eventespresso / event-espresso-core

core/EE_Data_Migration_Manager.core.php

Indentation +1234 added lines, -1234 removed lines

@@ -33,1238 +33,1238 @@
 class EE_Data_Migration_Manager implements ResettableInterface
 {
 
-    /**
-     *
-     * @var EE_Registry
-     */
-    // protected $EE;
-    /**
-     * name of the wordpress option which stores an array of data about
-     */
-    const data_migrations_option_name = 'ee_data_migration';
-
-
-    const data_migration_script_option_prefix = 'ee_data_migration_script_';
-
-    const data_migration_script_mapping_option_prefix = 'ee_dms_map_';
-
-    /**
-     * name of the wordpress option which stores the database' current version. IE, the code may be at version 4.2.0,
-     * but as migrations are performed the database will progress from 3.1.35 to 4.1.0 etc.
-     */
-    const current_database_state = 'ee_data_migration_current_db_state';
-
-    /**
-     * Special status string returned when we're positive there are no more data migration
-     * scripts that can be run.
-     */
-    const status_no_more_migration_scripts = 'no_more_migration_scripts';
-    /**
-     * string indicating the migration should continue
-     */
-    const status_continue = 'status_continue';
-    /**
-     * string indicating the migration has completed and should be ended
-     */
-    const status_completed = 'status_completed';
-    /**
-     * string indicating a fatal error occurred and the data migration should be completely aborted
-     */
-    const status_fatal_error = 'status_fatal_error';
-
-    /**
-     * the number of 'items' (usually DB rows) to migrate on each 'step' (ajax request sent
-     * during migration)
-     */
-    const step_size = 50;
-
-    /**
-     * option name that stores the queue of ee plugins needing to have
-     * their data initialized (or re-initialized) once we are done migrations
-     */
-    const db_init_queue_option_name = 'ee_db_init_queue';
-    /**
-     * Array of information concerning data migrations that have ran in the history
-     * of this EE installation. Keys should be the name of the version the script upgraded to
-     *
-     * @var EE_Data_Migration_Script_Base[]
-     */
-    private $_data_migrations_ran = null;
-    /**
-     * The last ran script. It's nice to store this somewhere accessible, as its easiest
-     * to know which was the last run by which is the newest wp option; but in most of the code
-     * we just use the local $_data_migration_ran array, which organized the scripts differently
-     *
-     * @var EE_Data_Migration_Script_Base
-     */
-    private $_last_ran_script = null;
-
-    /**
-     * Similarly to _last_ran_script, but this is the last INCOMPLETE migration script.
-     *
-     * @var EE_Data_Migration_Script_Base
-     */
-    private $_last_ran_incomplete_script = null;
-    /**
-     * array where keys are classnames, and values are filepaths of all the known migration scripts
-     *
-     * @var array
-     */
-    private $_data_migration_class_to_filepath_map;
-
-    /**
-     * the following 4 properties are fully set on construction.
-     * Note: the first two apply to whether to continue running ALL migration scripts (ie, even though we're finished
-     * one, we may want to start the next one); whereas the last two indicate whether to continue running a single
-     * data migration script
-     *
-     * @var array
-     */
-    public $stati_that_indicate_to_continue_migrations = array();
-
-    public $stati_that_indicate_to_stop_migrations = array();
-
-    public $stati_that_indicate_to_continue_single_migration_script = array();
-
-    public $stati_that_indicate_to_stop_single_migration_script = array();
-
-    /**
-     * @var \EventEspresso\core\services\database\TableManager $table_manager
-     */
-    protected $_table_manager;
-
-    /**
-     * @var \EventEspresso\core\services\database\TableAnalysis $table_analysis
-     */
-    protected $_table_analysis;
-
-    /**
-     * @var array $script_migration_versions
-     */
-    protected $script_migration_versions;
-
-    /**
-     * @var EE_Data_Migration_Manager $_instance
-     * @access    private
-     */
-    private static $_instance = null;
-
-
-    /**
-     * @singleton method used to instantiate class object
-     * @access    public
-     * @return EE_Data_Migration_Manager instance
-     */
-    public static function instance()
-    {
-        // check if class object is instantiated
-        if (! self::$_instance instanceof EE_Data_Migration_Manager) {
-            self::$_instance = new self();
-        }
-        return self::$_instance;
-    }
-
-    /**
-     * resets the singleton to its brand-new state (but does NOT delete old references to the old singleton. Meaning,
-     * all new usages of the singleton should be made with Classname::instance()) and returns it
-     *
-     * @return EE_Data_Migration_Manager
-     */
-    public static function reset()
-    {
-        self::$_instance = null;
-        return self::instance();
-    }
-
-
-    /**
-     * constructor
-     */
-    private function __construct()
-    {
-        $this->stati_that_indicate_to_continue_migrations = array(
-            self::status_continue,
-            self::status_completed,
-        );
-        $this->stati_that_indicate_to_stop_migrations = array(
-            self::status_fatal_error,
-            self::status_no_more_migration_scripts,
-        );
-        $this->stati_that_indicate_to_continue_single_migration_script = array(
-            self::status_continue,
-        );
-        $this->stati_that_indicate_to_stop_single_migration_script = array(
-            self::status_completed,
-            self::status_fatal_error
-            // note: status_no_more_migration_scripts doesn't apply
-        );
-        // make sure we've included the base migration script, because we may need the EE_DMS_Unknown_1_0_0 class
-        // to be defined, because right now it doesn't get autoloaded on its own
-        EE_Registry::instance()->load_core('Data_Migration_Class_Base', array(), true);
-        EE_Registry::instance()->load_core('Data_Migration_Script_Base', array(), true);
-        EE_Registry::instance()->load_core('DMS_Unknown_1_0_0', array(), true);
-        EE_Registry::instance()->load_core('Data_Migration_Script_Stage', array(), true);
-        EE_Registry::instance()->load_core('Data_Migration_Script_Stage_Table', array(), true);
-        $this->_table_manager = EE_Registry::instance()->create('TableManager', array(), true);
-        $this->_table_analysis = EE_Registry::instance()->create('TableAnalysis', array(), true);
-    }
-
-
-    /**
-     * Deciphers, from an option's name, what plugin and version it relates to (see _save_migrations_ran to see what
-     * the option names are like, but generally they're like
-     * 'ee_data_migration_script_Core.4.1.0' in 4.2 or 'ee_data_migration_script_4.1.0' before that).
