @access public
+	 * @return string
+	 * @throws EE_Error
+	 */
+	public function message_type()
+	{
+		return $this->get('MTP_message_type');
+	}
+
+
+	/**
+	 * get Message type OBJECT
+	 * If an attempt to get the corresponding message type object fails, then we set this message
+	 * template group to inactive, and save to db.  Then return null so client code can handle
+	 * appropriately.
+	 *
+	 * @throws EE_Error
+	 * @return EE_message_type|false if exception thrown.
+	 */
+	public function message_type_obj()
+	{
+		$message_type = $this->message_type();
+		try {
+			$message_type = EEH_MSG_Template::message_type_obj($message_type);
+		} catch (EE_Error $e) {
+			// if an exception was thrown then let's deactivate this message template group because it means there is no
+			// class for the message type in this group.
+			$this->set('MTP_is_active', false);
+			$this->save();
+			return null;
+		}
+		return $message_type;
+	}
+
+
+	/**
+	 * @return array
+	 * @throws EE_Error
+	 */
+	public function contexts_config()
+	{
+		return $this->message_type_obj()->get_contexts();
+	}
+
+
+	/**
+	 * This returns the context_label for contexts as set in the message type object
+	 * Note this is an array with singular and plural keys
+	 *
+	 * @access public
+	 * @return array labels for "context"
+	 * @throws EE_Error
+	 */
+	public function context_label()
+	{
+		$obj = $this->message_type_obj();
+		return $obj->get_context_label();
+	}
+
+
+	/**
+	 * This returns an array of EE_Message_Template objects indexed by context and field.
+	 *
+	 * @return array ()
+	 * @throws EE_Error
+	 */
+	public function context_templates()
+	{
+		$mtps_arr = array();
+		$mtps = $this->get_many_related('Message_Template');
+		if (empty($mtps)) {
+			return array();
+		}
+		// note contexts could have CHECKBOX fields per context. So we return the objects indexed by context AND field.
+		foreach ($mtps as $mtp) {
+			$mtps_arr[ $mtp->get('MTP_context') ][ $mtp->get('MTP_template_field') ] = $mtp;
+		}
+		return $mtps_arr;
+	}
+
+
+	/**
+	 * this returns if the template group this template belongs to is global
+	 *
+	 * @return bool true if it is, false if it isn't
+	 * @throws EE_Error
+	 */
+	public function is_global()
+	{
+		return $this->get('MTP_is_global');
+	}
+
+
+	/**
+	 * this returns if the template group this template belongs to is active (i.e. turned "on" or not)
+	 *
+	 * @return bool true if it is, false if it isn't
+	 * @throws EE_Error
+	 */
+	public function is_active()
+	{
+		return $this->get('MTP_is_active');
+	}
+
+
+	/**
+	 * This will return an array of shortcodes => labels from the messenger and message_type objects associated with
+	 * this template.
+	 *
+	 * @since 4.3.0
+	 * @uses  EEH_MSG_Template::get_shortcodes()
+	 * @param string $context what context we're going to return shortcodes for
+	 * @param array  $fields  what fields we're returning valid shortcodes for.  If empty then we assume all fields are
+	 *                        to be returned.
+	 * @param bool   $merged  If TRUE then we don't return shortcodes indexed by field but instead an array of the
+	 *                        unique shortcodes for all the given (or all) fields.
+	 * @return mixed (array|bool) an array of shortcodes in the format array( '[shortcode] => 'label') OR FALSE if no
+	 *                        shortcodes found.
+	 * @throws EE_Error
+	 */
+	public function get_shortcodes($context, $fields = array(), $merged = false)
+	{
+		$messenger = $this->messenger();
+		$message_type = $this->message_type();
+		return EEH_MSG_Template::get_shortcodes($message_type, $messenger, $fields, $context, $merged);
+	}
+
+
+	/**
+	 * This just gets the template pack name assigned to this message template group.  If it's not set, then we just
+	 * use the default template pack.
+	 *
+	 * @since 4.5.0
+	 * @return string
+	 * @throws EE_Error
+	 */
+	public function get_template_pack_name()
+	{
+		return $this->get_extra_meta('MTP_template_pack', true, 'default');
+	}
+
+
+	/**
+	 * This returns the specific template pack object referenced by the template pack name attached to this message
+	 * template group.  If no template pack is assigned then the default template pack is retrieved.
+	 *
+	 * @since 4.5.0
+	 * @return EE_Messages_Template_Pack
+	 * @throws EE_Error
+	 * @throws InvalidArgumentException
+	 * @throws ReflectionException
+	 * @throws \EventEspresso\core\exceptions\InvalidDataTypeException
+	 * @throws \EventEspresso\core\exceptions\InvalidInterfaceException
+	 */
+	public function get_template_pack()
+	{
+		$pack_name = $this->get_template_pack_name();
+		EE_Registry::instance()->load_helper('MSG_Template');
+		return EEH_MSG_Template::get_template_pack($pack_name);
+	}
+
+
+	/**
+	 * This retrieves the template variation assigned to this message template group.  If it's not set, then we just
+	 * use the default template variation.
+	 *
+	 * @since 4.5.0
+	 * @return string
+	 * @throws EE_Error
+	 */
+	public function get_template_pack_variation()
+	{
+		return $this->get_extra_meta('MTP_variation', true, 'default');
+	}
+
+
+	/**
+	 * This just sets the template pack name attached to this message template group.
+	 *
+	 * @since 4.5.0
+	 * @param string $template_pack_name What message template pack is assigned.
+	 * @return int
+	 * @throws EE_Error
+	 */
+	public function set_template_pack_name($template_pack_name)
+	{
+		return $this->update_extra_meta('MTP_template_pack', $template_pack_name);
+	}
+
+
+	/**
+	 * This just sets the template pack variation attached to this message template group.
+	 *
+	 * @since 4.5.0
+	 * @param string $variation What variation is being set on the message template group.
+	 * @return int
+	 * @throws EE_Error
+	 */
+	public function set_template_pack_variation($variation)
+	{
+		return $this->update_extra_meta('MTP_variation', $variation);
+	}
+
+
+	/**
+	 * Deactivates the given context.
+	 *
+	 * @param $context
+	 * @return bool|int
+	 * @throws EE_Error
+	 * @throws InvalidIdentifierException
+	 */
+	public function deactivate_context($context)
+	{
+		$this->validate_context($context);
+		return $this->update_extra_meta(self::ACTIVE_CONTEXT_RECORD_META_KEY_PREFIX . $context, false);
+	}
+
+
+	/**
+	 * Activates the given context.
+	 *
+	 * @param $context
+	 * @return bool|int
+	 * @throws EE_Error
+	 * @throws InvalidIdentifierException
+	 */
+	public function activate_context($context)
+	{
+		$this->validate_context($context);
+		return $this->update_extra_meta(self::ACTIVE_CONTEXT_RECORD_META_KEY_PREFIX . $context, true);
+	}
+
+
+	/**
+	 * Returns whether the context is active or not.
+	 * Note, this will default to true if the extra meta record doesn't exist.
+	 * Also, this does NOT account for whether the "To" field is empty or not. Some messengers may allow the "To" field
+	 * to be empty (@see EE_Messenger::allow_empty_to_field()) so an empty "To" field is not always an indicator of
+	 * whether a context is "active" or not.
+	 *
+	 * @param $context
+	 * @return bool
+	 * @throws EE_Error
+	 * @throws InvalidIdentifierException
+	 */
+	public function is_context_active($context)
+	{
+		$this->validate_context($context);
+		return filter_var(
+			$this->get_extra_meta(self::ACTIVE_CONTEXT_RECORD_META_KEY_PREFIX . $context, true, true),
+			FILTER_VALIDATE_BOOLEAN
+		);
+	}
+
+
+	/**
+	 * Validates the incoming context to verify it matches a registered context for the related message type.
+	 *
+	 * @param string $context
+	 * @throws EE_Error
+	 * @throws InvalidIdentifierException
+	 */
+	public function validate_context($context)
+	{
+		$contexts = $this->contexts_config();
+		if (! isset($contexts[ $context ])) {
+			throw new InvalidIdentifierException(
+				'',
+				'',
+				sprintf(
+					esc_html__(
+						'An invalid string identifying a context was provided.  "%1$s" was received, and one of "%2$s" was expected.',
+						'event_espresso'
+					),
+					$context,
+					implode(',', array_keys($contexts))
+				)
+			);
+		}
+	}
 }

core/db_classes/EE_Transaction.class.php

Indentation +1390 added lines, -1390 removed lines

@@ -13,1394 +13,1394 @@
 class EE_Transaction extends EE_Base_Class implements EEI_Transaction
 {
 