-     * The option name shouldn't ever be like 'ee_data_migration_script_Core.4.1.0.reg' because it's derived,
-     * indirectly, from the data migration's classname, which should always be like EE_DMS_%s_%d_%d_%d.dms.php (eg
-     * EE_DMS_Core_4_1_0.dms.php)
-     *
-     * @param string $option_name (see EE_Data_Migration_Manage::_save_migrations_ran() where the option name is set)
-     * @return array where the first item is the plugin slug (eg 'Core','Calendar',etc) and the 2nd is the version of
-     *               that plugin (eg '4.1.0')
-     */
-    private function _get_plugin_slug_and_version_string_from_dms_option_name($option_name)
-    {
-        $plugin_slug_and_version_string = str_replace(
-            EE_Data_Migration_Manager::data_migration_script_option_prefix,
-            "",
-            $option_name
-        );
-        // check if $plugin_slug_and_version_string is like '4.1.0' (4.1-style) or 'Core.4.1.0' (4.2-style)
-        $parts = explode(".", $plugin_slug_and_version_string);
-
-        if (count($parts) == 4) {
-            // it's 4.2-style.eg Core.4.1.0
-            $plugin_slug = $parts[0];// eg Core
-            $version_string = $parts[1] . "." . $parts[2] . "." . $parts[3]; // eg 4.1.0
-        } else {
-            // it's 4.1-style: eg 4.1.0
-            $plugin_slug = 'Core';
-            $version_string = $plugin_slug_and_version_string;// eg 4.1.0
-        }
-        return array($plugin_slug, $version_string);
-    }
-
-    /**
-     * Gets the DMS class from the wordpress option, otherwise throws an EE_Error if it's not
-     * for a known DMS class.
-     *
-     * @param string $dms_option_name
-     * @param string $dms_option_value (serialized)
-     * @return EE_Data_Migration_Script_Base
-     * @throws EE_Error
-     */
-    private function _get_dms_class_from_wp_option($dms_option_name, $dms_option_value)
-    {
-        $data_migration_data = maybe_unserialize($dms_option_value);
-        if (isset($data_migration_data['class']) && class_exists($data_migration_data['class'])) {
-            $class = LoaderFactory::getLoader()->getShared($data_migration_data['class']);
-            if ($class instanceof EE_Data_Migration_Script_Base) {
-                $class->instantiate_from_array_of_properties($data_migration_data);
-                return $class;
-            } else {
-                // huh, so its an object but not a data migration script?? that shouldn't happen
-                // just leave it as an array (which will probably just get ignored)
-                throw new EE_Error(
-                    sprintf(
-                        __(
-                            "Trying to retrieve DMS class from wp option. No DMS by the name '%s' exists",
-                            'event_espresso'
-                        ),
-                        $data_migration_data['class']
-                    )
-                );
-            }
-        } else {
-            // so the data doesn't specify a class. So it must either be a legacy array of info or some array (which we'll probably just ignore), or a class that no longer exists
-            throw new EE_Error(
-                sprintf(__("The wp option  with key '%s' does not represent a DMS", 'event_espresso'), $dms_option_name)
-            );
-        }
-    }
-
-    /**
-     * Gets the array describing what data migrations have run. Also has a side-effect of recording which was the last
-     * ran, and which was the last ran which hasn't finished yet
-     *
-     * @return array where each element should be an array of EE_Data_Migration_Script_Base (but also has a few legacy
-     *               arrays in there - which should probably be ignored)
-     */
-    public function get_data_migrations_ran()
-    {
-        if (! $this->_data_migrations_ran) {
-            // setup autoloaders for each of the scripts in there
-            $this->get_all_data_migration_scripts_available();
-            $data_migrations_options = $this->get_all_migration_script_options(
-            );// get_option(EE_Data_Migration_Manager::data_migrations_option_name,get_option('espresso_data_migrations',array()));
-
-            $data_migrations_ran = array();
-            // convert into data migration script classes where possible
-            foreach ($data_migrations_options as $data_migration_option) {
-                list($plugin_slug, $version_string) = $this->_get_plugin_slug_and_version_string_from_dms_option_name(
-                    $data_migration_option['option_name']
-                );
-
-                try {
-                    $class = $this->_get_dms_class_from_wp_option(
-                        $data_migration_option['option_name'],
-                        $data_migration_option['option_value']
-                    );
-                    $data_migrations_ran[ $plugin_slug ][ $version_string ] = $class;
-                    // ok so far THIS is the 'last-ran-script'... unless we find another on next iteration
-                    $this->_last_ran_script = $class;
-                    if (! $class->is_completed()) {
-                        // sometimes we also like to know which was the last incomplete script (or if there are any at all)
-                        $this->_last_ran_incomplete_script = $class;
-                    }
-                } catch (EE_Error $e) {
-                    // ok so its not a DMS. We'll just keep it, although other code will need to expect non-DMSs
-                    $data_migrations_ran[ $plugin_slug ][ $version_string ] = maybe_unserialize(
-                        $data_migration_option['option_value']
-                    );
-                }
-            }
-            // so here the array of $data_migrations_ran is actually a mix of classes and a few legacy arrays
-            $this->_data_migrations_ran = $data_migrations_ran;
-            if (! $this->_data_migrations_ran || ! is_array($this->_data_migrations_ran)) {
-                $this->_data_migrations_ran = array();
-            }
-        }
-        return $this->_data_migrations_ran;
-    }
-
-
-    /**
-     *
-     * @param string $script_name eg 'DMS_Core_4_1_0'
-     * @param string $old_table   eg 'wp_events_detail'
-     * @param string $old_pk      eg 'wp_esp_posts'
-     * @param        $new_table
-     * @return mixed string or int
-     */
-    public function get_mapping_new_pk($script_name, $old_table, $old_pk, $new_table)
-    {
-        $script = EE_Registry::instance()->load_dms($script_name);
-        $mapping = $script->get_mapping_new_pk($old_table, $old_pk, $new_table);
-        return $mapping;
-    }
-
-    /**
-     * Gets all the options containing migration scripts that have been run. Ordering is important: it's assumed that
-     * the last option returned in this array is the most-recently ran DMS option
-     *
-     * @return array
-     */
-    public function get_all_migration_script_options()
-    {
-        global $wpdb;
-        return $wpdb->get_results(
-            "SELECT * FROM {$wpdb->options} WHERE option_name like '" . EE_Data_Migration_Manager::data_migration_script_option_prefix . "%' ORDER BY option_id ASC",
-            ARRAY_A
-        );
-    }
-
-    /**
-     * Gets the array of folders which contain data migration scripts. Also adds them to be auto-loaded
-     *
-     * @return array where each value is the full folder path of a folder containing data migration scripts, WITH
-     *               slashes at the end of the folder name.