-    /**
-     * The length of time in seconds that a lock is applied before being considered expired.
-     * It is not long because a transaction should only be locked for the duration of the request that locked it
-     */
-    const LOCK_EXPIRATION = 2;
-
-    /**
-     * txn status upon initial construction.
-     *
-     * @var string
-     */
-    protected $_old_txn_status;
-
-
-    /**
-     * @param array  $props_n_values          incoming values
-     * @param string $timezone                incoming timezone
-     *                                        (if not set the timezone set for the website will be used.)
-     * @param array  $date_formats            incoming date_formats in an array where the first value is the
-     *                                        date_format and the second value is the time format
-     * @return EE_Transaction
-     * @throws EE_Error
-     */
-    public static function new_instance($props_n_values = array(), $timezone = null, $date_formats = array())
-    {
-        $has_object = parent::_check_for_object($props_n_values, __CLASS__, $timezone, $date_formats);
-        $txn = $has_object
-            ? $has_object
-            : new self($props_n_values, false, $timezone, $date_formats);
-        if (! $has_object) {
-            $txn->set_old_txn_status($txn->status_ID());
-        }
-        return $txn;
-    }
-
-
-    /**
-     * @param array  $props_n_values  incoming values from the database
-     * @param string $timezone        incoming timezone as set by the model.  If not set the timezone for
-     *                                the website will be used.
-     * @return EE_Transaction
-     * @throws EE_Error
-     */
-    public static function new_instance_from_db($props_n_values = array(), $timezone = null)
-    {
-        $txn = new self($props_n_values, true, $timezone);
-        $txn->set_old_txn_status($txn->status_ID());
-        return $txn;
-    }
-
-
-    /**
-     * Sets a meta field indicating that this TXN is locked and should not be updated in the db.
-     * If a lock has already been set, then we will attempt to remove it in case it has expired.
-     * If that also fails, then an exception is thrown.
-     *
-     * @throws EE_Error
-     */
-    public function lock()
-    {
-        // attempt to set lock, but if that fails...
-        if (! $this->add_extra_meta('lock', time(), true)) {
-            // then attempt to remove the lock in case it is expired
-            if ($this->_remove_expired_lock()) {
-                // if removal was successful, then try setting lock again
-                $this->lock();
-            } else {
-                // but if the lock can not be removed, then throw an exception
-                throw new EE_Error(
-                    sprintf(
-                        __(
-                            'Could not lock Transaction %1$d because it is already locked, meaning another part of the system is currently editing it. It should already be unlocked by the time you read this, so please refresh the page and try again.',
-                            'event_espresso'
-                        ),
-                        $this->ID()
-                    )
-                );
-            }
-        }
-    }
-
-
-    /**
-     * removes transaction lock applied in EE_Transaction::lock()
-     *
-     * @return int
-     * @throws EE_Error
-     */
-    public function unlock()
-    {
-        return $this->delete_extra_meta('lock');
-    }
-
-
-    /**
-     * Decides whether or not now is the right time to update the transaction.
-     * This is useful because we don't always know if it is safe to update the transaction
-     * and its related data. why?
-     * because it's possible that the transaction is being used in another
-     * request and could overwrite anything we save.
-     * So we want to only update the txn once we know that won't happen.
-     * We also check that the lock isn't expired, and remove it if it is
-     *
-     * @return boolean
-     * @throws EE_Error
-     */
-    public function is_locked()
-    {
-        // if TXN is not locked, then return false immediately
-        if (! $this->_get_lock()) {
-            return false;
-        }
-        // if not, then let's try and remove the lock in case it's expired...
-        // _remove_expired_lock() returns 0 when lock is valid (ie: removed = false)
-        // and a positive number if the lock was removed (ie: number of locks deleted),
-        // so we need to return the opposite
-        return ! $this->_remove_expired_lock() ? true : false;
-    }
-
-
-    /**
-     * Gets the meta field indicating that this TXN is locked
-     *
-     * @return int
-     * @throws EE_Error
-     */
-    protected function _get_lock()
-    {
-        return (int) $this->get_extra_meta('lock', true, 0);
-    }
-
-
-    /**
-     * If the lock on this transaction is expired, then we want to remove it so that the transaction can be updated
-     *
-     * @return int
-     * @throws EE_Error
-     */
-    protected function _remove_expired_lock()
-    {
-        $locked = $this->_get_lock();
-        if ($locked && time() - EE_Transaction::LOCK_EXPIRATION > $locked) {
-            return $this->unlock();
-        }
-        return 0;
-    }
-
-
-    /**
-     * Set transaction total
-     *
-     * @param float $total total value of transaction
-     * @throws EE_Error
-     */
-    public function set_total($total = 0.00)
-    {
-        $this->set('TXN_total', (float) $total);
-    }
-
-
-    /**
-     * Set Total Amount Paid to Date
-     *
-     * @param float $total_paid total amount paid to date (sum of all payments)
-     * @throws EE_Error
-     */
-    public function set_paid($total_paid = 0.00)
-    {
-        $this->set('TXN_paid', (float) $total_paid);
-    }
-
-
-    /**
-     * Set transaction status
-     *
-     * @param string $status        whether the transaction is open, declined, accepted,
-     *                              or any number of custom values that can be set
-     * @throws EE_Error
-     */
-    public function set_status($status = '')
-    {
-        $this->set('STS_ID', $status);
-    }
-
-
-    /**
-     * Set hash salt
-     *
-     * @param string $hash_salt required for some payment gateways
-     * @throws EE_Error
-     */
-    public function set_hash_salt($hash_salt = '')
-    {
-        $this->set('TXN_hash_salt', $hash_salt);
-    }
-
-
-    /**
-     * Sets TXN_reg_steps array
-     *
-     * @param array $txn_reg_steps
-     * @throws EE_Error
-     */
-    public function set_reg_steps(array $txn_reg_steps)
-    {
-        $this->set('TXN_reg_steps', $txn_reg_steps);
-    }
-
-
-    /**
-     * Gets TXN_reg_steps
-     *
-     * @return array
-     * @throws EE_Error
-     */
-    public function reg_steps()
-    {
-        $TXN_reg_steps = $this->get('TXN_reg_steps');
-        return is_array($TXN_reg_steps) ? (array) $TXN_reg_steps : array();
-    }
-
-
-    /**
-     * @return string of transaction's total cost, with currency symbol and decimal
-     * @throws EE_Error
-     */
-    public function pretty_total()
-    {
-        return $this->get_pretty('TXN_total');
-    }
-
-
-    /**
-     * Gets the amount paid in a pretty string (formatted and with currency symbol)
-     *
-     * @return string
-     * @throws EE_Error
-     */
-    public function pretty_paid()
-    {
-        return $this->get_pretty('TXN_paid');
-    }
-
-
-    /**
-     * calculate the amount remaining for this transaction and return;
-     *
-     * @return float amount remaining
-     * @throws EE_Error
-     */
-    public function remaining()
-    {
-        return $this->total() - $this->paid();
-    }
-
-
-    /**
-     * get Transaction Total
-     *
-     * @return float
-     * @throws EE_Error
-     */
-    public function total()
-    {
-        return (float) $this->get('TXN_total');
-    }
-
-
-    /**
-     * get Total Amount Paid to Date
-     *
-     * @return float
-     * @throws EE_Error
-     */
-    public function paid()
-    {
-        return (float) $this->get('TXN_paid');
-    }
-
-
-    /**
-     * @throws EE_Error
-     */
-    public function get_cart_session()
-    {
-        $session_data = (array) $this->get('TXN_session_data');
-        return isset($session_data['cart']) && $session_data['cart'] instanceof EE_Cart
-            ? $session_data['cart']
-            : null;
-    }
-
-
-    /**
-     * get Transaction session data
-     *
-     * @throws EE_Error
-     */
-    public function session_data()
-    {
-        $session_data = $this->get('TXN_session_data');
-        if (empty($session_data)) {
-            $session_data = array(
-                'id'            => null,
-                'user_id'       => null,
-                'ip_address'    => null,
-                'user_agent'    => null,
-                'init_access'   => null,
-                'last_access'   => null,
-                'pages_visited' => array(),
-            );
-        }
-        return $session_data;
-    }
-
-
-    /**
-     * Set session data within the TXN object
-     *
-     * @param EE_Session|array $session_data
-     * @throws EE_Error
-     */
-    public function set_txn_session_data($session_data)
-    {
-        if ($session_data instanceof EE_Session) {
-            $this->set('TXN_session_data', $session_data->get_session_data(null, true));
-        } else {
-            $this->set('TXN_session_data', $session_data);
-        }
-    }
-
-
-    /**
-     * get Transaction hash salt
-     *
-     * @throws EE_Error
-     */
-    public function hash_salt_()
-    {
-        return $this->get('TXN_hash_salt');
-    }
-
-
-    /**
-     * Returns the transaction datetime as either:
-     *            - unix timestamp format ($format = false, $gmt = true)
-     *            - formatted date string including the UTC (timezone) offset ($format = true ($gmt
-     *              has no affect with this option)), this also may include a timezone abbreviation if the
-     *              set timezone in this class differs from what the timezone is on the blog.
-     *            - formatted date string including the UTC (timezone) offset (default).
-     *
-     * @param boolean $format   - whether to return a unix timestamp (default) or formatted date string
-     * @param boolean $gmt      - whether to return a unix timestamp with UTC offset applied (default)
-     *                          or no UTC offset applied
-     * @return string | int
-     * @throws EE_Error
-     */
-    public function datetime($format = false, $gmt = false)
-    {
-        if ($format) {
-            return $this->get_pretty('TXN_timestamp');
-        }
-        if ($gmt) {
-            return $this->get_raw('TXN_timestamp');
-        }
-        return $this->get('TXN_timestamp');
-    }
-
-
-    /**
-     * Gets registrations on this transaction
-     *
-     * @param array   $query_params array of query parameters
-     * @param boolean $get_cached   TRUE to retrieve cached registrations or FALSE to pull from the db
-     * @return EE_Base_Class[]|EE_Registration[]
-     * @throws EE_Error
-     */
-    public function registrations($query_params = array(), $get_cached = false)
-    {
-        $query_params = (empty($query_params) || ! is_array($query_params))
-            ? array(
-                'order_by' => array(
-                    'Event.EVT_name'     => 'ASC',
-                    'Attendee.ATT_lname' => 'ASC',
-                    'Attendee.ATT_fname' => 'ASC',
-                ),
-            )
-            : $query_params;
-        $query_params = $get_cached ? array() : $query_params;
-        return $this->get_many_related('Registration', $query_params);
-    }
-
-
-    /**
-     * Gets all the attendees for this transaction (handy for use with EE_Attendee's get_registrations_for_event
-     * function for getting attendees and how many registrations they each have for an event)
-     *
-     * @return mixed EE_Attendee[] by default, int if $output is set to 'COUNT'
-     * @throws EE_Error
-     */
-    public function attendees()
-    {
-        return $this->get_many_related('Attendee', array(array('Registration.Transaction.TXN_ID' => $this->ID())));
-    }
-
-
-    /**
-     * Gets payments for this transaction. Unlike other such functions, order by 'DESC' by default
-     *
-     * @param array $query_params @see https://github.com/eventespresso/event-espresso-core/tree/master/docs/G--Model-System/model-query-params.md
-     * @return EE_Base_Class[]|EE_Payment[]
-     * @throws EE_Error
-     */
-    public function payments($query_params = array())
-    {
-        return $this->get_many_related('Payment', $query_params);
-    }
-
-
-    /**
-     * gets only approved payments for this transaction
-     *
-     * @return EE_Base_Class[]|EE_Payment[]
-     * @throws EE_Error
-     * @throws InvalidArgumentException
-     * @throws ReflectionException
-     * @throws InvalidDataTypeException
-     * @throws InvalidInterfaceException
-     */
-    public function approved_payments()
-    {
-        EE_Registry::instance()->load_model('Payment');
-        return $this->get_many_related(
-            'Payment',
-            array(
-                array('STS_ID' => EEM_Payment::status_id_approved),
-                'order_by' => array('PAY_timestamp' => 'DESC'),
-            )
-        );
-    }
-
-
-    /**
-     * Gets all payments which have not been approved
-     *
-     * @return EE_Base_Class[]|EEI_Payment[]
-     * @throws EE_Error if a model is misconfigured somehow
-     */
-    public function pending_payments()
-    {
-        return $this->get_many_related(
-            'Payment',
-            array(
-                array(
-                    'STS_ID' => EEM_Payment::status_id_pending,
-                ),
-                'order_by' => array(
-                    'PAY_timestamp' => 'DESC',
-                ),
-            )
-        );
-    }
-
-
-    /**
-     * echoes $this->pretty_status()
-     *
-     * @param bool $show_icons
-     * @throws EE_Error
-     * @throws InvalidArgumentException
-     * @throws InvalidDataTypeException
-     * @throws InvalidInterfaceException
-     */
-    public function e_pretty_status($show_icons = false)
-    {
-        echo $this->pretty_status($show_icons);
-    }
-
-
-    /**
-     * returns a pretty version of the status, good for displaying to users
-     *
-     * @param bool $show_icons
-     * @return string
-     * @throws EE_Error
-     * @throws InvalidArgumentException
-     * @throws InvalidDataTypeException
-     * @throws InvalidInterfaceException
-     */
-    public function pretty_status($show_icons = false)
-    {
-        $status = EEM_Status::instance()->localized_status(
-            array($this->status_ID() => __('unknown', 'event_espresso')),
-            false,
-            'sentence'
-        );
-        $icon = '';
-        switch ($this->status_ID()) {
-            case EEM_Transaction::complete_status_code:
-                $icon = $show_icons ? '<span class="dashicons dashicons-yes ee-icon-size-24 green-text"></span>' : '';
-                break;
-            case EEM_Transaction::incomplete_status_code:
-                $icon = $show_icons ? '<span class="dashicons dashicons-marker ee-icon-size-16 lt-blue-text"></span>'
-                    : '';
-                break;
-            case EEM_Transaction::abandoned_status_code:
-                $icon = $show_icons ? '<span class="dashicons dashicons-marker ee-icon-size-16 red-text"></span>' : '';
-                break;
-            case EEM_Transaction::failed_status_code:
-                $icon = $show_icons ? '<span class="dashicons dashicons-no ee-icon-size-16 red-text"></span>' : '';
-                break;
-            case EEM_Transaction::overpaid_status_code:
-                $icon = $show_icons ? '<span class="dashicons dashicons-plus ee-icon-size-16 orange-text"></span>' : '';
-                break;
-        }
-        return $icon . $status[ $this->status_ID() ];
-    }
-
-
-    /**
-     * get Transaction Status
-     *
-     * @throws EE_Error
-     */
-    public function status_ID()
-    {
-        return $this->get('STS_ID');
-    }
-
-
-    /**
-     * Returns TRUE or FALSE for whether or not this transaction cost any money
-     *
-     * @return boolean
-     * @throws EE_Error
-     */
-    public function is_free()
-    {
-        return EEH_Money::compare_floats($this->get('TXN_total'), 0, '==');
-    }
-
-
-    /**
-     * Returns whether this transaction is complete
-     * Useful in templates and other logic for deciding if we should ask for another payment...
-     *
-     * @return boolean
-     * @throws EE_Error
-     */
-    public function is_completed()
-    {
-        return $this->status_ID() === EEM_Transaction::complete_status_code;
-    }
-
-
-    /**
-     * Returns whether this transaction is incomplete
-     * Useful in templates and other logic for deciding if we should ask for another payment...
-     *
-     * @return boolean
-     * @throws EE_Error
-     */
-    public function is_incomplete()
-    {
-        return $this->status_ID() === EEM_Transaction::incomplete_status_code;
-    }
-
-
-    /**
-     * Returns whether this transaction is overpaid
-     * Useful in templates and other logic for deciding if monies need to be refunded
-     *
-     * @return boolean
-     * @throws EE_Error
-     */
-    public function is_overpaid()
-    {
-        return $this->status_ID() === EEM_Transaction::overpaid_status_code;
-    }
-
-
-    /**
-     * Returns whether this transaction was abandoned
-     * meaning that the transaction/registration process was somehow interrupted and never completed
-     * but that contact information exists for at least one registrant
-     *
-     * @return boolean
-     * @throws EE_Error
-     */
-    public function is_abandoned()
-    {
-        return $this->status_ID() === EEM_Transaction::abandoned_status_code;
-    }
-
-
-    /**
-     * Returns whether this transaction failed
-     * meaning that the transaction/registration process was somehow interrupted and never completed
-     * and that NO contact information exists for any registrants
-     *
-     * @return boolean
-     * @throws EE_Error
-     */
-    public function failed()
-    {
-        return $this->status_ID() === EEM_Transaction::failed_status_code;
-    }
-
-
-    /**
-     * This returns the url for the invoice of this transaction
-     *
-     * @param string $type 'html' or 'pdf' (default is pdf)
-     * @return string
-     * @throws EE_Error
-     */
-    public function invoice_url($type = 'html')
-    {
-        $REG = $this->primary_registration();
-        if (! $REG instanceof EE_Registration) {
-            return '';
-        }
-        return $REG->invoice_url($type);
-    }
-
-
-    /**
-     * Gets the primary registration only
-     *
-     * @return EE_Base_Class|EE_Registration
-     * @throws EE_Error
-     */
-    public function primary_registration()
-    {
-        $registrations = (array) $this->get_many_related(
-            'Registration',
-            array(array('REG_count' => EEM_Registration::PRIMARY_REGISTRANT_COUNT))
-        );
-        foreach ($registrations as $registration) {
-            // valid registration that is NOT cancelled or declined ?
-            if ($registration instanceof EE_Registration
-                && ! in_array($registration->status_ID(), EEM_Registration::closed_reg_statuses(), true)
-            ) {
-                return $registration;
-            }
-        }
-        // nothing valid found, so just return first thing from array of results
-        return reset($registrations);
-    }
-
-
-    /**
-     * Gets the URL for viewing the receipt
-     *
-     * @param string $type 'pdf' or 'html' (default is 'html')
-     * @return string
-     * @throws EE_Error
-     */
-    public function receipt_url($type = 'html')
-    {
-        $REG = $this->primary_registration();
-        if (! $REG instanceof EE_Registration) {
-            return '';
-        }
-        return $REG->receipt_url($type);
-    }
-
-
-    /**
-     * Gets the URL of the thank you page with this registration REG_url_link added as
-     * a query parameter
-     *
-     * @return string
-     * @throws EE_Error
-     */
-    public function payment_overview_url()
-    {
-        $primary_registration = $this->primary_registration();
-        return $primary_registration instanceof EE_Registration ? $primary_registration->payment_overview_url() : false;
-    }
-
-
-    /**
-     * @return string
-     * @throws EE_Error
-     */
-    public function gateway_response_on_transaction()
-    {
-        $payment = $this->get_first_related('Payment');
-        return $payment instanceof EE_Payment ? $payment->gateway_response() : '';
-    }
-
-
-    /**
-     * Get the status object of this object
-     *
-     * @return EE_Base_Class|EE_Status
-     * @throws EE_Error
-     */
-    public function status_obj()
-    {
-        return $this->get_first_related('Status');
-    }
-
-
-    /**
-     * Gets all the extra meta info on this payment
-     *
-     * @param array $query_params @see https://github.com/eventespresso/event-espresso-core/tree/master/docs/G--Model-System/model-query-params.md
-     * @return EE_Base_Class[]|EE_Extra_Meta
-     * @throws EE_Error
-     */
-    public function extra_meta($query_params = array())
-    {
-        return $this->get_many_related('Extra_Meta', $query_params);
-    }
-
-
-    /**
-     * Wrapper for _add_relation_to
-     *
-     * @param EE_Registration $registration
-     * @return EE_Base_Class the relation was added to
-     * @throws EE_Error
-     */
-    public function add_registration(EE_Registration $registration)
-    {
-        return $this->_add_relation_to($registration, 'Registration');
-    }
-
-
-    /**
-     * Removes the given registration from being related (even before saving this transaction).
-     * If an ID/index is provided and this transaction isn't saved yet, removes it from list of cached relations
-     *
-     * @param int $registration_or_id
-     * @return EE_Base_Class that was removed from being related
-     * @throws EE_Error
-     */
-    public function remove_registration_with_id($registration_or_id)
-    {
-        return $this->_remove_relation_to($registration_or_id, 'Registration');
-    }
-
-
-    /**
-     * Gets all the line items which are for ACTUAL items
-     *
-     * @return EE_Line_Item[]
-     * @throws EE_Error
-     */
-    public function items_purchased()
-    {
-        return $this->line_items(array(array('LIN_type' => EEM_Line_Item::type_line_item)));
-    }
-
-
-    /**
-     * Wrapper for _add_relation_to
-     *
-     * @param EE_Line_Item $line_item
-     * @return EE_Base_Class the relation was added to
-     * @throws EE_Error
-     */
-    public function add_line_item(EE_Line_Item $line_item)
-    {
-        return $this->_add_relation_to($line_item, 'Line_Item');
-    }
-
-
-    /**
-     * Gets ALL the line items related to this transaction (unstructured)
-     *
-     * @param array $query_params
-     * @return EE_Base_Class[]|EE_Line_Item[]
-     * @throws EE_Error
-     */
-    public function line_items($query_params = array())
-    {
-        return $this->get_many_related('Line_Item', $query_params);
-    }
-
-
-    /**
-     * Gets all the line items which are taxes on the total
-     *
-     * @return EE_Line_Item[]
-     * @throws EE_Error
-     */
-    public function tax_items()
-    {
-        return $this->line_items(array(array('LIN_type' => EEM_Line_Item::type_tax)));
-    }
-
-
-    /**
-     * Gets the total line item (which is a parent of all other related line items,
-     * meaning it takes them all into account on its total)
-     *
-     * @param bool $create_if_not_found
-     * @return \EE_Line_Item
-     * @throws EE_Error
-     */
-    public function total_line_item($create_if_not_found = true)
-    {
-        $item = $this->get_first_related('Line_Item', array(array('LIN_type' => EEM_Line_Item::type_total)));
-        if (! $item && $create_if_not_found) {
-            $item = EEH_Line_Item::create_total_line_item($this);
-        }
-        return $item;
-    }
-
-
-    /**
-     * Returns the total amount of tax on this transaction
-     * (assumes there's only one tax subtotal line item)
-     *
-     * @return float
-     * @throws EE_Error
-     */
-    public function tax_total()
-    {
-        $tax_line_item = $this->tax_total_line_item();
-        if ($tax_line_item) {
-            return (float) $tax_line_item->total();
-        }
-        return (float) 0;
-    }
-
-
-    /**
-     * Gets the tax subtotal line item (assumes there's only one)
-     *
-     * @return EE_Line_Item
-     * @throws EE_Error
-     */
-    public function tax_total_line_item()
-    {
-        return EEH_Line_Item::get_taxes_subtotal($this->total_line_item());
-    }
-
-
-    /**
-     * Gets the array of billing info for the gateway and for this transaction's primary registration's attendee.
-     *
-     * @return EE_Form_Section_Proper
-     * @throws EE_Error
-     */
-    public function billing_info()
-    {
-        $payment_method = $this->payment_method();
-        if (! $payment_method) {
-            EE_Error::add_error(
-                __(
-                    'Could not find billing info for transaction because no gateway has been used for it yet',
-                    'event_espresso'
-                ),
-                __FILE__,
-                __FUNCTION__,
-                __LINE__
-            );
-            return null;
-        }
-        $primary_reg = $this->primary_registration();
-        if (! $primary_reg) {
-            EE_Error::add_error(
-                __(
-                    'Cannot get billing info for gateway %s on transaction because no primary registration exists',
-                    'event_espresso'
-                ),
-                __FILE__,
-                __FUNCTION__,
-                __LINE__
-            );
-            return null;
-        }
-        $attendee = $primary_reg->attendee();
-        if (! $attendee) {
-            EE_Error::add_error(
-                __(
-                    'Cannot get billing info for gateway %s on transaction because the primary registration has no attendee exists',
-                    'event_espresso'
-                ),
-                __FILE__,
-                __FUNCTION__,
-                __LINE__
-            );
-            return null;
-        }
-        return $attendee->billing_info_for_payment_method($payment_method);
-    }
-
-
-    /**
-     * Gets PMD_ID
-     *
-     * @return int
-     * @throws EE_Error
-     */
-    public function payment_method_ID()
-    {
-        return $this->get('PMD_ID');
-    }
-
-
-    /**
-     * Sets PMD_ID
-     *
-     * @param int $PMD_ID
-     * @throws EE_Error
-     */
-    public function set_payment_method_ID($PMD_ID)
-    {
-        $this->set('PMD_ID', $PMD_ID);
-    }
-
-
-    /**
-     * Gets the last-used payment method on this transaction
-     * (we COULD just use the last-made payment, but some payment methods, namely
-     * offline ones, dont' create payments)
-     *
-     * @return EE_Payment_Method
-     * @throws EE_Error
-     */
-    public function payment_method()
-    {
-        $pm = $this->get_first_related('Payment_Method');
-        if ($pm instanceof EE_Payment_Method) {
-            return $pm;
-        }
-        $last_payment = $this->last_payment();
-        if ($last_payment instanceof EE_Payment && $last_payment->payment_method()) {
-            return $last_payment->payment_method();
-        }
-        return null;
-    }
-
-
-    /**
-     * Gets the last payment made
-     *
-     * @return EE_Base_Class|EE_Payment
-     * @throws EE_Error
-     */
-    public function last_payment()
-    {
-        return $this->get_first_related('Payment', array('order_by' => array('PAY_ID' => 'desc')));
-    }
-
-
-    /**
-     * Gets all the line items which are unrelated to tickets on this transaction
-     *
-     * @return EE_Line_Item[]
-     * @throws EE_Error
-     * @throws InvalidArgumentException
-     * @throws InvalidDataTypeException
-     * @throws InvalidInterfaceException
-     */
-    public function non_ticket_line_items()
-    {
-        return EEM_Line_Item::instance()->get_all_non_ticket_line_items_for_transaction($this->ID());
-    }
-
-
-    /**
-     * possibly toggles TXN status
-     *
-     * @param  boolean $update whether to save the TXN
-     * @return bool whether the TXN was saved
-     * @throws EE_Error
-     * @throws RuntimeException
-     */
-    public function update_status_based_on_total_paid($update = true)
-    {
-        // set transaction status based on comparison of TXN_paid vs TXN_total
-        if (EEH_Money::compare_floats($this->paid(), $this->total(), '>')) {
-            $new_txn_status = EEM_Transaction::overpaid_status_code;
-        } elseif (EEH_Money::compare_floats($this->paid(), $this->total())) {
-            $new_txn_status = EEM_Transaction::complete_status_code;
-        } elseif (EEH_Money::compare_floats($this->paid(), $this->total(), '<')) {
-            $new_txn_status = EEM_Transaction::incomplete_status_code;
-        } else {
-            throw new RuntimeException(
-                __('The total paid calculation for this transaction is inaccurate.', 'event_espresso')
-            );
-        }
-        if ($new_txn_status !== $this->status_ID()) {
-            $this->set_status($new_txn_status);
-            if ($update) {
-                return $this->save() ? true : false;
-            }
-        }
-        return false;
-    }
-
-
-    /**
-     * Updates the transaction's status and total_paid based on all the payments
-     * that apply to it
-     *
-     * @deprecated
-     * @return array|bool
-     * @throws EE_Error
-     * @throws InvalidArgumentException
-     * @throws ReflectionException
-     * @throws InvalidDataTypeException
-     * @throws InvalidInterfaceException
-     */
-    public function update_based_on_payments()
-    {
-        EE_Error::doing_it_wrong(
-            __CLASS__ . '::' . __FUNCTION__,
-            sprintf(
-                __('This method is deprecated. Please use "%s" instead', 'event_espresso'),
-                'EE_Transaction_Processor::update_transaction_and_registrations_after_checkout_or_payment()'
-            ),
-            '4.6.0'
-        );
-        /** @type EE_Transaction_Processor $transaction_processor */
-        $transaction_processor = EE_Registry::instance()->load_class('Transaction_Processor');
-        return $transaction_processor->update_transaction_and_registrations_after_checkout_or_payment($this);
-    }
-
-
-    /**
-     * @return string
-     */
-    public function old_txn_status()
-    {
-        return $this->_old_txn_status;
-    }
-
-
-    /**
-     * @param string $old_txn_status
-     */
-    public function set_old_txn_status($old_txn_status)
-    {
-        // only set the first time
-        if ($this->_old_txn_status === null) {
-            $this->_old_txn_status = $old_txn_status;
-        }
-    }
-
-
-    /**
-     * reg_status_updated
-     *
-     * @return bool
-     * @throws EE_Error
-     */
-    public function txn_status_updated()
-    {
-        return $this->status_ID() !== $this->_old_txn_status && $this->_old_txn_status !== null;
-    }
-
-
-    /**
-     * _reg_steps_completed
-     * if $check_all is TRUE, then returns TRUE if ALL reg steps have been marked as completed,
-     * if a $reg_step_slug is provided, then this step will be skipped when testing for completion
-     * if $check_all is FALSE and a $reg_step_slug is provided, then ONLY that reg step will be tested for completion
-     *
-     * @param string $reg_step_slug
-     * @param bool   $check_all
-     * @return bool|int
-     * @throws EE_Error
-     */
-    private function _reg_steps_completed($reg_step_slug = '', $check_all = true)
-    {
-        $reg_steps = $this->reg_steps();
-        if (! is_array($reg_steps) || empty($reg_steps)) {
-            return false;
-        }
-        // loop thru reg steps array)
-        foreach ($reg_steps as $slug => $reg_step_completed) {
-            // if NOT checking ALL steps (only checking one step)
-            if (! $check_all) {
-                // and this is the one
-                if ($slug === $reg_step_slug) {
-                    return $reg_step_completed;
-                }
-                // skip to next reg step in loop
-                continue;
-            }
-            // $check_all must be true, else we would never have gotten to this point
-            if ($slug === $reg_step_slug) {
-                // if we reach this point, then we are testing either:
-                // all_reg_steps_completed_except() or
-                // all_reg_steps_completed_except_final_step(),
-                // and since this is the reg step EXCEPTION being tested
-                // we want to return true (yes true) if this reg step is NOT completed
-                // ie: "is everything completed except the final step?"
-                // "that is correct... the final step is not completed, but all others are."
-                return $reg_step_completed !== true;
-            }
-            if ($reg_step_completed !== true) {
-                // if any reg step is NOT completed, then ALL steps are not completed
-                return false;
-            }
-        }
-        return true;
-    }
-
-
-    /**
-     * all_reg_steps_completed
-     * returns:
-     *    true if ALL reg steps have been marked as completed
-     *        or false if any step is not completed
-     *
-     * @return bool
-     * @throws EE_Error
-     */
-    public function all_reg_steps_completed()
-    {
-        return $this->_reg_steps_completed();
-    }
-
-
-    /**
-     * all_reg_steps_completed_except
-     * returns:
-     *        true if ALL reg steps, except a particular step that you wish to skip over, have been marked as completed
-     *        or false if any other step is not completed
-     *        or false if ALL steps are completed including the exception you are testing !!!
-     *
-     * @param string $exception
-     * @return bool
-     * @throws EE_Error
-     */
-    public function all_reg_steps_completed_except($exception = '')
-    {
-        return $this->_reg_steps_completed($exception);
-    }
-
-
-    /**
-     * all_reg_steps_completed_except
-     * returns:
-     *        true if ALL reg steps, except the final step, have been marked as completed
-     *        or false if any step is not completed
-     *    or false if ALL steps are completed including the final step !!!
-     *
-     * @return bool
-     * @throws EE_Error
-     */
-    public function all_reg_steps_completed_except_final_step()
-    {
-        return $this->_reg_steps_completed('finalize_registration');
-    }
-
-
-    /**
-     * reg_step_completed
-     * returns:
-     *    true if a specific reg step has been marked as completed
-     *    a Unix timestamp if it has been initialized but not yet completed,
-     *    or false if it has not yet been initialized
-     *
-     * @param string $reg_step_slug
-     * @return bool|int
-     * @throws EE_Error
-     */
-    public function reg_step_completed($reg_step_slug)
-    {
-        return $this->_reg_steps_completed($reg_step_slug, false);
-    }
-
-
-    /**
-     * completed_final_reg_step
-     * returns:
-     *    true if the finalize_registration reg step has been marked as completed
-     *    a Unix timestamp if it has been initialized but not yet completed,
-     *    or false if it has not yet been initialized
-     *
-     * @return bool|int
-     * @throws EE_Error
-     */
-    public function final_reg_step_completed()
-    {
-        return $this->_reg_steps_completed('finalize_registration', false);
-    }
-
-
-    /**
-     * set_reg_step_initiated
-     * given a valid TXN_reg_step, this sets it's value to a unix timestamp
-     *
-     * @param string $reg_step_slug
-     * @return boolean
-     * @throws EE_Error
-     */
-    public function set_reg_step_initiated($reg_step_slug)
-    {
-        return $this->_set_reg_step_completed_status($reg_step_slug, time());
-    }
-
-
-    /**
-     * set_reg_step_completed
-     * given a valid TXN_reg_step, this sets the step as completed
-     *
-     * @param string $reg_step_slug
-     * @return boolean
-     * @throws EE_Error
-     */
-    public function set_reg_step_completed($reg_step_slug)
-    {
-        return $this->_set_reg_step_completed_status($reg_step_slug, true);
-    }
-
-
-    /**
-     * set_reg_step_completed
-     * given a valid TXN_reg_step slug, this sets the step as NOT completed
-     *
-     * @param string $reg_step_slug
-     * @return boolean
-     * @throws EE_Error
-     */
-    public function set_reg_step_not_completed($reg_step_slug)
-    {
-        return $this->_set_reg_step_completed_status($reg_step_slug, false);
-    }
-
-
-    /**
-     * set_reg_step_completed
-     * given a valid reg step slug, this sets the TXN_reg_step completed status which is either:
-     *
-     * @param  string      $reg_step_slug
-     * @param  boolean|int $status
-     * @return boolean
-     * @throws EE_Error
-     */
-    private function _set_reg_step_completed_status($reg_step_slug, $status)
-    {
-        // validate status
-        $status = is_bool($status) || is_int($status) ? $status : false;
-        // get reg steps array
-        $txn_reg_steps = $this->reg_steps();
-        // if reg step does NOT exist
-        if (! isset($txn_reg_steps[ $reg_step_slug ])) {
-            return false;
-        }
-        // if  we're trying to complete a step that is already completed
-        if ($txn_reg_steps[ $reg_step_slug ] === true) {
-            return true;
-        }
-        // if  we're trying to complete a step that hasn't even started
-        if ($status === true && $txn_reg_steps[ $reg_step_slug ] === false) {
-            return false;
-        }
-        // if current status value matches the incoming value (no change)
-        // type casting as int means values should collapse to either 0, 1, or a timestamp like 1234567890
-        if ((int) $txn_reg_steps[ $reg_step_slug ] === (int) $status) {
-            // this will happen in cases where multiple AJAX requests occur during the same step
-            return true;
-        }
-        // if we're trying to set a start time, but it has already been set...
-        if (is_numeric($status) && is_numeric($txn_reg_steps[ $reg_step_slug ])) {
-            // skip the update below, but don't return FALSE so that errors won't be displayed
-            return true;
-        }
-        // update completed status
-        $txn_reg_steps[ $reg_step_slug ] = $status;
-        $this->set_reg_steps($txn_reg_steps);
-        $this->save();
-        return true;
-    }
-
-
-    /**
-     * remove_reg_step
-     * given a valid TXN_reg_step slug, this will remove (unset)
-     * the reg step from the TXN reg step array
-     *
-     * @param string $reg_step_slug
-     * @return void
-     * @throws EE_Error
-     */
-    public function remove_reg_step($reg_step_slug)
-    {
-        // get reg steps array
-        $txn_reg_steps = $this->reg_steps();
-        unset($txn_reg_steps[ $reg_step_slug ]);
-        $this->set_reg_steps($txn_reg_steps);
-    }
-
-
-    /**
-     * toggle_failed_transaction_status
-     * upgrades a TXNs status from failed to abandoned,
-     * meaning that contact information has been captured for at least one registrant
-     *
-     * @param bool $save
-     * @return bool
-     * @throws EE_Error
-     */
-    public function toggle_failed_transaction_status($save = true)
-    {
-        // if TXN status is still set as "failed"...
-        if ($this->status_ID() === EEM_Transaction::failed_status_code) {
-            $this->set_status(EEM_Transaction::abandoned_status_code);
-            if ($save) {
-                $this->save();
-            }
-            return true;
-        }
-        return false;
-    }
-
-
-    /**
-     * toggle_abandoned_transaction_status
-     * upgrades a TXNs status from failed or abandoned to incomplete
-     *
-     * @return bool
-     * @throws EE_Error
-     */
-    public function toggle_abandoned_transaction_status()
-    {
-        // if TXN status has not been updated already due to a payment, and is still set as "failed" or "abandoned"...
-        $txn_status = $this->status_ID();
-        if ($txn_status === EEM_Transaction::failed_status_code
-            || $txn_status === EEM_Transaction::abandoned_status_code
-        ) {
-            // if a contact record for the primary registrant has been created
-            if ($this->primary_registration() instanceof EE_Registration
-                && $this->primary_registration()->attendee() instanceof EE_Attendee
-            ) {
-                $this->set_status(EEM_Transaction::incomplete_status_code);
-            } else {
-                // no contact record? yer abandoned!
-                $this->set_status(EEM_Transaction::abandoned_status_code);
-            }
-            return true;
-        }
-        return false;
-    }
-
-
-    /**
-     * checks if an Abandoned TXN has any related payments, and if so,
-     * updates the TXN status based on the amount paid
-     *
-     * @throws EE_Error
-     * @throws InvalidDataTypeException
-     * @throws InvalidInterfaceException
-     * @throws InvalidArgumentException
-     * @throws RuntimeException
-     */
-    public function verify_abandoned_transaction_status()
-    {
-        if ($this->status_ID() !== EEM_Transaction::abandoned_status_code) {
-            return;
-        }
-        $payments = $this->get_many_related('Payment');
-        if (! empty($payments)) {
-            foreach ($payments as $payment) {
-                if ($payment instanceof EE_Payment) {
-                    // kk this TXN should NOT be abandoned
-                    $this->update_status_based_on_total_paid();
-                    if (! (defined('DOING_AJAX') && DOING_AJAX) && is_admin()) {
-                        EE_Error::add_attention(
-                            sprintf(
-                                esc_html__(
-                                    'The status for Transaction #%1$d has been updated from "Abandoned" to "%2$s", because at least one payment has been made towards it. If the payment appears in the "Payment Details" table below, you may need to edit its status and/or other details as well.',
-                                    'event_espresso'
-                                ),
-                                $this->ID(),
-                                $this->pretty_status()
-                            )
-                        );
-                    }
-                    // get final reg step status
-                    $finalized = $this->final_reg_step_completed();
-                    // if the 'finalize_registration' step has been initiated (has a timestamp)
-                    // but has not yet been fully completed (TRUE)
-                    if (is_int($finalized) && $finalized !== false && $finalized !== true) {
-                        $this->set_reg_step_completed('finalize_registration');
-                        $this->save();
-                    }
-                }
-            }
-        }
-    }
+	/**
+	 * The length of time in seconds that a lock is applied before being considered expired.
+	 * It is not long because a transaction should only be locked for the duration of the request that locked it
+	 */
+	const LOCK_EXPIRATION = 2;
+
+	/**
+	 * txn status upon initial construction.
+	 *
+	 * @var string
+	 */
+	protected $_old_txn_status;
+
+
+	/**
+	 * @param array  $props_n_values          incoming values
+	 * @param string $timezone                incoming timezone
+	 *                                        (if not set the timezone set for the website will be used.)
+	 * @param array  $date_formats            incoming date_formats in an array where the first value is the
+	 *                                        date_format and the second value is the time format
+	 * @return EE_Transaction
+	 * @throws EE_Error
+	 */
+	public static function new_instance($props_n_values = array(), $timezone = null, $date_formats = array())
+	{
+		$has_object = parent::_check_for_object($props_n_values, __CLASS__, $timezone, $date_formats);
+		$txn = $has_object
+			? $has_object
+			: new self($props_n_values, false, $timezone, $date_formats);
+		if (! $has_object) {
+			$txn->set_old_txn_status($txn->status_ID());
+		}
+		return $txn;
+	}
+
+
+	/**
+	 * @param array  $props_n_values  incoming values from the database
+	 * @param string $timezone        incoming timezone as set by the model.  If not set the timezone for
+	 *                                the website will be used.
+	 * @return EE_Transaction
+	 * @throws EE_Error
+	 */
+	public static function new_instance_from_db($props_n_values = array(), $timezone = null)
+	{
+		$txn = new self($props_n_values, true, $timezone);
+		$txn->set_old_txn_status($txn->status_ID());
+		return $txn;
+	}
+
+
+	/**
+	 * Sets a meta field indicating that this TXN is locked and should not be updated in the db.
+	 * If a lock has already been set, then we will attempt to remove it in case it has expired.
+	 * If that also fails, then an exception is thrown.
+	 *
+	 * @throws EE_Error
+	 */
+	public function lock()
+	{
+		// attempt to set lock, but if that fails...
+		if (! $this->add_extra_meta('lock', time(), true)) {
+			// then attempt to remove the lock in case it is expired
+			if ($this->_remove_expired_lock()) {
+				// if removal was successful, then try setting lock again
+				$this->lock();
+			} else {
+				// but if the lock can not be removed, then throw an exception
+				throw new EE_Error(
+					sprintf(
+						__(
+							'Could not lock Transaction %1$d because it is already locked, meaning another part of the system is currently editing it. It should already be unlocked by the time you read this, so please refresh the page and try again.',
+							'event_espresso'
+						),
+						$this->ID()
+					)
+				);
+			}
+		}
+	}
+
+
+	/**
+	 * removes transaction lock applied in EE_Transaction::lock()
+	 *
+	 * @return int
+	 * @throws EE_Error
+	 */
+	public function unlock()
+	{
+		return $this->delete_extra_meta('lock');
+	}
+
+
+	/**
+	 * Decides whether or not now is the right time to update the transaction.
+	 * This is useful because we don't always know if it is safe to update the transaction
+	 * and its related data. why?
+	 * because it's possible that the transaction is being used in another
+	 * request and could overwrite anything we save.
+	 * So we want to only update the txn once we know that won't happen.
+	 * We also check that the lock isn't expired, and remove it if it is
+	 *
+	 * @return boolean
+	 * @throws EE_Error
+	 */
+	public function is_locked()
+	{
+		// if TXN is not locked, then return false immediately
+		if (! $this->_get_lock()) {
+			return false;
+		}
+		// if not, then let's try and remove the lock in case it's expired...
+		// _remove_expired_lock() returns 0 when lock is valid (ie: removed = false)
+		// and a positive number if the lock was removed (ie: number of locks deleted),
+		// so we need to return the opposite
+		return ! $this->_remove_expired_lock() ? true : false;
+	}
+
+
+	/**
+	 * Gets the meta field indicating that this TXN is locked
+	 *
+	 * @return int
+	 * @throws EE_Error
+	 */
+	protected function _get_lock()
+	{
+		return (int) $this->get_extra_meta('lock', true, 0);
+	}
+
+
+	/**
+	 * If the lock on this transaction is expired, then we want to remove it so that the transaction can be updated
+	 *
+	 * @return int
+	 * @throws EE_Error
+	 */
+	protected function _remove_expired_lock()
+	{
+		$locked = $this->_get_lock();
+		if ($locked && time() - EE_Transaction::LOCK_EXPIRATION > $locked) {
+			return $this->unlock();
+		}
+		return 0;
+	}
+
+
+	/**
+	 * Set transaction total
+	 *
+	 * @param float $total total value of transaction
+	 * @throws EE_Error
+	 */
+	public function set_total($total = 0.00)
+	{
+		$this->set('TXN_total', (float) $total);
+	}
+
+
+	/**
+	 * Set Total Amount Paid to Date
+	 *
+	 * @param float $total_paid total amount paid to date (sum of all payments)
+	 * @throws EE_Error
+	 */
+	public function set_paid($total_paid = 0.00)
+	{
+		$this->set('TXN_paid', (float) $total_paid);
+	}
+
+
+	/**
+	 * Set transaction status
+	 *
+	 * @param string $status        whether the transaction is open, declined, accepted,
+	 *                              or any number of custom values that can be set
+	 * @throws EE_Error
+	 */
+	public function set_status($status = '')
+	{
+		$this->set('STS_ID', $status);
+	}
+
+
+	/**
+	 * Set hash salt
+	 *
+	 * @param string $hash_salt required for some payment gateways
+	 * @throws EE_Error
+	 */
+	public function set_hash_salt($hash_salt = '')
+	{
+		$this->set('TXN_hash_salt', $hash_salt);
+	}
+
+
+	/**
+	 * Sets TXN_reg_steps array
+	 *
+	 * @param array $txn_reg_steps
+	 * @throws EE_Error
+	 */
+	public function set_reg_steps(array $txn_reg_steps)
+	{
+		$this->set('TXN_reg_steps', $txn_reg_steps);
+	}
+
+
+	/**
+	 * Gets TXN_reg_steps
+	 *
+	 * @return array
+	 * @throws EE_Error
+	 */
+	public function reg_steps()
+	{
+		$TXN_reg_steps = $this->get('TXN_reg_steps');
+		return is_array($TXN_reg_steps) ? (array) $TXN_reg_steps : array();
+	}
+
+
+	/**
+	 * @return string of transaction's total cost, with currency symbol and decimal
+	 * @throws EE_Error
+	 */
+	public function pretty_total()
+	{
+		return $this->get_pretty('TXN_total');
+	}
+
+
+	/**
+	 * Gets the amount paid in a pretty string (formatted and with currency symbol)
+	 *
+	 * @return string
+	 * @throws EE_Error
+	 */
+	public function pretty_paid()
+	{
+		return $this->get_pretty('TXN_paid');
+	}
+
+
+	/**
+	 * calculate the amount remaining for this transaction and return;
+	 *
+	 * @return float amount remaining
+	 * @throws EE_Error
+	 */
+	public function remaining()
+	{
+		return $this->total() - $this->paid();
+	}
+
+
+	/**
+	 * get Transaction Total
+	 *
+	 * @return float
+	 * @throws EE_Error
+	 */
+	public function total()
+	{
+		return (float) $this->get('TXN_total');
+	}
+
+
+	/**
+	 * get Total Amount Paid to Date
+	 *
+	 * @return float
+	 * @throws EE_Error
+	 */
+	public function paid()
+	{
+		return (float) $this->get('TXN_paid');
+	}
+
+
+	/**
+	 * @throws EE_Error
+	 */
+	public function get_cart_session()
+	{
+		$session_data = (array) $this->get('TXN_session_data');
+		return isset($session_data['cart']) && $session_data['cart'] instanceof EE_Cart
+			? $session_data['cart']
+			: null;
+	}
+
+
+	/**
+	 * get Transaction session data
+	 *
+	 * @throws EE_Error
+	 */
+	public function session_data()
+	{
+		$session_data = $this->get('TXN_session_data');
+		if (empty($session_data)) {
+			$session_data = array(
+				'id'            => null,
+				'user_id'       => null,
+				'ip_address'    => null,
+				'user_agent'    => null,
+				'init_access'   => null,
+				'last_access'   => null,
+				'pages_visited' => array(),
+			);
+		}
+		return $session_data;
+	}
+
+
+	/**
+	 * Set session data within the TXN object
+	 *
+	 * @param EE_Session|array $session_data
+	 * @throws EE_Error
+	 */
+	public function set_txn_session_data($session_data)
+	{
+		if ($session_data instanceof EE_Session) {
+			$this->set('TXN_session_data', $session_data->get_session_data(null, true));
+		} else {
+			$this->set('TXN_session_data', $session_data);
+		}
+	}
+
+
+	/**
+	 * get Transaction hash salt
+	 *
+	 * @throws EE_Error
+	 */
+	public function hash_salt_()
+	{
+		return $this->get('TXN_hash_salt');
+	}
+
+
+	/**
+	 * Returns the transaction datetime as either:
+	 *            - unix timestamp format ($format = false, $gmt = true)
+	 *            - formatted date string including the UTC (timezone) offset ($format = true ($gmt
+	 *              has no affect with this option)), this also may include a timezone abbreviation if the
+	 *              set timezone in this class differs from what the timezone is on the blog.
+	 *            - formatted date string including the UTC (timezone) offset (default).
+	 *
+	 * @param boolean $format   - whether to return a unix timestamp (default) or formatted date string
+	 * @param boolean $gmt      - whether to return a unix timestamp with UTC offset applied (default)
+	 *                          or no UTC offset applied
+	 * @return string | int
+	 * @throws EE_Error
+	 */
+	public function datetime($format = false, $gmt = false)
+	{
+		if ($format) {
+			return $this->get_pretty('TXN_timestamp');
+		}
+		if ($gmt) {
+			return $this->get_raw('TXN_timestamp');
+		}
+		return $this->get('TXN_timestamp');
+	}
+
+
+	/**
+	 * Gets registrations on this transaction
+	 *
+	 * @param array   $query_params array of query parameters
+	 * @param boolean $get_cached   TRUE to retrieve cached registrations or FALSE to pull from the db
+	 * @return EE_Base_Class[]|EE_Registration[]
+	 * @throws EE_Error
+	 */
+	public function registrations($query_params = array(), $get_cached = false)
+	{
+		$query_params = (empty($query_params) || ! is_array($query_params))
+			? array(
+				'order_by' => array(
+					'Event.EVT_name'     => 'ASC',
+					'Attendee.ATT_lname' => 'ASC',
+					'Attendee.ATT_fname' => 'ASC',
+				),
+			)
+			: $query_params;
+		$query_params = $get_cached ? array() : $query_params;
+		return $this->get_many_related('Registration', $query_params);
+	}
+
+
+	/**
+	 * Gets all the attendees for this transaction (handy for use with EE_Attendee's get_registrations_for_event
+	 * function for getting attendees and how many registrations they each have for an event)
+	 *
+	 * @return mixed EE_Attendee[] by default, int if $output is set to 'COUNT'
+	 * @throws EE_Error
+	 */
+	public function attendees()
+	{
+		return $this->get_many_related('Attendee', array(array('Registration.Transaction.TXN_ID' => $this->ID())));
+	}
+
+
+	/**
+	 * Gets payments for this transaction. Unlike other such functions, order by 'DESC' by default
+	 *
+	 * @param array $query_params @see https://github.com/eventespresso/event-espresso-core/tree/master/docs/G--Model-System/model-query-params.md
+	 * @return EE_Base_Class[]|EE_Payment[]
+	 * @throws EE_Error
+	 */
+	public function payments($query_params = array())
+	{
+		return $this->get_many_related('Payment', $query_params);
+	}
+
+
+	/**
+	 * gets only approved payments for this transaction
+	 *
+	 * @return EE_Base_Class[]|EE_Payment[]
+	 * @throws EE_Error
+	 * @throws InvalidArgumentException
+	 * @throws ReflectionException
+	 * @throws InvalidDataTypeException
+	 * @throws InvalidInterfaceException
+	 */
+	public function approved_payments()
+	{
+		EE_Registry::instance()->load_model('Payment');
+		return $this->get_many_related(
+			'Payment',
+			array(
+				array('STS_ID' => EEM_Payment::status_id_approved),
+				'order_by' => array('PAY_timestamp' => 'DESC'),
+			)
+		);
+	}
+
+
+	/**
+	 * Gets all payments which have not been approved
+	 *
+	 * @return EE_Base_Class[]|EEI_Payment[]
+	 * @throws EE_Error if a model is misconfigured somehow
+	 */
+	public function pending_payments()
+	{
+		return $this->get_many_related(
+			'Payment',
+			array(
+				array(
+					'STS_ID' => EEM_Payment::status_id_pending,
+				),
+				'order_by' => array(
+					'PAY_timestamp' => 'DESC',
+				),
+			)
+		);
+	}
+
+
+	/**
+	 * echoes $this->pretty_status()
+	 *
+	 * @param bool $show_icons
+	 * @throws EE_Error
+	 * @throws InvalidArgumentException
+	 * @throws InvalidDataTypeException
+	 * @throws InvalidInterfaceException
+	 */
+	public function e_pretty_status($show_icons = false)
+	{
+		echo $this->pretty_status($show_icons);
+	}
+
+
+	/**
+	 * returns a pretty version of the status, good for displaying to users
+	 *
+	 * @param bool $show_icons
+	 * @return string
+	 * @throws EE_Error
+	 * @throws InvalidArgumentException
+	 * @throws InvalidDataTypeException
+	 * @throws InvalidInterfaceException
+	 */
+	public function pretty_status($show_icons = false)
+	{
+		$status = EEM_Status::instance()->localized_status(
+			array($this->status_ID() => __('unknown', 'event_espresso')),
+			false,
+			'sentence'
+		);
+		$icon = '';
+		switch ($this->status_ID()) {
+			case EEM_Transaction::complete_status_code:
+				$icon = $show_icons ? '<span class="dashicons dashicons-yes ee-icon-size-24 green-text"></span>' : '';
+				break;
+			case EEM_Transaction::incomplete_status_code:
+				$icon = $show_icons ? '<span class="dashicons dashicons-marker ee-icon-size-16 lt-blue-text"></span>'
+					: '';
+				break;
+			case EEM_Transaction::abandoned_status_code:
+				$icon = $show_icons ? '<span class="dashicons dashicons-marker ee-icon-size-16 red-text"></span>' : '';
+				break;
+			case EEM_Transaction::failed_status_code:
+				$icon = $show_icons ? '<span class="dashicons dashicons-no ee-icon-size-16 red-text"></span>' : '';
+				break;
+			case EEM_Transaction::overpaid_status_code:
+				$icon = $show_icons ? '<span class="dashicons dashicons-plus ee-icon-size-16 orange-text"></span>' : '';
+				break;
+		}
+		return $icon . $status[ $this->status_ID() ];
+	}
+
+
+	/**
+	 * get Transaction Status
+	 *
+	 * @throws EE_Error
+	 */
+	public function status_ID()
+	{
+		return $this->get('STS_ID');
+	}
+
+
+	/**
+	 * Returns TRUE or FALSE for whether or not this transaction cost any money
+	 *
+	 * @return boolean
+	 * @throws EE_Error
+	 */
+	public function is_free()
+	{
+		return EEH_Money::compare_floats($this->get('TXN_total'), 0, '==');
+	}
+
+
+	/**
+	 * Returns whether this transaction is complete
+	 * Useful in templates and other logic for deciding if we should ask for another payment...
+	 *
+	 * @return boolean
+	 * @throws EE_Error
+	 */
+	public function is_completed()
+	{
+		return $this->status_ID() === EEM_Transaction::complete_status_code;
+	}
+
+
+	/**
+	 * Returns whether this transaction is incomplete
+	 * Useful in templates and other logic for deciding if we should ask for another payment...
+	 *
+	 * @return boolean
+	 * @throws EE_Error
+	 */
+	public function is_incomplete()
+	{
+		return $this->status_ID() === EEM_Transaction::incomplete_status_code;
+	}
+
+
+	/**
+	 * Returns whether this transaction is overpaid
+	 * Useful in templates and other logic for deciding if monies need to be refunded
+	 *
+	 * @return boolean
+	 * @throws EE_Error
+	 */
+	public function is_overpaid()
+	{
+		return $this->status_ID() === EEM_Transaction::overpaid_status_code;
+	}
+
+
+	/**
+	 * Returns whether this transaction was abandoned
+	 * meaning that the transaction/registration process was somehow interrupted and never completed
+	 * but that contact information exists for at least one registrant
+	 *
+	 * @return boolean
+	 * @throws EE_Error
+	 */
+	public function is_abandoned()
+	{
+		return $this->status_ID() === EEM_Transaction::abandoned_status_code;
+	}
+
+
+	/**
+	 * Returns whether this transaction failed
+	 * meaning that the transaction/registration process was somehow interrupted and never completed
+	 * and that NO contact information exists for any registrants
+	 *
+	 * @return boolean
+	 * @throws EE_Error
+	 */
+	public function failed()
+	{
+		return $this->status_ID() === EEM_Transaction::failed_status_code;
+	}
+
+
+	/**
+	 * This returns the url for the invoice of this transaction
+	 *
+	 * @param string $type 'html' or 'pdf' (default is pdf)
+	 * @return string
+	 * @throws EE_Error
+	 */
+	public function invoice_url($type = 'html')
+	{
+		$REG = $this->primary_registration();
+		if (! $REG instanceof EE_Registration) {
+			return '';
+		}
+		return $REG->invoice_url($type);
+	}
+
+
+	/**
+	 * Gets the primary registration only
+	 *
+	 * @return EE_Base_Class|EE_Registration
+	 * @throws EE_Error
+	 */
+	public function primary_registration()
+	{
+		$registrations = (array) $this->get_many_related(
+			'Registration',
+			array(array('REG_count' => EEM_Registration::PRIMARY_REGISTRANT_COUNT))
+		);
+		foreach ($registrations as $registration) {
+			// valid registration that is NOT cancelled or declined ?
+			if ($registration instanceof EE_Registration
+				&& ! in_array($registration->status_ID(), EEM_Registration::closed_reg_statuses(), true)
+			) {
+				return $registration;
+			}
+		}
+		// nothing valid found, so just return first thing from array of results
+		return reset($registrations);
+	}
+
+
+	/**
+	 * Gets the URL for viewing the receipt
+	 *
+	 * @param string $type 'pdf' or 'html' (default is 'html')
+	 * @return string
+	 * @throws EE_Error
+	 */
+	public function receipt_url($type = 'html')
+	{
+		$REG = $this->primary_registration();
+		if (! $REG instanceof EE_Registration) {
+			return '';
+		}
+		return $REG->receipt_url($type);
+	}
+
+
+	/**
+	 * Gets the URL of the thank you page with this registration REG_url_link added as
+	 * a query parameter
+	 *
+	 * @return string
+	 * @throws EE_Error
+	 */
+	public function payment_overview_url()
+	{
+		$primary_registration = $this->primary_registration();
+		return $primary_registration instanceof EE_Registration ? $primary_registration->payment_overview_url() : false;
+	}
+
+
+	/**
+	 * @return string
+	 * @throws EE_Error
+	 */
+	public function gateway_response_on_transaction()
+	{
+		$payment = $this->get_first_related('Payment');
+		return $payment instanceof EE_Payment ? $payment->gateway_response() : '';
+	}
+
+
+	/**
+	 * Get the status object of this object
+	 *
+	 * @return EE_Base_Class|EE_Status
+	 * @throws EE_Error
+	 */
+	public function status_obj()
+	{
+		return $this->get_first_related('Status');
+	}
+
+
+	/**
+	 * Gets all the extra meta info on this payment
+	 *
+	 * @param array $query_params @see https://github.com/eventespresso/event-espresso-core/tree/master/docs/G--Model-System/model-query-params.md
+	 * @return EE_Base_Class[]|EE_Extra_Meta
+	 * @throws EE_Error
+	 */
+	public function extra_meta($query_params = array())
+	{
+		return $this->get_many_related('Extra_Meta', $query_params);
+	}
+
+
+	/**
+	 * Wrapper for _add_relation_to
+	 *
+	 * @param EE_Registration $registration
+	 * @return EE_Base_Class the relation was added to
+	 * @throws EE_Error
+	 */
+	public function add_registration(EE_Registration $registration)
+	{
+		return $this->_add_relation_to($registration, 'Registration');
+	}
+
+
+	/**
+	 * Removes the given registration from being related (even before saving this transaction).
+	 * If an ID/index is provided and this transaction isn't saved yet, removes it from list of cached relations
+	 *
+	 * @param int $registration_or_id
+	 * @return EE_Base_Class that was removed from being related
+	 * @throws EE_Error
+	 */
+	public function remove_registration_with_id($registration_or_id)
+	{
+		return $this->_remove_relation_to($registration_or_id, 'Registration');
+	}
+
+
+	/**
+	 * Gets all the line items which are for ACTUAL items
+	 *
+	 * @return EE_Line_Item[]
+	 * @throws EE_Error
+	 */
+	public function items_purchased()
+	{
+		return $this->line_items(array(array('LIN_type' => EEM_Line_Item::type_line_item)));
+	}
+
+
+	/**
+	 * Wrapper for _add_relation_to
+	 *
+	 * @param EE_Line_Item $line_item
+	 * @return EE_Base_Class the relation was added to
+	 * @throws EE_Error
+	 */
+	public function add_line_item(EE_Line_Item $line_item)
+	{
+		return $this->_add_relation_to($line_item, 'Line_Item');
+	}
+
+
+	/**
+	 * Gets ALL the line items related to this transaction (unstructured)
+	 *
+	 * @param array $query_params
+	 * @return EE_Base_Class[]|EE_Line_Item[]
+	 * @throws EE_Error
+	 */
+	public function line_items($query_params = array())
+	{
+		return $this->get_many_related('Line_Item', $query_params);
+	}
+
+
+	/**
+	 * Gets all the line items which are taxes on the total
+	 *
+	 * @return EE_Line_Item[]
+	 * @throws EE_Error
+	 */
+	public function tax_items()
+	{
+		return $this->line_items(array(array('LIN_type' => EEM_Line_Item::type_tax)));
+	}
+
+
+	/**
+	 * Gets the total line item (which is a parent of all other related line items,
+	 * meaning it takes them all into account on its total)
+	 *
+	 * @param bool $create_if_not_found
+	 * @return \EE_Line_Item
+	 * @throws EE_Error
+	 */
+	public function total_line_item($create_if_not_found = true)
+	{
+		$item = $this->get_first_related('Line_Item', array(array('LIN_type' => EEM_Line_Item::type_total)));
+		if (! $item && $create_if_not_found) {
+			$item = EEH_Line_Item::create_total_line_item($this);
+		}
+		return $item;
+	}
+
+
+	/**
+	 * Returns the total amount of tax on this transaction
+	 * (assumes there's only one tax subtotal line item)
+	 *
+	 * @return float
+	 * @throws EE_Error
+	 */
+	public function tax_total()
+	{
+		$tax_line_item = $this->tax_total_line_item();
+		if ($tax_line_item) {
+			return (float) $tax_line_item->total();
+		}
+		return (float) 0;
+	}
+
+
+	/**
+	 * Gets the tax subtotal line item (assumes there's only one)
+	 *
+	 * @return EE_Line_Item
+	 * @throws EE_Error
+	 */
+	public function tax_total_line_item()
+	{
+		return EEH_Line_Item::get_taxes_subtotal($this->total_line_item());
+	}
+
+
+	/**
+	 * Gets the array of billing info for the gateway and for this transaction's primary registration's attendee.
+	 *
+	 * @return EE_Form_Section_Proper
+	 * @throws EE_Error
+	 */
+	public function billing_info()
+	{
+		$payment_method = $this->payment_method();
+		if (! $payment_method) {
+			EE_Error::add_error(
+				__(
+					'Could not find billing info for transaction because no gateway has been used for it yet',
+					'event_espresso'
+				),
+				__FILE__,
+				__FUNCTION__,
+				__LINE__
+			);
+			return null;
+		}
+		$primary_reg = $this->primary_registration();
+		if (! $primary_reg) {
+			EE_Error::add_error(
+				__(
+					'Cannot get billing info for gateway %s on transaction because no primary registration exists',
+					'event_espresso'
+				),
+				__FILE__,
+				__FUNCTION__,
+				__LINE__
+			);
+			return null;
+		}
+		$attendee = $primary_reg->attendee();
+		if (! $attendee) {
+			EE_Error::add_error(
+				__(
+					'Cannot get billing info for gateway %s on transaction because the primary registration has no attendee exists',
+					'event_espresso'
+				),
+				__FILE__,
+				__FUNCTION__,
+				__LINE__
+			);
+			return null;
+		}
+		return $attendee->billing_info_for_payment_method($payment_method);
+	}
+
+
+	/**
+	 * Gets PMD_ID
+	 *
+	 * @return int
+	 * @throws EE_Error
+	 */
+	public function payment_method_ID()
+	{
+		return $this->get('PMD_ID');
+	}
+
+
+	/**
+	 * Sets PMD_ID
+	 *
+	 * @param int $PMD_ID
+	 * @throws EE_Error
+	 */
+	public function set_payment_method_ID($PMD_ID)
+	{
+		$this->set('PMD_ID', $PMD_ID);
+	}
+
+
+	/**
+	 * Gets the last-used payment method on this transaction
+	 * (we COULD just use the last-made payment, but some payment methods, namely
+	 * offline ones, dont' create payments)
+	 *
+	 * @return EE_Payment_Method
+	 * @throws EE_Error
+	 */
+	public function payment_method()
+	{
+		$pm = $this->get_first_related('Payment_Method');
+		if ($pm instanceof EE_Payment_Method) {
+			return $pm;
+		}
+		$last_payment = $this->last_payment();
+		if ($last_payment instanceof EE_Payment && $last_payment->payment_method()) {
+			return $last_payment->payment_method();
+		}
+		return null;
+	}
+
+
+	/**
+	 * Gets the last payment made
+	 *
+	 * @return EE_Base_Class|EE_Payment
+	 * @throws EE_Error
+	 */
+	public function last_payment()
+	{
+		return $this->get_first_related('Payment', array('order_by' => array('PAY_ID' => 'desc')));
+	}
+
+
+	/**
+	 * Gets all the line items which are unrelated to tickets on this transaction
+	 *
+	 * @return EE_Line_Item[]
+	 * @throws EE_Error
+	 * @throws InvalidArgumentException
+	 * @throws InvalidDataTypeException
+	 * @throws InvalidInterfaceException
+	 */
+	public function non_ticket_line_items()
+	{
+		return EEM_Line_Item::instance()->get_all_non_ticket_line_items_for_transaction($this->ID());
+	}
+
+
+	/**
+	 * possibly toggles TXN status
+	 *
+	 * @param  boolean $update whether to save the TXN
+	 * @return bool whether the TXN was saved
+	 * @throws EE_Error
+	 * @throws RuntimeException
+	 */
+	public function update_status_based_on_total_paid($update = true)
+	{
+		// set transaction status based on comparison of TXN_paid vs TXN_total
+		if (EEH_Money::compare_floats($this->paid(), $this->total(), '>')) {
+			$new_txn_status = EEM_Transaction::overpaid_status_code;
+		} elseif (EEH_Money::compare_floats($this->paid(), $this->total())) {
+			$new_txn_status = EEM_Transaction::complete_status_code;
+		} elseif (EEH_Money::compare_floats($this->paid(), $this->total(), '<')) {
+			$new_txn_status = EEM_Transaction::incomplete_status_code;
+		} else {
+			throw new RuntimeException(
+				__('The total paid calculation for this transaction is inaccurate.', 'event_espresso')
+			);
+		}
+		if ($new_txn_status !== $this->status_ID()) {
+			$this->set_status($new_txn_status);
+			if ($update) {
+				return $this->save() ? true : false;
+			}
+		}
+		return false;
+	}
+
+
+	/**
+	 * Updates the transaction's status and total_paid based on all the payments
+	 * that apply to it
+	 *
+	 * @deprecated
+	 * @return array|bool
+	 * @throws EE_Error
+	 * @throws InvalidArgumentException
+	 * @throws ReflectionException
+	 * @throws InvalidDataTypeException
+	 * @throws InvalidInterfaceException
+	 */
+	public function update_based_on_payments()
+	{
+		EE_Error::doing_it_wrong(
+			__CLASS__ . '::' . __FUNCTION__,
+			sprintf(
+				__('This method is deprecated. Please use "%s" instead', 'event_espresso'),
+				'EE_Transaction_Processor::update_transaction_and_registrations_after_checkout_or_payment()'
+			),
+			'4.6.0'
+		);
+		/** @type EE_Transaction_Processor $transaction_processor */
+		$transaction_processor = EE_Registry::instance()->load_class('Transaction_Processor');
+		return $transaction_processor->update_transaction_and_registrations_after_checkout_or_payment($this);
+	}
+
+
+	/**
+	 * @return string
+	 */
+	public function old_txn_status()
+	{
+		return $this->_old_txn_status;
+	}
+
+
+	/**
+	 * @param string $old_txn_status
+	 */
+	public function set_old_txn_status($old_txn_status)
+	{
+		// only set the first time
+		if ($this->_old_txn_status === null) {
+			$this->_old_txn_status = $old_txn_status;
+		}
+	}
+
+
+	/**
+	 * reg_status_updated
+	 *
+	 * @return bool
+	 * @throws EE_Error
+	 */
+	public function txn_status_updated()
+	{
+		return $this->status_ID() !== $this->_old_txn_status && $this->_old_txn_status !== null;
+	}
+
+
+	/**
+	 * _reg_steps_completed
+	 * if $check_all is TRUE, then returns TRUE if ALL reg steps have been marked as completed,
+	 * if a $reg_step_slug is provided, then this step will be skipped when testing for completion
+	 * if $check_all is FALSE and a $reg_step_slug is provided, then ONLY that reg step will be tested for completion
+	 *
+	 * @param string $reg_step_slug
+	 * @param bool   $check_all
+	 * @return bool|int
+	 * @throws EE_Error
+	 */
+	private function _reg_steps_completed($reg_step_slug = '', $check_all = true)
+	{
+		$reg_steps = $this->reg_steps();
+		if (! is_array($reg_steps) || empty($reg_steps)) {
+			return false;
+		}
+		// loop thru reg steps array)
+		foreach ($reg_steps as $slug => $reg_step_completed) {
+			// if NOT checking ALL steps (only checking one step)
+			if (! $check_all) {
+				// and this is the one
+				if ($slug === $reg_step_slug) {
+					return $reg_step_completed;
+				}
+				// skip to next reg step in loop
+				continue;
+			}
+			// $check_all must be true, else we would never have gotten to this point
+			if ($slug === $reg_step_slug) {
+				// if we reach this point, then we are testing either:
+				// all_reg_steps_completed_except() or
+				// all_reg_steps_completed_except_final_step(),
+				// and since this is the reg step EXCEPTION being tested
+				// we want to return true (yes true) if this reg step is NOT completed
+				// ie: "is everything completed except the final step?"
+				// "that is correct... the final step is not completed, but all others are."
+				return $reg_step_completed !== true;
+			}
+			if ($reg_step_completed !== true) {
+				// if any reg step is NOT completed, then ALL steps are not completed
+				return false;
+			}
+		}
+		return true;
+	}
+
+
+	/**
+	 * all_reg_steps_completed
+	 * returns:
+	 *    true if ALL reg steps have been marked as completed
+	 *        or false if any step is not completed
+	 *
+	 * @return bool
+	 * @throws EE_Error
+	 */
+	public function all_reg_steps_completed()
+	{
+		return $this->_reg_steps_completed();
+	}
+
+
+	/**
+	 * all_reg_steps_completed_except
+	 * returns:
+	 *        true if ALL reg steps, except a particular step that you wish to skip over, have been marked as completed
+	 *        or false if any other step is not completed
+	 *        or false if ALL steps are completed including the exception you are testing !!!
+	 *
+	 * @param string $exception
+	 * @return bool
+	 * @throws EE_Error
+	 */
+	public function all_reg_steps_completed_except($exception = '')
+	{
+		return $this->_reg_steps_completed($exception);
+	}
+
+
+	/**
+	 * all_reg_steps_completed_except
+	 * returns:
+	 *        true if ALL reg steps, except the final step, have been marked as completed
+	 *        or false if any step is not completed
+	 *    or false if ALL steps are completed including the final step !!!
+	 *
+	 * @return bool
+	 * @throws EE_Error
+	 */
+	public function all_reg_steps_completed_except_final_step()
+	{
+		return $this->_reg_steps_completed('finalize_registration');
+	}
+
+
+	/**
+	 * reg_step_completed
+	 * returns:
+	 *    true if a specific reg step has been marked as completed
+	 *    a Unix timestamp if it has been initialized but not yet completed,
+	 *    or false if it has not yet been initialized
+	 *
+	 * @param string $reg_step_slug
+	 * @return bool|int
+	 * @throws EE_Error
+	 */
+	public function reg_step_completed($reg_step_slug)
+	{
+		return $this->_reg_steps_completed($reg_step_slug, false);
+	}
+
+
+	/**
+	 * completed_final_reg_step
+	 * returns:
+	 *    true if the finalize_registration reg step has been marked as completed
+	 *    a Unix timestamp if it has been initialized but not yet completed,
+	 *    or false if it has not yet been initialized
+	 *
+	 * @return bool|int
+	 * @throws EE_Error
+	 */
+	public function final_reg_step_completed()
+	{
+		return $this->_reg_steps_completed('finalize_registration', false);
+	}
+
+
+	/**
+	 * set_reg_step_initiated
+	 * given a valid TXN_reg_step, this sets it's value to a unix timestamp
+	 *
+	 * @param string $reg_step_slug
+	 * @return boolean
+	 * @throws EE_Error
+	 */
+	public function set_reg_step_initiated($reg_step_slug)
+	{
+		return $this->_set_reg_step_completed_status($reg_step_slug, time());
+	}
+
+
+	/**
+	 * set_reg_step_completed
+	 * given a valid TXN_reg_step, this sets the step as completed
+	 *
+	 * @param string $reg_step_slug
+	 * @return boolean
+	 * @throws EE_Error
+	 */
+	public function set_reg_step_completed($reg_step_slug)
+	{
+		return $this->_set_reg_step_completed_status($reg_step_slug, true);
+	}
+
+
+	/**
+	 * set_reg_step_completed
+	 * given a valid TXN_reg_step slug, this sets the step as NOT completed
+	 *
+	 * @param string $reg_step_slug
+	 * @return boolean
+	 * @throws EE_Error
+	 */
+	public function set_reg_step_not_completed($reg_step_slug)
+	{
+		return $this->_set_reg_step_completed_status($reg_step_slug, false);
+	}
+
+
+	/**
+	 * set_reg_step_completed
+	 * given a valid reg step slug, this sets the TXN_reg_step completed status which is either:
+	 *
+	 * @param  string      $reg_step_slug
+	 * @param  boolean|int $status
+	 * @return boolean
+	 * @throws EE_Error
+	 */
+	private function _set_reg_step_completed_status($reg_step_slug, $status)
+	{
+		// validate status
+		$status = is_bool($status) || is_int($status) ? $status : false;
+		// get reg steps array
+		$txn_reg_steps = $this->reg_steps();
+		// if reg step does NOT exist
+		if (! isset($txn_reg_steps[ $reg_step_slug ])) {
+			return false;
+		}
+		// if  we're trying to complete a step that is already completed
+		if ($txn_reg_steps[ $reg_step_slug ] === true) {
+			return true;
+		}
+		// if  we're trying to complete a step that hasn't even started
+		if ($status === true && $txn_reg_steps[ $reg_step_slug ] === false) {
+			return false;
+		}
+		// if current status value matches the incoming value (no change)
+		// type casting as int means values should collapse to either 0, 1, or a timestamp like 1234567890
+		if ((int) $txn_reg_steps[ $reg_step_slug ] === (int) $status) {
+			// this will happen in cases where multiple AJAX requests occur during the same step
+			return true;
+		}
+		// if we're trying to set a start time, but it has already been set...
+		if (is_numeric($status) && is_numeric($txn_reg_steps[ $reg_step_slug ])) {
+			// skip the update below, but don't return FALSE so that errors won't be displayed
+			return true;
+		}
+		// update completed status
+		$txn_reg_steps[ $reg_step_slug ] = $status;
+		$this->set_reg_steps($txn_reg_steps);
+		$this->save();
+		return true;
+	}
+
+
+	/**
+	 * remove_reg_step
+	 * given a valid TXN_reg_step slug, this will remove (unset)
+	 * the reg step from the TXN reg step array
+	 *
+	 * @param string $reg_step_slug
+	 * @return void
+	 * @throws EE_Error
+	 */
+	public function remove_reg_step($reg_step_slug)
+	{
+		// get reg steps array
+		$txn_reg_steps = $this->reg_steps();
+		unset($txn_reg_steps[ $reg_step_slug ]);
+		$this->set_reg_steps($txn_reg_steps);
+	}
+
+
+	/**
+	 * toggle_failed_transaction_status
+	 * upgrades a TXNs status from failed to abandoned,
+	 * meaning that contact information has been captured for at least one registrant
+	 *
+	 * @param bool $save
+	 * @return bool
+	 * @throws EE_Error
+	 */
+	public function toggle_failed_transaction_status($save = true)
+	{
+		// if TXN status is still set as "failed"...
+		if ($this->status_ID() === EEM_Transaction::failed_status_code) {
+			$this->set_status(EEM_Transaction::abandoned_status_code);
+			if ($save) {
+				$this->save();
+			}
+			return true;
+		}
+		return false;
+	}
+
+
+	/**
+	 * toggle_abandoned_transaction_status
+	 * upgrades a TXNs status from failed or abandoned to incomplete
+	 *
+	 * @return bool
+	 * @throws EE_Error
+	 */
+	public function toggle_abandoned_transaction_status()
+	{
+		// if TXN status has not been updated already due to a payment, and is still set as "failed" or "abandoned"...
+		$txn_status = $this->status_ID();
+		if ($txn_status === EEM_Transaction::failed_status_code
+			|| $txn_status === EEM_Transaction::abandoned_status_code
+		) {
+			// if a contact record for the primary registrant has been created
+			if ($this->primary_registration() instanceof EE_Registration
+				&& $this->primary_registration()->attendee() instanceof EE_Attendee
+			) {
+				$this->set_status(EEM_Transaction::incomplete_status_code);
+			} else {
+				// no contact record? yer abandoned!
+				$this->set_status(EEM_Transaction::abandoned_status_code);
+			}
+			return true;
+		}
+		return false;
+	}
+
+
+	/**
+	 * checks if an Abandoned TXN has any related payments, and if so,
+	 * updates the TXN status based on the amount paid
+	 *
+	 * @throws EE_Error
+	 * @throws InvalidDataTypeException
+	 * @throws InvalidInterfaceException
+	 * @throws InvalidArgumentException
+	 * @throws RuntimeException
+	 */
+	public function verify_abandoned_transaction_status()
+	{
+		if ($this->status_ID() !== EEM_Transaction::abandoned_status_code) {
+			return;
+		}
+		$payments = $this->get_many_related('Payment');
+		if (! empty($payments)) {
+			foreach ($payments as $payment) {
+				if ($payment instanceof EE_Payment) {
+					// kk this TXN should NOT be abandoned
+					$this->update_status_based_on_total_paid();
+					if (! (defined('DOING_AJAX') && DOING_AJAX) && is_admin()) {
+						EE_Error::add_attention(
+							sprintf(
+								esc_html__(
+									'The status for Transaction #%1$d has been updated from "Abandoned" to "%2$s", because at least one payment has been made towards it. If the payment appears in the "Payment Details" table below, you may need to edit its status and/or other details as well.',
+									'event_espresso'
+								),
+								$this->ID(),
+								$this->pretty_status()
+							)
+						);
+					}
+					// get final reg step status
+					$finalized = $this->final_reg_step_completed();
+					// if the 'finalize_registration' step has been initiated (has a timestamp)
+					// but has not yet been fully completed (TRUE)
+					if (is_int($finalized) && $finalized !== false && $finalized !== true) {
+						$this->set_reg_step_completed('finalize_registration');
+						$this->save();
+					}
+				}
+			}
+		}
+	}
 }

core/db_classes/EE_Venue.class.php

Indentation +560 added lines, -560 removed lines

@@ -10,564 +10,564 @@
 class EE_Venue extends EE_CPT_Base implements EEI_Address
 {
 
-    /**
-     *
-     * @param array  $props_n_values          incoming values
-     * @param string $timezone                incoming timezone (if not set the timezone set for the website will be
-     *                                        used.)
-     * @param array  $date_formats            incoming date_formats in an array where the first value is the
-     *                                        date_format and the second value is the time format
-     * @return EE_Attendee
-     */
-    public static function new_instance($props_n_values = array(), $timezone = null, $date_formats = array())
-    {
-        $has_object = parent::_check_for_object($props_n_values, __CLASS__, $timezone, $date_formats);
-        return $has_object ? $has_object : new self($props_n_values, false, $timezone, $date_formats);
-    }
-
-
-    /**
-     * @param array  $props_n_values  incoming values from the database
-     * @param string $timezone        incoming timezone as set by the model.  If not set the timezone for
-     *                                the website will be used.
-     * @return EE_Attendee
-     */
-    public static function new_instance_from_db($props_n_values = array(), $timezone = null)
-    {
-        return new self($props_n_values, true, $timezone);
-    }
-
-
-    /**
-     * Gets name
-     *
-     * @return string
-     */
-    public function name()
-    {
-        return $this->get('VNU_name');
-    }
-
-
-    /**
-     * Gets phone
-     *
-     * @return string
-     */
-    public function phone()
-    {
-        return $this->get('VNU_phone');
-    }
-
-
-    /**
-     * venue_url
-     *
-     * @return string
-     */
-    public function venue_url()
-    {
-        return $this->get('VNU_url');
-    }
-
-
-    /**
-     * Gets desc
-     *
-     * @return string
-     */
-    public function description()
-    {
-        return $this->get('VNU_desc');
-    }
-
-
-    /**
-     * Gets short description (AKA: the excerpt)
-     *
-     * @return string
-     */
-    public function excerpt()
-    {
-        return $this->get('VNU_short_desc');
-    }
-
-
-    /**
-     * Gets identifier
-     *
-     * @return string
-     */
-    public function identifier()
-    {
-        return $this->get('VNU_identifier');
-    }
-
-
-    /**
-     * Gets address
-     *
-     * @return string
-     */
-    public function address()
-    {
-        return $this->get('VNU_address');
-    }
-
-
-    /**
-     * Gets address2
-     *
-     * @return string
-     */
-    public function address2()
-    {
-        return $this->get('VNU_address2');
-    }
-
-
-    /**
-     * Gets city
-     *
-     * @return string
-     */
-    public function city()
-    {
-        return $this->get('VNU_city');
-    }
-
-    /**
-     * Gets state
-     *
-     * @return int
-     */
-    public function state_ID()
-    {
-        return $this->get('STA_ID');
-    }
-
-
-    /**
-     * @return string
-     */
-    public function state_abbrev()
-    {
-        return $this->state_obj() instanceof EE_State ? $this->state_obj()->abbrev() : '';
-    }
-
-
-    /**
-     * @return string
-     */
-    public function state_name()
-    {
-        return $this->state_obj() instanceof EE_State ? $this->state_obj()->name() : '';
-    }
-
-
-    /**
-     * Gets the state for this venue
-     *
-     * @return EE_State
-     */
-    public function state_obj()
-    {
-        return $this->get_first_related('State');
-    }
-
-
-    /**
-     * either displays the state abbreviation or the state name, as determined
-     * by the "FHEE__EEI_Address__state__use_abbreviation" filter.
-     * defaults to abbreviation
-     *
-     * @return string
-     */
-    public function state()
-    {
-        if (apply_filters('FHEE__EEI_Address__state__use_abbreviation', true, $this->state_obj())) {
-            return $this->state_abbrev();
-        } else {
-            return $this->state_name();
-        }
-    }
-
-
-    /**
-     * country_ID
-     *
-     * @return string
-     */
-    public function country_ID()
-    {
-        return $this->get('CNT_ISO');
-    }
-
-
-    /**
-     * @return string
-     */
-    public function country_name()
-    {
-        return $this->country_obj() instanceof EE_Country ? $this->country_obj()->name() : '';
-    }
-
-
-    /**
-     * Gets the country of this venue
-     *
-     * @return EE_Country
-     */
-    public function country_obj()
-    {
-        return $this->get_first_related('Country');
-    }
-
-
-    /**
-     * either displays the country ISO2 code or the country name, as determined
-     * by the "FHEE__EEI_Address__country__use_abbreviation" filter.
-     * defaults to abbreviation
-     *
-     * @return string
-     */
-    public function country()
-    {
-        if (apply_filters('FHEE__EEI_Address__country__use_abbreviation', true, $this->country_obj())) {
-            return $this->country_ID();
-        } else {
-            return $this->country_name();
-        }
-    }
-
-
-    /**
-     * Gets zip
-     *
-     * @return string
-     */
-    public function zip()
-    {
-        return $this->get('VNU_zip');
-    }
-
-
-    /**
-     * Gets capacity
-     *
-     * @return int
-     */
-    public function capacity()
-    {
-        return $this->get_pretty('VNU_capacity', 'symbol');
-    }
-
-
-    /**
-     * Gets created
-     *
-     * @return string
-     */
-    public function created()
-    {
-        return $this->get('VNU_created');
-    }
-
-
-    /**
-     * Gets modified
-     *
-     * @return string
-     */
-    public function modified()
-    {
-        return $this->get('VNU_modified');
-    }
-
-
-    /**
-     * Gets order
-     *
-     * @return int
-     */
-    public function order()
-    {
-        return $this->get('VNU_order');
-    }
-
-
-    /**
-     * Gets wp_user
-     *
-     * @return int
-     */
-    public function wp_user()
-    {
-        return $this->get('VNU_wp_user');
-    }
-
-
-    /**
-     * @return string
-     */
-    public function virtual_phone()
-    {
-        return $this->get('VNU_virtual_phone');
-    }
-
-
-    /**
-     * @return string
-     */
-    public function virtual_url()
-    {
-        return $this->get('VNU_virtual_url');
-    }
-
-
-    /**
-     * @return bool
-     */
-    public function enable_for_gmap()
-    {
-        return $this->get('VNU_enable_for_gmap');
-    }
-
-
-    /**
-     * @return string
-     */
-    public function google_map_link()
-    {
-        return $this->get('VNU_google_map_link');
-    }
-
-
-    /**
-     * Gets all events happening at this venue. Query parameters can be added to
-     * fetch a subset of those events.
-     *
-     * @param array $query_params @see https://github.com/eventespresso/event-espresso-core/tree/master/docs/G--Model-System/model-query-params.md
-     * @param bool  $upcoming
-     * @return EE_Event[]
-     */
-    public function events($query_params = array(), $upcoming = false)
-    {
-        if ($upcoming) {
-            $query_params = array(
-                array(
-                    'status'                 => 'publish',
-                    'Datetime.DTT_EVT_start' => array(
-                        '>',
-                        EEM_Datetime::instance()->current_time_for_query('DTT_EVT_start'),
-                    ),
-                ),
-            );
-        }
-        return $this->get_many_related('Event', $query_params);
-    }
-
-
-    /**
-     * Sets address
-     */
-    public function set_address($address = '')
-    {
-        $this->set('VNU_address', $address);
-    }
-
-
-    /**
-     * @param string $address2
-     */
-    public function set_address2($address2 = '')
-    {
-        $this->set('VNU_address2', $address2);
-    }
-
-
-    /**
-     * @param string $city
-     */
-    public function set_city($city = '')
-    {
-        $this->set('VNU_city', $city);
-    }
-
-
-    /**
-     * @param int $state
-     */
-    public function set_state_ID($state = 0)
-    {
-        $this->set('STA_ID', $state);
-    }
-
-
-    /**
-     * Sets the state, given either a state id or state object
-     *
-     * @param EE_State /int $state_id_or_obj
-     * @return EE_State
-     */
-    public function set_state_obj($state_id_or_obj)
-    {
-        return $this->_add_relation_to($state_id_or_obj, 'State');
-    }
-
-
-    /**
-     * @param int $country_ID
-     */
-    public function set_country_ID($country_ID = 0)
-    {
-        $this->set('CNT_ISO', $country_ID);
-    }
-
-
-    /**
-     * Sets the country on the venue
-     *
-     * @param EE_Country /string $country_id_or_obj
-     * @return EE_Country
-     */
-    public function set_country_obj($country_id_or_obj)
-    {
-        return $this->_add_relation_to($country_id_or_obj, 'Country');
-    }
-
-
-    /**
-     * @param string $zip
-     */
-    public function set_zip($zip = '')
-    {
-        $this->set('VNU_zip', $zip);
-    }
-
-
-    /**
-     * @param int $capacity
-     */
-    public function set_capacity($capacity = 0)
-    {
-        $this->set('VNU_capacity', $capacity);
-    }
-
-
-    /**
-     * @param string $created
-     */
-    public function set_created($created = '')
-    {
-        $this->set('VNU_created', $created);
-    }
-
-
-    /**
-     * @param string $desc
-     */
-    public function set_description($desc = '')
-    {
-        $this->set('VNU_desc', $desc);
-    }
-
-
-    /**
-     * @param string $identifier
-     */
-    public function set_identifier($identifier = '')
-    {
-        $this->set('VNU_identifier', $identifier);
-    }
-
-
-    /**
-     * @param string $modified
-     */
-    public function set_modified($modified = '')
-    {
-        $this->set('VNU_modified', $modified);
-    }
-
-
-    /**
-     * @param string $name
-     */
-    public function set_name($name = '')
-    {
-        $this->set('VNU_name', $name);
-    }
-
-
-    /**
-     * @param int $order
-     */
-    public function set_order($order = 0)
-    {
-        $this->set('VNU_order', $order);
-    }
-
-
-    /**
-     * @param string $phone
-     */
-    public function set_phone($phone = '')
-    {
-        $this->set('VNU_phone', $phone);
-    }
-
-
-    /**
-     * @param int $wp_user
-     */
-    public function set_wp_user($wp_user = 1)
-    {
-        $this->set('VNU_wp_user', $wp_user);
-    }
-
-
-    /**
-     * @param string $url
-     */
-    public function set_venue_url($url = '')
-    {
-        $this->set('VNU_url', $url);
-    }
-
-
-    /**
-     * @param string $phone
-     */
-    public function set_virtual_phone($phone = '')
-    {
-        $this->set('VNU_virtual_phone', $phone);
-    }
-
-
-    /**
-     * @param string $url
-     */
-    public function set_virtual_url($url = '')
-    {
-        $this->set('VNU_virtual_url', $url);
-    }
-
-
-    /**
-     * @param string $enable
-     */
-    public function set_enable_for_gmap($enable = '')
-    {
-        $this->set('VNU_enable_for_gmap', $enable);
-    }
-
-
-    /**
-     * @param string $google_map_link
-     */
-    public function set_google_map_link($google_map_link = '')
-    {
-        $this->set('VNU_google_map_link', $google_map_link);
-    }
+	/**
+	 *
+	 * @param array  $props_n_values          incoming values
+	 * @param string $timezone                incoming timezone (if not set the timezone set for the website will be
+	 *                                        used.)
+	 * @param array  $date_formats            incoming date_formats in an array where the first value is the
+	 *                                        date_format and the second value is the time format
+	 * @return EE_Attendee
+	 */
+	public static function new_instance($props_n_values = array(), $timezone = null, $date_formats = array())
+	{
+		$has_object = parent::_check_for_object($props_n_values, __CLASS__, $timezone, $date_formats);
+		return $has_object ? $has_object : new self($props_n_values, false, $timezone, $date_formats);
+	}
+
+
+	/**
+	 * @param array  $props_n_values  incoming values from the database
+	 * @param string $timezone        incoming timezone as set by the model.  If not set the timezone for
+	 *                                the website will be used.
+	 * @return EE_Attendee
+	 */
+	public static function new_instance_from_db($props_n_values = array(), $timezone = null)
+	{
+		return new self($props_n_values, true, $timezone);
+	}
+
+
+	/**
+	 * Gets name
+	 *
+	 * @return string
+	 */
+	public function name()
+	{
+		return $this->get('VNU_name');
+	}
+
+
+	/**
+	 * Gets phone
+	 *
+	 * @return string
+	 */
+	public function phone()
+	{
+		return $this->get('VNU_phone');
+	}
+
+
+	/**
+	 * venue_url
+	 *
+	 * @return string
+	 */
+	public function venue_url()
+	{
+		return $this->get('VNU_url');
+	}
+
+
+	/**
+	 * Gets desc
+	 *
+	 * @return string
+	 */
+	public function description()
+	{
+		return $this->get('VNU_desc');
+	}
+
+
+	/**
+	 * Gets short description (AKA: the excerpt)
+	 *
+	 * @return string
+	 */
+	public function excerpt()
+	{
+		return $this->get('VNU_short_desc');
+	}
+
+
+	/**
+	 * Gets identifier
+	 *
+	 * @return string
+	 */
+	public function identifier()
+	{
+		return $this->get('VNU_identifier');
+	}
+
+
+	/**
+	 * Gets address
+	 *
+	 * @return string
+	 */
+	public function address()
+	{
+		return $this->get('VNU_address');
+	}
+
+
+	/**
+	 * Gets address2
+	 *
+	 * @return string
+	 */
+	public function address2()
+	{
+		return $this->get('VNU_address2');
+	}
+
+
+	/**
+	 * Gets city
+	 *
+	 * @return string
+	 */
+	public function city()
+	{
+		return $this->get('VNU_city');
+	}
+
+	/**
+	 * Gets state
+	 *
+	 * @return int
+	 */
+	public function state_ID()
+	{
+		return $this->get('STA_ID');
+	}
+
+
+	/**
+	 * @return string
+	 */
+	public function state_abbrev()
+	{
+		return $this->state_obj() instanceof EE_State ? $this->state_obj()->abbrev() : '';
+	}
+
+
+	/**
+	 * @return string
+	 */
+	public function state_name()
+	{
+		return $this->state_obj() instanceof EE_State ? $this->state_obj()->name() : '';
+	}
+
+
+	/**
+	 * Gets the state for this venue
+	 *
+	 * @return EE_State
+	 */
+	public function state_obj()
+	{
+		return $this->get_first_related('State');
+	}
+
+
+	/**
+	 * either displays the state abbreviation or the state name, as determined
+	 * by the "FHEE__EEI_Address__state__use_abbreviation" filter.
+	 * defaults to abbreviation
+	 *
+	 * @return string
+	 */
+	public function state()
+	{
+		if (apply_filters('FHEE__EEI_Address__state__use_abbreviation', true, $this->state_obj())) {
+			return $this->state_abbrev();
+		} else {
+			return $this->state_name();
+		}
+	}
+
+
+	/**
+	 * country_ID
+	 *
+	 * @return string
+	 */
+	public function country_ID()
+	{
+		return $this->get('CNT_ISO');
+	}
+
+
+	/**
+	 * @return string
+	 */
+	public function country_name()
+	{
+		return $this->country_obj() instanceof EE_Country ? $this->country_obj()->name() : '';
+	}
+
+
+	/**
+	 * Gets the country of this venue
+	 *
+	 * @return EE_Country
+	 */
+	public function country_obj()
+	{
+		return $this->get_first_related('Country');
+	}
+
+
+	/**
+	 * either displays the country ISO2 code or the country name, as determined
+	 * by the "FHEE__EEI_Address__country__use_abbreviation" filter.
+	 * defaults to abbreviation
+	 *
+	 * @return string
+	 */
+	public function country()
+	{
+		if (apply_filters('FHEE__EEI_Address__country__use_abbreviation', true, $this->country_obj())) {
+			return $this->country_ID();
+		} else {
+			return $this->country_name();
+		}
+	}
+
+
+	/**
+	 * Gets zip
+	 *
+	 * @return string
+	 */
+	public function zip()
+	{
+		return $this->get('VNU_zip');
+	}
+
+
+	/**
+	 * Gets capacity
+	 *
+	 * @return int
+	 */
+	public function capacity()
+	{
+		return $this->get_pretty('VNU_capacity', 'symbol');
+	}
+
+
+	/**
+	 * Gets created
+	 *
+	 * @return string
+	 */
+	public function created()
+	{
+		return $this->get('VNU_created');
+	}
+
+
+	/**
+	 * Gets modified
+	 *
+	 * @return string
+	 */
+	public function modified()
+	{
+		return $this->get('VNU_modified');
+	}
+
+
+	/**
+	 * Gets order
+	 *
+	 * @return int
+	 */
+	public function order()
+	{
+		return $this->get('VNU_order');
+	}
+
+
+	/**
+	 * Gets wp_user
+	 *
+	 * @return int
+	 */
+	public function wp_user()
+	{
+		return $this->get('VNU_wp_user');
+	}
+
+
+	/**
+	 * @return string
+	 */
+	public function virtual_phone()
+	{
+		return $this->get('VNU_virtual_phone');
+	}
+
+
+	/**
+	 * @return string
+	 */
+	public function virtual_url()
+	{
+		return $this->get('VNU_virtual_url');
+	}
+
+
+	/**
+	 * @return bool
+	 */
+	public function enable_for_gmap()
+	{
+		return $this->get('VNU_enable_for_gmap');
+	}
+
+
+	/**
+	 * @return string
+	 */
+	public function google_map_link()
+	{
+		return $this->get('VNU_google_map_link');
+	}
+
+
+	/**
+	 * Gets all events happening at this venue. Query parameters can be added to
+	 * fetch a subset of those events.
+	 *
+	 * @param array $query_params @see https://github.com/eventespresso/event-espresso-core/tree/master/docs/G--Model-System/model-query-params.md
+	 * @param bool  $upcoming
+	 * @return EE_Event[]
+	 */
+	public function events($query_params = array(), $upcoming = false)
+	{
+		if ($upcoming) {
+			$query_params = array(
+				array(
+					'status'                 => 'publish',
+					'Datetime.DTT_EVT_start' => array(
+						'>',
+						EEM_Datetime::instance()->current_time_for_query('DTT_EVT_start'),
+					),
+				),
+			);
+		}
+		return $this->get_many_related('Event', $query_params);
+	}
+
+
+	/**
+	 * Sets address
+	 */
+	public function set_address($address = '')
+	{
+		$this->set('VNU_address', $address);
+	}
+
+
+	/**
+	 * @param string $address2
+	 */
+	public function set_address2($address2 = '')
+	{
+		$this->set('VNU_address2', $address2);
+	}
+
+
+	/**
+	 * @param string $city
+	 */
+	public function set_city($city = '')
+	{
+		$this->set('VNU_city', $city);
+	}
+
+
+	/**
+	 * @param int $state
+	 */
+	public function set_state_ID($state = 0)
+	{
+		$this->set('STA_ID', $state);
+	}
+
+
+	/**
+	 * Sets the state, given either a state id or state object
+	 *
+	 * @param EE_State /int $state_id_or_obj
+	 * @return EE_State
+	 */
+	public function set_state_obj($state_id_or_obj)
+	{
+		return $this->_add_relation_to($state_id_or_obj, 'State');
+	}
+
+
+	/**
+	 * @param int $country_ID
+	 */
+	public function set_country_ID($country_ID = 0)
+	{
+		$this->set('CNT_ISO', $country_ID);
+	}
+
+
+	/**
+	 * Sets the country on the venue
+	 *
+	 * @param EE_Country /string $country_id_or_obj
+	 * @return EE_Country
+	 */
+	public function set_country_obj($country_id_or_obj)
+	{
+		return $this->_add_relation_to($country_id_or_obj, 'Country');
+	}
+
+
+	/**
+	 * @param string $zip
+	 */
+	public function set_zip($zip = '')
+	{
+		$this->set('VNU_zip', $zip);
+	}
+
+
+	/**
+	 * @param int $capacity
+	 */
+	public function set_capacity($capacity = 0)
+	{
+		$this->set('VNU_capacity', $capacity);
+	}
+
+
+	/**
+	 * @param string $created
+	 */
+	public function set_created($created = '')
+	{
+		$this->set('VNU_created', $created);
+	}
+
+
+	/**
+	 * @param string $desc
+	 */
+	public function set_description($desc = '')
+	{
+		$this->set('VNU_desc', $desc);
+	}
+
+
+	/**
+	 * @param string $identifier
+	 */
+	public function set_identifier($identifier = '')
+	{
+		$this->set('VNU_identifier', $identifier);
+	}
+
+
+	/**
+	 * @param string $modified
+	 */
+	public function set_modified($modified = '')
+	{
+		$this->set('VNU_modified', $modified);
+	}
+
+
+	/**
+	 * @param string $name
+	 */
+	public function set_name($name = '')
+	{
+		$this->set('VNU_name', $name);
+	}
+
+
+	/**
+	 * @param int $order
+	 */
+	public function set_order($order = 0)
+	{
+		$this->set('VNU_order', $order);
+	}
+
+
+	/**
+	 * @param string $phone
+	 */
+	public function set_phone($phone = '')
+	{
+		$this->set('VNU_phone', $phone);
+	}
+
+
+	/**
+	 * @param int $wp_user
+	 */
+	public function set_wp_user($wp_user = 1)
+	{
+		$this->set('VNU_wp_user', $wp_user);
+	}
+
+
+	/**
+	 * @param string $url
+	 */
+	public function set_venue_url($url = '')
+	{
+		$this->set('VNU_url', $url);
+	}
+
+
+	/**
+	 * @param string $phone
+	 */
+	public function set_virtual_phone($phone = '')
+	{
+		$this->set('VNU_virtual_phone', $phone);
+	}
+
+
+	/**
+	 * @param string $url
+	 */
+	public function set_virtual_url($url = '')
+	{
+		$this->set('VNU_virtual_url', $url);
+	}
+
+
+	/**
+	 * @param string $enable
+	 */
+	public function set_enable_for_gmap($enable = '')
+	{
+		$this->set('VNU_enable_for_gmap', $enable);
+	}
+
+
+	/**
+	 * @param string $google_map_link
+	 */
+	public function set_google_map_link($google_map_link = '')
+	{
+		$this->set('VNU_google_map_link', $google_map_link);
+	}
 }