-     */
-    public function get_data_migration_script_folders()
-    {
-        return apply_filters(
-            'FHEE__EE_Data_Migration_Manager__get_data_migration_script_folders',
-            array('Core' => EE_CORE . 'data_migration_scripts')
-        );
-    }
-
-    /**
-     * Gets the version the migration script upgrades to
-     *
-     * @param string $migration_script_name eg 'EE_DMS_Core_4_1_0'
-     * @return array {
-     * @type string  $slug                  like 'Core','Calendar',etc
-     * @type string  $version               like 4.3.0
-     *                                      }
-     * @throws EE_Error
-     */
-    public function script_migrates_to_version($migration_script_name, $eeAddonClass = '')
-    {
-        if (isset($this->script_migration_versions[ $migration_script_name ])) {
-            return $this->script_migration_versions[ $migration_script_name ];
-        }
-        $dms_info = $this->parse_dms_classname($migration_script_name);
-        $this->script_migration_versions[ $migration_script_name ] = array(
-            'slug'    => $eeAddonClass !== '' ? $eeAddonClass : $dms_info['slug'],
-            'version' => $dms_info['major_version'] . "." . $dms_info['minor_version'] . "." . $dms_info['micro_version'],
-        );
-        return $this->script_migration_versions[ $migration_script_name ];
-    }
-
-    /**
-     * Gets the juicy details out of a dms filename like 'EE_DMS_Core_4_1_0'
-     *
-     * @param string $classname
-     * @return array with keys 'slug','major_version','minor_version', and 'micro_version' (the last 3 are ints)
-     * @throws EE_Error
-     */
-    public function parse_dms_classname($classname)
-    {
-        $matches = array();
-        preg_match('~EE_DMS_(.*)_([0-9]*)_([0-9]*)_([0-9]*)~', $classname, $matches);
-        if (! $matches || ! (isset($matches[1]) && isset($matches[2]) && isset($matches[3]))) {
-            throw new EE_Error(
-                sprintf(
-                    __(
-                        "%s is not a valid Data Migration Script. The classname should be like EE_DMS_w_x_y_z, where w is either 'Core' or the slug of an addon and x, y and z are numbers, ",
-                        "event_espresso"
-                    ),
-                    $classname
-                )
-            );
-        }
-        return array(
-            'slug'          => $matches[1],
-            'major_version' => intval($matches[2]),
-            'minor_version' => intval($matches[3]),
-            'micro_version' => intval($matches[4]),
-        );
-    }
-
-    /**
-     * Ensures that the option indicating the current DB version is set. This should only be
-     * a concern when activating EE for the first time, THEORETICALLY.
-     * If we detect that we're activating EE4 over top of EE3.1, then we set the current db state to 3.1.x, otherwise
-     * to 4.1.x.
-     *
-     * @return string of current db state
-     */
-    public function ensure_current_database_state_is_set()
-    {
-        $espresso_db_core_updates = get_option('espresso_db_update', array());
-        $db_state = get_option(EE_Data_Migration_Manager::current_database_state);
-        if (! $db_state) {
-            // mark the DB as being in the state as the last version in there.
-            // this is done to trigger maintenance mode and do data migration scripts
-            // if the admin installed this version of EE over 3.1.x or 4.0.x
-            // otherwise, the normal maintenance mode code is fine
-            $previous_versions_installed = array_keys($espresso_db_core_updates);
-            $previous_version_installed = end($previous_versions_installed);
-            if (version_compare('4.1.0', $previous_version_installed)) {
-                // last installed version was less than 4.1
-                // so we want the data migrations to happen. SO, we're going to say the DB is at that state
-                $db_state = array('Core' => $previous_version_installed);
-            } else {
-                $db_state = array('Core' => EVENT_ESPRESSO_VERSION);
-            }
-            update_option(EE_Data_Migration_Manager::current_database_state, $db_state);
-        }
-        // in 4.1, $db_state would have only been a simple string like '4.1.0',
-        // but in 4.2+ it should be an array with at least key 'Core' and the value of that plugin's
-        // db, and possibly other keys for other addons like 'Calendar','Permissions',etc
-        if (! is_array($db_state)) {
-            $db_state = array('Core' => $db_state);
-            update_option(EE_Data_Migration_Manager::current_database_state, $db_state);
-        }
-        return $db_state;
-    }
-
-    /**
-     * Checks if there are any data migration scripts that ought to be run. If found,
-     * returns the instantiated classes. If none are found (ie, they've all already been run
-     * or they don't apply), returns an empty array
-     *
-     * @return EE_Data_Migration_Script_Base[]
-     */
-    public function check_for_applicable_data_migration_scripts()
-    {
-        // get the option describing what options have already run
-        $scripts_ran = $this->get_data_migrations_ran();
-        // $scripts_ran = array('4.1.0.core'=>array('monkey'=>null));
-        $script_class_and_filepaths_available = $this->get_all_data_migration_scripts_available();
-
-
-        $current_database_state = $this->ensure_current_database_state_is_set();
-        // determine which have already been run
-        $script_classes_that_should_run_per_iteration = array();
-        $iteration = 0;
-        $next_database_state_to_consider = $current_database_state;
-        $theoretical_database_state = null;
-        do {
-            // the next state after the currently-considered one will start off looking the same as the current, but we may make additions...
-            $theoretical_database_state = $next_database_state_to_consider;
-            // the next db state to consider is "what would the DB be like had we run all the scripts we found that applied last time?)
-            foreach ($script_class_and_filepaths_available as $classname => $filepath) {
-                $migrates_to_version = $this->script_migrates_to_version($classname);
-                $script_converts_plugin_slug = $migrates_to_version['slug'];
-                $script_converts_to_version = $migrates_to_version['version'];
-                // check if this version script is DONE or not; or if it's never been ran
-                if (! $scripts_ran ||
-                    ! isset($scripts_ran[ $script_converts_plugin_slug ]) ||
-                    ! isset($scripts_ran[ $script_converts_plugin_slug ][ $script_converts_to_version ])) {
-                    // we haven't ran this conversion script before
-                    // now check if it applies... note that we've added an autoloader for it on get_all_data_migration_scripts_available
-                    $script = LoaderFactory::getLoader()->load($classname);
-                    /* @var $script EE_Data_Migration_Script_Base */
-                    $can_migrate = $script->can_migrate_from_version($theoretical_database_state);
-                    if ($can_migrate) {
-                        $script_classes_that_should_run_per_iteration[ $iteration ][ $script->priority() ][] = $script;
-                        $migrates_to_version = $script->migrates_to_version();
-                        $next_database_state_to_consider[ $migrates_to_version['slug'] ] = $migrates_to_version['version'];
-                        unset($script_class_and_filepaths_available[ $classname ]);
-                    }
-                } elseif ($scripts_ran[ $script_converts_plugin_slug ][ $script_converts_to_version ] instanceof EE_Data_Migration_Script_Base) {
-                    // this script has been ran, or at least started
-                    $script = $scripts_ran[ $script_converts_plugin_slug ][ $script_converts_to_version ];
-                    if ($script->get_status() != self::status_completed) {
-                        // this script is already underway... keep going with it
-                        $script_classes_that_should_run_per_iteration[ $iteration ][ $script->priority() ][] = $script;
-                        $migrates_to_version = $script->migrates_to_version();
-                        $next_database_state_to_consider[ $migrates_to_version['slug'] ] = $migrates_to_version['version'];
-                        unset($script_class_and_filepaths_available[ $classname ]);
-                    } else {
-                        // it must have a status that indicates it has finished, so we don't want to try and run it again
-                    }
-                } else {
-                    // it exists but it's not  a proper data migration script
-                    // maybe the script got renamed? or was simply removed from EE?
-                    // either way, its certainly not runnable!
-                }
-            }
-            $iteration++;
-        } while ($next_database_state_to_consider != $theoretical_database_state && $iteration < 6);
-        // ok we have all the scripts that should run, now let's make them into flat array
-        $scripts_that_should_run = array();
-        foreach ($script_classes_that_should_run_per_iteration as $scripts_at_priority) {
-            ksort($scripts_at_priority);
-            foreach ($scripts_at_priority as $scripts) {
-                foreach ($scripts as $script) {
-                    $scripts_that_should_run[ get_class($script) ] = $script;
-                }
-            }
-        }
-
-        do_action(
-            'AHEE__EE_Data_Migration_Manager__check_for_applicable_data_migration_scripts__scripts_that_should_run',
-            $scripts_that_should_run
-        );
-        return $scripts_that_should_run;
-    }
-
-
-    /**
-     * Gets the script which is currently being ran, if there is one. If $include_completed_scripts is set to TRUE
-     * it will return the last ran script even if its complete.
-     * This means: if you want to find the currently-executing script, leave it as FALSE.
-     * If you really just want to find the script which ran most recently, regardless of status, leave it as TRUE.
-     *
-     * @param bool $include_completed_scripts
-     * @return EE_Data_Migration_Script_Base
-     */
-    public function get_last_ran_script($include_completed_scripts = false)
-    {
-        // make sure we've setup the class properties _last_ran_script and _last_ran_incomplete_script
-        if (! $this->_data_migrations_ran) {
-            $this->get_data_migrations_ran();
-        }
-        if ($include_completed_scripts) {
-            return $this->_last_ran_script;
-        } else {
-            return $this->_last_ran_incomplete_script;
-        }
-    }
-
-
-    /**
-     * Runs the data migration scripts (well, each request to this method calls one of the
-     * data migration scripts' migration_step() functions).
-     *
-     * @param int   $step_size
-     * @throws EE_Error
-     * @return array {
-     *                                  // where the first item is one EE_Data_Migration_Script_Base's stati,
-     *                                  //and the second item is a string describing what was done
-     * @type int    $records_to_migrate from the current migration script
-     * @type int    $records_migrated
-     * @type string $status             one of EE_Data_Migration_Manager::status_*
-     * @type string $script             verbose name of the current DMS
-     * @type string $message            string describing what was done during this step
-     *                                  }
-     */
-    public function migration_step($step_size = 0)
-    {
-
-        // bandaid fix for issue https://events.codebasehq.com/projects/event-espresso/tickets/7535
-        if (class_exists('EE_CPT_Strategy')) {
-            remove_action('pre_get_posts', array(EE_CPT_Strategy::instance(), 'pre_get_posts'), 5);
-        }
-
-        try {
-            $currently_executing_script = $this->get_last_ran_script();
-            if (! $currently_executing_script) {
-                // Find the next script that needs to execute
-                $scripts = $this->check_for_applicable_data_migration_scripts();
-                if (! $scripts) {
-                    // huh, no more scripts to run... apparently we're done!
-                    // but dont forget to make sure initial data is there
-                    // we should be good to allow them to exit maintenance mode now
-                    EE_Maintenance_Mode::instance()->set_maintenance_level(
-                        intval(EE_Maintenance_Mode::level_0_not_in_maintenance)
-                    );
-                    // saving migrations ran should actually be unnecessary, but leaving in place just in case
-                    // remember this migration was finished (even if we timeout initing db for core and plugins)
-                    $this->_save_migrations_ran();
-                    // make sure DB was updated AFTER we've recorded the migration was done
-                    $this->initialize_db_for_enqueued_ee_plugins();
-                    return array(
-                        'records_to_migrate' => 1,
-                        'records_migrated'   => 1,
-                        'status'             => self::status_no_more_migration_scripts,
-                        'script'             => __("Data Migration Completed Successfully", "event_espresso"),
-                        'message'            => __("All done!", "event_espresso"),
-                    );
-                }
-                $currently_executing_script = array_shift($scripts);
-                // and add to the array/wp option showing the scripts ran
-
-                $migrates_to = $this->script_migrates_to_version(get_class($currently_executing_script));
-                $plugin_slug = $migrates_to['slug'];
-                $version = $migrates_to['version'];
-                $this->_data_migrations_ran[ $plugin_slug ][ $version ] = $currently_executing_script;
-            }
-            $current_script_name = get_class($currently_executing_script);
-        } catch (Exception $e) {
-            // an exception occurred while trying to get migration scripts
-
-            $message = sprintf(
-                __("Error Message: %sStack Trace:%s", "event_espresso"),
-                $e->getMessage() . '<br>',
-                $e->getTraceAsString()
-            );
-            // record it on the array of data migration scripts ran. This will be overwritten next time we try and try to run data migrations
-            // but that's ok-- it's just an FYI to support that we couldn't even run any data migrations
-            $this->add_error_to_migrations_ran(
-                sprintf(__("Could not run data migrations because: %s", "event_espresso"), $message)
-            );
-            return array(
-                'records_to_migrate' => 1,
-                'records_migrated'   => 0,
-                'status'             => self::status_fatal_error,
-                'script'             => __("Error loading data migration scripts", "event_espresso"),
-                'message'            => $message,
-            );
-        }
-        // ok so we definitely have a data migration script
-        try {
-            // how big of a bite do we want to take? Allow users to easily override via their wp-config
-            if (absint($step_size) < 1) {
-                $step_size = defined('EE_MIGRATION_STEP_SIZE') && absint(EE_MIGRATION_STEP_SIZE)
-                    ? EE_MIGRATION_STEP_SIZE : EE_Data_Migration_Manager::step_size;
-            }
-            // do what we came to do!