core/db_classes/EE_Registration.class.php

Indentation +2067 added lines, -2067 removed lines

@@ -17,2071 +17,2071 @@
 {
 
 
-    /**
-     * Used to reference when a registration has never been checked in.
-     *
-     * @deprecated use \EE_Checkin::status_checked_never instead
-     * @type int
-     */
-    const checkin_status_never = 2;
-
-    /**
-     * Used to reference when a registration has been checked in.
-     *
-     * @deprecated use \EE_Checkin::status_checked_in instead
-     * @type int
-     */
-    const checkin_status_in = 1;
-
-
-    /**
-     * Used to reference when a registration has been checked out.
-     *
-     * @deprecated use \EE_Checkin::status_checked_out instead
-     * @type int
-     */
-    const checkin_status_out = 0;
-
-
-    /**
-     * extra meta key for tracking reg status os trashed registrations
-     *
-     * @type string
-     */
-    const PRE_TRASH_REG_STATUS_KEY = 'pre_trash_registration_status';
-
-
-    /**
-     * extra meta key for tracking if registration has reserved ticket
-     *
-     * @type string
-     */
-    const HAS_RESERVED_TICKET_KEY = 'has_reserved_ticket';
-
-
-    /**
-     * @param array  $props_n_values          incoming values
-     * @param string $timezone                incoming timezone (if not set the timezone set for the website will be
-     *                                        used.)
-     * @param array  $date_formats            incoming date_formats in an array where the first value is the
-     *                                        date_format and the second value is the time format
-     * @return EE_Registration
-     * @throws EE_Error
-     */
-    public static function new_instance($props_n_values = array(), $timezone = null, $date_formats = array())
-    {
-        $has_object = parent::_check_for_object($props_n_values, __CLASS__, $timezone, $date_formats);
-        return $has_object ? $has_object : new self($props_n_values, false, $timezone, $date_formats);
-    }
-
-
-    /**
-     * @param array  $props_n_values  incoming values from the database
-     * @param string $timezone        incoming timezone as set by the model.  If not set the timezone for
-     *                                the website will be used.
-     * @return EE_Registration
-     */
-    public static function new_instance_from_db($props_n_values = array(), $timezone = null)
-    {
-        return new self($props_n_values, true, $timezone);
-    }
-
-
-    /**
-     *        Set Event ID
-     *
-     * @param        int $EVT_ID Event ID
-     * @throws EE_Error
-     * @throws RuntimeException
-     */
-    public function set_event($EVT_ID = 0)
-    {
-        $this->set('EVT_ID', $EVT_ID);
-    }
-
-
-    /**
-     * Overrides parent set() method so that all calls to set( 'REG_code', $REG_code ) OR set( 'STS_ID', $STS_ID ) can
-     * be routed to internal methods
-     *
-     * @param string $field_name
-     * @param mixed  $field_value
-     * @param bool   $use_default
-     * @throws EE_Error
-     * @throws EntityNotFoundException
-     * @throws InvalidArgumentException
-     * @throws InvalidDataTypeException
-     * @throws InvalidInterfaceException
-     * @throws ReflectionException
-     * @throws RuntimeException
-     */
-    public function set($field_name, $field_value, $use_default = false)
-    {
-        switch ($field_name) {
-            case 'REG_code':
-                if (! empty($field_value) && $this->reg_code() === null) {
-                    $this->set_reg_code($field_value, $use_default);
-                }
-                break;
-            case 'STS_ID':
-                $this->set_status($field_value, $use_default);
-                break;
-            default:
-                parent::set($field_name, $field_value, $use_default);
-        }
-    }
-
-
-    /**
-     * Set Status ID
-     * updates the registration status and ALSO...
-     * calls reserve_registration_space() if the reg status changes TO approved from any other reg status
-     * calls release_registration_space() if the reg status changes FROM approved to any other reg status
-     *
-     * @param string                $new_STS_ID
-     * @param boolean               $use_default
-     * @param ContextInterface|null $context
-     * @return bool
-     * @throws EE_Error
-     * @throws EntityNotFoundException
-     * @throws InvalidArgumentException
-     * @throws ReflectionException
-     * @throws RuntimeException
-     * @throws InvalidDataTypeException
-     * @throws InvalidInterfaceException
-     */
-    public function set_status($new_STS_ID = null, $use_default = false, ContextInterface $context = null)
-    {
-        // get current REG_Status
-        $old_STS_ID = $this->status_ID();
-        // if status has changed
-        if ($old_STS_ID !== $new_STS_ID // and that status has actually changed
-            && ! empty($old_STS_ID) // and that old status is actually set
-            && ! empty($new_STS_ID) // as well as the new status
-            && $this->ID() // ensure registration is in the db
-        ) {
-            // TO approved
-            if ($new_STS_ID === EEM_Registration::status_id_approved) {
-                // reserve a space by incrementing ticket and datetime sold values
-                $this->_reserve_registration_space();
-                do_action('AHEE__EE_Registration__set_status__to_approved', $this, $old_STS_ID, $new_STS_ID, $context);
-                // OR FROM  approved
-            } elseif ($old_STS_ID === EEM_Registration::status_id_approved) {
-                // release a space by decrementing ticket and datetime sold values
-                $this->_release_registration_space();
-                do_action(
-                    'AHEE__EE_Registration__set_status__from_approved',
-                    $this,
-                    $old_STS_ID,
-                    $new_STS_ID,
-                    $context
-                );
-            }
-            // update status
-            parent::set('STS_ID', $new_STS_ID, $use_default);
-            $this->_update_if_canceled_or_declined($new_STS_ID, $old_STS_ID, $context);
-            if ($this->statusChangeUpdatesTransaction($context)) {
-                $this->updateTransactionAfterStatusChange();
-            }
-            do_action('AHEE__EE_Registration__set_status__after_update', $this, $old_STS_ID, $new_STS_ID, $context);
-            return true;
-        }
-        // even though the old value matches the new value, it's still good to
-        // allow the parent set method to have a say
-        parent::set('STS_ID', $new_STS_ID, $use_default);
-        return true;
-    }
-
-
-    /**
-     * update REGs and TXN when cancelled or declined registrations involved
-     *
-     * @param string                $new_STS_ID
-     * @param string                $old_STS_ID
-     * @param ContextInterface|null $context
-     * @throws EE_Error
-     * @throws InvalidArgumentException
-     * @throws InvalidDataTypeException
-     * @throws InvalidInterfaceException
-     * @throws ReflectionException
-     */
-    private function _update_if_canceled_or_declined($new_STS_ID, $old_STS_ID, ContextInterface $context = null)
-    {
-        // these reg statuses should not be considered in any calculations involving monies owing
-        $closed_reg_statuses = EEM_Registration::closed_reg_statuses();
-        // true if registration has been cancelled or declined
-        $this->updateIfCanceled(
-            $closed_reg_statuses,
-            $new_STS_ID,
-            $old_STS_ID,
-            $context
-        );
-        $this->updateIfDeclined(
-            $closed_reg_statuses,
-            $new_STS_ID,
-            $old_STS_ID,
-            $context
-        );
-    }
-
-
-    /**
-     * update REGs and TXN when cancelled or declined registrations involved
-     *
-     * @param array                 $closed_reg_statuses
-     * @param string                $new_STS_ID
-     * @param string                $old_STS_ID
-     * @param ContextInterface|null $context
-     * @throws EE_Error
-     * @throws InvalidArgumentException
-     * @throws InvalidDataTypeException
-     * @throws InvalidInterfaceException
-     * @throws ReflectionException
-     */
-    private function updateIfCanceled(
-        array $closed_reg_statuses,
-        $new_STS_ID,
-        $old_STS_ID,
-        ContextInterface $context = null
-    ) {
-        // true if registration has been cancelled or declined
-        if (in_array($new_STS_ID, $closed_reg_statuses, true)
-            && ! in_array($old_STS_ID, $closed_reg_statuses, true)
-        ) {
-            /** @type EE_Registration_Processor $registration_processor */
-            $registration_processor = EE_Registry::instance()->load_class('Registration_Processor');
-            /** @type EE_Transaction_Processor $transaction_processor */
-            $transaction_processor = EE_Registry::instance()->load_class('Transaction_Processor');
-            // cancelled or declined registration
-            $registration_processor->update_registration_after_being_canceled_or_declined(
-                $this,
-                $closed_reg_statuses
-            );
-            $transaction_processor->update_transaction_after_canceled_or_declined_registration(
-                $this,
-                $closed_reg_statuses,
-                false
-            );
-            do_action(
-                'AHEE__EE_Registration__set_status__canceled_or_declined',
-                $this,
-                $old_STS_ID,
-                $new_STS_ID,
-                $context
-            );
-            return;
-        }
-    }
-
-
-    /**
-     * update REGs and TXN when cancelled or declined registrations involved
-     *
-     * @param array                 $closed_reg_statuses
-     * @param string                $new_STS_ID
-     * @param string                $old_STS_ID
-     * @param ContextInterface|null $context
-     * @throws EE_Error
-     * @throws InvalidArgumentException
-     * @throws InvalidDataTypeException
-     * @throws InvalidInterfaceException
-     * @throws ReflectionException
-     */
-    private function updateIfDeclined(
-        array $closed_reg_statuses,
-        $new_STS_ID,
-        $old_STS_ID,
-        ContextInterface $context = null
-    ) {
-        // true if reinstating cancelled or declined registration
-        if (in_array($old_STS_ID, $closed_reg_statuses, true)
-            && ! in_array($new_STS_ID, $closed_reg_statuses, true)
-        ) {
-            /** @type EE_Registration_Processor $registration_processor */
-            $registration_processor = EE_Registry::instance()->load_class('Registration_Processor');
-            /** @type EE_Transaction_Processor $transaction_processor */
-            $transaction_processor = EE_Registry::instance()->load_class('Transaction_Processor');
-            // reinstating cancelled or declined registration
-            $registration_processor->update_canceled_or_declined_registration_after_being_reinstated(
-                $this,
-                $closed_reg_statuses
-            );
-            $transaction_processor->update_transaction_after_reinstating_canceled_registration(
-                $this,
-                $closed_reg_statuses,
-                false
-            );
-            do_action(
-                'AHEE__EE_Registration__set_status__after_reinstated',
-                $this,
-                $old_STS_ID,
-                $new_STS_ID,
-                $context
-            );
-        }
-    }
-
-
-    /**
-     * @param ContextInterface|null $context
-     * @return bool
-     */
-    private function statusChangeUpdatesTransaction(ContextInterface $context = null)
-    {
-        $contexts_that_do_not_update_transaction = (array) apply_filters(
-            'AHEE__EE_Registration__statusChangeUpdatesTransaction__contexts_that_do_not_update_transaction',
-            array('spco_reg_step_attendee_information_process_registrations'),
-            $context,
-            $this
-        );
-        return ! (
-            $context instanceof ContextInterface
-            && in_array($context->slug(), $contexts_that_do_not_update_transaction, true)
-        );
-    }
-
-
-    /**
-     * @throws EE_Error
-     * @throws EntityNotFoundException
-     * @throws InvalidArgumentException
-     * @throws InvalidDataTypeException
-     * @throws InvalidInterfaceException
-     * @throws ReflectionException
-     * @throws RuntimeException
-     */
-    private function updateTransactionAfterStatusChange()
-    {
-        /** @type EE_Transaction_Payments $transaction_payments */
-        $transaction_payments = EE_Registry::instance()->load_class('Transaction_Payments');
-        $transaction_payments->recalculate_transaction_total($this->transaction(), false);
-        $this->transaction()->update_status_based_on_total_paid(true);
-    }
-
-
-    /**
-     *        get Status ID
-     */
-    public function status_ID()
-    {
-        return $this->get('STS_ID');
-    }
-
-
-    /**
-     * Gets the ticket this registration is for
-     *
-     * @param boolean $include_archived whether to include archived tickets or not.
-     *
-     * @return EE_Ticket|EE_Base_Class
-     * @throws EE_Error
-     */
-    public function ticket($include_archived = true)
-    {
-        $query_params = array();
-        if ($include_archived) {
-            $query_params['default_where_conditions'] = 'none';
-        }
-        return $this->get_first_related('Ticket', $query_params);
-    }
-
-
-    /**
-     * Gets the event this registration is for
-     *
-     * @return EE_Event
-     * @throws EE_Error
-     * @throws EntityNotFoundException
-     */
-    public function event()
-    {
-        $event = $this->get_first_related('Event');
-        if (! $event instanceof \EE_Event) {
-            throw new EntityNotFoundException('Event ID', $this->event_ID());
-        }
-        return $event;
-    }
-
-
-    /**
-     * Gets the "author" of the registration.  Note that for the purposes of registrations, the author will correspond
-     * with the author of the event this registration is for.
-     *
-     * @since 4.5.0
-     * @return int
-     * @throws EE_Error
-     * @throws EntityNotFoundException
-     */
-    public function wp_user()
-    {
-        $event = $this->event();
-        if ($event instanceof EE_Event) {
-            return $event->wp_user();
-        }
-        return 0;
-    }
-
-
-    /**
-     * increments this registration's related ticket sold and corresponding datetime sold values
-     *
-     * @return void
-     * @throws DomainException
-     * @throws EE_Error
-     * @throws EntityNotFoundException
-     * @throws InvalidArgumentException
-     * @throws InvalidDataTypeException
-     * @throws InvalidInterfaceException
-     * @throws ReflectionException
-     * @throws UnexpectedEntityException
-     */
-    private function _reserve_registration_space()
-    {
-        // reserved ticket and datetime counts will be decremented as sold counts are incremented
-        // so stop tracking that this reg has a ticket reserved
-        $this->release_reserved_ticket(false, "REG: {$this->ID()} (ln:" . __LINE__ . ')');
-        $ticket = $this->ticket();
-        $ticket->increase_sold();
-        $ticket->save();
-        // possibly set event status to sold out
-        $this->event()->perform_sold_out_status_check();
-    }
-
-
-    /**
-     * decrements (subtracts) this registration's related ticket sold and corresponding datetime sold values
-     *
-     * @return void
-     * @throws DomainException
-     * @throws EE_Error
-     * @throws EntityNotFoundException
-     * @throws InvalidArgumentException
-     * @throws InvalidDataTypeException
-     * @throws InvalidInterfaceException
-     * @throws ReflectionException
-     * @throws UnexpectedEntityException
-     */
-    private function _release_registration_space()
-    {
-        $ticket = $this->ticket();
-        $ticket->decrease_sold();
-        $ticket->save();
-        // possibly change event status from sold out back to previous status
-        $this->event()->perform_sold_out_status_check();
-    }
-
-
-    /**
-     * tracks this registration's ticket reservation in extra meta
-     * and can increment related ticket reserved and corresponding datetime reserved values
-     *
-     * @param bool $update_ticket if true, will increment ticket and datetime reserved count
-     * @return void
-     * @throws EE_Error
-     * @throws InvalidArgumentException
-     * @throws InvalidDataTypeException
-     * @throws InvalidInterfaceException
-     * @throws ReflectionException
-     */
-    public function reserve_ticket($update_ticket = false, $source = 'unknown')
-    {
-        // only reserve ticket if space is not currently reserved
-        if ((bool) $this->get_extra_meta(EE_Registration::HAS_RESERVED_TICKET_KEY, true) !== true) {
-            $this->update_extra_meta('reserve_ticket', "{$this->ticket_ID()} from {$source}");
-            // IMPORTANT !!!
-            // although checking $update_ticket first would be more efficient,
-            // we NEED to ALWAYS call update_extra_meta(), which is why that is done first
-            if ($this->update_extra_meta(EE_Registration::HAS_RESERVED_TICKET_KEY, true)
-                && $update_ticket
-            ) {
-                $ticket = $this->ticket();
-                $ticket->increase_reserved(1, "REG: {$this->ID()} (ln:" . __LINE__ . ')');
-                $ticket->save();
-            }
-        }
-    }
-
-
-    /**
-     * stops tracking this registration's ticket reservation in extra meta
-     * decrements (subtracts) related ticket reserved and corresponding datetime reserved values
-     *
-     * @param bool $update_ticket if true, will decrement ticket and datetime reserved count
-     * @return void
-     * @throws EE_Error
-     * @throws InvalidArgumentException
-     * @throws InvalidDataTypeException
-     * @throws InvalidInterfaceException
-     * @throws ReflectionException
-     */
-    public function release_reserved_ticket($update_ticket = false, $source = 'unknown')
-    {
-        // only release ticket if space is currently reserved
-        if ((bool) $this->get_extra_meta(EE_Registration::HAS_RESERVED_TICKET_KEY, true) === true) {
-            $this->update_extra_meta('release_reserved_ticket', "{$this->ticket_ID()} from {$source}");
-            // IMPORTANT !!!
-            // although checking $update_ticket first would be more efficient,
-            // we NEED to ALWAYS call update_extra_meta(), which is why that is done first
-            if ($this->update_extra_meta(EE_Registration::HAS_RESERVED_TICKET_KEY, false)
-                && $update_ticket
-            ) {
-                $ticket = $this->ticket();
-                $ticket->decrease_reserved(1, true, "REG: {$this->ID()} (ln:" . __LINE__ . ')');
-                $ticket->save();
-            }
-        }
-    }
-
-
-    /**
-     * Set Attendee ID
-     *
-     * @param        int $ATT_ID Attendee ID
-     * @throws EE_Error
-     * @throws RuntimeException
-     */
-    public function set_attendee_id($ATT_ID = 0)
-    {
-        $this->set('ATT_ID', $ATT_ID);
-    }
-
-
-    /**
-     *        Set Transaction ID
-     *
-     * @param        int $TXN_ID Transaction ID
-     * @throws EE_Error
-     * @throws RuntimeException
-     */
-    public function set_transaction_id($TXN_ID = 0)
-    {
-        $this->set('TXN_ID', $TXN_ID);
-    }
-
-
-    /**
-     *        Set Session
-     *
-     * @param    string $REG_session PHP Session ID
-     * @throws EE_Error
-     * @throws RuntimeException
-     */
-    public function set_session($REG_session = '')
-    {
-        $this->set('REG_session', $REG_session);
-    }
-
-
-    /**
-     *        Set Registration URL Link
-     *
-     * @param    string $REG_url_link Registration URL Link
-     * @throws EE_Error
-     * @throws RuntimeException
-     */
-    public function set_reg_url_link($REG_url_link = '')
-    {
-        $this->set('REG_url_link', $REG_url_link);
-    }
-
-
-    /**
-     *        Set Attendee Counter
-     *
-     * @param        int $REG_count Primary Attendee
-     * @throws EE_Error
-     * @throws RuntimeException
-     */
-    public function set_count($REG_count = 1)
-    {
-        $this->set('REG_count', $REG_count);
-    }
-
-
-    /**
-     *        Set Group Size
-     *
-     * @param        boolean $REG_group_size Group Registration
-     * @throws EE_Error
-     * @throws RuntimeException
-     */
-    public function set_group_size($REG_group_size = false)
-    {
-        $this->set('REG_group_size', $REG_group_size);
-    }
-
-
-    /**
-     *    is_not_approved -  convenience method that returns TRUE if REG status ID ==
-     *    EEM_Registration::status_id_not_approved
-     *
-     * @return        boolean
-     */
-    public function is_not_approved()
-    {
-        return $this->status_ID() == EEM_Registration::status_id_not_approved ? true : false;
-    }
-
-
-    /**
-     *    is_pending_payment -  convenience method that returns TRUE if REG status ID ==
-     *    EEM_Registration::status_id_pending_payment
-     *
-     * @return        boolean
-     */
-    public function is_pending_payment()
-    {
-        return $this->status_ID() == EEM_Registration::status_id_pending_payment ? true : false;
-    }
-
-
-    /**
-     *    is_approved -  convenience method that returns TRUE if REG status ID == EEM_Registration::status_id_approved
-     *
-     * @return        boolean
-     */
-    public function is_approved()
-    {
-        return $this->status_ID() == EEM_Registration::status_id_approved ? true : false;
-    }
-
-
-    /**
-     *    is_cancelled -  convenience method that returns TRUE if REG status ID == EEM_Registration::status_id_cancelled
-     *
-     * @return        boolean
-     */
-    public function is_cancelled()
-    {
-        return $this->status_ID() == EEM_Registration::status_id_cancelled ? true : false;
-    }
-
-
-    /**
-     *    is_declined -  convenience method that returns TRUE if REG status ID == EEM_Registration::status_id_declined
-     *
-     * @return        boolean
-     */
-    public function is_declined()
-    {
-        return $this->status_ID() == EEM_Registration::status_id_declined ? true : false;
-    }
-
-
-    /**
-     *    is_incomplete -  convenience method that returns TRUE if REG status ID ==
-     *    EEM_Registration::status_id_incomplete
-     *
-     * @return        boolean
-     */
-    public function is_incomplete()
-    {
-        return $this->status_ID() == EEM_Registration::status_id_incomplete ? true : false;
-    }
-
-
-    /**
-     *        Set Registration Date
-     *
-     * @param        mixed ( int or string ) $REG_date Registration Date - Unix timestamp or string representation of
-     *                                                 Date
-     * @throws EE_Error
-     * @throws RuntimeException
-     */
-    public function set_reg_date($REG_date = false)
-    {
-        $this->set('REG_date', $REG_date);
-    }
-
-
-    /**
-     *    Set final price owing for this registration after all ticket/price modifications
-     *
-     * @access    public
-     * @param    float $REG_final_price
-     * @throws EE_Error
-     * @throws RuntimeException
-     */
-    public function set_final_price($REG_final_price = 0.00)
-    {
-        $this->set('REG_final_price', $REG_final_price);
-    }
-
-
-    /**
-     *    Set amount paid towards this registration's final price
-     *
-     * @access    public
-     * @param    float $REG_paid
-     * @throws EE_Error
-     * @throws RuntimeException
-     */
-    public function set_paid($REG_paid = 0.00)
-    {
-        $this->set('REG_paid', $REG_paid);
-    }
-
-
-    /**
-     *        Attendee Is Going
-     *
-     * @param        boolean $REG_att_is_going Attendee Is Going
-     * @throws EE_Error
-     * @throws RuntimeException
-     */
-    public function set_att_is_going($REG_att_is_going = false)
-    {
-        $this->set('REG_att_is_going', $REG_att_is_going);
-    }
-
-
-    /**
-     * Gets the related attendee
-     *
-     * @return EE_Attendee
-     * @throws EE_Error
-     */
-    public function attendee()
-    {
-        return $this->get_first_related('Attendee');
-    }
-
-
-    /**
-     *        get Event ID
-     */
-    public function event_ID()
-    {
-        return $this->get('EVT_ID');
-    }
-
-
-    /**
-     *        get Event ID
-     */
-    public function event_name()
-    {
-        $event = $this->event_obj();
-        if ($event) {
-            return $event->name();
-        } else {
-            return null;
-        }
-    }
-
-
-    /**
-     * Fetches the event this registration is for
-     *
-     * @return EE_Event
-     * @throws EE_Error
-     */
-    public function event_obj()
-    {
-        return $this->get_first_related('Event');
-    }
-
-
-    /**
-     *        get Attendee ID
-     */
-    public function attendee_ID()
-    {
-        return $this->get('ATT_ID');
-    }
-
-
-    /**
-     *        get PHP Session ID
-     */
-    public function session_ID()
-    {
-        return $this->get('REG_session');
-    }
-
-
-    /**
-     * Gets the string which represents the URL trigger for the receipt template in the message template system.
-     *
-     * @param string $messenger 'pdf' or 'html'.  Default 'html'.
-     * @return string
-     */
-    public function receipt_url($messenger = 'html')
-    {
-
-        /**
-         * The below will be deprecated one version after this.  We check first if there is a custom receipt template
-         * already in use on old system.  If there is then we just return the standard url for it.
-         *
-         * @since 4.5.0
-         */
-        $template_relative_path = 'modules/gateways/Invoice/lib/templates/receipt_body.template.php';
-        $has_custom = EEH_Template::locate_template(
-            $template_relative_path,
-            array(),
-            true,
-            true,
-            true
-        );
-
-        if ($has_custom) {
-            return add_query_arg(array('receipt' => 'true'), $this->invoice_url('launch'));
-        }
-        return apply_filters('FHEE__EE_Registration__receipt_url__receipt_url', '', $this, $messenger, 'receipt');
-    }
-
-
-    /**
-     * Gets the string which represents the URL trigger for the invoice template in the message template system.
-     *
-     * @param string $messenger 'pdf' or 'html'.  Default 'html'.
-     * @return string
-     * @throws EE_Error
-     */
-    public function invoice_url($messenger = 'html')
-    {
-        /**
-         * The below will be deprecated one version after this.  We check first if there is a custom invoice template
-         * already in use on old system.  If there is then we just return the standard url for it.
-         *
-         * @since 4.5.0
-         */
-        $template_relative_path = 'modules/gateways/Invoice/lib/templates/invoice_body.template.php';
-        $has_custom = EEH_Template::locate_template(
-            $template_relative_path,
-            array(),
-            true,
-            true,
-            true
-        );
-
-        if ($has_custom) {
-            if ($messenger == 'html') {
-                return $this->invoice_url('launch');
-            }
-            $route = $messenger == 'download' || $messenger == 'pdf' ? 'download_invoice' : 'launch_invoice';
-
-            $query_args = array('ee' => $route, 'id' => $this->reg_url_link());
-            if ($messenger == 'html') {
-                $query_args['html'] = true;
-            }
-            return add_query_arg($query_args, get_permalink(EE_Registry::instance()->CFG->core->thank_you_page_id));
-        }
-        return apply_filters('FHEE__EE_Registration__invoice_url__invoice_url', '', $this, $messenger, 'invoice');
-    }
-
-
-    /**
-     * get Registration URL Link
-     *
-     * @access public
-     * @return string
-     * @throws EE_Error
-     */
-    public function reg_url_link()
-    {
-        return (string) $this->get('REG_url_link');
-    }
-
-
-    /**
-     * Echoes out invoice_url()
-     *
-     * @param string $type 'download','launch', or 'html' (default is 'launch')
-     * @return void
-     * @throws EE_Error
-     */
-    public function e_invoice_url($type = 'launch')
-    {
-        echo $this->invoice_url($type);
-    }
-
-
-    /**
-     * Echoes out payment_overview_url
-     */
-    public function e_payment_overview_url()
-    {
-        echo $this->payment_overview_url();
-    }
-
-
-    /**
-     * Gets the URL for the checkout payment options reg step
-     * with this registration's REG_url_link added as a query parameter
-     *
-     * @param bool $clear_session Set to true when you want to clear the session on revisiting the
-     *                            payment overview url.
-     * @return string
-     * @throws InvalidInterfaceException
-     * @throws InvalidDataTypeException
-     * @throws EE_Error
-     * @throws InvalidArgumentException
-     */
-    public function payment_overview_url($clear_session = false)
-    {
-        return add_query_arg(
-            (array) apply_filters(
-                'FHEE__EE_Registration__payment_overview_url__query_args',
-                array(
-                    'e_reg_url_link' => $this->reg_url_link(),
-                    'step'           => 'payment_options',
-                    'revisit'        => true,
-                    'clear_session'  => (bool) $clear_session,
-                ),
-                $this
-            ),
-            EE_Registry::instance()->CFG->core->reg_page_url()
-        );
-    }
-
-
-    /**
-     * Gets the URL for the checkout attendee information reg step
-     * with this registration's REG_url_link added as a query parameter
-     *
-     * @return string
-     * @throws InvalidInterfaceException
-     * @throws InvalidDataTypeException
-     * @throws EE_Error
-     * @throws InvalidArgumentException
-     */
-    public function edit_attendee_information_url()
-    {
-        return add_query_arg(
-            (array) apply_filters(
-                'FHEE__EE_Registration__edit_attendee_information_url__query_args',
-                array(
-                    'e_reg_url_link' => $this->reg_url_link(),
-                    'step'           => 'attendee_information',
-                    'revisit'        => true,
-                ),
-                $this
-            ),
-            EE_Registry::instance()->CFG->core->reg_page_url()
-        );
-    }
-
-
-    /**
-     * Simply generates and returns the appropriate admin_url link to edit this registration
-     *
-     * @return string
-     * @throws EE_Error
-     */
-    public function get_admin_edit_url()
-    {
-        return EEH_URL::add_query_args_and_nonce(
-            array(
-                'page'    => 'espresso_registrations',
-                'action'  => 'view_registration',
-                '_REG_ID' => $this->ID(),
-            ),
-            admin_url('admin.php')
-        );
-    }
-
-
-    /**
-     *    is_primary_registrant?
-     */
-    public function is_primary_registrant()
-    {
-        return $this->get('REG_count') == 1 ? true : false;
-    }
-
-
-    /**
-     * This returns the primary registration object for this registration group (which may be this object).
-     *
-     * @return EE_Registration
-     * @throws EE_Error
-     */
-    public function get_primary_registration()
-    {
-        if ($this->is_primary_registrant()) {
-            return $this;
-        }
-
-        // k reg_count !== 1 so let's get the EE_Registration object matching this txn_id and reg_count == 1
-        /** @var EE_Registration $primary_registrant */
-        $primary_registrant = EEM_Registration::instance()->get_one(
-            array(
-                array(
-                    'TXN_ID'    => $this->transaction_ID(),
-                    'REG_count' => 1,
-                ),
-            )
-        );
-        return $primary_registrant;
-    }
-
-
-    /**
-     *        get  Attendee Number
-     *
-     * @access        public
-     */
-    public function count()
-    {
-        return $this->get('REG_count');
-    }
-
-
-    /**
-     *        get Group Size
-     */
-    public function group_size()
-    {
-        return $this->get('REG_group_size');
-    }
-
-
-    /**
-     *        get Registration Date
-     */
-    public function date()
-    {
-        return $this->get('REG_date');
-    }
-
-
-    /**
-     * gets a pretty date
-     *
-     * @param string $date_format
-     * @param string $time_format
-     * @return string
-     * @throws EE_Error
-     */
-    public function pretty_date($date_format = null, $time_format = null)
-    {
-        return $this->get_datetime('REG_date', $date_format, $time_format);
-    }
-
-
-    /**
-     * final_price
-     * the registration's share of the transaction total, so that the
-     * sum of all the transaction's REG_final_prices equal the transaction's total
-     *
-     * @return float
-     * @throws EE_Error
-     */
-    public function final_price()
-    {
-        return $this->get('REG_final_price');
-    }
-
-
-    /**
-     * pretty_final_price
-     *  final price as formatted string, with correct decimal places and currency symbol
-     *
-     * @return string
-     * @throws EE_Error
-     */
-    public function pretty_final_price()
-    {
-        return $this->get_pretty('REG_final_price');
-    }
-
-
-    /**
-     * get paid (yeah)
-     *
-     * @return float
-     * @throws EE_Error
-     */
-    public function paid()
-    {
-        return $this->get('REG_paid');
-    }
-
-
-    /**
-     * pretty_paid
-     *
-     * @return float
-     * @throws EE_Error
-     */
-    public function pretty_paid()
-    {
-        return $this->get_pretty('REG_paid');
-    }
-
-
-    /**
-     * owes_monies_and_can_pay
-     * whether or not this registration has monies owing and it's' status allows payment
-     *
-     * @param array $requires_payment
-     * @return bool
-     * @throws EE_Error
-     */
-    public function owes_monies_and_can_pay($requires_payment = array())
-    {
-        // these reg statuses require payment (if event is not free)
-        $requires_payment = ! empty($requires_payment)
-            ? $requires_payment
-            : EEM_Registration::reg_statuses_that_allow_payment();
-        if (in_array($this->status_ID(), $requires_payment) &&
-            $this->final_price() != 0 &&
-            $this->final_price() != $this->paid()
-        ) {
-            return true;
-        } else {
-            return false;
-        }
-    }
-
-
-    /**
-     * Prints out the return value of $this->pretty_status()
-     *
-     * @param bool $show_icons
-     * @return void
-     * @throws EE_Error
-     */
-    public function e_pretty_status($show_icons = false)
-    {
-        echo $this->pretty_status($show_icons);
-    }
-
-
-    /**
-     * Returns a nice version of the status for displaying to customers
-     *
-     * @param bool $show_icons
-     * @return string
-     * @throws EE_Error
-     */
-    public function pretty_status($show_icons = false)
-    {
-        $status = EEM_Status::instance()->localized_status(
-            array($this->status_ID() => esc_html__('unknown', 'event_espresso')),
-            false,
-            'sentence'
-        );
-        $icon = '';
-        switch ($this->status_ID()) {
-            case EEM_Registration::status_id_approved:
-                $icon = $show_icons
-                    ? '<span class="dashicons dashicons-star-filled ee-icon-size-16 green-text"></span>'
-                    : '';
-                break;
-            case EEM_Registration::status_id_pending_payment:
-                $icon = $show_icons
-                    ? '<span class="dashicons dashicons-star-half ee-icon-size-16 orange-text"></span>'
-                    : '';
-                break;
-            case EEM_Registration::status_id_not_approved:
-                $icon = $show_icons
-                    ? '<span class="dashicons dashicons-marker ee-icon-size-16 orange-text"></span>'
-                    : '';
-                break;
-            case EEM_Registration::status_id_cancelled:
-                $icon = $show_icons
-                    ? '<span class="dashicons dashicons-no ee-icon-size-16 lt-grey-text"></span>'
-                    : '';
-                break;
-            case EEM_Registration::status_id_incomplete:
-                $icon = $show_icons
-                    ? '<span class="dashicons dashicons-no ee-icon-size-16 lt-orange-text"></span>'
-                    : '';
-                break;
-            case EEM_Registration::status_id_declined:
-                $icon = $show_icons
-                    ? '<span class="dashicons dashicons-no ee-icon-size-16 red-text"></span>'
-                    : '';
-                break;
-            case EEM_Registration::status_id_wait_list:
-                $icon = $show_icons
-                    ? '<span class="dashicons dashicons-clipboard ee-icon-size-16 purple-text"></span>'
-                    : '';
-                break;
-        }
-        return $icon . $status[ $this->status_ID() ];
-    }
-
-
-    /**
-     *        get Attendee Is Going
-     */
-    public function att_is_going()
-    {
-        return $this->get('REG_att_is_going');
-    }
-
-
-    /**
-     * Gets related answers
-     *
-     * @param array $query_params @see https://github.com/eventespresso/event-espresso-core/tree/master/docs/G--Model-System/model-query-params.md
-     * @return EE_Answer[]
-     * @throws EE_Error
-     */
-    public function answers($query_params = null)
-    {
-        return $this->get_many_related('Answer', $query_params);
-    }
-
-
-    /**
-     * Gets the registration's answer value to the specified question
-     * (either the question's ID or a question object)
-     *
-     * @param EE_Question|int $question
-     * @param bool            $pretty_value
-     * @return array|string if pretty_value= true, the result will always be a string
-     * (because the answer might be an array of answer values, so passing pretty_value=true
-     * will convert it into some kind of string)
-     * @throws EE_Error
-     */
-    public function answer_value_to_question($question, $pretty_value = true)
-    {
-        $question_id = EEM_Question::instance()->ensure_is_ID($question);
-        return EEM_Answer::instance()->get_answer_value_to_question($this, $question_id, $pretty_value);
-    }
-
-
-    /**
-     * question_groups
-     * returns an array of EE_Question_Group objects for this registration
-     *
-     * @return EE_Question_Group[]
-     * @throws EE_Error
-     * @throws EntityNotFoundException
-     */
-    public function question_groups()
-    {
-        $question_groups = array();
-        if ($this->event() instanceof EE_Event) {
-            $question_groups = $this->event()->question_groups(
-                array(
-                    array(
-                        'Event_Question_Group.EQG_primary' => $this->count() == 1 ? true : false,
-                    ),
-                    'order_by' => array('QSG_order' => 'ASC'),
-                )
-            );
-        }
-        return $question_groups;
-    }
-
-
-    /**
-     * count_question_groups
-     * returns a count of the number of EE_Question_Group objects for this registration
-     *
-     * @return int
-     * @throws EE_Error
-     * @throws EntityNotFoundException
-     */
-    public function count_question_groups()
-    {
-        $qg_count = 0;
-        if ($this->event() instanceof EE_Event) {
-            $qg_count = $this->event()->count_related(
-                'Question_Group',
-                array(
-                    array(
-                        'Event_Question_Group.EQG_primary' => $this->count() == 1 ? true : false,
-                    ),
-                )
-            );
-        }
-        return $qg_count;
-    }
-
-
-    /**
-     * Returns the registration date in the 'standard' string format
-     * (function may be improved in the future to allow for different formats and timezones)
-     *
-     * @return string
-     * @throws EE_Error
-     */
-    public function reg_date()
-    {
-        return $this->get_datetime('REG_date');
-    }
-
-
-    /**
-     * Gets the datetime-ticket for this registration (ie, it can be used to isolate
-     * the ticket this registration purchased, or the datetime they have registered
-     * to attend)
-     *
-     * @return EE_Datetime_Ticket
-     * @throws EE_Error
-     */
-    public function datetime_ticket()
-    {
-        return $this->get_first_related('Datetime_Ticket');
-    }
-
-
-    /**