-            $currently_executing_script->migration_step($step_size);
-            // can we wrap it up and verify default data?
-            $init_dbs = false;
-            switch ($currently_executing_script->get_status()) {
-                case EE_Data_Migration_Manager::status_continue:
-                    $response_array = array(
-                        'records_to_migrate' => $currently_executing_script->count_records_to_migrate(),
-                        'records_migrated'   => $currently_executing_script->count_records_migrated(),
-                        'status'             => EE_Data_Migration_Manager::status_continue,
-                        'message'            => $currently_executing_script->get_feedback_message(),
-                        'script'             => $currently_executing_script->pretty_name(),
-                    );
-                    break;
-                case EE_Data_Migration_Manager::status_completed:
-                    // ok so THAT script has completed
-                    $this->update_current_database_state_to($this->script_migrates_to_version($current_script_name));
-                    $response_array = array(
-                        'records_to_migrate' => $currently_executing_script->count_records_to_migrate(),
-                        'records_migrated'   => $currently_executing_script->count_records_migrated(),
-                        'status'             => EE_Data_Migration_Manager::status_completed,
-                        'message'            => $currently_executing_script->get_feedback_message(),
-                        'script'             => sprintf(
-                            __("%s Completed", 'event_espresso'),
-                            $currently_executing_script->pretty_name()
-                        ),
-                    );
-                    // check if there are any more after this one.
-                    $scripts_remaining = $this->check_for_applicable_data_migration_scripts();
-                    if (! $scripts_remaining) {
-                        // we should be good to allow them to exit maintenance mode now
-                        EE_Maintenance_Mode::instance()->set_maintenance_level(
-                            intval(EE_Maintenance_Mode::level_0_not_in_maintenance)
-                        );
-                        // huh, no more scripts to run... apparently we're done!
-                        // but dont forget to make sure initial data is there
-                        $init_dbs = true;
-                        $response_array['status'] = self::status_no_more_migration_scripts;
-                    }
-                    break;
-                default:
-                    $response_array = array(
-                        'records_to_migrate' => $currently_executing_script->count_records_to_migrate(),
-                        'records_migrated'   => $currently_executing_script->count_records_migrated(),
-                        'status'             => $currently_executing_script->get_status(),
-                        'message'            => sprintf(
-                            __("Minor errors occurred during %s: %s", "event_espresso"),
-                            $currently_executing_script->pretty_name(),
-                            implode(", ", $currently_executing_script->get_errors())
-                        ),
-                        'script'             => $currently_executing_script->pretty_name(),
-                    );
-                    break;
-            }
-        } catch (Exception $e) {
-            // ok so some exception was thrown which killed the data migration script
-            // double-check we have a real script
-            if ($currently_executing_script instanceof EE_Data_Migration_Script_Base) {
-                $script_name = $currently_executing_script->pretty_name();
-                $currently_executing_script->set_broken();
-                $currently_executing_script->add_error($e->getMessage());
-            } else {
-                $script_name = __("Error getting Migration Script", "event_espresso");
-            }
-            $response_array = array(
-                'records_to_migrate' => 1,
-                'records_migrated'   => 0,
-                'status'             => self::status_fatal_error,
-                'message'            => sprintf(
-                    __("A fatal error occurred during the migration: %s", "event_espresso"),
-                    $e->getMessage()
-                ),
-                'script'             => $script_name,
-            );
-        }
-        $successful_save = $this->_save_migrations_ran();
-        if ($successful_save !== true) {
-            // ok so the current wp option didn't save. that's tricky, because we'd like to update it
-            // and mark it as having a fatal error, but remember- WE CAN'T SAVE THIS WP OPTION!
-            // however, if we throw an exception, and return that, then the next request
-            // won't have as much info in it, and it may be able to save
-            throw new EE_Error(
-                sprintf(
-                    __(
-                        "The error '%s' occurred updating the status of the migration. This is a FATAL ERROR, but the error is preventing the system from remembering that. Please contact event espresso support.",
-                        "event_espresso"
-                    ),
-                    $successful_save
-                )
-            );
-        }
-        // if we're all done, initialize EE plugins' default data etc.
-        if ($init_dbs) {
-            $this->initialize_db_for_enqueued_ee_plugins();
-        }
-        return $response_array;
-    }
-
-
-    /**
-     * Echo out JSON response to migration script AJAX requests. Takes precautions
-     * to buffer output so that we don't throw junk into our json.
-     *
-     * @return array with keys:
-     * 'records_to_migrate' which counts ALL the records for the current migration, and should remain constant. (ie,
-     * it's NOT the count of hwo many remain)
-     * 'records_migrated' which also counts ALL the records which have been migrated (ie, percent_complete =
-     * records_migrated/records_to_migrate)
-     * 'status'=>a string, one of EE_Data_migration_Manager::status_*
-     * 'message'=>a string, containing any message you want to show to the user. We may decide to split this up into
-     * errors, notifications, and successes
-     * 'script'=>a pretty name of the script currently running
-     */
-    public function response_to_migration_ajax_request()
-    {
-        ob_start();
-        try {
-            $response = $this->migration_step();
-        } catch (Exception $e) {
-            $response = array(
-                'records_to_migrate' => 0,
-                'records_migrated'   => 0,
-                'status'             => EE_Data_Migration_Manager::status_fatal_error,
-                'message'            => sprintf(
-                    __("Unknown fatal error occurred: %s", "event_espresso"),
-                    $e->getMessage()
-                ),
-                'script'             => 'Unknown',
-            );
-            $this->add_error_to_migrations_ran($e->getMessage() . "; Stack trace:" . $e->getTraceAsString());
-        }
-        $warnings_etc = @ob_get_contents();
-        ob_end_clean();
-        $response['message'] .= $warnings_etc;
-        return $response;
-    }
-
-    /**
-     * Updates the wordpress option that keeps track of which which EE version the database
-     * is at (ie, the code may be at 4.1.0, but the database is still at 3.1.35)
-     *
-     * @param array $slug_and_version {
-     * @type string $slug             like 'Core' or 'Calendar',
-     * @type string $version          like '4.1.0'
-     *                                }
-     * @return void
-     */
-    public function update_current_database_state_to($slug_and_version = null)
-    {
-        if (! $slug_and_version) {
-            // no version was provided, assume it should be at the current code version
-            $slug_and_version = array('slug' => 'Core', 'version' => espresso_version());
-        }
-        $current_database_state = get_option(self::current_database_state);
-        $current_database_state[ $slug_and_version['slug'] ] = $slug_and_version['version'];
-        update_option(self::current_database_state, $current_database_state);
-    }
-
-    /**
-     * Determines if the database is currently at a state matching what's indicated in $slug and $version.