-     * Sets the registration's datetime_ticket.
-     *
-     * @param EE_Datetime_Ticket $datetime_ticket
-     * @return EE_Datetime_Ticket
-     * @throws EE_Error
-     */
-    public function set_datetime_ticket($datetime_ticket)
-    {
-        return $this->_add_relation_to($datetime_ticket, 'Datetime_Ticket');
-    }
-
-    /**
-     * Gets deleted
-     *
-     * @return bool
-     * @throws EE_Error
-     */
-    public function deleted()
-    {
-        return $this->get('REG_deleted');
-    }
-
-    /**
-     * Sets deleted
-     *
-     * @param boolean $deleted
-     * @return bool
-     * @throws EE_Error
-     * @throws RuntimeException
-     */
-    public function set_deleted($deleted)
-    {
-        if ($deleted) {
-            $this->delete();
-        } else {
-            $this->restore();
-        }
-    }
-
-
-    /**
-     * Get the status object of this object
-     *
-     * @return EE_Status
-     * @throws EE_Error
-     */
-    public function status_obj()
-    {
-        return $this->get_first_related('Status');
-    }
-
-
-    /**
-     * Returns the number of times this registration has checked into any of the datetimes
-     * its available for
-     *
-     * @return int
-     * @throws EE_Error
-     */
-    public function count_checkins()
-    {
-        return $this->get_model()->count_related($this, 'Checkin');
-    }
-
-
-    /**
-     * Returns the number of current Check-ins this registration is checked into for any of the datetimes the
-     * registration is for.  Note, this is ONLY checked in (does not include checkedout)
-     *
-     * @return int
-     * @throws EE_Error
-     */
-    public function count_checkins_not_checkedout()
-    {
-        return $this->get_model()->count_related($this, 'Checkin', array(array('CHK_in' => 1)));
-    }
-
-
-    /**
-     * The purpose of this method is simply to check whether this registration can checkin to the given datetime.
-     *
-     * @param int | EE_Datetime $DTT_OR_ID      The datetime the registration is being checked against
-     * @param bool              $check_approved This is used to indicate whether the caller wants can_checkin to also
-     *                                          consider registration status as well as datetime access.
-     * @return bool
-     * @throws EE_Error
-     */
-    public function can_checkin($DTT_OR_ID, $check_approved = true)
-    {
-        $DTT_ID = EEM_Datetime::instance()->ensure_is_ID($DTT_OR_ID);
-
-        // first check registration status
-        if (($check_approved && ! $this->is_approved()) || ! $DTT_ID) {
-            return false;
-        }
-        // is there a datetime ticket that matches this dtt_ID?
-        if (! (EEM_Datetime_Ticket::instance()->exists(
-            array(
-                array(
-                    'TKT_ID' => $this->get('TKT_ID'),
-                    'DTT_ID' => $DTT_ID,
-                ),
-            )
-        ))
-        ) {
-            return false;
-        }
-
-        // final check is against TKT_uses
-        return $this->verify_can_checkin_against_TKT_uses($DTT_ID);
-    }
-
-
-    /**
-     * This method verifies whether the user can checkin for the given datetime considering the max uses value set on
-     * the ticket. To do this,  a query is done to get the count of the datetime records already checked into.  If the
-     * datetime given does not have a check-in record and checking in for that datetime will exceed the allowed uses,
-     * then return false.  Otherwise return true.
-     *
-     * @param int | EE_Datetime $DTT_OR_ID The datetime the registration is being checked against
-     * @return bool true means can checkin.  false means cannot checkin.
-     * @throws EE_Error
-     */
-    public function verify_can_checkin_against_TKT_uses($DTT_OR_ID)
-    {
-        $DTT_ID = EEM_Datetime::instance()->ensure_is_ID($DTT_OR_ID);
-
-        if (! $DTT_ID) {
-            return false;
-        }
-
-        $max_uses = $this->ticket() instanceof EE_Ticket ? $this->ticket()->uses() : EE_INF;
-
-        // if max uses is not set or equals infinity then return true cause its not a factor for whether user can
-        // check-in or not.
-        if (! $max_uses || $max_uses === EE_INF) {
-            return true;
-        }
-
-        // does this datetime have a checkin record?  If so, then the dtt count has already been verified so we can just
-        // go ahead and toggle.
-        if (EEM_Checkin::instance()->exists(array(array('REG_ID' => $this->ID(), 'DTT_ID' => $DTT_ID)))) {
-            return true;
-        }
-
-        // made it here so the last check is whether the number of checkins per unique datetime on this registration
-        // disallows further check-ins.
-        $count_unique_dtt_checkins = EEM_Checkin::instance()->count(
-            array(
-                array(
-                    'REG_ID' => $this->ID(),
-                    'CHK_in' => true,
-                ),
-            ),
-            'DTT_ID',
-            true
-        );
-        // checkins have already reached their max number of uses
-        // so registrant can NOT checkin
-        if ($count_unique_dtt_checkins >= $max_uses) {
-            EE_Error::add_error(
-                esc_html__(
-                    'Check-in denied because number of datetime uses for the ticket has been reached or exceeded.',
-                    'event_espresso'
-                ),
-                __FILE__,
-                __FUNCTION__,
-                __LINE__
-            );
-            return false;
-        }
-        return true;
-    }
-
-
-    /**
-     * toggle Check-in status for this registration
-     * Check-ins are toggled in the following order:
-     * never checked in -> checked in
-     * checked in -> checked out
-     * checked out -> checked in
-     *
-     * @param  int $DTT_ID  include specific datetime to toggle Check-in for.
-     *                      If not included or null, then it is assumed latest datetime is being toggled.
-     * @param bool $verify  If true then can_checkin() is used to verify whether the person
-     *                      can be checked in or not.  Otherwise this forces change in checkin status.
-     * @return bool|int     the chk_in status toggled to OR false if nothing got changed.
-     * @throws EE_Error
-     */
-    public function toggle_checkin_status($DTT_ID = null, $verify = false)
-    {
-        if (empty($DTT_ID)) {
-            $datetime = $this->get_latest_related_datetime();
-            $DTT_ID = $datetime instanceof EE_Datetime ? $datetime->ID() : 0;
-            // verify the registration can checkin for the given DTT_ID
-        } elseif (! $this->can_checkin($DTT_ID, $verify)) {
-            EE_Error::add_error(
-                sprintf(
-                    esc_html__(
-                        'The given registration (ID:%1$d) can not be checked in to the given DTT_ID (%2$d), because the registration does not have access',
-                        'event_espresso'
-                    ),
-                    $this->ID(),
-                    $DTT_ID
-                ),
-                __FILE__,
-                __FUNCTION__,
-                __LINE__
-            );
-            return false;
-        }
-        $status_paths = array(
-            EE_Checkin::status_checked_never => EE_Checkin::status_checked_in,
-            EE_Checkin::status_checked_in    => EE_Checkin::status_checked_out,
-            EE_Checkin::status_checked_out   => EE_Checkin::status_checked_in,
-        );
-        // start by getting the current status so we know what status we'll be changing to.
-        $cur_status = $this->check_in_status_for_datetime($DTT_ID, null);
-        $status_to = $status_paths[ $cur_status ];
-        // database only records true for checked IN or false for checked OUT
-        // no record ( null ) means checked in NEVER, but we obviously don't save that
-        $new_status = $status_to === EE_Checkin::status_checked_in ? true : false;
-        // add relation - note Check-ins are always creating new rows
-        // because we are keeping track of Check-ins over time.
-        // Eventually we'll probably want to show a list table
-        // for the individual Check-ins so that they can be managed.
-        $checkin = EE_Checkin::new_instance(
-            array(
-                'REG_ID' => $this->ID(),
-                'DTT_ID' => $DTT_ID,
-                'CHK_in' => $new_status,
-            )
-        );
-        // if the record could not be saved then return false
-        if ($checkin->save() === 0) {
-            if (WP_DEBUG) {
-                global $wpdb;
-                $error = sprintf(
-                    esc_html__(
-                        'Registration check in update failed because of the following database error: %1$s%2$s',
-                        'event_espresso'
-                    ),
-                    '<br />',
-                    $wpdb->last_error
-                );
-            } else {
-                $error = esc_html__(
-                    'Registration check in update failed because of an unknown database error',
-                    'event_espresso'
-                );
-            }
-            EE_Error::add_error($error, __FILE__, __FUNCTION__, __LINE__);
-            return false;
-        }
-        return $status_to;
-    }
-
-
-    /**
-     * Returns the latest datetime related to this registration (via the ticket attached to the registration).
-     * "Latest" is defined by the `DTT_EVT_start` column.
-     *
-     * @return EE_Datetime|null
-     * @throws EE_Error
-     */
-    public function get_latest_related_datetime()
-    {
-        return EEM_Datetime::instance()->get_one(
-            array(
-                array(
-                    'Ticket.Registration.REG_ID' => $this->ID(),
-                ),
-                'order_by' => array('DTT_EVT_start' => 'DESC'),
-            )
-        );
-    }
-
-
-    /**
-     * Returns the earliest datetime related to this registration (via the ticket attached to the registration).
-     * "Earliest" is defined by the `DTT_EVT_start` column.
-     *
-     * @throws EE_Error
-     */
-    public function get_earliest_related_datetime()
-    {
-        return EEM_Datetime::instance()->get_one(
-            array(
-                array(
-                    'Ticket.Registration.REG_ID' => $this->ID(),
-                ),
-                'order_by' => array('DTT_EVT_start' => 'ASC'),
-            )
-        );
-    }
-
-
-    /**
-     * This method simply returns the check-in status for this registration and the given datetime.
-     * If neither the datetime nor the checkin values are provided as arguments,
-     * then this will return the LATEST check-in status for the registration across all datetimes it belongs to.
-     *
-     * @param  int       $DTT_ID  The ID of the datetime we're checking against
-     *                            (if empty we'll get the primary datetime for
-     *                            this registration (via event) and use it's ID);
-     * @param EE_Checkin $checkin If present, we use the given checkin object rather than the dtt_id.
-     *
-     * @return int                Integer representing Check-in status.
-     * @throws EE_Error
-     */
-    public function check_in_status_for_datetime($DTT_ID = 0, $checkin = null)
-    {
-        $checkin_query_params = array(
-            'order_by' => array('CHK_timestamp' => 'DESC'),
-        );
-
-        if ($DTT_ID > 0) {
-            $checkin_query_params[0] = array('DTT_ID' => $DTT_ID);
-        }
-
-        // get checkin object (if exists)
-        $checkin = $checkin instanceof EE_Checkin
-            ? $checkin
-            : $this->get_first_related('Checkin', $checkin_query_params);
-        if ($checkin instanceof EE_Checkin) {
-            if ($checkin->get('CHK_in')) {
-                return EE_Checkin::status_checked_in; // checked in
-            }
-            return EE_Checkin::status_checked_out; // had checked in but is now checked out.
-        }
-        return EE_Checkin::status_checked_never; // never been checked in
-    }
-
-
-    /**
-     * This method returns a localized message for the toggled Check-in message.
-     *
-     * @param  int $DTT_ID include specific datetime to get the correct Check-in message.  If not included or null,
-     *                     then it is assumed Check-in for primary datetime was toggled.
-     * @param bool $error  This just flags that you want an error message returned. This is put in so that the error
-     *                     message can be customized with the attendee name.
-     * @return string internationalized message
-     * @throws EE_Error
-     */
-    public function get_checkin_msg($DTT_ID, $error = false)
-    {
-        // let's get the attendee first so we can include the name of the attendee
-        $attendee = $this->get_first_related('Attendee');
-        if ($attendee instanceof EE_Attendee) {
-            if ($error) {
-                return sprintf(__("%s's check-in status was not changed.", "event_espresso"), $attendee->full_name());
-            }
-            $cur_status = $this->check_in_status_for_datetime($DTT_ID);
-            // what is the status message going to be?
-            switch ($cur_status) {
-                case EE_Checkin::status_checked_never:
-                    return sprintf(
-                        __("%s has been removed from Check-in records", "event_espresso"),
-                        $attendee->full_name()
-                    );
-                    break;
-                case EE_Checkin::status_checked_in:
-                    return sprintf(__('%s has been checked in', 'event_espresso'), $attendee->full_name());
-                    break;
-                case EE_Checkin::status_checked_out:
-                    return sprintf(__('%s has been checked out', 'event_espresso'), $attendee->full_name());
-                    break;
-            }
-        }
-        return esc_html__("The check-in status could not be determined.", "event_espresso");
-    }
-
-
-    /**
-     * Returns the related EE_Transaction to this registration
-     *
-     * @return EE_Transaction
-     * @throws EE_Error
-     * @throws EntityNotFoundException
-     */
-    public function transaction()
-    {
-        $transaction = $this->get_first_related('Transaction');
-        if (! $transaction instanceof \EE_Transaction) {
-            throw new EntityNotFoundException('Transaction ID', $this->transaction_ID());
-        }
-        return $transaction;
-    }
-
-
-    /**
-     *        get Registration Code
-     */
-    public function reg_code()
-    {
-        return $this->get('REG_code');
-    }
-
-
-    /**
-     *        get Transaction ID
-     */
-    public function transaction_ID()
-    {
-        return $this->get('TXN_ID');
-    }
-
-
-    /**
-     * @return int
-     * @throws EE_Error
-     */
-    public function ticket_ID()
-    {
-        return $this->get('TKT_ID');
-    }
-
-
-    /**
-     *        Set Registration Code
-     *
-     * @access    public
-     * @param    string  $REG_code Registration Code
-     * @param    boolean $use_default
-     * @throws EE_Error
-     */
-    public function set_reg_code($REG_code, $use_default = false)
-    {
-        if (empty($REG_code)) {
-            EE_Error::add_error(
-                esc_html__('REG_code can not be empty.', 'event_espresso'),
-                __FILE__,
-                __FUNCTION__,
-                __LINE__
-            );
-            return;
-        }
-        if (! $this->reg_code()) {
-            parent::set('REG_code', $REG_code, $use_default);
-        } else {
-            EE_Error::doing_it_wrong(
-                __CLASS__ . '::' . __FUNCTION__,
-                esc_html__('Can not change a registration REG_code once it has been set.', 'event_espresso'),
-                '4.6.0'
-            );
-        }
-    }
-
-
-    /**
-     * Returns all other registrations in the same group as this registrant who have the same ticket option.
-     * Note, if you want to just get all registrations in the same transaction (group), use:
-     *    $registration->transaction()->registrations();
-     *
-     * @since 4.5.0
-     * @return EE_Registration[] or empty array if this isn't a group registration.
-     * @throws EE_Error
-     */
-    public function get_all_other_registrations_in_group()
-    {
-        if ($this->group_size() < 2) {
-            return array();
-        }
-
-        $query[0] = array(
-            'TXN_ID' => $this->transaction_ID(),
-            'REG_ID' => array('!=', $this->ID()),
-            'TKT_ID' => $this->ticket_ID(),
-        );
-        /** @var EE_Registration[] $registrations */
-        $registrations = $this->get_model()->get_all($query);
-        return $registrations;
-    }
-
-    /**
-     * Return the link to the admin details for the object.
-     *
-     * @return string
-     * @throws EE_Error
-     */
-    public function get_admin_details_link()
-    {
-        EE_Registry::instance()->load_helper('URL');
-        return EEH_URL::add_query_args_and_nonce(
-            array(
-                'page'    => 'espresso_registrations',
-                'action'  => 'view_registration',
-                '_REG_ID' => $this->ID(),
-            ),
-            admin_url('admin.php')
-        );
-    }
-
-    /**
-     * Returns the link to the editor for the object.  Sometimes this is the same as the details.
-     *
-     * @return string
-     * @throws EE_Error
-     */
-    public function get_admin_edit_link()
-    {
-        return $this->get_admin_details_link();
-    }
-
-    /**
-     * Returns the link to a settings page for the object.
-     *
-     * @return string
-     * @throws EE_Error
-     */
-    public function get_admin_settings_link()
-    {
-        return $this->get_admin_details_link();
-    }
-
-    /**
-     * Returns the link to the "overview" for the object (typically the "list table" view).
-     *
-     * @return string
-     */
-    public function get_admin_overview_link()
-    {
-        EE_Registry::instance()->load_helper('URL');
-        return EEH_URL::add_query_args_and_nonce(
-            array(
-                'page' => 'espresso_registrations',
-            ),
-            admin_url('admin.php')
-        );
-    }
-
-
-    /**
-     * @param array $query_params
-     *
-     * @return \EE_Registration[]
-     * @throws EE_Error
-     */
-    public function payments($query_params = array())
-    {
-        return $this->get_many_related('Payment', $query_params);
-    }
-
-
-    /**
-     * @param array $query_params
-     *
-     * @return \EE_Registration_Payment[]
-     * @throws EE_Error
-     */
-    public function registration_payments($query_params = array())
-    {
-        return $this->get_many_related('Registration_Payment', $query_params);
-    }
-
-
-    /**
-     * This grabs the payment method corresponding to the last payment made for the amount owing on the registration.
-     * Note: if there are no payments on the registration there will be no payment method returned.
-     *
-     * @return EE_Payment_Method|null
-     */
-    public function payment_method()
-    {
-        return EEM_Payment_Method::instance()->get_last_used_for_registration($this);
-    }
-
-
-    /**
-     * @return \EE_Line_Item
-     * @throws EntityNotFoundException
-     * @throws EE_Error
-     */
-    public function ticket_line_item()
-    {
-        $ticket = $this->ticket();
-        $transaction = $this->transaction();
-        $line_item = null;
-        $ticket_line_items = \EEH_Line_Item::get_line_items_by_object_type_and_IDs(
-            $transaction->total_line_item(),
-            'Ticket',
-            array($ticket->ID())
-        );
-        foreach ($ticket_line_items as $ticket_line_item) {
-            if ($ticket_line_item instanceof \EE_Line_Item
-                && $ticket_line_item->OBJ_type() === 'Ticket'
-                && $ticket_line_item->OBJ_ID() === $ticket->ID()
-            ) {
-                $line_item = $ticket_line_item;
-                break;
-            }
-        }
-        if (! ($line_item instanceof \EE_Line_Item && $line_item->OBJ_type() === 'Ticket')) {
-            throw new EntityNotFoundException('Line Item Ticket ID', $ticket->ID());
-        }
-        return $line_item;
-    }
-
-
-    /**
-     * Soft Deletes this model object.
-     *
-     * @return boolean | int
-     * @throws RuntimeException
-     * @throws EE_Error
-     */
-    public function delete()
-    {
-        if ($this->update_extra_meta(EE_Registration::PRE_TRASH_REG_STATUS_KEY, $this->status_ID()) === true) {
-            $this->set_status(EEM_Registration::status_id_cancelled);
-        }
-        return parent::delete();
-    }
-
-
-    /**
-     * Restores whatever the previous status was on a registration before it was trashed (if possible)
-     *
-     * @throws EE_Error
-     * @throws RuntimeException
-     */
-    public function restore()
-    {
-        $previous_status = $this->get_extra_meta(
-            EE_Registration::PRE_TRASH_REG_STATUS_KEY,
-            true,
-            EEM_Registration::status_id_cancelled
-        );
-        if ($previous_status) {
-            $this->delete_extra_meta(EE_Registration::PRE_TRASH_REG_STATUS_KEY);
-            $this->set_status($previous_status);
-        }
-        return parent::restore();
-    }
-
-
-    /**
-     * possibly toggle Registration status based on comparison of REG_paid vs REG_final_price
-     *
-     * @param  boolean $trigger_set_status_logic EE_Registration::set_status() can trigger additional logic
-     *                                           depending on whether the reg status changes to or from "Approved"
-     * @return boolean whether the Registration status was updated
-     * @throws EE_Error
-     * @throws RuntimeException
-     */
-    public function updateStatusBasedOnTotalPaid($trigger_set_status_logic = true)
-    {
-        $paid = $this->paid();
-        $price = $this->final_price();
-        switch (true) {
-            // overpaid or paid
-            case EEH_Money::compare_floats($paid, $price, '>'):
-            case EEH_Money::compare_floats($paid, $price):
-                $new_status = EEM_Registration::status_id_approved;
-                break;
-            //  underpaid
-            case EEH_Money::compare_floats($paid, $price, '<'):
-                $new_status = EEM_Registration::status_id_pending_payment;
-                break;
-            // uhhh Houston...
-            default:
-                throw new RuntimeException(
-                    esc_html__('The total paid calculation for this registration is inaccurate.', 'event_espresso')
-                );
-        }
-        if ($new_status !== $this->status_ID()) {
-            if ($trigger_set_status_logic) {
-                return $this->set_status($new_status);
-            }
-            parent::set('STS_ID', $new_status);
-            return true;
-        }
-        return false;
-    }
-
-
-    /*************************** DEPRECATED ***************************/
-
-
-    /**
-     * @deprecated
-     * @since     4.7.0
-     * @access    public
-     */
-    public function price_paid()
-    {
-        EE_Error::doing_it_wrong(
-            'EE_Registration::price_paid()',
-            esc_html__(
-                'This method is deprecated, please use EE_Registration::final_price() instead.',
-                'event_espresso'
-            ),
-            '4.7.0'
-        );
-        return $this->final_price();
-    }
-
-
-    /**
-     * @deprecated
-     * @since     4.7.0
-     * @access    public
-     * @param    float $REG_final_price
-     * @throws EE_Error
-     * @throws RuntimeException
-     */
-    public function set_price_paid($REG_final_price = 0.00)
-    {
-        EE_Error::doing_it_wrong(
-            'EE_Registration::set_price_paid()',
-            esc_html__(
-                'This method is deprecated, please use EE_Registration::set_final_price() instead.',
-                'event_espresso'
-            ),
-            '4.7.0'
-        );
-        $this->set_final_price($REG_final_price);
-    }
-
-
-    /**
-     * @deprecated
-     * @since 4.7.0
-     * @return string
-     * @throws EE_Error
-     */
-    public function pretty_price_paid()
-    {
-        EE_Error::doing_it_wrong(
-            'EE_Registration::pretty_price_paid()',
-            esc_html__(
-                'This method is deprecated, please use EE_Registration::pretty_final_price() instead.',
-                'event_espresso'
-            ),
-            '4.7.0'
-        );
-        return $this->pretty_final_price();
-    }
-
-
-    /**
-     * Gets the primary datetime related to this registration via the related Event to this registration
-     *
-     * @deprecated 4.9.17
-     * @return EE_Datetime
-     * @throws EE_Error
-     * @throws EntityNotFoundException
-     */
-    public function get_related_primary_datetime()
-    {
-        EE_Error::doing_it_wrong(
-            __METHOD__,
-            esc_html__(
-                'Use EE_Registration::get_latest_related_datetime() or EE_Registration::get_earliest_related_datetime()',
-                'event_espresso'
-            ),
-            '4.9.17',
-            '5.0.0'
-        );
-        return $this->event()->primary_datetime();
-    }
+	/**
+	 * Used to reference when a registration has never been checked in.
+	 *
+	 * @deprecated use \EE_Checkin::status_checked_never instead
+	 * @type int
+	 */
+	const checkin_status_never = 2;
+
+	/**
+	 * Used to reference when a registration has been checked in.
+	 *
+	 * @deprecated use \EE_Checkin::status_checked_in instead
+	 * @type int
+	 */
+	const checkin_status_in = 1;
+
+
+	/**
+	 * Used to reference when a registration has been checked out.
+	 *
+	 * @deprecated use \EE_Checkin::status_checked_out instead
+	 * @type int
+	 */
+	const checkin_status_out = 0;
+
+
+	/**
+	 * extra meta key for tracking reg status os trashed registrations
+	 *
+	 * @type string
+	 */
+	const PRE_TRASH_REG_STATUS_KEY = 'pre_trash_registration_status';
+
+
+	/**
+	 * extra meta key for tracking if registration has reserved ticket
+	 *
+	 * @type string
+	 */
+	const HAS_RESERVED_TICKET_KEY = 'has_reserved_ticket';
+
+
+	/**
+	 * @param array  $props_n_values          incoming values
+	 * @param string $timezone                incoming timezone (if not set the timezone set for the website will be
+	 *                                        used.)
+	 * @param array  $date_formats            incoming date_formats in an array where the first value is the
+	 *                                        date_format and the second value is the time format
+	 * @return EE_Registration
+	 * @throws EE_Error
+	 */
+	public static function new_instance($props_n_values = array(), $timezone = null, $date_formats = array())
+	{
+		$has_object = parent::_check_for_object($props_n_values, __CLASS__, $timezone, $date_formats);
+		return $has_object ? $has_object : new self($props_n_values, false, $timezone, $date_formats);
+	}
+
+
+	/**
+	 * @param array  $props_n_values  incoming values from the database
+	 * @param string $timezone        incoming timezone as set by the model.  If not set the timezone for
+	 *                                the website will be used.
+	 * @return EE_Registration
+	 */
+	public static function new_instance_from_db($props_n_values = array(), $timezone = null)
+	{
+		return new self($props_n_values, true, $timezone);
+	}
+
+
+	/**
+	 *        Set Event ID
+	 *
+	 * @param        int $EVT_ID Event ID
+	 * @throws EE_Error
+	 * @throws RuntimeException
+	 */
+	public function set_event($EVT_ID = 0)
+	{
+		$this->set('EVT_ID', $EVT_ID);
+	}
+
+
+	/**
+	 * Overrides parent set() method so that all calls to set( 'REG_code', $REG_code ) OR set( 'STS_ID', $STS_ID ) can
+	 * be routed to internal methods
+	 *
+	 * @param string $field_name
+	 * @param mixed  $field_value
+	 * @param bool   $use_default
+	 * @throws EE_Error
+	 * @throws EntityNotFoundException
+	 * @throws InvalidArgumentException
+	 * @throws InvalidDataTypeException
+	 * @throws InvalidInterfaceException
+	 * @throws ReflectionException
+	 * @throws RuntimeException
+	 */
+	public function set($field_name, $field_value, $use_default = false)
+	{
+		switch ($field_name) {
+			case 'REG_code':
+				if (! empty($field_value) && $this->reg_code() === null) {
+					$this->set_reg_code($field_value, $use_default);
+				}
+				break;
+			case 'STS_ID':
+				$this->set_status($field_value, $use_default);
+				break;
+			default:
+				parent::set($field_name, $field_value, $use_default);
+		}
+	}
+
+
+	/**
+	 * Set Status ID
+	 * updates the registration status and ALSO...
+	 * calls reserve_registration_space() if the reg status changes TO approved from any other reg status
+	 * calls release_registration_space() if the reg status changes FROM approved to any other reg status
+	 *
+	 * @param string                $new_STS_ID
+	 * @param boolean               $use_default
+	 * @param ContextInterface|null $context
+	 * @return bool
+	 * @throws EE_Error
+	 * @throws EntityNotFoundException
+	 * @throws InvalidArgumentException
+	 * @throws ReflectionException
+	 * @throws RuntimeException
+	 * @throws InvalidDataTypeException
+	 * @throws InvalidInterfaceException
+	 */
+	public function set_status($new_STS_ID = null, $use_default = false, ContextInterface $context = null)
+	{
+		// get current REG_Status
+		$old_STS_ID = $this->status_ID();
+		// if status has changed
+		if ($old_STS_ID !== $new_STS_ID // and that status has actually changed
+			&& ! empty($old_STS_ID) // and that old status is actually set
+			&& ! empty($new_STS_ID) // as well as the new status
+			&& $this->ID() // ensure registration is in the db
+		) {
+			// TO approved
+			if ($new_STS_ID === EEM_Registration::status_id_approved) {
+				// reserve a space by incrementing ticket and datetime sold values
+				$this->_reserve_registration_space();
+				do_action('AHEE__EE_Registration__set_status__to_approved', $this, $old_STS_ID, $new_STS_ID, $context);
+				// OR FROM  approved
+			} elseif ($old_STS_ID === EEM_Registration::status_id_approved) {
+				// release a space by decrementing ticket and datetime sold values
+				$this->_release_registration_space();
+				do_action(
+					'AHEE__EE_Registration__set_status__from_approved',
+					$this,
+					$old_STS_ID,
+					$new_STS_ID,
+					$context
+				);
+			}
+			// update status
+			parent::set('STS_ID', $new_STS_ID, $use_default);
+			$this->_update_if_canceled_or_declined($new_STS_ID, $old_STS_ID, $context);
+			if ($this->statusChangeUpdatesTransaction($context)) {
+				$this->updateTransactionAfterStatusChange();
+			}
+			do_action('AHEE__EE_Registration__set_status__after_update', $this, $old_STS_ID, $new_STS_ID, $context);
+			return true;
+		}
+		// even though the old value matches the new value, it's still good to
+		// allow the parent set method to have a say
+		parent::set('STS_ID', $new_STS_ID, $use_default);
+		return true;
+	}
+
+
+	/**
+	 * update REGs and TXN when cancelled or declined registrations involved
+	 *
+	 * @param string                $new_STS_ID
+	 * @param string                $old_STS_ID
+	 * @param ContextInterface|null $context
+	 * @throws EE_Error
+	 * @throws InvalidArgumentException
+	 * @throws InvalidDataTypeException
+	 * @throws InvalidInterfaceException
+	 * @throws ReflectionException
+	 */
+	private function _update_if_canceled_or_declined($new_STS_ID, $old_STS_ID, ContextInterface $context = null)
+	{
+		// these reg statuses should not be considered in any calculations involving monies owing
+		$closed_reg_statuses = EEM_Registration::closed_reg_statuses();
+		// true if registration has been cancelled or declined
+		$this->updateIfCanceled(
+			$closed_reg_statuses,
+			$new_STS_ID,
+			$old_STS_ID,
+			$context
+		);
+		$this->updateIfDeclined(
+			$closed_reg_statuses,
+			$new_STS_ID,
+			$old_STS_ID,
+			$context
+		);
+	}
+
+
+	/**
+	 * update REGs and TXN when cancelled or declined registrations involved
+	 *
+	 * @param array                 $closed_reg_statuses
+	 * @param string                $new_STS_ID
+	 * @param string                $old_STS_ID
+	 * @param ContextInterface|null $context
+	 * @throws EE_Error
+	 * @throws InvalidArgumentException
+	 * @throws InvalidDataTypeException
+	 * @throws InvalidInterfaceException
+	 * @throws ReflectionException
+	 */
+	private function updateIfCanceled(
+		array $closed_reg_statuses,
+		$new_STS_ID,
+		$old_STS_ID,
+		ContextInterface $context = null
+	) {
+		// true if registration has been cancelled or declined
+		if (in_array($new_STS_ID, $closed_reg_statuses, true)
+			&& ! in_array($old_STS_ID, $closed_reg_statuses, true)
+		) {
+			/** @type EE_Registration_Processor $registration_processor */
+			$registration_processor = EE_Registry::instance()->load_class('Registration_Processor');
+			/** @type EE_Transaction_Processor $transaction_processor */
+			$transaction_processor = EE_Registry::instance()->load_class('Transaction_Processor');
+			// cancelled or declined registration
+			$registration_processor->update_registration_after_being_canceled_or_declined(
+				$this,
+				$closed_reg_statuses
+			);
+			$transaction_processor->update_transaction_after_canceled_or_declined_registration(
+				$this,
+				$closed_reg_statuses,
+				false
+			);
+			do_action(
+				'AHEE__EE_Registration__set_status__canceled_or_declined',
+				$this,
+				$old_STS_ID,
+				$new_STS_ID,
+				$context
+			);
+			return;
+		}
+	}
+
+
+	/**
+	 * update REGs and TXN when cancelled or declined registrations involved
+	 *
+	 * @param array                 $closed_reg_statuses
+	 * @param string                $new_STS_ID
+	 * @param string                $old_STS_ID
+	 * @param ContextInterface|null $context
+	 * @throws EE_Error
+	 * @throws InvalidArgumentException
+	 * @throws InvalidDataTypeException
+	 * @throws InvalidInterfaceException
+	 * @throws ReflectionException
+	 */
+	private function updateIfDeclined(
+		array $closed_reg_statuses,
+		$new_STS_ID,
+		$old_STS_ID,
+		ContextInterface $context = null
+	) {
+		// true if reinstating cancelled or declined registration
+		if (in_array($old_STS_ID, $closed_reg_statuses, true)
+			&& ! in_array($new_STS_ID, $closed_reg_statuses, true)
+		) {
+			/** @type EE_Registration_Processor $registration_processor */
+			$registration_processor = EE_Registry::instance()->load_class('Registration_Processor');
+			/** @type EE_Transaction_Processor $transaction_processor */
+			$transaction_processor = EE_Registry::instance()->load_class('Transaction_Processor');
+			// reinstating cancelled or declined registration
+			$registration_processor->update_canceled_or_declined_registration_after_being_reinstated(
+				$this,
+				$closed_reg_statuses
+			);
+			$transaction_processor->update_transaction_after_reinstating_canceled_registration(
+				$this,
+				$closed_reg_statuses,
+				false
+			);
+			do_action(
+				'AHEE__EE_Registration__set_status__after_reinstated',
+				$this,
+				$old_STS_ID,
+				$new_STS_ID,
+				$context
+			);
+		}
+	}
+
+
+	/**
+	 * @param ContextInterface|null $context
+	 * @return bool
+	 */
+	private function statusChangeUpdatesTransaction(ContextInterface $context = null)
+	{
+		$contexts_that_do_not_update_transaction = (array) apply_filters(
+			'AHEE__EE_Registration__statusChangeUpdatesTransaction__contexts_that_do_not_update_transaction',
+			array('spco_reg_step_attendee_information_process_registrations'),
+			$context,
+			$this
+		);
+		return ! (
+			$context instanceof ContextInterface
+			&& in_array($context->slug(), $contexts_that_do_not_update_transaction, true)
+		);
+	}
+
+
+	/**
+	 * @throws EE_Error
+	 * @throws EntityNotFoundException
+	 * @throws InvalidArgumentException
+	 * @throws InvalidDataTypeException
+	 * @throws InvalidInterfaceException
+	 * @throws ReflectionException
+	 * @throws RuntimeException
+	 */
+	private function updateTransactionAfterStatusChange()
+	{
+		/** @type EE_Transaction_Payments $transaction_payments */
+		$transaction_payments = EE_Registry::instance()->load_class('Transaction_Payments');
+		$transaction_payments->recalculate_transaction_total($this->transaction(), false);
+		$this->transaction()->update_status_based_on_total_paid(true);
+	}
+
+
+	/**
+	 *        get Status ID
+	 */
+	public function status_ID()
+	{
+		return $this->get('STS_ID');
+	}
+
+
+	/**
+	 * Gets the ticket this registration is for
+	 *
+	 * @param boolean $include_archived whether to include archived tickets or not.
+	 *
+	 * @return EE_Ticket|EE_Base_Class
+	 * @throws EE_Error
+	 */
+	public function ticket($include_archived = true)
+	{
+		$query_params = array();
+		if ($include_archived) {
+			$query_params['default_where_conditions'] = 'none';
+		}
+		return $this->get_first_related('Ticket', $query_params);
+	}
+
+
+	/**
+	 * Gets the event this registration is for
+	 *
+	 * @return EE_Event
+	 * @throws EE_Error
+	 * @throws EntityNotFoundException
+	 */
+	public function event()
+	{
+		$event = $this->get_first_related('Event');
+		if (! $event instanceof \EE_Event) {
+			throw new EntityNotFoundException('Event ID', $this->event_ID());
+		}
+		return $event;
+	}
+
+
+	/**
+	 * Gets the "author" of the registration.  Note that for the purposes of registrations, the author will correspond
+	 * with the author of the event this registration is for.
+	 *
+	 * @since 4.5.0
+	 * @return int
+	 * @throws EE_Error
+	 * @throws EntityNotFoundException
+	 */
+	public function wp_user()
+	{
+		$event = $this->event();
+		if ($event instanceof EE_Event) {
+			return $event->wp_user();
+		}
+		return 0;
+	}
+
+
+	/**
+	 * increments this registration's related ticket sold and corresponding datetime sold values
+	 *
+	 * @return void
+	 * @throws DomainException
+	 * @throws EE_Error
+	 * @throws EntityNotFoundException
+	 * @throws InvalidArgumentException
+	 * @throws InvalidDataTypeException
+	 * @throws InvalidInterfaceException
+	 * @throws ReflectionException
+	 * @throws UnexpectedEntityException
+	 */
+	private function _reserve_registration_space()
+	{
+		// reserved ticket and datetime counts will be decremented as sold counts are incremented
+		// so stop tracking that this reg has a ticket reserved
+		$this->release_reserved_ticket(false, "REG: {$this->ID()} (ln:" . __LINE__ . ')');
+		$ticket = $this->ticket();
+		$ticket->increase_sold();
+		$ticket->save();
+		// possibly set event status to sold out
+		$this->event()->perform_sold_out_status_check();
+	}
+
+
+	/**
+	 * decrements (subtracts) this registration's related ticket sold and corresponding datetime sold values
+	 *
+	 * @return void
+	 * @throws DomainException
+	 * @throws EE_Error
+	 * @throws EntityNotFoundException
+	 * @throws InvalidArgumentException
+	 * @throws InvalidDataTypeException
+	 * @throws InvalidInterfaceException
+	 * @throws ReflectionException
+	 * @throws UnexpectedEntityException
+	 */
+	private function _release_registration_space()
+	{
+		$ticket = $this->ticket();
+		$ticket->decrease_sold();
+		$ticket->save();
+		// possibly change event status from sold out back to previous status
+		$this->event()->perform_sold_out_status_check();
+	}
+
+
+	/**
+	 * tracks this registration's ticket reservation in extra meta
+	 * and can increment related ticket reserved and corresponding datetime reserved values
+	 *
+	 * @param bool $update_ticket if true, will increment ticket and datetime reserved count
+	 * @return void
+	 * @throws EE_Error
+	 * @throws InvalidArgumentException
+	 * @throws InvalidDataTypeException
+	 * @throws InvalidInterfaceException
+	 * @throws ReflectionException
+	 */
+	public function reserve_ticket($update_ticket = false, $source = 'unknown')
+	{
+		// only reserve ticket if space is not currently reserved
+		if ((bool) $this->get_extra_meta(EE_Registration::HAS_RESERVED_TICKET_KEY, true) !== true) {
+			$this->update_extra_meta('reserve_ticket', "{$this->ticket_ID()} from {$source}");
+			// IMPORTANT !!!
+			// although checking $update_ticket first would be more efficient,
+			// we NEED to ALWAYS call update_extra_meta(), which is why that is done first
+			if ($this->update_extra_meta(EE_Registration::HAS_RESERVED_TICKET_KEY, true)
+				&& $update_ticket
+			) {
+				$ticket = $this->ticket();
+				$ticket->increase_reserved(1, "REG: {$this->ID()} (ln:" . __LINE__ . ')');
+				$ticket->save();
+			}
+		}
+	}
+
+
+	/**
+	 * stops tracking this registration's ticket reservation in extra meta
+	 * decrements (subtracts) related ticket reserved and corresponding datetime reserved values
+	 *
+	 * @param bool $update_ticket if true, will decrement ticket and datetime reserved count
+	 * @return void
+	 * @throws EE_Error
+	 * @throws InvalidArgumentException
+	 * @throws InvalidDataTypeException
+	 * @throws InvalidInterfaceException
+	 * @throws ReflectionException
+	 */
+	public function release_reserved_ticket($update_ticket = false, $source = 'unknown')
+	{
+		// only release ticket if space is currently reserved
+		if ((bool) $this->get_extra_meta(EE_Registration::HAS_RESERVED_TICKET_KEY, true) === true) {
+			$this->update_extra_meta('release_reserved_ticket', "{$this->ticket_ID()} from {$source}");
+			// IMPORTANT !!!
+			// although checking $update_ticket first would be more efficient,
+			// we NEED to ALWAYS call update_extra_meta(), which is why that is done first
+			if ($this->update_extra_meta(EE_Registration::HAS_RESERVED_TICKET_KEY, false)
+				&& $update_ticket
+			) {
+				$ticket = $this->ticket();
+				$ticket->decrease_reserved(1, true, "REG: {$this->ID()} (ln:" . __LINE__ . ')');
+				$ticket->save();
+			}
+		}
+	}
+
+
+	/**
+	 * Set Attendee ID
+	 *
+	 * @param        int $ATT_ID Attendee ID
+	 * @throws EE_Error
+	 * @throws RuntimeException
+	 */
+	public function set_attendee_id($ATT_ID = 0)
+	{
+		$this->set('ATT_ID', $ATT_ID);
+	}
+
+
+	/**
+	 *        Set Transaction ID
+	 *
+	 * @param        int $TXN_ID Transaction ID
+	 * @throws EE_Error
+	 * @throws RuntimeException
+	 */
+	public function set_transaction_id($TXN_ID = 0)
+	{
+		$this->set('TXN_ID', $TXN_ID);
+	}
+
+
+	/**
+	 *        Set Session
+	 *
+	 * @param    string $REG_session PHP Session ID
+	 * @throws EE_Error
+	 * @throws RuntimeException
+	 */
+	public function set_session($REG_session = '')
+	{
+		$this->set('REG_session', $REG_session);
+	}
+
+
+	/**
+	 *        Set Registration URL Link
+	 *
+	 * @param    string $REG_url_link Registration URL Link
+	 * @throws EE_Error
+	 * @throws RuntimeException
+	 */
+	public function set_reg_url_link($REG_url_link = '')
+	{
+		$this->set('REG_url_link', $REG_url_link);
+	}
+
+
+	/**
+	 *        Set Attendee Counter
+	 *
+	 * @param        int $REG_count Primary Attendee
+	 * @throws EE_Error
+	 * @throws RuntimeException
+	 */
+	public function set_count($REG_count = 1)
+	{
+		$this->set('REG_count', $REG_count);
+	}
+
+
+	/**
+	 *        Set Group Size
+	 *
+	 * @param        boolean $REG_group_size Group Registration
+	 * @throws EE_Error
+	 * @throws RuntimeException
+	 */
+	public function set_group_size($REG_group_size = false)
+	{
+		$this->set('REG_group_size', $REG_group_size);
+	}
+
+
+	/**
+	 *    is_not_approved -  convenience method that returns TRUE if REG status ID ==
+	 *    EEM_Registration::status_id_not_approved
+	 *
+	 * @return        boolean
+	 */
+	public function is_not_approved()
+	{
+		return $this->status_ID() == EEM_Registration::status_id_not_approved ? true : false;
+	}
+
+
+	/**
+	 *    is_pending_payment -  convenience method that returns TRUE if REG status ID ==
+	 *    EEM_Registration::status_id_pending_payment
+	 *
+	 * @return        boolean
+	 */
+	public function is_pending_payment()
+	{
+		return $this->status_ID() == EEM_Registration::status_id_pending_payment ? true : false;
+	}
+
+
+	/**
+	 *    is_approved -  convenience method that returns TRUE if REG status ID == EEM_Registration::status_id_approved
+	 *
+	 * @return        boolean
+	 */
+	public function is_approved()
+	{
+		return $this->status_ID() == EEM_Registration::status_id_approved ? true : false;
+	}
+
+
+	/**
+	 *    is_cancelled -  convenience method that returns TRUE if REG status ID == EEM_Registration::status_id_cancelled
+	 *
+	 * @return        boolean
+	 */
+	public function is_cancelled()
+	{
+		return $this->status_ID() == EEM_Registration::status_id_cancelled ? true : false;
+	}
+
+
+	/**
+	 *    is_declined -  convenience method that returns TRUE if REG status ID == EEM_Registration::status_id_declined
+	 *
+	 * @return        boolean
+	 */
+	public function is_declined()
+	{
+		return $this->status_ID() == EEM_Registration::status_id_declined ? true : false;
+	}
+
+
+	/**
+	 *    is_incomplete -  convenience method that returns TRUE if REG status ID ==
+	 *    EEM_Registration::status_id_incomplete
+	 *
+	 * @return        boolean
+	 */
+	public function is_incomplete()
+	{
+		return $this->status_ID() == EEM_Registration::status_id_incomplete ? true : false;
+	}
+
+
+	/**
+	 *        Set Registration Date
+	 *
+	 * @param        mixed ( int or string ) $REG_date Registration Date - Unix timestamp or string representation of
+	 *                                                 Date
+	 * @throws EE_Error
+	 * @throws RuntimeException
+	 */
+	public function set_reg_date($REG_date = false)
+	{
+		$this->set('REG_date', $REG_date);
+	}
+
+
+	/**
+	 *    Set final price owing for this registration after all ticket/price modifications
+	 *
+	 * @access    public
+	 * @param    float $REG_final_price
+	 * @throws EE_Error
+	 * @throws RuntimeException
+	 */
+	public function set_final_price($REG_final_price = 0.00)
+	{
+		$this->set('REG_final_price', $REG_final_price);
+	}
+
+
+	/**
+	 *    Set amount paid towards this registration's final price
+	 *
+	 * @access    public
+	 * @param    float $REG_paid
+	 * @throws EE_Error
+	 * @throws RuntimeException
+	 */
+	public function set_paid($REG_paid = 0.00)
+	{
+		$this->set('REG_paid', $REG_paid);
+	}
+
+
+	/**
+	 *        Attendee Is Going
+	 *
+	 * @param        boolean $REG_att_is_going Attendee Is Going
+	 * @throws EE_Error
+	 * @throws RuntimeException
+	 */
+	public function set_att_is_going($REG_att_is_going = false)
+	{
+		$this->set('REG_att_is_going', $REG_att_is_going);
+	}
+
+
+	/**
+	 * Gets the related attendee
+	 *
+	 * @return EE_Attendee
+	 * @throws EE_Error
+	 */
+	public function attendee()
+	{
+		return $this->get_first_related('Attendee');
+	}
+
+
+	/**
+	 *        get Event ID
+	 */
+	public function event_ID()
+	{
+		return $this->get('EVT_ID');
+	}
+
+
+	/**
+	 *        get Event ID
+	 */
+	public function event_name()
+	{
+		$event = $this->event_obj();
+		if ($event) {
+			return $event->name();
+		} else {
+			return null;
+		}
+	}
+
+
+	/**
+	 * Fetches the event this registration is for
+	 *
+	 * @return EE_Event
+	 * @throws EE_Error
+	 */
+	public function event_obj()
+	{
+		return $this->get_first_related('Event');
+	}
+
+
+	/**
+	 *        get Attendee ID
+	 */
+	public function attendee_ID()
+	{
+		return $this->get('ATT_ID');
+	}
+
+
+	/**
+	 *        get PHP Session ID
+	 */
+	public function session_ID()
+	{
+		return $this->get('REG_session');
+	}
+
+
+	/**
+	 * Gets the string which represents the URL trigger for the receipt template in the message template system.
+	 *
+	 * @param string $messenger 'pdf' or 'html'.  Default 'html'.
+	 * @return string
+	 */
+	public function receipt_url($messenger = 'html')
+	{
+
+		/**
+		 * The below will be deprecated one version after this.  We check first if there is a custom receipt template
+		 * already in use on old system.  If there is then we just return the standard url for it.
+		 *
+		 * @since 4.5.0
+		 */
+		$template_relative_path = 'modules/gateways/Invoice/lib/templates/receipt_body.template.php';
+		$has_custom = EEH_Template::locate_template(
+			$template_relative_path,
+			array(),
+			true,
+			true,
+			true
+		);
+
+		if ($has_custom) {
+			return add_query_arg(array('receipt' => 'true'), $this->invoice_url('launch'));
+		}
+		return apply_filters('FHEE__EE_Registration__receipt_url__receipt_url', '', $this, $messenger, 'receipt');
+	}
+
+
+	/**
+	 * Gets the string which represents the URL trigger for the invoice template in the message template system.
+	 *
+	 * @param string $messenger 'pdf' or 'html'.  Default 'html'.
+	 * @return string
+	 * @throws EE_Error
+	 */
+	public function invoice_url($messenger = 'html')
+	{
+		/**
+		 * The below will be deprecated one version after this.  We check first if there is a custom invoice template
+		 * already in use on old system.  If there is then we just return the standard url for it.
+		 *
+		 * @since 4.5.0
+		 */
+		$template_relative_path = 'modules/gateways/Invoice/lib/templates/invoice_body.template.php';
+		$has_custom = EEH_Template::locate_template(
+			$template_relative_path,
+			array(),
+			true,
+			true,
+			true
+		);
+
+		if ($has_custom) {
+			if ($messenger == 'html') {
+				return $this->invoice_url('launch');
+			}
+			$route = $messenger == 'download' || $messenger == 'pdf' ? 'download_invoice' : 'launch_invoice';
+
+			$query_args = array('ee' => $route, 'id' => $this->reg_url_link());
+			if ($messenger == 'html') {
+				$query_args['html'] = true;
+			}
+			return add_query_arg($query_args, get_permalink(EE_Registry::instance()->CFG->core->thank_you_page_id));
+		}
+		return apply_filters('FHEE__EE_Registration__invoice_url__invoice_url', '', $this, $messenger, 'invoice');
+	}
+
+
+	/**
+	 * get Registration URL Link
+	 *
+	 * @access public
+	 * @return string
+	 * @throws EE_Error
+	 */
+	public function reg_url_link()
+	{
+		return (string) $this->get('REG_url_link');
+	}
+
+
+	/**
+	 * Echoes out invoice_url()
+	 *
+	 * @param string $type 'download','launch', or 'html' (default is 'launch')
+	 * @return void
+	 * @throws EE_Error
+	 */
+	public function e_invoice_url($type = 'launch')
+	{
+		echo $this->invoice_url($type);
+	}
+
+
+	/**
+	 * Echoes out payment_overview_url
+	 */
+	public function e_payment_overview_url()
+	{
+		echo $this->payment_overview_url();
+	}
+
+
+	/**
+	 * Gets the URL for the checkout payment options reg step
+	 * with this registration's REG_url_link added as a query parameter
+	 *
+	 * @param bool $clear_session Set to true when you want to clear the session on revisiting the
+	 *                            payment overview url.
+	 * @return string
+	 * @throws InvalidInterfaceException
+	 * @throws InvalidDataTypeException
+	 * @throws EE_Error
+	 * @throws InvalidArgumentException
+	 */
+	public function payment_overview_url($clear_session = false)
+	{
+		return add_query_arg(
+			(array) apply_filters(
+				'FHEE__EE_Registration__payment_overview_url__query_args',
+				array(
+					'e_reg_url_link' => $this->reg_url_link(),
+					'step'           => 'payment_options',
+					'revisit'        => true,
+					'clear_session'  => (bool) $clear_session,
+				),
+				$this
+			),
+			EE_Registry::instance()->CFG->core->reg_page_url()
+		);
+	}
+
+
+	/**
+	 * Gets the URL for the checkout attendee information reg step
+	 * with this registration's REG_url_link added as a query parameter
+	 *
+	 * @return string
+	 * @throws InvalidInterfaceException
+	 * @throws InvalidDataTypeException
+	 * @throws EE_Error
+	 * @throws InvalidArgumentException
+	 */
+	public function edit_attendee_information_url()
+	{
+		return add_query_arg(
+			(array) apply_filters(
+				'FHEE__EE_Registration__edit_attendee_information_url__query_args',
+				array(
+					'e_reg_url_link' => $this->reg_url_link(),
+					'step'           => 'attendee_information',
+					'revisit'        => true,
+				),
+				$this
+			),
+			EE_Registry::instance()->CFG->core->reg_page_url()
+		);
+	}
+
+
+	/**
+	 * Simply generates and returns the appropriate admin_url link to edit this registration
+	 *
+	 * @return string
+	 * @throws EE_Error
+	 */
+	public function get_admin_edit_url()
+	{
+		return EEH_URL::add_query_args_and_nonce(
+			array(
+				'page'    => 'espresso_registrations',
+				'action'  => 'view_registration',
+				'_REG_ID' => $this->ID(),
+			),
+			admin_url('admin.php')
+		);
+	}
+
+
+	/**
+	 *    is_primary_registrant?
+	 */
+	public function is_primary_registrant()
+	{
+		return $this->get('REG_count') == 1 ? true : false;
+	}
+
+
+	/**
+	 * This returns the primary registration object for this registration group (which may be this object).
+	 *
+	 * @return EE_Registration
+	 * @throws EE_Error
+	 */
+	public function get_primary_registration()
+	{
+		if ($this->is_primary_registrant()) {
+			return $this;
+		}
+
+		// k reg_count !== 1 so let's get the EE_Registration object matching this txn_id and reg_count == 1
+		/** @var EE_Registration $primary_registrant */
+		$primary_registrant = EEM_Registration::instance()->get_one(
+			array(
+				array(
+					'TXN_ID'    => $this->transaction_ID(),
+					'REG_count' => 1,
+				),
+			)
+		);
+		return $primary_registrant;
+	}
+
+
+	/**
+	 *        get  Attendee Number
+	 *
+	 * @access        public
+	 */
+	public function count()
+	{
+		return $this->get('REG_count');
+	}
+
+
+	/**
+	 *        get Group Size
+	 */
+	public function group_size()
+	{
+		return $this->get('REG_group_size');
+	}
+
+
+	/**
+	 *        get Registration Date
+	 */
+	public function date()
+	{
+		return $this->get('REG_date');
+	}
+
+
+	/**
+	 * gets a pretty date
+	 *
+	 * @param string $date_format
+	 * @param string $time_format
+	 * @return string
+	 * @throws EE_Error
+	 */
+	public function pretty_date($date_format = null, $time_format = null)
+	{
+		return $this->get_datetime('REG_date', $date_format, $time_format);
+	}
+
+
+	/**
+	 * final_price
+	 * the registration's share of the transaction total, so that the
+	 * sum of all the transaction's REG_final_prices equal the transaction's total
+	 *
+	 * @return float
+	 * @throws EE_Error
+	 */
+	public function final_price()
+	{
+		return $this->get('REG_final_price');
+	}
+
+
+	/**
+	 * pretty_final_price
+	 *  final price as formatted string, with correct decimal places and currency symbol
+	 *
+	 * @return string
+	 * @throws EE_Error
+	 */
+	public function pretty_final_price()
+	{
+		return $this->get_pretty('REG_final_price');
+	}
+
+
+	/**
+	 * get paid (yeah)
+	 *
+	 * @return float
+	 * @throws EE_Error
+	 */
+	public function paid()
+	{
+		return $this->get('REG_paid');
+	}
+
+
+	/**
+	 * pretty_paid
+	 *
+	 * @return float
+	 * @throws EE_Error
+	 */
+	public function pretty_paid()
+	{
+		return $this->get_pretty('REG_paid');
+	}
+
+
+	/**
+	 * owes_monies_and_can_pay
+	 * whether or not this registration has monies owing and it's' status allows payment
+	 *
+	 * @param array $requires_payment
+	 * @return bool
+	 * @throws EE_Error
+	 */
+	public function owes_monies_and_can_pay($requires_payment = array())
+	{
+		// these reg statuses require payment (if event is not free)
+		$requires_payment = ! empty($requires_payment)
+			? $requires_payment
+			: EEM_Registration::reg_statuses_that_allow_payment();
+		if (in_array($this->status_ID(), $requires_payment) &&
+			$this->final_price() != 0 &&
+			$this->final_price() != $this->paid()
+		) {
+			return true;
+		} else {
+			return false;
+		}
+	}
+
+
+	/**
+	 * Prints out the return value of $this->pretty_status()
+	 *
+	 * @param bool $show_icons
+	 * @return void
+	 * @throws EE_Error
+	 */
+	public function e_pretty_status($show_icons = false)
+	{
+		echo $this->pretty_status($show_icons);
+	}
+
+
+	/**
+	 * Returns a nice version of the status for displaying to customers
+	 *
+	 * @param bool $show_icons
+	 * @return string
+	 * @throws EE_Error
+	 */
+	public function pretty_status($show_icons = false)
+	{
+		$status = EEM_Status::instance()->localized_status(
+			array($this->status_ID() => esc_html__('unknown', 'event_espresso')),
+			false,
+			'sentence'
+		);
+		$icon = '';
+		switch ($this->status_ID()) {
+			case EEM_Registration::status_id_approved:
+				$icon = $show_icons
+					? '<span class="dashicons dashicons-star-filled ee-icon-size-16 green-text"></span>'
+					: '';
+				break;
+			case EEM_Registration::status_id_pending_payment:
+				$icon = $show_icons
+					? '<span class="dashicons dashicons-star-half ee-icon-size-16 orange-text"></span>'
+					: '';
+				break;
+			case EEM_Registration::status_id_not_approved:
+				$icon = $show_icons
+					? '<span class="dashicons dashicons-marker ee-icon-size-16 orange-text"></span>'
+					: '';
+				break;
+			case EEM_Registration::status_id_cancelled:
+				$icon = $show_icons
+					? '<span class="dashicons dashicons-no ee-icon-size-16 lt-grey-text"></span>'
+					: '';
+				break;
+			case EEM_Registration::status_id_incomplete:
+				$icon = $show_icons
+					? '<span class="dashicons dashicons-no ee-icon-size-16 lt-orange-text"></span>'
+					: '';
+				break;
+			case EEM_Registration::status_id_declined:
+				$icon = $show_icons
+					? '<span class="dashicons dashicons-no ee-icon-size-16 red-text"></span>'
+					: '';
+				break;
+			case EEM_Registration::status_id_wait_list:
+				$icon = $show_icons
+					? '<span class="dashicons dashicons-clipboard ee-icon-size-16 purple-text"></span>'
+					: '';
+				break;
+		}
+		return $icon . $status[ $this->status_ID() ];
+	}
+
+
+	/**
+	 *        get Attendee Is Going
+	 */
+	public function att_is_going()
+	{
+		return $this->get('REG_att_is_going');
+	}
+
+
+	/**
+	 * Gets related answers
+	 *
+	 * @param array $query_params @see https://github.com/eventespresso/event-espresso-core/tree/master/docs/G--Model-System/model-query-params.md
+	 * @return EE_Answer[]
+	 * @throws EE_Error
+	 */
+	public function answers($query_params = null)
+	{
+		return $this->get_many_related('Answer', $query_params);
+	}
+
+
+	/**
+	 * Gets the registration's answer value to the specified question
+	 * (either the question's ID or a question object)
+	 *
+	 * @param EE_Question|int $question
+	 * @param bool            $pretty_value
+	 * @return array|string if pretty_value= true, the result will always be a string
+	 * (because the answer might be an array of answer values, so passing pretty_value=true
+	 * will convert it into some kind of string)
+	 * @throws EE_Error
+	 */
+	public function answer_value_to_question($question, $pretty_value = true)
+	{
+		$question_id = EEM_Question::instance()->ensure_is_ID($question);
+		return EEM_Answer::instance()->get_answer_value_to_question($this, $question_id, $pretty_value);
+	}
+
+
+	/**
+	 * question_groups
+	 * returns an array of EE_Question_Group objects for this registration
+	 *
+	 * @return EE_Question_Group[]
+	 * @throws EE_Error
+	 * @throws EntityNotFoundException
+	 */
+	public function question_groups()
+	{
+		$question_groups = array();
+		if ($this->event() instanceof EE_Event) {
+			$question_groups = $this->event()->question_groups(
+				array(
+					array(
+						'Event_Question_Group.EQG_primary' => $this->count() == 1 ? true : false,
+					),
+					'order_by' => array('QSG_order' => 'ASC'),
+				)
+			);
+		}
+		return $question_groups;
+	}
+
+
+	/**
+	 * count_question_groups
+	 * returns a count of the number of EE_Question_Group objects for this registration
+	 *
+	 * @return int
+	 * @throws EE_Error
+	 * @throws EntityNotFoundException
+	 */
+	public function count_question_groups()
+	{
+		$qg_count = 0;
+		if ($this->event() instanceof EE_Event) {
+			$qg_count = $this->event()->count_related(
+				'Question_Group',
+				array(
+					array(
+						'Event_Question_Group.EQG_primary' => $this->count() == 1 ? true : false,
+					),
+				)
+			);
+		}
+		return $qg_count;
+	}
+
+
+	/**
+	 * Returns the registration date in the 'standard' string format
+	 * (function may be improved in the future to allow for different formats and timezones)
+	 *
+	 * @return string
+	 * @throws EE_Error
+	 */
+	public function reg_date()
+	{
+		return $this->get_datetime('REG_date');
+	}
+
+
+	/**
+	 * Gets the datetime-ticket for this registration (ie, it can be used to isolate
+	 * the ticket this registration purchased, or the datetime they have registered
+	 * to attend)
+	 *
+	 * @return EE_Datetime_Ticket
+	 * @throws EE_Error
+	 */
+	public function datetime_ticket()
+	{
+		return $this->get_first_related('Datetime_Ticket');
+	}
+
+
+	/**
+	 * Sets the registration's datetime_ticket.
+	 *
+	 * @param EE_Datetime_Ticket $datetime_ticket
+	 * @return EE_Datetime_Ticket
+	 * @throws EE_Error
+	 */
+	public function set_datetime_ticket($datetime_ticket)
+	{
+		return $this->_add_relation_to($datetime_ticket, 'Datetime_Ticket');
+	}
+
+	/**
+	 * Gets deleted
+	 *
+	 * @return bool
+	 * @throws EE_Error
+	 */
+	public function deleted()
+	{
+		return $this->get('REG_deleted');
+	}
+
+	/**
+	 * Sets deleted
+	 *
+	 * @param boolean $deleted
+	 * @return bool
+	 * @throws EE_Error
+	 * @throws RuntimeException
+	 */
+	public function set_deleted($deleted)
+	{
+		if ($deleted) {
+			$this->delete();
+		} else {
+			$this->restore();
+		}
+	}
+
+
+	/**
+	 * Get the status object of this object
+	 *
+	 * @return EE_Status
+	 * @throws EE_Error
+	 */
+	public function status_obj()
+	{
+		return $this->get_first_related('Status');
+	}
+
+
+	/**
+	 * Returns the number of times this registration has checked into any of the datetimes
+	 * its available for
+	 *
+	 * @return int
+	 * @throws EE_Error
+	 */
+	public function count_checkins()
+	{
+		return $this->get_model()->count_related($this, 'Checkin');
+	}
+
+
+	/**
+	 * Returns the number of current Check-ins this registration is checked into for any of the datetimes the
+	 * registration is for.  Note, this is ONLY checked in (does not include checkedout)
+	 *
+	 * @return int
+	 * @throws EE_Error
+	 */
+	public function count_checkins_not_checkedout()
+	{
+		return $this->get_model()->count_related($this, 'Checkin', array(array('CHK_in' => 1)));
+	}
+
+
+	/**
+	 * The purpose of this method is simply to check whether this registration can checkin to the given datetime.
+	 *
+	 * @param int | EE_Datetime $DTT_OR_ID      The datetime the registration is being checked against
+	 * @param bool              $check_approved This is used to indicate whether the caller wants can_checkin to also
+	 *                                          consider registration status as well as datetime access.
+	 * @return bool
+	 * @throws EE_Error
+	 */
+	public function can_checkin($DTT_OR_ID, $check_approved = true)
+	{
+		$DTT_ID = EEM_Datetime::instance()->ensure_is_ID($DTT_OR_ID);
+
+		// first check registration status
+		if (($check_approved && ! $this->is_approved()) || ! $DTT_ID) {
+			return false;
+		}
+		// is there a datetime ticket that matches this dtt_ID?
+		if (! (EEM_Datetime_Ticket::instance()->exists(
+			array(
+				array(
+					'TKT_ID' => $this->get('TKT_ID'),
+					'DTT_ID' => $DTT_ID,
+				),
+			)
+		))
+		) {
+			return false;
+		}
+
+		// final check is against TKT_uses
+		return $this->verify_can_checkin_against_TKT_uses($DTT_ID);
+	}
+
+
+	/**
+	 * This method verifies whether the user can checkin for the given datetime considering the max uses value set on
+	 * the ticket. To do this,  a query is done to get the count of the datetime records already checked into.  If the
+	 * datetime given does not have a check-in record and checking in for that datetime will exceed the allowed uses,
+	 * then return false.  Otherwise return true.
+	 *
+	 * @param int | EE_Datetime $DTT_OR_ID The datetime the registration is being checked against
+	 * @return bool true means can checkin.  false means cannot checkin.
+	 * @throws EE_Error
+	 */
+	public function verify_can_checkin_against_TKT_uses($DTT_OR_ID)
+	{
+		$DTT_ID = EEM_Datetime::instance()->ensure_is_ID($DTT_OR_ID);
+
+		if (! $DTT_ID) {
+			return false;
+		}
+
+		$max_uses = $this->ticket() instanceof EE_Ticket ? $this->ticket()->uses() : EE_INF;
+
+		// if max uses is not set or equals infinity then return true cause its not a factor for whether user can
+		// check-in or not.
+		if (! $max_uses || $max_uses === EE_INF) {
+			return true;
+		}
+
+		// does this datetime have a checkin record?  If so, then the dtt count has already been verified so we can just
+		// go ahead and toggle.
+		if (EEM_Checkin::instance()->exists(array(array('REG_ID' => $this->ID(), 'DTT_ID' => $DTT_ID)))) {
+			return true;
+		}
+
+		// made it here so the last check is whether the number of checkins per unique datetime on this registration
+		// disallows further check-ins.
+		$count_unique_dtt_checkins = EEM_Checkin::instance()->count(
+			array(
+				array(
+					'REG_ID' => $this->ID(),
+					'CHK_in' => true,
+				),
+			),
+			'DTT_ID',
+			true
+		);
+		// checkins have already reached their max number of uses
+		// so registrant can NOT checkin
+		if ($count_unique_dtt_checkins >= $max_uses) {
+			EE_Error::add_error(
+				esc_html__(
+					'Check-in denied because number of datetime uses for the ticket has been reached or exceeded.',
+					'event_espresso'
+				),
+				__FILE__,
+				__FUNCTION__,
+				__LINE__
+			);
+			return false;
+		}
+		return true;
+	}
+
+
+	/**
+	 * toggle Check-in status for this registration
+	 * Check-ins are toggled in the following order:
+	 * never checked in -> checked in
+	 * checked in -> checked out
+	 * checked out -> checked in
+	 *
+	 * @param  int $DTT_ID  include specific datetime to toggle Check-in for.
+	 *                      If not included or null, then it is assumed latest datetime is being toggled.
+	 * @param bool $verify  If true then can_checkin() is used to verify whether the person
+	 *                      can be checked in or not.  Otherwise this forces change in checkin status.
+	 * @return bool|int     the chk_in status toggled to OR false if nothing got changed.
+	 * @throws EE_Error
+	 */
+	public function toggle_checkin_status($DTT_ID = null, $verify = false)
+	{
+		if (empty($DTT_ID)) {
+			$datetime = $this->get_latest_related_datetime();
+			$DTT_ID = $datetime instanceof EE_Datetime ? $datetime->ID() : 0;
+			// verify the registration can checkin for the given DTT_ID
+		} elseif (! $this->can_checkin($DTT_ID, $verify)) {
+			EE_Error::add_error(
+				sprintf(
+					esc_html__(
+						'The given registration (ID:%1$d) can not be checked in to the given DTT_ID (%2$d), because the registration does not have access',
+						'event_espresso'
+					),
+					$this->ID(),
+					$DTT_ID
+				),
+				__FILE__,
+				__FUNCTION__,
+				__LINE__
+			);
+			return false;
+		}
+		$status_paths = array(
+			EE_Checkin::status_checked_never => EE_Checkin::status_checked_in,
+			EE_Checkin::status_checked_in    => EE_Checkin::status_checked_out,
+			EE_Checkin::status_checked_out   => EE_Checkin::status_checked_in,
+		);
+		// start by getting the current status so we know what status we'll be changing to.
+		$cur_status = $this->check_in_status_for_datetime($DTT_ID, null);
+		$status_to = $status_paths[ $cur_status ];
+		// database only records true for checked IN or false for checked OUT
+		// no record ( null ) means checked in NEVER, but we obviously don't save that
+		$new_status = $status_to === EE_Checkin::status_checked_in ? true : false;
+		// add relation - note Check-ins are always creating new rows
+		// because we are keeping track of Check-ins over time.
+		// Eventually we'll probably want to show a list table
+		// for the individual Check-ins so that they can be managed.
+		$checkin = EE_Checkin::new_instance(
+			array(
+				'REG_ID' => $this->ID(),
+				'DTT_ID' => $DTT_ID,
+				'CHK_in' => $new_status,
+			)
+		);
+		// if the record could not be saved then return false
+		if ($checkin->save() === 0) {
+			if (WP_DEBUG) {
+				global $wpdb;
+				$error = sprintf(
+					esc_html__(
+						'Registration check in update failed because of the following database error: %1$s%2$s',
+						'event_espresso'
+					),
+					'<br />',
+					$wpdb->last_error
+				);
+			} else {
+				$error = esc_html__(
+					'Registration check in update failed because of an unknown database error',
+					'event_espresso'
+				);
+			}
+			EE_Error::add_error($error, __FILE__, __FUNCTION__, __LINE__);
+			return false;
+		}
+		return $status_to;
+	}
+
+
+	/**
+	 * Returns the latest datetime related to this registration (via the ticket attached to the registration).
+	 * "Latest" is defined by the `DTT_EVT_start` column.
+	 *
+	 * @return EE_Datetime|null
+	 * @throws EE_Error
+	 */
+	public function get_latest_related_datetime()
+	{
+		return EEM_Datetime::instance()->get_one(
+			array(
+				array(
+					'Ticket.Registration.REG_ID' => $this->ID(),
+				),
+				'order_by' => array('DTT_EVT_start' => 'DESC'),
+			)
+		);
+	}
+
+
+	/**
+	 * Returns the earliest datetime related to this registration (via the ticket attached to the registration).
+	 * "Earliest" is defined by the `DTT_EVT_start` column.
+	 *
+	 * @throws EE_Error
+	 */
+	public function get_earliest_related_datetime()
+	{
+		return EEM_Datetime::instance()->get_one(
+			array(
+				array(
+					'Ticket.Registration.REG_ID' => $this->ID(),
+				),
+				'order_by' => array('DTT_EVT_start' => 'ASC'),
+			)
+		);
+	}
+
+
+	/**
+	 * This method simply returns the check-in status for this registration and the given datetime.
+	 * If neither the datetime nor the checkin values are provided as arguments,
+	 * then this will return the LATEST check-in status for the registration across all datetimes it belongs to.
+	 *
+	 * @param  int       $DTT_ID  The ID of the datetime we're checking against
+	 *                            (if empty we'll get the primary datetime for
+	 *                            this registration (via event) and use it's ID);
+	 * @param EE_Checkin $checkin If present, we use the given checkin object rather than the dtt_id.
+	 *
+	 * @return int                Integer representing Check-in status.
+	 * @throws EE_Error
+	 */
+	public function check_in_status_for_datetime($DTT_ID = 0, $checkin = null)
+	{
+		$checkin_query_params = array(
+			'order_by' => array('CHK_timestamp' => 'DESC'),
+		);
+
+		if ($DTT_ID > 0) {
+			$checkin_query_params[0] = array('DTT_ID' => $DTT_ID);
+		}
+
+		// get checkin object (if exists)
+		$checkin = $checkin instanceof EE_Checkin
+			? $checkin
+			: $this->get_first_related('Checkin', $checkin_query_params);
+		if ($checkin instanceof EE_Checkin) {
+			if ($checkin->get('CHK_in')) {
+				return EE_Checkin::status_checked_in; // checked in
+			}
+			return EE_Checkin::status_checked_out; // had checked in but is now checked out.
+		}
+		return EE_Checkin::status_checked_never; // never been checked in
+	}
+
+
+	/**
+	 * This method returns a localized message for the toggled Check-in message.
+	 *
+	 * @param  int $DTT_ID include specific datetime to get the correct Check-in message.  If not included or null,
+	 *                     then it is assumed Check-in for primary datetime was toggled.
+	 * @param bool $error  This just flags that you want an error message returned. This is put in so that the error
+	 *                     message can be customized with the attendee name.
+	 * @return string internationalized message
+	 * @throws EE_Error
+	 */
+	public function get_checkin_msg($DTT_ID, $error = false)
+	{
+		// let's get the attendee first so we can include the name of the attendee
+		$attendee = $this->get_first_related('Attendee');
+		if ($attendee instanceof EE_Attendee) {
+			if ($error) {
+				return sprintf(__("%s's check-in status was not changed.", "event_espresso"), $attendee->full_name());
+			}
+			$cur_status = $this->check_in_status_for_datetime($DTT_ID);
+			// what is the status message going to be?
+			switch ($cur_status) {
+				case EE_Checkin::status_checked_never:
+					return sprintf(
+						__("%s has been removed from Check-in records", "event_espresso"),
+						$attendee->full_name()
+					);
+					break;
+				case EE_Checkin::status_checked_in:
+					return sprintf(__('%s has been checked in', 'event_espresso'), $attendee->full_name());
+					break;
+				case EE_Checkin::status_checked_out:
+					return sprintf(__('%s has been checked out', 'event_espresso'), $attendee->full_name());
+					break;
+			}
+		}
+		return esc_html__("The check-in status could not be determined.", "event_espresso");
+	}
+
+
+	/**
+	 * Returns the related EE_Transaction to this registration
+	 *
+	 * @return EE_Transaction
+	 * @throws EE_Error
+	 * @throws EntityNotFoundException
+	 */
+	public function transaction()
+	{
+		$transaction = $this->get_first_related('Transaction');
+		if (! $transaction instanceof \EE_Transaction) {
+			throw new EntityNotFoundException('Transaction ID', $this->transaction_ID());
+		}
+		return $transaction;
+	}
+
+
+	/**
+	 *        get Registration Code
+	 */
+	public function reg_code()
+	{
+		return $this->get('REG_code');
+	}
+
+
+	/**
+	 *        get Transaction ID
+	 */
+	public function transaction_ID()
+	{
+		return $this->get('TXN_ID');
+	}
+
+
+	/**
+	 * @return int
+	 * @throws EE_Error
+	 */
+	public function ticket_ID()
+	{
+		return $this->get('TKT_ID');
+	}
+
+
+	/**
+	 *        Set Registration Code
+	 *
+	 * @access    public
+	 * @param    string  $REG_code Registration Code
+	 * @param    boolean $use_default
+	 * @throws EE_Error
+	 */
+	public function set_reg_code($REG_code, $use_default = false)
+	{
+		if (empty($REG_code)) {
+			EE_Error::add_error(
+				esc_html__('REG_code can not be empty.', 'event_espresso'),
+				__FILE__,
+				__FUNCTION__,
+				__LINE__
+			);
+			return;
+		}
+		if (! $this->reg_code()) {
+			parent::set('REG_code', $REG_code, $use_default);
+		} else {
+			EE_Error::doing_it_wrong(
+				__CLASS__ . '::' . __FUNCTION__,
+				esc_html__('Can not change a registration REG_code once it has been set.', 'event_espresso'),
+				'4.6.0'
+			);
+		}
+	}
+
+
+	/**
+	 * Returns all other registrations in the same group as this registrant who have the same ticket option.
+	 * Note, if you want to just get all registrations in the same transaction (group), use:
+	 *    $registration->transaction()->registrations();
+	 *
+	 * @since 4.5.0
+	 * @return EE_Registration[] or empty array if this isn't a group registration.
+	 * @throws EE_Error
+	 */
+	public function get_all_other_registrations_in_group()
+	{
+		if ($this->group_size() < 2) {
+			return array();
+		}
+
+		$query[0] = array(
+			'TXN_ID' => $this->transaction_ID(),
+			'REG_ID' => array('!=', $this->ID()),
+			'TKT_ID' => $this->ticket_ID(),
+		);
+		/** @var EE_Registration[] $registrations */
+		$registrations = $this->get_model()->get_all($query);
+		return $registrations;
+	}
+
+	/**
+	 * Return the link to the admin details for the object.
+	 *
+	 * @return string
+	 * @throws EE_Error
+	 */
+	public function get_admin_details_link()
+	{
+		EE_Registry::instance()->load_helper('URL');
+		return EEH_URL::add_query_args_and_nonce(
+			array(
+				'page'    => 'espresso_registrations',
+				'action'  => 'view_registration',
+				'_REG_ID' => $this->ID(),
+			),
+			admin_url('admin.php')
+		);
+	}
+
+	/**
+	 * Returns the link to the editor for the object.  Sometimes this is the same as the details.
+	 *
+	 * @return string
+	 * @throws EE_Error
+	 */
+	public function get_admin_edit_link()
+	{
+		return $this->get_admin_details_link();
+	}
+
+	/**
+	 * Returns the link to a settings page for the object.
+	 *
+	 * @return string
+	 * @throws EE_Error
+	 */
+	public function get_admin_settings_link()
+	{
+		return $this->get_admin_details_link();
+	}
+
+	/**
+	 * Returns the link to the "overview" for the object (typically the "list table" view).
+	 *
+	 * @return string
+	 */
+	public function get_admin_overview_link()
+	{
+		EE_Registry::instance()->load_helper('URL');
+		return EEH_URL::add_query_args_and_nonce(
+			array(
+				'page' => 'espresso_registrations',
+			),
+			admin_url('admin.php')
+		);
+	}
+
+
+	/**
+	 * @param array $query_params
+	 *
+	 * @return \EE_Registration[]
+	 * @throws EE_Error
+	 */
+	public function payments($query_params = array())
+	{
+		return $this->get_many_related('Payment', $query_params);
+	}
+
+
+	/**
+	 * @param array $query_params
+	 *
+	 * @return \EE_Registration_Payment[]
+	 * @throws EE_Error
+	 */
+	public function registration_payments($query_params = array())
+	{
+		return $this->get_many_related('Registration_Payment', $query_params);
+	}
+
+
+	/**
+	 * This grabs the payment method corresponding to the last payment made for the amount owing on the registration.
+	 * Note: if there are no payments on the registration there will be no payment method returned.
+	 *
+	 * @return EE_Payment_Method|null
+	 */
+	public function payment_method()
+	{
+		return EEM_Payment_Method::instance()->get_last_used_for_registration($this);
+	}
+
+
+	/**
+	 * @return \EE_Line_Item
+	 * @throws EntityNotFoundException
+	 * @throws EE_Error
+	 */
+	public function ticket_line_item()
+	{
+		$ticket = $this->ticket();
+		$transaction = $this->transaction();
+		$line_item = null;
+		$ticket_line_items = \EEH_Line_Item::get_line_items_by_object_type_and_IDs(
+			$transaction->total_line_item(),
+			'Ticket',
+			array($ticket->ID())
+		);
+		foreach ($ticket_line_items as $ticket_line_item) {
+			if ($ticket_line_item instanceof \EE_Line_Item
+				&& $ticket_line_item->OBJ_type() === 'Ticket'
+				&& $ticket_line_item->OBJ_ID() === $ticket->ID()
+			) {
+				$line_item = $ticket_line_item;
+				break;
+			}
+		}
+		if (! ($line_item instanceof \EE_Line_Item && $line_item->OBJ_type() === 'Ticket')) {
+			throw new EntityNotFoundException('Line Item Ticket ID', $ticket->ID());
+		}
+		return $line_item;
+	}
+
+
+	/**
+	 * Soft Deletes this model object.
+	 *
+	 * @return boolean | int
+	 * @throws RuntimeException
+	 * @throws EE_Error
+	 */
+	public function delete()
+	{
+		if ($this->update_extra_meta(EE_Registration::PRE_TRASH_REG_STATUS_KEY, $this->status_ID()) === true) {
+			$this->set_status(EEM_Registration::status_id_cancelled);
+		}
+		return parent::delete();
+	}
+
+
+	/**
+	 * Restores whatever the previous status was on a registration before it was trashed (if possible)
+	 *
+	 * @throws EE_Error
+	 * @throws RuntimeException
+	 */
+	public function restore()
+	{
+		$previous_status = $this->get_extra_meta(
+			EE_Registration::PRE_TRASH_REG_STATUS_KEY,
+			true,
+			EEM_Registration::status_id_cancelled
+		);
+		if ($previous_status) {
+			$this->delete_extra_meta(EE_Registration::PRE_TRASH_REG_STATUS_KEY);
+			$this->set_status($previous_status);
+		}
+		return parent::restore();
+	}
+
+
+	/**
+	 * possibly toggle Registration status based on comparison of REG_paid vs REG_final_price
+	 *
+	 * @param  boolean $trigger_set_status_logic EE_Registration::set_status() can trigger additional logic
+	 *                                           depending on whether the reg status changes to or from "Approved"
+	 * @return boolean whether the Registration status was updated
+	 * @throws EE_Error
+	 * @throws RuntimeException
+	 */
+	public function updateStatusBasedOnTotalPaid($trigger_set_status_logic = true)
+	{
+		$paid = $this->paid();
+		$price = $this->final_price();
+		switch (true) {
+			// overpaid or paid
+			case EEH_Money::compare_floats($paid, $price, '>'):
+			case EEH_Money::compare_floats($paid, $price):
+				$new_status = EEM_Registration::status_id_approved;
+				break;
+			//  underpaid
+			case EEH_Money::compare_floats($paid, $price, '<'):
+				$new_status = EEM_Registration::status_id_pending_payment;
+				break;
+			// uhhh Houston...
+			default:
+				throw new RuntimeException(
+					esc_html__('The total paid calculation for this registration is inaccurate.', 'event_espresso')
+				);
+		}
+		if ($new_status !== $this->status_ID()) {
+			if ($trigger_set_status_logic) {
+				return $this->set_status($new_status);
+			}
+			parent::set('STS_ID', $new_status);
+			return true;
+		}
+		return false;
+	}
+
+
+	/*************************** DEPRECATED ***************************/
+
+
+	/**
+	 * @deprecated
+	 * @since     4.7.0
+	 * @access    public
+	 */
+	public function price_paid()
+	{
+		EE_Error::doing_it_wrong(
+			'EE_Registration::price_paid()',
+			esc_html__(
+				'This method is deprecated, please use EE_Registration::final_price() instead.',
+				'event_espresso'
+			),
+			'4.7.0'
+		);
+		return $this->final_price();
+	}
+
+
+	/**
+	 * @deprecated
+	 * @since     4.7.0
+	 * @access    public
+	 * @param    float $REG_final_price
+	 * @throws EE_Error
+	 * @throws RuntimeException
+	 */
+	public function set_price_paid($REG_final_price = 0.00)
+	{
+		EE_Error::doing_it_wrong(
+			'EE_Registration::set_price_paid()',
+			esc_html__(
+				'This method is deprecated, please use EE_Registration::set_final_price() instead.',
+				'event_espresso'
+			),
+			'4.7.0'
+		);
+		$this->set_final_price($REG_final_price);
+	}
+
+
+	/**
+	 * @deprecated
+	 * @since 4.7.0
+	 * @return string
+	 * @throws EE_Error
+	 */
+	public function pretty_price_paid()
+	{
+		EE_Error::doing_it_wrong(
+			'EE_Registration::pretty_price_paid()',
+			esc_html__(
+				'This method is deprecated, please use EE_Registration::pretty_final_price() instead.',
+				'event_espresso'
+			),
+			'4.7.0'
+		);
+		return $this->pretty_final_price();
+	}
+
+
+	/**
+	 * Gets the primary datetime related to this registration via the related Event to this registration
+	 *
+	 * @deprecated 4.9.17
+	 * @return EE_Datetime
+	 * @throws EE_Error
+	 * @throws EntityNotFoundException
+	 */
+	public function get_related_primary_datetime()
+	{
+		EE_Error::doing_it_wrong(
+			__METHOD__,
+			esc_html__(
+				'Use EE_Registration::get_latest_related_datetime() or EE_Registration::get_earliest_related_datetime()',
+				'event_espresso'
+			),
+			'4.9.17',
+			'5.0.0'
+		);
+		return $this->event()->primary_datetime();
+	}
 }