-     *
-     * @param array $slug_and_version {
-     * @type string $slug             like 'Core' or 'Calendar',
-     * @type string $version          like '4.1.0'
-     *                                }
-     * @return boolean
-     */
-    public function database_needs_updating_to($slug_and_version)
-    {
-
-        $slug = $slug_and_version['slug'];
-        $version = $slug_and_version['version'];
-        $current_database_state = get_option(self::current_database_state);
-        if (! isset($current_database_state[ $slug ])) {
-            return true;
-        } else {
-            // just compare the first 3 parts of version string, eg "4.7.1", not "4.7.1.dev.032" because DBs shouldn't change on nano version changes
-            $version_parts_current_db_state = array_slice(explode('.', $current_database_state[ $slug ]), 0, 3);
-            $version_parts_of_provided_db_state = array_slice(explode('.', $version), 0, 3);
-            $needs_updating = false;
-            foreach ($version_parts_current_db_state as $offset => $version_part_in_current_db_state) {
-                if ($version_part_in_current_db_state < $version_parts_of_provided_db_state[ $offset ]) {
-                    $needs_updating = true;
-                    break;
-                }
-            }
-            return $needs_updating;
-        }
-    }
-
-
-    /**
-     * Gets all the data migration scripts available in the core folder and folders
-     * in addons. Has the side effect of adding them for autoloading
-     *
-     * @return array keys are expected classnames, values are their filepaths
-     * @throws InvalidInterfaceException
-     * @throws InvalidDataTypeException
-     * @throws EE_Error
-     * @throws InvalidArgumentException
-     */
-    public function get_all_data_migration_scripts_available()
-    {
-        if (! $this->_data_migration_class_to_filepath_map) {
-            $this->_data_migration_class_to_filepath_map = array();
-            foreach ($this->get_data_migration_script_folders() as $eeAddonClass => $folder_path) {
-                // strip any placeholders added to classname to make it a unique array key
-                $eeAddonClass = trim($eeAddonClass, '*');
-                $eeAddonClass = $eeAddonClass === 'Core' || class_exists($eeAddonClass)
-                    ? $eeAddonClass
-                    : '';
-                $folder_path = EEH_File::end_with_directory_separator($folder_path);
-                $files = glob($folder_path . '*.dms.php');
-                if (empty($files)) {
-                    continue;
-                }
-                foreach ($files as $file) {
-                    $pos_of_last_slash = strrpos($file, DS);
-                    $classname = str_replace('.dms.php', '', substr($file, $pos_of_last_slash + 1));
-                    $migrates_to = $this->script_migrates_to_version($classname, $eeAddonClass);
-                    $slug = $migrates_to['slug'];
-                    // check that the slug as contained in the DMS is associated with
-                    // the slug of an addon or core
-                    if ($slug !== 'Core' && EE_Registry::instance()->get_addon_by_name($slug) === null) {
-                        EE_Error::doing_it_wrong(
-                            __FUNCTION__,
-                            sprintf(
-                                esc_html__(
-                                    'The data migration script "%s" migrates the "%s" data, but there is no EE addon with that name. There is only: %s. ',
-                                    'event_espresso'
-                                ),
-                                $classname,
-                                $slug,
-                                implode(', ', array_keys(EE_Registry::instance()->get_addons_by_name()))
-                            ),
-                            '4.3.0.alpha.019'
-                        );
-                    }
-                    $this->_data_migration_class_to_filepath_map[ $classname ] = $file;
-                }
-            }
-            EEH_Autoloader::register_autoloader($this->_data_migration_class_to_filepath_map);
-        }
-        return $this->_data_migration_class_to_filepath_map;
-    }
-
-
-    /**
-     * Once we have an addon that works with EE4.1, we will actually want to fetch the PUE slugs
-     * from each addon, and check if they need updating,
-     *
-     * @return boolean
-     */
-    public function addons_need_updating()
-    {
-        return false;
-    }
-
-    /**
-     * Adds this error string to the data_migrations_ran array, but we dont necessarily know
-     * where to put it, so we just throw it in there... better than nothing...
-     *
-     * @param string $error_message
-     * @throws EE_Error
-     */
-    public function add_error_to_migrations_ran($error_message)
-    {
-        // get last-ran migration script
-        global $wpdb;
-        $last_migration_script_option = $wpdb->get_row(
-            "SELECT * FROM $wpdb->options WHERE option_name like '" . EE_Data_Migration_Manager::data_migration_script_option_prefix . "%' ORDER BY option_id DESC LIMIT 1",
-            ARRAY_A
-        );
-
-        $last_ran_migration_script_properties = isset($last_migration_script_option['option_value'])
-            ? maybe_unserialize($last_migration_script_option['option_value']) : null;
-        // now, tread lightly because we're here because a FATAL non-catchable error
-        // was thrown last time when we were trying to run a data migration script
-        // so the fatal error could have happened while getting the migration script
-        // or doing running it...