core/db_classes/EE_Ticket.class.php

Indentation +1460 added lines, -1460 removed lines

@@ -12,1464 +12,1464 @@
 class EE_Ticket extends EE_Soft_Delete_Base_Class implements EEI_Line_Item_Object, EEI_Event_Relation, EEI_Has_Icon
 {
 
-    /**
-     * The following constants are used by the ticket_status() method to indicate whether a ticket is on sale or not.
-     */
-    const sold_out = 'TKS';
-
-    /**
-     *
-     */
-    const expired = 'TKE';
-
-    /**
-     *
-     */
-    const archived = 'TKA';
-
-    /**
-     *
-     */
-    const pending = 'TKP';
-
-    /**
-     *
-     */
-    const onsale = 'TKO';
-
-    /**
-     * extra meta key for tracking ticket reservations
-     *
-     * @type string
-     */
-    const META_KEY_TICKET_RESERVATIONS = 'ticket_reservations';
-
-    /**
-     * cached result from method of the same name
-     *
-     * @var float $_ticket_total_with_taxes
-     */
-    private $_ticket_total_with_taxes;
-
-
-    /**
-     * @param array  $props_n_values          incoming values
-     * @param string $timezone                incoming timezone (if not set the timezone set for the website will be
-     *                                        used.)
-     * @param array  $date_formats            incoming date_formats in an array where the first value is the
-     *                                        date_format and the second value is the time format
-     * @return EE_Ticket
-     * @throws \EE_Error
-     */
-    public static function new_instance($props_n_values = array(), $timezone = null, $date_formats = array())
-    {
-        $has_object = parent::_check_for_object($props_n_values, __CLASS__, $timezone, $date_formats);
-        return $has_object ? $has_object : new self($props_n_values, false, $timezone, $date_formats);
-    }
-
-
-    /**
-     * @param array  $props_n_values  incoming values from the database
-     * @param string $timezone        incoming timezone as set by the model.  If not set the timezone for
-     *                                the website will be used.
-     * @return EE_Ticket
-     * @throws \EE_Error
-     */
-    public static function new_instance_from_db($props_n_values = array(), $timezone = null)
-    {
-        return new self($props_n_values, true, $timezone);
-    }
-
-
-    /**
-     * @return bool
-     * @throws \EE_Error
-     */
-    public function parent()
-    {
-        return $this->get('TKT_parent');
-    }
-
-
-    /**
-     * return if a ticket has quantities available for purchase
-     *
-     * @param  int $DTT_ID the primary key for a particular datetime
-     * @return boolean
-     * @throws \EE_Error
-     */
-    public function available($DTT_ID = 0)
-    {
-        // are we checking availability for a particular datetime ?
-        if ($DTT_ID) {
-            // get that datetime object
-            $datetime = $this->get_first_related('Datetime', array(array('DTT_ID' => $DTT_ID)));
-            // if  ticket sales for this datetime have exceeded the reg limit...
-            if ($datetime instanceof EE_Datetime && $datetime->sold_out()) {
-                return false;
-            }
-        }
-        // datetime is still open for registration, but is this ticket sold out ?
-        return $this->qty() < 1 || $this->qty() > $this->sold() ? true : false;
-    }
-
-
-    /**
-     * Using the start date and end date this method calculates whether the ticket is On Sale, Pending, or Expired
-     *
-     * @param bool        $display   true = we'll return a localized string, otherwise we just return the value of the
-     *                               relevant status const
-     * @param bool | null $remaining if it is already known that tickets are available, then simply pass a bool to save
-     *               further processing
-     * @return mixed status int if the display string isn't requested
-     * @throws \EE_Error
-     */
-    public function ticket_status($display = false, $remaining = null)
-    {
-        $remaining = is_bool($remaining) ? $remaining : $this->is_remaining();
-        if (! $remaining) {
-            return $display ? EEH_Template::pretty_status(EE_Ticket::sold_out, false, 'sentence') : EE_Ticket::sold_out;
-        }
-        if ($this->get('TKT_deleted')) {
-            return $display ? EEH_Template::pretty_status(EE_Ticket::archived, false, 'sentence') : EE_Ticket::archived;
-        }
-        if ($this->is_expired()) {
-            return $display ? EEH_Template::pretty_status(EE_Ticket::expired, false, 'sentence') : EE_Ticket::expired;
-        }
-        if ($this->is_pending()) {
-            return $display ? EEH_Template::pretty_status(EE_Ticket::pending, false, 'sentence') : EE_Ticket::pending;
-        }
-        if ($this->is_on_sale()) {
-            return $display ? EEH_Template::pretty_status(EE_Ticket::onsale, false, 'sentence') : EE_Ticket::onsale;
-        }
-        return '';
-    }
-
-
-    /**
-     * The purpose of this method is to simply return a boolean for whether there are any tickets remaining for sale
-     * considering ALL the factors used for figuring that out.
-     *
-     * @access public
-     * @param  int $DTT_ID if an int above 0 is included here then we get a specific dtt.
-     * @return boolean         true = tickets remaining, false not.
-     * @throws \EE_Error
-     */
-    public function is_remaining($DTT_ID = 0)
-    {
-        $num_remaining = $this->remaining($DTT_ID);
-        if ($num_remaining === 0) {
-            return false;
-        }
-        if ($num_remaining > 0 && $num_remaining < $this->min()) {
-            return false;
-        }
-        return true;
-    }
-
-
-    /**
-     * return the total number of tickets available for purchase
-     *
-     * @param  int $DTT_ID the primary key for a particular datetime.
-     *                     set to 0 for all related datetimes
-     * @return int
-     * @throws \EE_Error
-     */
-    public function remaining($DTT_ID = 0)
-    {
-        return $this->real_quantity_on_ticket('saleable', $DTT_ID);
-    }
-
-
-    /**
-     * Gets min
-     *
-     * @return int
-     * @throws \EE_Error
-     */
-    public function min()
-    {
-        return $this->get('TKT_min');
-    }
-
-
-    /**
-     * return if a ticket is no longer available cause its available dates have expired.
-     *
-     * @return boolean
-     * @throws \EE_Error
-     */
-    public function is_expired()
-    {
-        return ($this->get_raw('TKT_end_date') < time());
-    }
-
-
-    /**
-     * Return if a ticket is yet to go on sale or not
-     *
-     * @return boolean
-     * @throws \EE_Error
-     */
-    public function is_pending()
-    {
-        return ($this->get_raw('TKT_start_date') > time());
-    }
-
-
-    /**
-     * Return if a ticket is on sale or not
-     *
-     * @return boolean
-     * @throws \EE_Error
-     */
-    public function is_on_sale()
-    {
-        return ($this->get_raw('TKT_start_date') < time() && $this->get_raw('TKT_end_date') > time());
-    }
-
-
-    /**
-     * This returns the chronologically last datetime that this ticket is associated with
-     *
-     * @param string $dt_frmt
-     * @param string $conjunction - conjunction junction what's your function ? this string joins the start date with
-     *                            the end date ie: Jan 01 "to" Dec 31
-     * @return string
-     * @throws \EE_Error
-     */
-    public function date_range($dt_frmt = '', $conjunction = ' - ')
-    {
-        $first_date = $this->first_datetime() instanceof EE_Datetime ? $this->first_datetime()->start_date($dt_frmt)
-            : '';
-        $last_date = $this->last_datetime() instanceof EE_Datetime ? $this->last_datetime()->end_date($dt_frmt) : '';
-
-        return $first_date && $last_date ? $first_date . $conjunction . $last_date : '';
-    }
-
-
-    /**
-     * This returns the chronologically first datetime that this ticket is associated with
-     *
-     * @return EE_Datetime
-     * @throws \EE_Error
-     */
-    public function first_datetime()
-    {
-        $datetimes = $this->datetimes(array('limit' => 1));
-        return reset($datetimes);
-    }
-
-
-    /**
-     * Gets all the datetimes this ticket can be used for attending.
-     * Unless otherwise specified, orders datetimes by start date.
-     *
-     * @param array $query_params @see https://github.com/eventespresso/event-espresso-core/tree/master/docs/G--Model-System/model-query-params.md
-     * @return EE_Datetime[]|EE_Base_Class[]
-     * @throws \EE_Error
-     */
-    public function datetimes($query_params = array())
-    {
-        if (! isset($query_params['order_by'])) {
-            $query_params['order_by']['DTT_order'] = 'ASC';
-        }
-        return $this->get_many_related('Datetime', $query_params);
-    }
-
-
-    /**
-     * This returns the chronologically last datetime that this ticket is associated with
-     *
-     * @return EE_Datetime
-     * @throws \EE_Error
-     */
-    public function last_datetime()
-    {
-        $datetimes = $this->datetimes(array('limit' => 1, 'order_by' => array('DTT_EVT_start' => 'DESC')));
-        return end($datetimes);
-    }
-
-
-    /**
-     * This returns the total tickets sold depending on the given parameters.
-     *
-     * @param  string $what   Can be one of two options: 'ticket', 'datetime'.
-     *                        'ticket' = total ticket sales for all datetimes this ticket is related to
-     *                        'datetime' = total ticket sales for a specified datetime (required $dtt_id)
-     *                        'datetime' = total ticket sales in the datetime_ticket table.
-     *                        If $dtt_id is not given then we return an array of sales indexed by datetime.
-     *                        If $dtt_id IS given then we return the tickets sold for that given datetime.
-     * @param  int    $dtt_id [optional] include the dtt_id with $what = 'datetime'.
-     * @return mixed (array|int)          how many tickets have sold
-     * @throws \EE_Error
-     */
-    public function tickets_sold($what = 'ticket', $dtt_id = null)
-    {
-        $total = 0;
-        $tickets_sold = $this->_all_tickets_sold();
-        switch ($what) {
-            case 'ticket':
-                return $tickets_sold['ticket'];
-                break;
-            case 'datetime':
-                if (empty($tickets_sold['datetime'])) {
-                    return $total;
-                }
-                if (! empty($dtt_id) && ! isset($tickets_sold['datetime'][ $dtt_id ])) {
-                    EE_Error::add_error(
-                        __(
-                            'You\'ve requested the amount of tickets sold for a given ticket and datetime, however there are no records for the datetime id you included.  Are you SURE that is a datetime related to this ticket?',
-                            'event_espresso'
-                        ),
-                        __FILE__,
-                        __FUNCTION__,
-                        __LINE__
-                    );
-                    return $total;
-                }
-                return empty($dtt_id) ? $tickets_sold['datetime'] : $tickets_sold['datetime'][ $dtt_id ];
-                break;
-            default:
-                return $total;
-        }
-    }
-
-
-    /**
-     * This returns an array indexed by datetime_id for tickets sold with this ticket.
-     *
-     * @return EE_Ticket[]
-     * @throws \EE_Error
-     */
-    protected function _all_tickets_sold()
-    {
-        $datetimes = $this->get_many_related('Datetime');
-        $tickets_sold = array();
-        if (! empty($datetimes)) {
-            foreach ($datetimes as $datetime) {
-                $tickets_sold['datetime'][ $datetime->ID() ] = $datetime->get('DTT_sold');
-            }
-        }
-        // Tickets sold
-        $tickets_sold['ticket'] = $this->sold();
-        return $tickets_sold;
-    }
-
-
-    /**
-     * This returns the base price object for the ticket.
-     *
-     * @param  bool $return_array whether to return as an array indexed by price id or just the object.
-     * @return EE_Price|EE_Base_Class|EE_Price[]|EE_Base_Class[]
-     * @throws \EE_Error
-     */
-    public function base_price($return_array = false)
-    {
-        $_where = array('Price_Type.PBT_ID' => EEM_Price_Type::base_type_base_price);
-        return $return_array
-            ? $this->get_many_related('Price', array($_where))
-            : $this->get_first_related('Price', array($_where));
-    }
-
-
-    /**
-     * This returns ONLY the price modifiers for the ticket (i.e. no taxes or base price)
-     *
-     * @access public
-     * @return EE_Price[]
-     * @throws \EE_Error
-     */
-    public function price_modifiers()
-    {
-        $query_params = array(
-            0 => array(
-                'Price_Type.PBT_ID' => array(
-                    'NOT IN',
-                    array(EEM_Price_Type::base_type_base_price, EEM_Price_Type::base_type_tax),
-                ),
-            ),
-        );
-        return $this->prices($query_params);
-    }
-
-
-    /**
-     * Gets all the prices that combine to form the final price of this ticket
-     *
-     * @param array $query_params @see https://github.com/eventespresso/event-espresso-core/tree/master/docs/G--Model-System/model-query-params.md
-     * @return EE_Price[]|EE_Base_Class[]
-     * @throws \EE_Error
-     */
-    public function prices($query_params = array())
-    {
-        return $this->get_many_related('Price', $query_params);
-    }
-
-
-    /**
-     * Gets all the ticket applicabilities (ie, relations between datetimes and tickets)
-     *
-     * @param array $query_params @see https://github.com/eventespresso/event-espresso-core/tree/master/docs/G--Model-System/model-query-params.md
-     * @return EE_Datetime_Ticket|EE_Base_Class[]
-     * @throws \EE_Error
-     */
-    public function datetime_tickets($query_params = array())
-    {
-        return $this->get_many_related('Datetime_Ticket', $query_params);
-    }
-
-
-    /**
-     * Gets all the datetimes from the db ordered by DTT_order
-     *
-     * @param boolean $show_expired
-     * @param boolean $show_deleted
-     * @return EE_Datetime[]
-     * @throws \EE_Error
-     */
-    public function datetimes_ordered($show_expired = true, $show_deleted = false)
-    {
-        return EEM_Datetime::instance($this->_timezone)->get_datetimes_for_ticket_ordered_by_DTT_order(
-            $this->ID(),
-            $show_expired,
-            $show_deleted
-        );
-    }
-
-
-    /**
-     * Gets ID
-     *
-     * @return string
-     * @throws \EE_Error
-     */
-    public function ID()
-    {
-        return $this->get('TKT_ID');
-    }
-
-
-    /**
-     * get the author of the ticket.
-     *
-     * @since 4.5.0
-     * @return int
-     * @throws \EE_Error
-     */
-    public function wp_user()
-    {
-        return $this->get('TKT_wp_user');
-    }
-
-
-    /**
-     * Gets the template for the ticket
-     *
-     * @return EE_Ticket_Template|EE_Base_Class
-     * @throws \EE_Error
-     */
-    public function template()
-    {
-        return $this->get_first_related('Ticket_Template');
-    }
-
-
-    /**
-     * Simply returns an array of EE_Price objects that are taxes.
-     *
-     * @return EE_Price[]
-     * @throws \EE_Error
-     */
-    public function get_ticket_taxes_for_admin()
-    {
-        return EE_Taxes::get_taxes_for_admin();
-    }
-
-
-    /**
-     * @return float
-     * @throws \EE_Error
-     */
-    public function ticket_price()
-    {
-        return $this->get('TKT_price');
-    }
-
-
-    /**
-     * @return mixed
-     * @throws \EE_Error
-     */
-    public function pretty_price()
-    {
-        return $this->get_pretty('TKT_price');
-    }
-
-
-    /**
-     * @return bool
-     * @throws \EE_Error
-     */
-    public function is_free()
-    {
-        return $this->get_ticket_total_with_taxes() === (float) 0;
-    }
-
-
-    /**
-     * get_ticket_total_with_taxes
-     *
-     * @param bool $no_cache
-     * @return float
-     * @throws \EE_Error
-     */
-    public function get_ticket_total_with_taxes($no_cache = false)
-    {
-        if ($this->_ticket_total_with_taxes === null || $no_cache) {
-            $this->_ticket_total_with_taxes = $this->get_ticket_subtotal() + $this->get_ticket_taxes_total_for_admin();
-        }
-        return (float) $this->_ticket_total_with_taxes;
-    }
-
-
-    public function ensure_TKT_Price_correct()
-    {
-        $this->set('TKT_price', EE_Taxes::get_subtotal_for_admin($this));
-        $this->save();
-    }
-
-
-    /**
-     * @return float
-     * @throws \EE_Error
-     */
-    public function get_ticket_subtotal()
-    {
-        return EE_Taxes::get_subtotal_for_admin($this);
-    }
-
-
-    /**
-     * Returns the total taxes applied to this ticket
-     *
-     * @return float
-     * @throws \EE_Error
-     */
-    public function get_ticket_taxes_total_for_admin()
-    {
-        return EE_Taxes::get_total_taxes_for_admin($this);
-    }
-
-
-    /**
-     * Sets name
-     *
-     * @param string $name
-     * @throws \EE_Error
-     */
-    public function set_name($name)
-    {
-        $this->set('TKT_name', $name);
-    }
-
-
-    /**
-     * Gets description
-     *
-     * @return string
-     * @throws \EE_Error
-     */
-    public function description()
-    {
-        return $this->get('TKT_description');
-    }
-
-
-    /**
-     * Sets description
-     *
-     * @param string $description
-     * @throws \EE_Error
-     */
-    public function set_description($description)
-    {
-        $this->set('TKT_description', $description);
-    }
-
-
-    /**
-     * Gets start_date
-     *
-     * @param string $dt_frmt
-     * @param string $tm_frmt
-     * @return string
-     * @throws \EE_Error
-     */
-    public function start_date($dt_frmt = '', $tm_frmt = '')
-    {
-        return $this->_get_datetime('TKT_start_date', $dt_frmt, $tm_frmt);
-    }
-
-
-    /**
-     * Sets start_date
-     *
-     * @param string $start_date
-     * @return void
-     * @throws \EE_Error
-     */
-    public function set_start_date($start_date)
-    {
-        $this->_set_date_time('B', $start_date, 'TKT_start_date');
-    }
-
-
-    /**
-     * Gets end_date
-     *
-     * @param string $dt_frmt
-     * @param string $tm_frmt
-     * @return string
-     * @throws \EE_Error
-     */
-    public function end_date($dt_frmt = '', $tm_frmt = '')
-    {
-        return $this->_get_datetime('TKT_end_date', $dt_frmt, $tm_frmt);
-    }
-
-
-    /**
-     * Sets end_date
-     *
-     * @param string $end_date
-     * @return void
-     * @throws \EE_Error
-     */
-    public function set_end_date($end_date)
-    {
-        $this->_set_date_time('B', $end_date, 'TKT_end_date');
-    }
-
-
-    /**
-     * Sets sell until time
-     *
-     * @since 4.5.0
-     * @param string $time a string representation of the sell until time (ex 9am or 7:30pm)
-     * @throws \EE_Error
-     */
-    public function set_end_time($time)
-    {
-        $this->_set_time_for($time, 'TKT_end_date');
-    }
-
-
-    /**
-     * Sets min
-     *
-     * @param int $min
-     * @return void
-     * @throws \EE_Error
-     */
-    public function set_min($min)
-    {
-        $this->set('TKT_min', $min);
-    }
-
-
-    /**
-     * Gets max
-     *
-     * @return int
-     * @throws \EE_Error
-     */
-    public function max()
-    {
-        return $this->get('TKT_max');
-    }
-
-
-    /**
-     * Sets max
-     *
-     * @param int $max
-     * @return void
-     * @throws \EE_Error
-     */
-    public function set_max($max)
-    {
-        $this->set('TKT_max', $max);
-    }
-
-
-    /**
-     * Sets price
-     *
-     * @param float $price
-     * @return void
-     * @throws \EE_Error
-     */
-    public function set_price($price)
-    {
-        $this->set('TKT_price', $price);
-    }
-
-
-    /**
-     * Gets sold
-     *
-     * @return int
-     * @throws \EE_Error
-     */
-    public function sold()
-    {
-        return $this->get_raw('TKT_sold');
-    }
-
-
-    /**
-     * Sets sold
-     *
-     * @param int $sold
-     * @return void
-     * @throws \EE_Error
-     */
-    public function set_sold($sold)
-    {
-        // sold can not go below zero
-        $sold = max(0, $sold);
-        $this->set('TKT_sold', $sold);
-    }
-
-
-    /**
-     * increments sold by amount passed by $qty
-     *
-     * @param int $qty
-     * @return void
-     * @throws \EE_Error
-     */
-    public function increase_sold($qty = 1)
-    {
-        $sold = $this->sold() + $qty;
-        // remove ticket reservation, but don't adjust datetime reservations,  because that will happen
-        // via \EE_Datetime::increase_sold() when \EE_Ticket::_increase_sold_for_datetimes() is called
-        $this->decrease_reserved($qty, false, "TKT: {$this->ID()} (ln:" . __LINE__ . ')');
-        $this->_increase_sold_for_datetimes($qty);
-        $this->set_sold($sold);
-        do_action(
-            'AHEE__EE_Ticket__increase_sold',
-            $this,
-            $qty,
-            $sold
-        );
-    }
-
-
-    /**
-     * Increases sold on related datetimes
-     *
-     * @param int $qty
-     * @return void
-     * @throws \EE_Error
-     */
-    protected function _increase_sold_for_datetimes($qty = 1)
-    {
-        $datetimes = $this->datetimes();
-        if (is_array($datetimes)) {
-            foreach ($datetimes as $datetime) {
-                if ($datetime instanceof EE_Datetime) {
-                    $datetime->increase_sold($qty);
-                    $datetime->save();
-                }
-            }
-        }
-    }
-
-
-    /**
-     * decrements (subtracts) sold by amount passed by $qty
-     *
-     * @param int $qty
-     * @return void
-     * @throws \EE_Error
-     */
-    public function decrease_sold($qty = 1)
-    {
-        $sold = $this->sold() - $qty;
-        $this->_decrease_sold_for_datetimes($qty);
-        $this->set_sold($sold);
-        do_action(
-            'AHEE__EE_Ticket__decrease_sold',
-            $this,
-            $qty,
-            $sold
-        );
-    }
-
-
-    /**
-     * Decreases sold on related datetimes
-     *
-     * @param int $qty
-     * @return void
-     * @throws \EE_Error
-     */
-    protected function _decrease_sold_for_datetimes($qty = 1)
-    {
-        $datetimes = $this->datetimes();
-        if (is_array($datetimes)) {
-            foreach ($datetimes as $datetime) {
-                if ($datetime instanceof EE_Datetime) {
-                    $datetime->decrease_sold($qty);
-                    $datetime->save();
-                }
-            }
-        }
-    }
-
-
-    /**
-     * Gets qty of reserved tickets
-     *
-     * @return int
-     * @throws \EE_Error
-     */
-    public function reserved()
-    {
-        return $this->get_raw('TKT_reserved');
-    }
-
-
-    /**
-     * Sets reserved
-     *
-     * @param int $reserved
-     * @return void
-     * @throws \EE_Error
-     */
-    public function set_reserved($reserved)
-    {
-        // reserved can not go below zero
-        $reserved = max(0, (int) $reserved);
-        $this->set('TKT_reserved', $reserved);
-    }
-
-
-    /**
-     * increments reserved by amount passed by $qty
-     *
-     * @param int    $qty
-     * @param string $source
-     * @return void
-     * @throws EE_Error
-     * @throws InvalidArgumentException
-     * @throws ReflectionException
-     * @throws \EventEspresso\core\exceptions\InvalidDataTypeException
-     * @throws \EventEspresso\core\exceptions\InvalidInterfaceException
-     */
-    public function increase_reserved($qty = 1, $source = 'unknown')
-    {
-        $qty = absint($qty);
-        $reserved = $this->reserved() + $qty;
-        if ($reserved
-            && $this->add_extra_meta(
-                EE_Ticket::META_KEY_TICKET_RESERVATIONS,
-                "{$qty} from {$source}"
-            )
-        ) {
-            $this->_increase_reserved_for_datetimes($qty);
-            $this->set_reserved($reserved);
-            do_action(
-                'AHEE__EE_Ticket__increase_reserved',
-                $this,
-                $qty,
-                $reserved
-            );
-        }
-    }
-
-
-    /**
-     * Increases sold on related datetimes
-     *
-     * @param int $qty
-     * @return void
-     * @throws \EE_Error
-     */
-    protected function _increase_reserved_for_datetimes($qty = 1)
-    {
-        $datetimes = $this->datetimes();
-        if (is_array($datetimes)) {
-            foreach ($datetimes as $datetime) {
-                if ($datetime instanceof EE_Datetime) {
-                    $datetime->increase_reserved($qty);
-                    $datetime->save();
-                }
-            }
-        }
-    }
-
-
-    /**
-     * decrements (subtracts) reserved by amount passed by $qty
-     *
-     * @param int    $qty
-     * @param bool   $adjust_datetimes
-     * @param string $source
-     * @return void
-     * @throws EE_Error
-     * @throws InvalidArgumentException
-     * @throws ReflectionException
-     * @throws \EventEspresso\core\exceptions\InvalidDataTypeException
-     * @throws \EventEspresso\core\exceptions\InvalidInterfaceException
-     */
-    public function decrease_reserved($qty = 1, $adjust_datetimes = true, $source = 'unknown')
-    {
-        $reserved = $this->reserved() - absint($qty);
-        if ($this->add_extra_meta(
-            EE_Ticket::META_KEY_TICKET_RESERVATIONS,
-            "-{$qty} from {$source}"
-        )) {
-            if ($adjust_datetimes) {
-                $this->_decrease_reserved_for_datetimes($qty);
-            }
-            $this->set_reserved($reserved);
-            do_action(
-                'AHEE__EE_Ticket__decrease_reserved',
-                $this,
-                $qty,
-                $reserved
-            );
-        }
-    }
-
-
-    /**
-     * Increases sold on related datetimes
-     *
-     * @param int $qty
-     * @return void
-     * @throws \EE_Error
-     */
-    protected function _decrease_reserved_for_datetimes($qty = 1)
-    {
-        $datetimes = $this->datetimes();
-        if (is_array($datetimes)) {
-            foreach ($datetimes as $datetime) {
-                if ($datetime instanceof EE_Datetime) {
-                    $datetime->decrease_reserved($qty);
-                    $datetime->save();
-                }
-            }
-        }
-    }
-
-
-    /**
-     * Gets ticket quantity
-     *
-     * @param string $context     ticket quantity is somewhat subjective depending on the exact information sought
-     *                            therefore $context can be one of three values: '', 'reg_limit', or 'saleable'
-     *                            '' (default) quantity is the actual db value for TKT_qty, unaffected by other objects
-     *                            REG LIMIT: caps qty based on DTT_reg_limit for ALL related datetimes
-     *                            SALEABLE: also considers datetime sold and returns zero if ANY DTT is sold out, and
-     *                            is therefore the truest measure of tickets that can be purchased at the moment
-     * @return int
-     * @throws \EE_Error
-     */
-    public function qty($context = '')
-    {
-        switch ($context) {
-            case 'reg_limit':
-                return $this->real_quantity_on_ticket();
-            case 'saleable':
-                return $this->real_quantity_on_ticket('saleable');
-            default:
-                return $this->get_raw('TKT_qty');
-        }
-    }
-
-
-    /**
-     * Gets ticket quantity
-     *
-     * @param string $context     ticket quantity is somewhat subjective depending on the exact information sought
-     *                            therefore $context can be one of two values: 'reg_limit', or 'saleable'
-     *                            REG LIMIT: caps qty based on DTT_reg_limit for ALL related datetimes
-     *                            SALEABLE: also considers datetime sold and returns zero if ANY DTT is sold out, and
-     *                            is therefore the truest measure of tickets that can be purchased at the moment
-     * @param  int   $DTT_ID      the primary key for a particular datetime.
-     *                            set to 0 for all related datetimes
-     * @return int
-     * @throws \EE_Error
-     */
-    public function real_quantity_on_ticket($context = 'reg_limit', $DTT_ID = 0)
-    {
-        $raw = $this->get_raw('TKT_qty');
-        // return immediately if it's zero
-        if ($raw === 0) {
-            return $raw;
-        }
-        // echo "\n\n<br />Ticket: " . $this->name() . '<br />';
-        // ensure qty doesn't exceed raw value for THIS ticket
-        $qty = min(EE_INF, $raw);
-        // echo "\n . qty: " . $qty . '<br />';
-        // calculate this ticket's total sales and reservations
-        $sold_and_reserved_for_this_ticket = $this->sold() + $this->reserved();
-        // echo "\n . sold: " . $this->sold() . '<br />';
-        // echo "\n . reserved: " . $this->reserved() . '<br />';
-        // echo "\n . sold_and_reserved_for_this_ticket: " . $sold_and_reserved_for_this_ticket . '<br />';
-        // first we need to calculate the maximum number of tickets available for the datetime
-        // do we want data for one datetime or all of them ?
-        $query_params = $DTT_ID ? array(array('DTT_ID' => $DTT_ID)) : array();
-        $datetimes = $this->datetimes($query_params);
-        if (is_array($datetimes) && ! empty($datetimes)) {
-            foreach ($datetimes as $datetime) {
-                if ($datetime instanceof EE_Datetime) {
-                    $datetime->refresh_from_db();
-                    // echo "\n . . datetime name: " . $datetime->name() . '<br />';
-                    // echo "\n . . datetime ID: " . $datetime->ID() . '<br />';
-                    // initialize with no restrictions for each datetime
-                    // but adjust datetime qty based on datetime reg limit
-                    $datetime_qty = min(EE_INF, $datetime->reg_limit());
-                    // echo "\n . . . datetime reg_limit: " . $datetime->reg_limit() . '<br />';
-                    // echo "\n . . . datetime_qty: " . $datetime_qty . '<br />';
-                    // if we want the actual saleable amount, then we need to consider OTHER ticket sales
-                    // and reservations for this datetime, that do NOT include sales and reservations
-                    // for this ticket (so we add $this->sold() and $this->reserved() back in)
-                    if ($context === 'saleable') {
-                        $datetime_qty = max(
-                            $datetime_qty - $datetime->sold_and_reserved() + $sold_and_reserved_for_this_ticket,
-                            0
-                        );
-                        // echo "\n . . . datetime sold: " . $datetime->sold() . '<br />';
-                        // echo "\n . . . datetime reserved: " . $datetime->reserved() . '<br />';
-                        // echo "\n . . . datetime sold_and_reserved: " . $datetime->sold_and_reserved() . '<br />';
-                        // echo "\n . . . datetime_qty: " . $datetime_qty . '<br />';
-                        $datetime_qty = ! $datetime->sold_out() ? $datetime_qty : 0;
-                        // echo "\n . . . datetime_qty: " . $datetime_qty . '<br />';
-                    }
-                    $qty = min($datetime_qty, $qty);
-                    // echo "\n . . qty: " . $qty . '<br />';
-                }
-            }
-        }
-        // NOW that we know the  maximum number of tickets available for the datetime
-        // we can finally factor in the details for this specific ticket
-        if ($qty > 0 && $context === 'saleable') {
-            // and subtract the sales for THIS ticket
-            $qty = max($qty - $sold_and_reserved_for_this_ticket, 0);
-            // echo "\n . qty: " . $qty . '<br />';
-        }
-        // echo "\nFINAL QTY: " . $qty . "<br /><br />";
-        return $qty;
-    }
-
-
-    /**
-     * Sets qty - IMPORTANT!!! Does NOT allow QTY to be set higher than the lowest reg limit of any related datetimes
-     *
-     * @param int $qty
-     * @return void
-     * @throws \EE_Error
-     */
-    public function set_qty($qty)
-    {
-        $datetimes = $this->datetimes();
-        foreach ($datetimes as $datetime) {
-            if ($datetime instanceof EE_Datetime) {
-                $qty = min($qty, $datetime->reg_limit());
-            }
-        }
-        $this->set('TKT_qty', $qty);
-    }
-
-
-    /**
-     * Gets uses
-     *
-     * @return int
-     * @throws \EE_Error
-     */
-    public function uses()
-    {
-        return $this->get('TKT_uses');
-    }
-
-
-    /**
-     * Sets uses
-     *
-     * @param int $uses
-     * @return void
-     * @throws \EE_Error
-     */
-    public function set_uses($uses)
-    {
-        $this->set('TKT_uses', $uses);
-    }
-
-
-    /**
-     * returns whether ticket is required or not.
-     *
-     * @return boolean
-     * @throws \EE_Error
-     */
-    public function required()
-    {
-        return $this->get('TKT_required');
-    }
-
-
-    /**
-     * sets the TKT_required property
-     *
-     * @param boolean $required
-     * @return void
-     * @throws \EE_Error
-     */
-    public function set_required($required)
-    {
-        $this->set('TKT_required', $required);
-    }
-
-
-    /**
-     * Gets taxable
-     *
-     * @return boolean
-     * @throws \EE_Error
-     */
-    public function taxable()
-    {
-        return $this->get('TKT_taxable');
-    }
-
-
-    /**
-     * Sets taxable
-     *
-     * @param boolean $taxable
-     * @return void
-     * @throws \EE_Error
-     */
-    public function set_taxable($taxable)
-    {
-        $this->set('TKT_taxable', $taxable);
-    }
-
-
-    /**
-     * Gets is_default
-     *
-     * @return boolean
-     * @throws \EE_Error
-     */
-    public function is_default()
-    {
-        return $this->get('TKT_is_default');
-    }
-
-
-    /**
-     * Sets is_default
-     *
-     * @param boolean $is_default
-     * @return void
-     * @throws \EE_Error
-     */
-    public function set_is_default($is_default)
-    {
-        $this->set('TKT_is_default', $is_default);
-    }
-
-
-    /**
-     * Gets order
-     *
-     * @return int
-     * @throws \EE_Error
-     */
-    public function order()
-    {
-        return $this->get('TKT_order');
-    }
-
-
-    /**
-     * Sets order
-     *
-     * @param int $order
-     * @return void
-     * @throws \EE_Error
-     */
-    public function set_order($order)
-    {
-        $this->set('TKT_order', $order);
-    }
-
-
-    /**
-     * Gets row
-     *
-     * @return int
-     * @throws \EE_Error
-     */
-    public function row()
-    {
-        return $this->get('TKT_row');
-    }
-
-
-    /**
-     * Sets row
-     *
-     * @param int $row
-     * @return void
-     * @throws \EE_Error
-     */
-    public function set_row($row)
-    {
-        $this->set('TKT_row', $row);
-    }
-
-
-    /**
-     * Gets deleted
-     *
-     * @return boolean
-     * @throws \EE_Error
-     */
-    public function deleted()
-    {
-        return $this->get('TKT_deleted');
-    }
-
-
-    /**
-     * Sets deleted
-     *
-     * @param boolean $deleted
-     * @return void
-     * @throws \EE_Error
-     */
-    public function set_deleted($deleted)
-    {
-        $this->set('TKT_deleted', $deleted);
-    }
-
-
-    /**
-     * Gets parent
-     *
-     * @return int
-     * @throws \EE_Error
-     */
-    public function parent_ID()
-    {
-        return $this->get('TKT_parent');
-    }
-
-
-    /**
-     * Sets parent
-     *
-     * @param int $parent
-     * @return void
-     * @throws \EE_Error
-     */
-    public function set_parent_ID($parent)
-    {
-        $this->set('TKT_parent', $parent);
-    }
-
-
-    /**
-     * Gets a string which is handy for showing in gateways etc that describes the ticket.
-     *
-     * @return string
-     * @throws \EE_Error
-     */
-    public function name_and_info()
-    {
-        $times = array();
-        foreach ($this->datetimes() as $datetime) {
-            $times[] = $datetime->start_date_and_time();
-        }
-        return $this->name() . ' @ ' . implode(', ', $times) . ' for ' . $this->pretty_price();
-    }
-
-
-    /**
-     * Gets name
-     *
-     * @return string
-     * @throws \EE_Error
-     */
-    public function name()
-    {
-        return $this->get('TKT_name');
-    }
-
-
-    /**
-     * Gets price
-     *
-     * @return float
-     * @throws \EE_Error
-     */
-    public function price()
-    {
-        return $this->get('TKT_price');
-    }
-
-
-    /**
-     * Gets all the registrations for this ticket
-     *
-     * @param array $query_params @see https://github.com/eventespresso/event-espresso-core/tree/master/docs/G--Model-System/model-query-params.md
-     * @return EE_Registration[]|EE_Base_Class[]
-     * @throws \EE_Error
-     */
-    public function registrations($query_params = array())
-    {
-        return $this->get_many_related('Registration', $query_params);
-    }
-
-
-    /**
-     * Updates the TKT_sold attribute (and saves) based on the number of APPROVED registrations for this ticket.
-     * into account
-     *
-     * @return int
-     * @throws \EE_Error
-     */
-    public function update_tickets_sold()
-    {
-        $count_regs_for_this_ticket = $this->count_registrations(
-            array(
-                array(
-                    'STS_ID'      => EEM_Registration::status_id_approved,
-                    'REG_deleted' => 0,
-                ),
-            )
-        );
-        $sold = $this->sold();
-        if ($count_regs_for_this_ticket > $sold) {
-            $this->increase_sold($count_regs_for_this_ticket - $sold);
-            $this->save();
-        } elseif ($count_regs_for_this_ticket < $sold) {
-            $this->decrease_sold($count_regs_for_this_ticket - $sold);
-            $this->save();
-        }
-        return $count_regs_for_this_ticket;
-    }
-
-
-    /**
-     * Counts the registrations for this ticket
-     *
-     * @param array $query_params @see https://github.com/eventespresso/event-espresso-core/tree/master/docs/G--Model-System/model-query-params.md
-     * @return int
-     */
-    public function count_registrations($query_params = array())
-    {
-        return $this->count_related('Registration', $query_params);
-    }
-
-
-    /**
-     * Implementation for EEI_Has_Icon interface method.
-     *
-     * @see EEI_Visual_Representation for comments
-     * @return string
-     */
-    public function get_icon()
-    {
-        return '<span class="dashicons dashicons-tickets-alt"></span>';
-    }
-
-
-    /**
-     * Implementation of the EEI_Event_Relation interface method
-     *
-     * @see EEI_Event_Relation for comments
-     * @return EE_Event
-     * @throws \EE_Error
-     * @throws UnexpectedEntityException
-     */
-    public function get_related_event()
-    {
-        // get one datetime to use for getting the event
-        $datetime = $this->first_datetime();
-        if (! $datetime instanceof \EE_Datetime) {
-            throw new UnexpectedEntityException(
-                $datetime,
-                'EE_Datetime',
-                sprintf(
-                    __('The ticket (%s) is not associated with any valid datetimes.', 'event_espresso'),
-                    $this->name()
-                )
-            );
-        }
-        $event = $datetime->event();
-        if (! $event instanceof \EE_Event) {
-            throw new UnexpectedEntityException(
-                $event,
-                'EE_Event',
-                sprintf(
-                    __('The ticket (%s) is not associated with a valid event.', 'event_espresso'),
-                    $this->name()
-                )
-            );
-        }
-        return $event;
-    }
-
-
-    /**
-     * Implementation of the EEI_Event_Relation interface method
-     *
-     * @see EEI_Event_Relation for comments
-     * @return string
-     * @throws UnexpectedEntityException
-     * @throws \EE_Error
-     */
-    public function get_event_name()
-    {
-        $event = $this->get_related_event();
-        return $event instanceof EE_Event ? $event->name() : '';
-    }
-
-
-    /**
-     * Implementation of the EEI_Event_Relation interface method
-     *
-     * @see EEI_Event_Relation for comments
-     * @return int
-     * @throws UnexpectedEntityException
-     * @throws \EE_Error
-     */
-    public function get_event_ID()
-    {
-        $event = $this->get_related_event();
-        return $event instanceof EE_Event ? $event->ID() : 0;
-    }
-
-
-    /**
-     * This simply returns whether a ticket can be permanently deleted or not.
-     * The criteria for determining this is whether the ticket has any related registrations.
-     * If there are none then it can be permanently deleted.
-     *
-     * @return bool
-     */
-    public function is_permanently_deleteable()
-    {
-        return $this->count_registrations() === 0;
-    }
+	/**
+	 * The following constants are used by the ticket_status() method to indicate whether a ticket is on sale or not.
+	 */
+	const sold_out = 'TKS';
+
+	/**
+	 *
+	 */
+	const expired = 'TKE';
+
+	/**
+	 *
+	 */
+	const archived = 'TKA';
+
+	/**
+	 *
+	 */
+	const pending = 'TKP';
+
+	/**
+	 *
+	 */
+	const onsale = 'TKO';
+
+	/**
+	 * extra meta key for tracking ticket reservations
+	 *
+	 * @type string
+	 */
+	const META_KEY_TICKET_RESERVATIONS = 'ticket_reservations';
+
+	/**
+	 * cached result from method of the same name
+	 *
+	 * @var float $_ticket_total_with_taxes
+	 */
+	private $_ticket_total_with_taxes;
+
+
+	/**
+	 * @param array  $props_n_values          incoming values
+	 * @param string $timezone                incoming timezone (if not set the timezone set for the website will be
+	 *                                        used.)
+	 * @param array  $date_formats            incoming date_formats in an array where the first value is the
+	 *                                        date_format and the second value is the time format
+	 * @return EE_Ticket
+	 * @throws \EE_Error
+	 */
+	public static function new_instance($props_n_values = array(), $timezone = null, $date_formats = array())
+	{
+		$has_object = parent::_check_for_object($props_n_values, __CLASS__, $timezone, $date_formats);
+		return $has_object ? $has_object : new self($props_n_values, false, $timezone, $date_formats);
+	}
+
+
+	/**
+	 * @param array  $props_n_values  incoming values from the database
+	 * @param string $timezone        incoming timezone as set by the model.  If not set the timezone for
+	 *                                the website will be used.
+	 * @return EE_Ticket
+	 * @throws \EE_Error
+	 */
+	public static function new_instance_from_db($props_n_values = array(), $timezone = null)
+	{
+		return new self($props_n_values, true, $timezone);
+	}
+
+
+	/**
+	 * @return bool
+	 * @throws \EE_Error
+	 */
+	public function parent()
+	{
+		return $this->get('TKT_parent');
+	}
+
+
+	/**
+	 * return if a ticket has quantities available for purchase
+	 *
+	 * @param  int $DTT_ID the primary key for a particular datetime
+	 * @return boolean
+	 * @throws \EE_Error
+	 */
+	public function available($DTT_ID = 0)
+	{
+		// are we checking availability for a particular datetime ?
+		if ($DTT_ID) {
+			// get that datetime object
+			$datetime = $this->get_first_related('Datetime', array(array('DTT_ID' => $DTT_ID)));
+			// if  ticket sales for this datetime have exceeded the reg limit...
+			if ($datetime instanceof EE_Datetime && $datetime->sold_out()) {
+				return false;
+			}
+		}
+		// datetime is still open for registration, but is this ticket sold out ?
+		return $this->qty() < 1 || $this->qty() > $this->sold() ? true : false;
+	}
+
+
+	/**
+	 * Using the start date and end date this method calculates whether the ticket is On Sale, Pending, or Expired
+	 *
+	 * @param bool        $display   true = we'll return a localized string, otherwise we just return the value of the
+	 *                               relevant status const
+	 * @param bool | null $remaining if it is already known that tickets are available, then simply pass a bool to save
+	 *               further processing
+	 * @return mixed status int if the display string isn't requested
+	 * @throws \EE_Error
+	 */
+	public function ticket_status($display = false, $remaining = null)
+	{
+		$remaining = is_bool($remaining) ? $remaining : $this->is_remaining();
+		if (! $remaining) {
+			return $display ? EEH_Template::pretty_status(EE_Ticket::sold_out, false, 'sentence') : EE_Ticket::sold_out;
+		}
+		if ($this->get('TKT_deleted')) {
+			return $display ? EEH_Template::pretty_status(EE_Ticket::archived, false, 'sentence') : EE_Ticket::archived;
+		}
+		if ($this->is_expired()) {
+			return $display ? EEH_Template::pretty_status(EE_Ticket::expired, false, 'sentence') : EE_Ticket::expired;
+		}
+		if ($this->is_pending()) {
+			return $display ? EEH_Template::pretty_status(EE_Ticket::pending, false, 'sentence') : EE_Ticket::pending;
+		}
+		if ($this->is_on_sale()) {
+			return $display ? EEH_Template::pretty_status(EE_Ticket::onsale, false, 'sentence') : EE_Ticket::onsale;
+		}
+		return '';
+	}
+
+
+	/**
+	 * The purpose of this method is to simply return a boolean for whether there are any tickets remaining for sale
+	 * considering ALL the factors used for figuring that out.
+	 *
+	 * @access public
+	 * @param  int $DTT_ID if an int above 0 is included here then we get a specific dtt.
+	 * @return boolean         true = tickets remaining, false not.
+	 * @throws \EE_Error
+	 */
+	public function is_remaining($DTT_ID = 0)
+	{
+		$num_remaining = $this->remaining($DTT_ID);
+		if ($num_remaining === 0) {
+			return false;
+		}
+		if ($num_remaining > 0 && $num_remaining < $this->min()) {
+			return false;
+		}
+		return true;
+	}
+
+
+	/**
+	 * return the total number of tickets available for purchase
+	 *
+	 * @param  int $DTT_ID the primary key for a particular datetime.
+	 *                     set to 0 for all related datetimes
+	 * @return int
+	 * @throws \EE_Error
+	 */
+	public function remaining($DTT_ID = 0)
+	{
+		return $this->real_quantity_on_ticket('saleable', $DTT_ID);
+	}
+
+
+	/**
+	 * Gets min
+	 *
+	 * @return int
+	 * @throws \EE_Error
+	 */
+	public function min()
+	{
+		return $this->get('TKT_min');
+	}
+
+
+	/**
+	 * return if a ticket is no longer available cause its available dates have expired.
+	 *
+	 * @return boolean
+	 * @throws \EE_Error
+	 */
+	public function is_expired()
+	{
+		return ($this->get_raw('TKT_end_date') < time());
+	}
+
+
+	/**
+	 * Return if a ticket is yet to go on sale or not
+	 *
+	 * @return boolean
+	 * @throws \EE_Error
+	 */
+	public function is_pending()
+	{
+		return ($this->get_raw('TKT_start_date') > time());
+	}
+
+
+	/**
+	 * Return if a ticket is on sale or not
+	 *
+	 * @return boolean
+	 * @throws \EE_Error
+	 */
+	public function is_on_sale()
+	{
+		return ($this->get_raw('TKT_start_date') < time() && $this->get_raw('TKT_end_date') > time());
+	}
+
+
+	/**
+	 * This returns the chronologically last datetime that this ticket is associated with
+	 *
+	 * @param string $dt_frmt
+	 * @param string $conjunction - conjunction junction what's your function ? this string joins the start date with
+	 *                            the end date ie: Jan 01 "to" Dec 31
+	 * @return string
+	 * @throws \EE_Error
+	 */
+	public function date_range($dt_frmt = '', $conjunction = ' - ')
+	{
+		$first_date = $this->first_datetime() instanceof EE_Datetime ? $this->first_datetime()->start_date($dt_frmt)
+			: '';
+		$last_date = $this->last_datetime() instanceof EE_Datetime ? $this->last_datetime()->end_date($dt_frmt) : '';
+
+		return $first_date && $last_date ? $first_date . $conjunction . $last_date : '';
+	}
+
+
+	/**
+	 * This returns the chronologically first datetime that this ticket is associated with
+	 *
+	 * @return EE_Datetime
+	 * @throws \EE_Error
+	 */
+	public function first_datetime()
+	{
+		$datetimes = $this->datetimes(array('limit' => 1));
+		return reset($datetimes);
+	}
+
+
+	/**
+	 * Gets all the datetimes this ticket can be used for attending.
+	 * Unless otherwise specified, orders datetimes by start date.
+	 *
+	 * @param array $query_params @see https://github.com/eventespresso/event-espresso-core/tree/master/docs/G--Model-System/model-query-params.md
+	 * @return EE_Datetime[]|EE_Base_Class[]
+	 * @throws \EE_Error
+	 */
+	public function datetimes($query_params = array())
+	{
+		if (! isset($query_params['order_by'])) {
+			$query_params['order_by']['DTT_order'] = 'ASC';
+		}
+		return $this->get_many_related('Datetime', $query_params);
+	}
+
+
+	/**
+	 * This returns the chronologically last datetime that this ticket is associated with
+	 *
+	 * @return EE_Datetime
+	 * @throws \EE_Error
+	 */
+	public function last_datetime()
+	{
+		$datetimes = $this->datetimes(array('limit' => 1, 'order_by' => array('DTT_EVT_start' => 'DESC')));
+		return end($datetimes);
+	}
+
+
+	/**
+	 * This returns the total tickets sold depending on the given parameters.
+	 *
+	 * @param  string $what   Can be one of two options: 'ticket', 'datetime'.
+	 *                        'ticket' = total ticket sales for all datetimes this ticket is related to
+	 *                        'datetime' = total ticket sales for a specified datetime (required $dtt_id)
+	 *                        'datetime' = total ticket sales in the datetime_ticket table.
+	 *                        If $dtt_id is not given then we return an array of sales indexed by datetime.
+	 *                        If $dtt_id IS given then we return the tickets sold for that given datetime.
+	 * @param  int    $dtt_id [optional] include the dtt_id with $what = 'datetime'.
+	 * @return mixed (array|int)          how many tickets have sold
+	 * @throws \EE_Error
+	 */
+	public function tickets_sold($what = 'ticket', $dtt_id = null)
+	{
+		$total = 0;
+		$tickets_sold = $this->_all_tickets_sold();
+		switch ($what) {
+			case 'ticket':
+				return $tickets_sold['ticket'];
+				break;
+			case 'datetime':
+				if (empty($tickets_sold['datetime'])) {
+					return $total;
+				}
+				if (! empty($dtt_id) && ! isset($tickets_sold['datetime'][ $dtt_id ])) {
+					EE_Error::add_error(
+						__(
+							'You\'ve requested the amount of tickets sold for a given ticket and datetime, however there are no records for the datetime id you included.  Are you SURE that is a datetime related to this ticket?',
+							'event_espresso'
+						),
+						__FILE__,
+						__FUNCTION__,
+						__LINE__
+					);
+					return $total;
+				}
+				return empty($dtt_id) ? $tickets_sold['datetime'] : $tickets_sold['datetime'][ $dtt_id ];
+				break;
+			default:
+				return $total;
+		}
+	}
+
+
+	/**
+	 * This returns an array indexed by datetime_id for tickets sold with this ticket.
+	 *
+	 * @return EE_Ticket[]
+	 * @throws \EE_Error
+	 */
+	protected function _all_tickets_sold()
+	{
+		$datetimes = $this->get_many_related('Datetime');
+		$tickets_sold = array();
+		if (! empty($datetimes)) {
+			foreach ($datetimes as $datetime) {
+				$tickets_sold['datetime'][ $datetime->ID() ] = $datetime->get('DTT_sold');
+			}
+		}
+		// Tickets sold
+		$tickets_sold['ticket'] = $this->sold();
+		return $tickets_sold;
+	}
+
+
+	/**
+	 * This returns the base price object for the ticket.
+	 *
+	 * @param  bool $return_array whether to return as an array indexed by price id or just the object.
+	 * @return EE_Price|EE_Base_Class|EE_Price[]|EE_Base_Class[]
+	 * @throws \EE_Error
+	 */
+	public function base_price($return_array = false)
+	{
+		$_where = array('Price_Type.PBT_ID' => EEM_Price_Type::base_type_base_price);
+		return $return_array
+			? $this->get_many_related('Price', array($_where))
+			: $this->get_first_related('Price', array($_where));
+	}
+
+
+	/**
+	 * This returns ONLY the price modifiers for the ticket (i.e. no taxes or base price)
+	 *
+	 * @access public
+	 * @return EE_Price[]
+	 * @throws \EE_Error
+	 */
+	public function price_modifiers()
+	{
+		$query_params = array(
+			0 => array(
+				'Price_Type.PBT_ID' => array(
+					'NOT IN',
+					array(EEM_Price_Type::base_type_base_price, EEM_Price_Type::base_type_tax),
+				),
+			),
+		);
+		return $this->prices($query_params);
+	}
+
+
+	/**
+	 * Gets all the prices that combine to form the final price of this ticket
+	 *
+	 * @param array $query_params @see https://github.com/eventespresso/event-espresso-core/tree/master/docs/G--Model-System/model-query-params.md
+	 * @return EE_Price[]|EE_Base_Class[]
+	 * @throws \EE_Error
+	 */
+	public function prices($query_params = array())
+	{
+		return $this->get_many_related('Price', $query_params);
+	}
+
+
+	/**
+	 * Gets all the ticket applicabilities (ie, relations between datetimes and tickets)
+	 *
+	 * @param array $query_params @see https://github.com/eventespresso/event-espresso-core/tree/master/docs/G--Model-System/model-query-params.md
+	 * @return EE_Datetime_Ticket|EE_Base_Class[]
+	 * @throws \EE_Error
+	 */
+	public function datetime_tickets($query_params = array())
+	{
+		return $this->get_many_related('Datetime_Ticket', $query_params);
+	}
+
+
+	/**
+	 * Gets all the datetimes from the db ordered by DTT_order
+	 *
+	 * @param boolean $show_expired
+	 * @param boolean $show_deleted
+	 * @return EE_Datetime[]
+	 * @throws \EE_Error
+	 */
+	public function datetimes_ordered($show_expired = true, $show_deleted = false)
+	{
+		return EEM_Datetime::instance($this->_timezone)->get_datetimes_for_ticket_ordered_by_DTT_order(
+			$this->ID(),
+			$show_expired,
+			$show_deleted
+		);
+	}
+
+
+	/**
+	 * Gets ID
+	 *
+	 * @return string
+	 * @throws \EE_Error
+	 */
+	public function ID()
+	{
+		return $this->get('TKT_ID');
+	}
+
+
+	/**
+	 * get the author of the ticket.
+	 *
+	 * @since 4.5.0
+	 * @return int
+	 * @throws \EE_Error
+	 */
+	public function wp_user()
+	{
+		return $this->get('TKT_wp_user');
+	}
+
+
+	/**
+	 * Gets the template for the ticket
+	 *
+	 * @return EE_Ticket_Template|EE_Base_Class
+	 * @throws \EE_Error
+	 */
+	public function template()
+	{
+		return $this->get_first_related('Ticket_Template');
+	}
+
+
+	/**
+	 * Simply returns an array of EE_Price objects that are taxes.
+	 *
+	 * @return EE_Price[]
+	 * @throws \EE_Error
+	 */
+	public function get_ticket_taxes_for_admin()
+	{
+		return EE_Taxes::get_taxes_for_admin();
+	}
+
+
+	/**
+	 * @return float
+	 * @throws \EE_Error
+	 */
+	public function ticket_price()
+	{
+		return $this->get('TKT_price');
+	}
+
+
+	/**
+	 * @return mixed
+	 * @throws \EE_Error
+	 */
+	public function pretty_price()
+	{
+		return $this->get_pretty('TKT_price');
+	}
+
+
+	/**
+	 * @return bool
+	 * @throws \EE_Error
+	 */
+	public function is_free()
+	{
+		return $this->get_ticket_total_with_taxes() === (float) 0;
+	}
+
+
+	/**
+	 * get_ticket_total_with_taxes
+	 *
+	 * @param bool $no_cache
+	 * @return float
+	 * @throws \EE_Error
+	 */
+	public function get_ticket_total_with_taxes($no_cache = false)
+	{
+		if ($this->_ticket_total_with_taxes === null || $no_cache) {
+			$this->_ticket_total_with_taxes = $this->get_ticket_subtotal() + $this->get_ticket_taxes_total_for_admin();
+		}
+		return (float) $this->_ticket_total_with_taxes;
+	}
+
+
+	public function ensure_TKT_Price_correct()
+	{
+		$this->set('TKT_price', EE_Taxes::get_subtotal_for_admin($this));
+		$this->save();
+	}
+
+
+	/**
+	 * @return float
+	 * @throws \EE_Error
+	 */
+	public function get_ticket_subtotal()
+	{
+		return EE_Taxes::get_subtotal_for_admin($this);
+	}
+
+
+	/**
+	 * Returns the total taxes applied to this ticket
+	 *
+	 * @return float
+	 * @throws \EE_Error
+	 */
+	public function get_ticket_taxes_total_for_admin()
+	{
+		return EE_Taxes::get_total_taxes_for_admin($this);
+	}
+
+
+	/**
+	 * Sets name
+	 *
+	 * @param string $name
+	 * @throws \EE_Error
+	 */
+	public function set_name($name)
+	{
+		$this->set('TKT_name', $name);
+	}
+
+
+	/**
+	 * Gets description
+	 *
+	 * @return string
+	 * @throws \EE_Error
+	 */
+	public function description()
+	{
+		return $this->get('TKT_description');
+	}
+
+
+	/**
+	 * Sets description
+	 *
+	 * @param string $description
+	 * @throws \EE_Error
+	 */
+	public function set_description($description)
+	{
+		$this->set('TKT_description', $description);
+	}
+
+
+	/**
+	 * Gets start_date
+	 *
+	 * @param string $dt_frmt
+	 * @param string $tm_frmt
+	 * @return string
+	 * @throws \EE_Error
+	 */
+	public function start_date($dt_frmt = '', $tm_frmt = '')
+	{
+		return $this->_get_datetime('TKT_start_date', $dt_frmt, $tm_frmt);
+	}
+
+
+	/**
+	 * Sets start_date
+	 *
+	 * @param string $start_date
+	 * @return void
+	 * @throws \EE_Error
+	 */
+	public function set_start_date($start_date)
+	{
+		$this->_set_date_time('B', $start_date, 'TKT_start_date');
+	}
+
+
+	/**
+	 * Gets end_date
+	 *
+	 * @param string $dt_frmt
+	 * @param string $tm_frmt
+	 * @return string
+	 * @throws \EE_Error
+	 */
+	public function end_date($dt_frmt = '', $tm_frmt = '')
+	{
+		return $this->_get_datetime('TKT_end_date', $dt_frmt, $tm_frmt);
+	}
+
+
+	/**
+	 * Sets end_date
+	 *
+	 * @param string $end_date
+	 * @return void
+	 * @throws \EE_Error
+	 */
+	public function set_end_date($end_date)
+	{
+		$this->_set_date_time('B', $end_date, 'TKT_end_date');
+	}
+
+
+	/**
+	 * Sets sell until time
+	 *
+	 * @since 4.5.0
+	 * @param string $time a string representation of the sell until time (ex 9am or 7:30pm)
+	 * @throws \EE_Error
+	 */
+	public function set_end_time($time)
+	{
+		$this->_set_time_for($time, 'TKT_end_date');
+	}
+
+
+	/**
+	 * Sets min
+	 *
+	 * @param int $min
+	 * @return void
+	 * @throws \EE_Error
+	 */
+	public function set_min($min)
+	{
+		$this->set('TKT_min', $min);
+	}
+
+
+	/**
+	 * Gets max
+	 *
+	 * @return int
+	 * @throws \EE_Error
+	 */
+	public function max()
+	{
+		return $this->get('TKT_max');
+	}
+
+
+	/**
+	 * Sets max
+	 *
+	 * @param int $max
+	 * @return void
+	 * @throws \EE_Error
+	 */
+	public function set_max($max)
+	{
+		$this->set('TKT_max', $max);
+	}
+
+
+	/**
+	 * Sets price
+	 *
+	 * @param float $price
+	 * @return void
+	 * @throws \EE_Error
+	 */
+	public function set_price($price)
+	{
+		$this->set('TKT_price', $price);
+	}
+
+
+	/**
+	 * Gets sold
+	 *
+	 * @return int
+	 * @throws \EE_Error
+	 */
+	public function sold()
+	{
+		return $this->get_raw('TKT_sold');
+	}
+
+
+	/**
+	 * Sets sold
+	 *
+	 * @param int $sold
+	 * @return void
+	 * @throws \EE_Error
+	 */
+	public function set_sold($sold)
+	{
+		// sold can not go below zero
+		$sold = max(0, $sold);
+		$this->set('TKT_sold', $sold);
+	}
+
+
+	/**
+	 * increments sold by amount passed by $qty
+	 *
+	 * @param int $qty
+	 * @return void
+	 * @throws \EE_Error
+	 */
+	public function increase_sold($qty = 1)
+	{
+		$sold = $this->sold() + $qty;
+		// remove ticket reservation, but don't adjust datetime reservations,  because that will happen
+		// via \EE_Datetime::increase_sold() when \EE_Ticket::_increase_sold_for_datetimes() is called
+		$this->decrease_reserved($qty, false, "TKT: {$this->ID()} (ln:" . __LINE__ . ')');
+		$this->_increase_sold_for_datetimes($qty);
+		$this->set_sold($sold);
+		do_action(
+			'AHEE__EE_Ticket__increase_sold',
+			$this,
+			$qty,
+			$sold
+		);
+	}
+
+
+	/**
+	 * Increases sold on related datetimes
+	 *
+	 * @param int $qty
+	 * @return void
+	 * @throws \EE_Error
+	 */
+	protected function _increase_sold_for_datetimes($qty = 1)
+	{
+		$datetimes = $this->datetimes();
+		if (is_array($datetimes)) {
+			foreach ($datetimes as $datetime) {
+				if ($datetime instanceof EE_Datetime) {
+					$datetime->increase_sold($qty);
+					$datetime->save();
+				}
+			}
+		}
+	}
+
+
+	/**
+	 * decrements (subtracts) sold by amount passed by $qty
+	 *
+	 * @param int $qty
+	 * @return void
+	 * @throws \EE_Error
+	 */
+	public function decrease_sold($qty = 1)
+	{
+		$sold = $this->sold() - $qty;
+		$this->_decrease_sold_for_datetimes($qty);
+		$this->set_sold($sold);
+		do_action(
+			'AHEE__EE_Ticket__decrease_sold',
+			$this,
+			$qty,
+			$sold
+		);
+	}
+
+
+	/**
+	 * Decreases sold on related datetimes
+	 *
+	 * @param int $qty
+	 * @return void
+	 * @throws \EE_Error
+	 */
+	protected function _decrease_sold_for_datetimes($qty = 1)
+	{
+		$datetimes = $this->datetimes();
+		if (is_array($datetimes)) {
+			foreach ($datetimes as $datetime) {
+				if ($datetime instanceof EE_Datetime) {
+					$datetime->decrease_sold($qty);
+					$datetime->save();
+				}
+			}
+		}
+	}
+
+
+	/**
+	 * Gets qty of reserved tickets
+	 *
+	 * @return int
+	 * @throws \EE_Error
+	 */
+	public function reserved()
+	{
+		return $this->get_raw('TKT_reserved');
+	}
+
+
+	/**
+	 * Sets reserved
+	 *
+	 * @param int $reserved
+	 * @return void
+	 * @throws \EE_Error
+	 */
+	public function set_reserved($reserved)
+	{
+		// reserved can not go below zero
+		$reserved = max(0, (int) $reserved);
+		$this->set('TKT_reserved', $reserved);
+	}
+
+
+	/**
+	 * increments reserved by amount passed by $qty
+	 *
+	 * @param int    $qty
+	 * @param string $source
+	 * @return void
+	 * @throws EE_Error
+	 * @throws InvalidArgumentException
+	 * @throws ReflectionException
+	 * @throws \EventEspresso\core\exceptions\InvalidDataTypeException
+	 * @throws \EventEspresso\core\exceptions\InvalidInterfaceException
+	 */
+	public function increase_reserved($qty = 1, $source = 'unknown')
+	{
+		$qty = absint($qty);
+		$reserved = $this->reserved() + $qty;
+		if ($reserved
+			&& $this->add_extra_meta(
+				EE_Ticket::META_KEY_TICKET_RESERVATIONS,
+				"{$qty} from {$source}"
+			)
+		) {
+			$this->_increase_reserved_for_datetimes($qty);
+			$this->set_reserved($reserved);
+			do_action(
+				'AHEE__EE_Ticket__increase_reserved',
+				$this,
+				$qty,
+				$reserved
+			);
+		}
+	}
+
+
+	/**
+	 * Increases sold on related datetimes
+	 *
+	 * @param int $qty
+	 * @return void
+	 * @throws \EE_Error
+	 */
+	protected function _increase_reserved_for_datetimes($qty = 1)
+	{
+		$datetimes = $this->datetimes();
+		if (is_array($datetimes)) {
+			foreach ($datetimes as $datetime) {
+				if ($datetime instanceof EE_Datetime) {
+					$datetime->increase_reserved($qty);
+					$datetime->save();
+				}
+			}
+		}
+	}
+
+
+	/**
+	 * decrements (subtracts) reserved by amount passed by $qty
+	 *
+	 * @param int    $qty
+	 * @param bool   $adjust_datetimes
+	 * @param string $source
+	 * @return void
+	 * @throws EE_Error
+	 * @throws InvalidArgumentException
+	 * @throws ReflectionException
+	 * @throws \EventEspresso\core\exceptions\InvalidDataTypeException
+	 * @throws \EventEspresso\core\exceptions\InvalidInterfaceException
+	 */
+	public function decrease_reserved($qty = 1, $adjust_datetimes = true, $source = 'unknown')
+	{
+		$reserved = $this->reserved() - absint($qty);
+		if ($this->add_extra_meta(
+			EE_Ticket::META_KEY_TICKET_RESERVATIONS,
+			"-{$qty} from {$source}"
+		)) {
+			if ($adjust_datetimes) {
+				$this->_decrease_reserved_for_datetimes($qty);
+			}
+			$this->set_reserved($reserved);
+			do_action(
+				'AHEE__EE_Ticket__decrease_reserved',
+				$this,
+				$qty,
+				$reserved
+			);
+		}
+	}
+
+
+	/**
+	 * Increases sold on related datetimes
+	 *
+	 * @param int $qty
+	 * @return void
+	 * @throws \EE_Error
+	 */
+	protected function _decrease_reserved_for_datetimes($qty = 1)
+	{
+		$datetimes = $this->datetimes();
+		if (is_array($datetimes)) {
+			foreach ($datetimes as $datetime) {
+				if ($datetime instanceof EE_Datetime) {
+					$datetime->decrease_reserved($qty);
+					$datetime->save();
+				}
+			}
+		}
+	}
+
+
+	/**
+	 * Gets ticket quantity
+	 *
+	 * @param string $context     ticket quantity is somewhat subjective depending on the exact information sought
+	 *                            therefore $context can be one of three values: '', 'reg_limit', or 'saleable'
+	 *                            '' (default) quantity is the actual db value for TKT_qty, unaffected by other objects
+	 *                            REG LIMIT: caps qty based on DTT_reg_limit for ALL related datetimes
+	 *                            SALEABLE: also considers datetime sold and returns zero if ANY DTT is sold out, and
+	 *                            is therefore the truest measure of tickets that can be purchased at the moment
+	 * @return int
+	 * @throws \EE_Error
+	 */
+	public function qty($context = '')
+	{
+		switch ($context) {
+			case 'reg_limit':
+				return $this->real_quantity_on_ticket();
+			case 'saleable':
+				return $this->real_quantity_on_ticket('saleable');
+			default:
+				return $this->get_raw('TKT_qty');
+		}
+	}
+
+
+	/**
+	 * Gets ticket quantity
+	 *
+	 * @param string $context     ticket quantity is somewhat subjective depending on the exact information sought
+	 *                            therefore $context can be one of two values: 'reg_limit', or 'saleable'
+	 *                            REG LIMIT: caps qty based on DTT_reg_limit for ALL related datetimes
+	 *                            SALEABLE: also considers datetime sold and returns zero if ANY DTT is sold out, and
+	 *                            is therefore the truest measure of tickets that can be purchased at the moment
+	 * @param  int   $DTT_ID      the primary key for a particular datetime.
+	 *                            set to 0 for all related datetimes
+	 * @return int
+	 * @throws \EE_Error
+	 */
+	public function real_quantity_on_ticket($context = 'reg_limit', $DTT_ID = 0)
+	{
+		$raw = $this->get_raw('TKT_qty');
+		// return immediately if it's zero
+		if ($raw === 0) {
+			return $raw;
+		}
+		// echo "\n\n<br />Ticket: " . $this->name() . '<br />';
+		// ensure qty doesn't exceed raw value for THIS ticket
+		$qty = min(EE_INF, $raw);
+		// echo "\n . qty: " . $qty . '<br />';
+		// calculate this ticket's total sales and reservations
+		$sold_and_reserved_for_this_ticket = $this->sold() + $this->reserved();
+		// echo "\n . sold: " . $this->sold() . '<br />';
+		// echo "\n . reserved: " . $this->reserved() . '<br />';
+		// echo "\n . sold_and_reserved_for_this_ticket: " . $sold_and_reserved_for_this_ticket . '<br />';
+		// first we need to calculate the maximum number of tickets available for the datetime
+		// do we want data for one datetime or all of them ?
+		$query_params = $DTT_ID ? array(array('DTT_ID' => $DTT_ID)) : array();
+		$datetimes = $this->datetimes($query_params);
+		if (is_array($datetimes) && ! empty($datetimes)) {
+			foreach ($datetimes as $datetime) {
+				if ($datetime instanceof EE_Datetime) {
+					$datetime->refresh_from_db();
+					// echo "\n . . datetime name: " . $datetime->name() . '<br />';
+					// echo "\n . . datetime ID: " . $datetime->ID() . '<br />';
+					// initialize with no restrictions for each datetime
+					// but adjust datetime qty based on datetime reg limit
+					$datetime_qty = min(EE_INF, $datetime->reg_limit());
+					// echo "\n . . . datetime reg_limit: " . $datetime->reg_limit() . '<br />';
+					// echo "\n . . . datetime_qty: " . $datetime_qty . '<br />';
+					// if we want the actual saleable amount, then we need to consider OTHER ticket sales
+					// and reservations for this datetime, that do NOT include sales and reservations
+					// for this ticket (so we add $this->sold() and $this->reserved() back in)
+					if ($context === 'saleable') {
+						$datetime_qty = max(
+							$datetime_qty - $datetime->sold_and_reserved() + $sold_and_reserved_for_this_ticket,
+							0
+						);
+						// echo "\n . . . datetime sold: " . $datetime->sold() . '<br />';
+						// echo "\n . . . datetime reserved: " . $datetime->reserved() . '<br />';
+						// echo "\n . . . datetime sold_and_reserved: " . $datetime->sold_and_reserved() . '<br />';
+						// echo "\n . . . datetime_qty: " . $datetime_qty . '<br />';
+						$datetime_qty = ! $datetime->sold_out() ? $datetime_qty : 0;
+						// echo "\n . . . datetime_qty: " . $datetime_qty . '<br />';
+					}
+					$qty = min($datetime_qty, $qty);
+					// echo "\n . . qty: " . $qty . '<br />';
+				}
+			}
+		}
+		// NOW that we know the  maximum number of tickets available for the datetime
+		// we can finally factor in the details for this specific ticket
+		if ($qty > 0 && $context === 'saleable') {
+			// and subtract the sales for THIS ticket
+			$qty = max($qty - $sold_and_reserved_for_this_ticket, 0);
+			// echo "\n . qty: " . $qty . '<br />';
+		}
+		// echo "\nFINAL QTY: " . $qty . "<br /><br />";
+		return $qty;
+	}
+
+
+	/**
+	 * Sets qty - IMPORTANT!!! Does NOT allow QTY to be set higher than the lowest reg limit of any related datetimes
+	 *
+	 * @param int $qty
+	 * @return void
+	 * @throws \EE_Error
+	 */
+	public function set_qty($qty)
+	{
+		$datetimes = $this->datetimes();
+		foreach ($datetimes as $datetime) {
+			if ($datetime instanceof EE_Datetime) {
+				$qty = min($qty, $datetime->reg_limit());
+			}
+		}
+		$this->set('TKT_qty', $qty);
+	}
+
+
+	/**
+	 * Gets uses
+	 *
+	 * @return int
+	 * @throws \EE_Error
+	 */
+	public function uses()
+	{
+		return $this->get('TKT_uses');
+	}
+
+
+	/**
+	 * Sets uses
+	 *
+	 * @param int $uses
+	 * @return void
+	 * @throws \EE_Error
+	 */
+	public function set_uses($uses)
+	{
+		$this->set('TKT_uses', $uses);
+	}
+
+
+	/**
+	 * returns whether ticket is required or not.
+	 *
+	 * @return boolean
+	 * @throws \EE_Error
+	 */
+	public function required()
+	{
+		return $this->get('TKT_required');
+	}
+
+
+	/**
+	 * sets the TKT_required property
+	 *
+	 * @param boolean $required
+	 * @return void
+	 * @throws \EE_Error
+	 */
+	public function set_required($required)
+	{
+		$this->set('TKT_required', $required);
+	}
+
+
+	/**
+	 * Gets taxable
+	 *
+	 * @return boolean
+	 * @throws \EE_Error
+	 */
+	public function taxable()
+	{
+		return $this->get('TKT_taxable');
+	}
+
+
+	/**
+	 * Sets taxable
+	 *
+	 * @param boolean $taxable
+	 * @return void
+	 * @throws \EE_Error
+	 */
+	public function set_taxable($taxable)
+	{
+		$this->set('TKT_taxable', $taxable);
+	}
+
+
+	/**
+	 * Gets is_default
+	 *
+	 * @return boolean
+	 * @throws \EE_Error
+	 */
+	public function is_default()
+	{
+		return $this->get('TKT_is_default');
+	}
+
+
+	/**
+	 * Sets is_default
+	 *
+	 * @param boolean $is_default
+	 * @return void
+	 * @throws \EE_Error
+	 */
+	public function set_is_default($is_default)
+	{
+		$this->set('TKT_is_default', $is_default);
+	}
+
+
+	/**
+	 * Gets order
+	 *
+	 * @return int
+	 * @throws \EE_Error
+	 */
+	public function order()
+	{
+		return $this->get('TKT_order');
+	}
+
+
+	/**
+	 * Sets order
+	 *
+	 * @param int $order
+	 * @return void
+	 * @throws \EE_Error
+	 */
+	public function set_order($order)
+	{
+		$this->set('TKT_order', $order);
+	}
+
+
+	/**
+	 * Gets row
+	 *
+	 * @return int
+	 * @throws \EE_Error
+	 */
+	public function row()
+	{
+		return $this->get('TKT_row');
+	}
+
+
+	/**
+	 * Sets row
+	 *
+	 * @param int $row
+	 * @return void
+	 * @throws \EE_Error
+	 */
+	public function set_row($row)
+	{
+		$this->set('TKT_row', $row);
+	}
+
+
+	/**
+	 * Gets deleted
+	 *
+	 * @return boolean
+	 * @throws \EE_Error
+	 */
+	public function deleted()
+	{
+		return $this->get('TKT_deleted');
+	}
+
+
+	/**
+	 * Sets deleted
+	 *
+	 * @param boolean $deleted
+	 * @return void
+	 * @throws \EE_Error
+	 */
+	public function set_deleted($deleted)
+	{
+		$this->set('TKT_deleted', $deleted);
+	}
+
+
+	/**
+	 * Gets parent
+	 *
+	 * @return int
+	 * @throws \EE_Error
+	 */
+	public function parent_ID()
+	{
+		return $this->get('TKT_parent');
+	}
+
+
+	/**
+	 * Sets parent
+	 *
+	 * @param int $parent
+	 * @return void
+	 * @throws \EE_Error
+	 */
+	public function set_parent_ID($parent)
+	{
+		$this->set('TKT_parent', $parent);
+	}
+
+
+	/**
+	 * Gets a string which is handy for showing in gateways etc that describes the ticket.
+	 *
+	 * @return string
+	 * @throws \EE_Error
+	 */
+	public function name_and_info()
+	{
+		$times = array();
+		foreach ($this->datetimes() as $datetime) {
+			$times[] = $datetime->start_date_and_time();
+		}
+		return $this->name() . ' @ ' . implode(', ', $times) . ' for ' . $this->pretty_price();
+	}
+
+
+	/**
+	 * Gets name
+	 *
+	 * @return string
+	 * @throws \EE_Error
+	 */
+	public function name()
+	{
+		return $this->get('TKT_name');
+	}
+
+
+	/**
+	 * Gets price
+	 *
+	 * @return float
+	 * @throws \EE_Error
+	 */
+	public function price()
+	{
+		return $this->get('TKT_price');
+	}
+
+
+	/**
+	 * Gets all the registrations for this ticket
+	 *
+	 * @param array $query_params @see https://github.com/eventespresso/event-espresso-core/tree/master/docs/G--Model-System/model-query-params.md
+	 * @return EE_Registration[]|EE_Base_Class[]
+	 * @throws \EE_Error
+	 */
+	public function registrations($query_params = array())
+	{
+		return $this->get_many_related('Registration', $query_params);
+	}
+
+
+	/**
+	 * Updates the TKT_sold attribute (and saves) based on the number of APPROVED registrations for this ticket.
+	 * into account
+	 *
+	 * @return int
+	 * @throws \EE_Error
+	 */
+	public function update_tickets_sold()
+	{
+		$count_regs_for_this_ticket = $this->count_registrations(
+			array(
+				array(
+					'STS_ID'      => EEM_Registration::status_id_approved,
+					'REG_deleted' => 0,
+				),
+			)
+		);
+		$sold = $this->sold();
+		if ($count_regs_for_this_ticket > $sold) {
+			$this->increase_sold($count_regs_for_this_ticket - $sold);
+			$this->save();
+		} elseif ($count_regs_for_this_ticket < $sold) {
+			$this->decrease_sold($count_regs_for_this_ticket - $sold);
+			$this->save();
+		}
+		return $count_regs_for_this_ticket;
+	}
+
+
+	/**
+	 * Counts the registrations for this ticket
+	 *
+	 * @param array $query_params @see https://github.com/eventespresso/event-espresso-core/tree/master/docs/G--Model-System/model-query-params.md
+	 * @return int
+	 */
+	public function count_registrations($query_params = array())
+	{
+		return $this->count_related('Registration', $query_params);
+	}
+
+
+	/**
+	 * Implementation for EEI_Has_Icon interface method.
+	 *
+	 * @see EEI_Visual_Representation for comments
+	 * @return string
+	 */
+	public function get_icon()
+	{
+		return '<span class="dashicons dashicons-tickets-alt"></span>';
+	}
+
+
+	/**
+	 * Implementation of the EEI_Event_Relation interface method
+	 *
+	 * @see EEI_Event_Relation for comments
+	 * @return EE_Event
+	 * @throws \EE_Error
+	 * @throws UnexpectedEntityException
+	 */
+	public function get_related_event()
+	{
+		// get one datetime to use for getting the event
+		$datetime = $this->first_datetime();
+		if (! $datetime instanceof \EE_Datetime) {
+			throw new UnexpectedEntityException(
+				$datetime,
+				'EE_Datetime',
+				sprintf(
+					__('The ticket (%s) is not associated with any valid datetimes.', 'event_espresso'),
+					$this->name()
+				)
+			);
+		}
+		$event = $datetime->event();
+		if (! $event instanceof \EE_Event) {
+			throw new UnexpectedEntityException(
+				$event,
+				'EE_Event',
+				sprintf(
+					__('The ticket (%s) is not associated with a valid event.', 'event_espresso'),
+					$this->name()
+				)
+			);
+		}
+		return $event;
+	}
+
+
+	/**
+	 * Implementation of the EEI_Event_Relation interface method
+	 *
+	 * @see EEI_Event_Relation for comments
+	 * @return string
+	 * @throws UnexpectedEntityException
+	 * @throws \EE_Error
+	 */
+	public function get_event_name()
+	{
+		$event = $this->get_related_event();
+		return $event instanceof EE_Event ? $event->name() : '';
+	}
+
+
+	/**
+	 * Implementation of the EEI_Event_Relation interface method
+	 *
+	 * @see EEI_Event_Relation for comments
+	 * @return int
+	 * @throws UnexpectedEntityException
+	 * @throws \EE_Error
+	 */
+	public function get_event_ID()
+	{
+		$event = $this->get_related_event();
+		return $event instanceof EE_Event ? $event->ID() : 0;
+	}
+
+
+	/**
+	 * This simply returns whether a ticket can be permanently deleted or not.
+	 * The criteria for determining this is whether the ticket has any related registrations.
+	 * If there are none then it can be permanently deleted.
+	 *
+	 * @return bool
+	 */
+	public function is_permanently_deleteable()
+	{
+		return $this->count_registrations() === 0;
+	}
 }