-        $versions_migrated_to = isset($last_migration_script_option['option_name']) ? str_replace(
-            EE_Data_Migration_Manager::data_migration_script_option_prefix,
-            "",
-            $last_migration_script_option['option_name']
-        ) : null;
-
-        // check if it THINKS its a data migration script and especially if it's one that HASN'T finished yet
-        // because if it has finished, then it obviously couldn't be the cause of this error, right? (because its all done)
-        if (isset($last_ran_migration_script_properties['class']) && isset($last_ran_migration_script_properties['_status']) && $last_ran_migration_script_properties['_status'] != self::status_completed) {
-            // ok then just add this error to its list of errors
-            $last_ran_migration_script_properties['_errors'][] = $error_message;
-            $last_ran_migration_script_properties['_status'] = self::status_fatal_error;
-        } else {
-            // so we don't even know which script was last running
-            // use the data migration error stub, which is designed specifically for this type of thing
-            $general_migration_error = new EE_DMS_Unknown_1_0_0();
-            $general_migration_error->add_error($error_message);
-            $general_migration_error->set_broken();
-            $last_ran_migration_script_properties = $general_migration_error->properties_as_array();
-            $versions_migrated_to = 'Unknown.1.0.0';
-            // now just to make sure appears as last (in case the were previously a fatal error like this)
-            // delete the old one
-            delete_option(self::data_migration_script_option_prefix . $versions_migrated_to);
-        }
-        update_option(
-            self::data_migration_script_option_prefix . $versions_migrated_to,
-            $last_ran_migration_script_properties
-        );
-    }
-
-    /**
-     * saves what data migrations have ran to the database
-     *
-     * @return mixed TRUE if successfully saved migrations ran, string if an error occurred
-     */
-    protected function _save_migrations_ran()
-    {
-        if ($this->_data_migrations_ran == null) {
-            $this->get_data_migrations_ran();
-        }
-        // now, we don't want to save actual classes to the DB because that's messy
-        $successful_updates = true;
-        foreach ($this->_data_migrations_ran as $plugin_slug => $migrations_ran_for_plugin) {
-            foreach ($migrations_ran_for_plugin as $version_string => $array_or_migration_obj) {
-                $plugin_slug_for_use_in_option_name = $plugin_slug . ".";
-                $option_name = self::data_migration_script_option_prefix . $plugin_slug_for_use_in_option_name . $version_string;
-                $old_option_value = get_option($option_name);
-                if ($array_or_migration_obj instanceof EE_Data_Migration_Script_Base) {
-                    $script_array_for_saving = $array_or_migration_obj->properties_as_array();
-                    if ($old_option_value != $script_array_for_saving) {
-                        $successful_updates = update_option($option_name, $script_array_for_saving);
-                    }
-                } else {// we don't know what this array-thing is. So just save it as-is
-                    if ($old_option_value != $array_or_migration_obj) {
-                        $successful_updates = update_option($option_name, $array_or_migration_obj);
-                    }
-                }
-                if (! $successful_updates) {
-                    global $wpdb;
-                    return $wpdb->last_error;
-                }
-            }
-        }
-        return true;
-        // $updated = update_option(self::data_migrations_option_name, $array_of_migrations);
-        // if ($updated !== true) {
-        //     global $wpdb;
-        //     return $wpdb->last_error;
-        // } else {
-        //     return true;
-        // }
-        // wp_mail(
-        //     "michael@eventespresso.com",
-        //     time() . " price debug info",
-        //     "updated: $updated, last error: $last_error, byte length of option: " . strlen(
-        //         serialize($array_of_migrations)
-        //     )
-        // );
-    }
-
-    /**
-     * Takes an array of data migration script properties and re-creates the class from
-     * them. The argument $properties_array is assumed to have been made by
-     * EE_Data_Migration_Script_Base::properties_as_array()
-     *
-     * @param array $properties_array
-     * @return EE_Data_Migration_Script_Base
-     * @throws EE_Error
-     */
-    public function _instantiate_script_from_properties_array($properties_array)
-    {
-        if (! isset($properties_array['class'])) {
-            throw new EE_Error(
-                sprintf(
-                    __("Properties array  has no 'class' properties. Here's what it has: %s", "event_espresso"),
-                    implode(",", $properties_array)
-                )
-            );
-        }
-        $class_name = $properties_array['class'];
-        if (! class_exists($class_name)) {
-            throw new EE_Error(sprintf(__("There is no migration script named %s", "event_espresso"), $class_name));
-        }
-        $class = new $class_name;
-        if (! $class instanceof EE_Data_Migration_Script_Base) {
-            throw new EE_Error(
-                sprintf(
-                    __("Class '%s' is supposed to be a migration script. Its not, its a '%s'", "event_espresso"),
-                    $class_name,
-                    get_class($class)
-                )
-            );
-        }
-        $class->instantiate_from_array_of_properties($properties_array);
-        return $class;
-    }
-
-    /**
-     * Gets the classname for the most up-to-date DMS (ie, the one that will finally
-     * leave the DB in a state usable by the current plugin code).
-     *
-     * @param string $plugin_slug the slug for the ee plugin we are searching for. Default is 'Core'
-     * @return string
-     */
-    public function get_most_up_to_date_dms($plugin_slug = 'Core')
-    {
-        $class_to_filepath_map = $this->get_all_data_migration_scripts_available();
-        $most_up_to_date_dms_classname = null;
-        foreach ($class_to_filepath_map as $classname => $filepath) {
-            if ($most_up_to_date_dms_classname === null) {
-                $migrates_to = $this->script_migrates_to_version($classname);
-                $this_plugin_slug = $migrates_to['slug'];
-                if ($this_plugin_slug == $plugin_slug) {
-                    // if it's for core, it wins
-                    $most_up_to_date_dms_classname = $classname;
-                }
-                // if it wasn't for core, we must keep searching for one that is!
-                continue;
-            } else {
-                $champion_migrates_to = $this->script_migrates_to_version($most_up_to_date_dms_classname);
-                $contender_migrates_to = $this->script_migrates_to_version($classname);
-                if ($contender_migrates_to['slug'] == $plugin_slug
-                    && version_compare(
-                        $champion_migrates_to['version'],
-                        $contender_migrates_to['version'],
-                        '<'
-                    )) {
-                    // so the contenders version is higher and its for Core
-                    $most_up_to_date_dms_classname = $classname;
-                }
-            }
-        }
-        return $most_up_to_date_dms_classname;
-    }
-
-    /**
-     * Gets the migration script specified but ONLY if it has already ran.
-     *
-     * Eg, if you wanted to see if 'EE_DMS_Core_4_1_0' has ran, you would run the following code:
-     * <code> $core_4_1_0_dms_ran = EE_Data_Migration_Manager::instance()->get_migration_ran( '4.1.0', 'Core' ) !==
-     * NULL;</code> This is especially useful in addons' data migration scripts, this way they can tell if a core (or
-     * other addon) DMS has ran, in case the current DMS depends on it.
-     *
-     * @param string $version     the version the DMS searched for migrates to. Usually just the content before the 3rd
-     *                            period. Eg '4.1.0'
-     * @param string $plugin_slug like 'Core', 'Mailchimp', 'Calendar', etc
-     * @return EE_Data_Migration_Script_Base
-     */
-    public function get_migration_ran($version, $plugin_slug = 'Core')
-    {
-        $migrations_ran = $this->get_data_migrations_ran();
-        if (isset($migrations_ran[ $plugin_slug ]) && isset($migrations_ran[ $plugin_slug ][ $version ])) {
-            return $migrations_ran[ $plugin_slug ][ $version ];
-        } else {
-            return null;
-        }
-    }
-
-    /**
-     * Resets the borked data migration scripts so they're no longer borked
-     * so we can again attempt to migrate
-     *
-     * @return bool
-     * @throws EE_Error
-     */
-    public function reattempt()
-    {
-        // find if the last-ran script was borked
-        // set it as being non-borked (we shouldn't ever get DMSs that we don't recognize)
-        // add an 'error' saying that we attempted to reset
-        // does it have a stage that was borked too? if so make it no longer borked
-        // add an 'error' saying we attempted to reset
-        $last_ran_script = $this->get_last_ran_script();
-        if ($last_ran_script instanceof EE_DMS_Unknown_1_0_0) {
-            // if it was an error DMS, just mark it as complete (if another error occurs it will overwrite it)
-            $last_ran_script->set_completed();
-        } elseif ($last_ran_script instanceof EE_Data_Migration_Script_Base) {
-            $last_ran_script->reattempt();
-        } else {
-            throw new EE_Error(
-                sprintf(
-                    __(
-                        'Unable to reattempt the last ran migration script because it was not a valid migration script. || It was %s',
-                        'event_espresso'
-                    ),
-                    print_r($last_ran_script, true)
-                )
-            );
-        }
-        return $this->_save_migrations_ran();
-    }
-
-    /**
-     * Gets whether or not this particular migration has run or not
-     *
-     * @param string $version     the version the DMS searched for migrates to. Usually just the content before the 3rd
-     *                            period. Eg '4.1.0'
-     * @param string $plugin_slug like 'Core', 'Mailchimp', 'Calendar', etc
-     * @return boolean
-     */
-    public function migration_has_ran($version, $plugin_slug = 'Core')
-    {
-        return $this->get_migration_ran($version, $plugin_slug) !== null;
-    }
-
-    /**
-     * Enqueues this ee plugin to have its data initialized
-     *
-     * @param string $plugin_slug either 'Core' or EE_Addon::name()'s return value
-     */
-    public function enqueue_db_initialization_for($plugin_slug)
-    {
-        $queue = $this->get_db_initialization_queue();
-        if (! in_array($plugin_slug, $queue)) {
-            $queue[] = $plugin_slug;
-        }
-        update_option(self::db_init_queue_option_name, $queue);
-    }
-
-    /**
-     * Calls EE_Addon::initialize_db_if_no_migrations_required() on each addon
-     * specified in EE_Data_Migration_Manager::get_db_init_queue(), and if 'Core' is
-     * in the queue, calls EE_System::initialize_db_if_no_migrations_required().
-     */
-    public function initialize_db_for_enqueued_ee_plugins()
-    {
-        $queue = $this->get_db_initialization_queue();
-        foreach ($queue as $plugin_slug) {
-            $most_up_to_date_dms = $this->get_most_up_to_date_dms($plugin_slug);
-            if (! $most_up_to_date_dms) {
-                // if there is NO DMS for this plugin, obviously there's no schema to verify anyways
-                $verify_db = false;
-            } else {
-                $most_up_to_date_dms_migrates_to = $this->script_migrates_to_version($most_up_to_date_dms);
-                $verify_db = $this->database_needs_updating_to($most_up_to_date_dms_migrates_to);
-            }
-            if ($plugin_slug == 'Core') {
-                EE_System::instance()->initialize_db_if_no_migrations_required(
-                    false,
-                    $verify_db
-                );
-            } else {
-                // just loop through the addons to make sure their database is setup
-                foreach (EE_Registry::instance()->addons as $addon) {
-                    if ($addon->name() == $plugin_slug) {
-                        $addon->initialize_db_if_no_migrations_required($verify_db);
-                        break;
-                    }
-                }
-            }
-        }
-        // because we just initialized the DBs for the enqueued ee plugins
-        // we don't need to keep remembering which ones needed to be initialized
-        delete_option(self::db_init_queue_option_name);
-    }
-
-    /**
-     * Gets a numerically-indexed array of plugin slugs that need to have their databases
-     * (re-)initialized after migrations are complete. ie, each element should be either
-     * 'Core', or the return value of EE_Addon::name() for an addon
-     *
-     * @return array
-     */
-    public function get_db_initialization_queue()
-    {
-        return get_option(self::db_init_queue_option_name, array());
-    }
-
-    /**
-     * 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 $this->_table_analysis;
-        } else {
-            throw new EE_Error(
-                sprintf(
-                    __('Table analysis class on class %1$s is not set properly.', 'event_espresso'),
-                    get_class($this)
-                )
-            );
-        }
-    }
-
-    /**
-     * Gets the injected table manager, or throws an exception
-     *
-     * @return TableManager
-     * @throws EE_Error
-     */
-    protected function _get_table_manager()
-    {
-        if ($this->_table_manager instanceof TableManager) {
-            return $this->_table_manager;
-        } else {
-            throw new EE_Error(
-                sprintf(
-                    __('Table manager class on class %1$s is not set properly.', 'event_espresso'),
-                    get_class($this)
-                )
-            );
-        }
-    }
+	/**
+	 *
+	 * @var EE_Registry
+	 */
+	// protected $EE;
+	/**
+	 * name of the wordpress option which stores an array of data about
+	 */
+	const data_migrations_option_name = 'ee_data_migration';
+
+
+	const data_migration_script_option_prefix = 'ee_data_migration_script_';
+
+	const data_migration_script_mapping_option_prefix = 'ee_dms_map_';
+
+	/**
+	 * name of the wordpress option which stores the database' current version. IE, the code may be at version 4.2.0,
+	 * but as migrations are performed the database will progress from 3.1.35 to 4.1.0 etc.
+	 */
+	const current_database_state = 'ee_data_migration_current_db_state';
+
+	/**
+	 * Special status string returned when we're positive there are no more data migration
+	 * scripts that can be run.
+	 */
+	const status_no_more_migration_scripts = 'no_more_migration_scripts';
+	/**
+	 * string indicating the migration should continue
+	 */
+	const status_continue = 'status_continue';
+	/**
+	 * string indicating the migration has completed and should be ended
+	 */
+	const status_completed = 'status_completed';
+	/**
+	 * string indicating a fatal error occurred and the data migration should be completely aborted
+	 */
+	const status_fatal_error = 'status_fatal_error';
+
+	/**
+	 * the number of 'items' (usually DB rows) to migrate on each 'step' (ajax request sent
+	 * during migration)
+	 */
+	const step_size = 50;
+
+	/**
+	 * option name that stores the queue of ee plugins needing to have
+	 * their data initialized (or re-initialized) once we are done migrations
+	 */
+	const db_init_queue_option_name = 'ee_db_init_queue';
+	/**
+	 * Array of information concerning data migrations that have ran in the history
+	 * of this EE installation. Keys should be the name of the version the script upgraded to
+	 *
+	 * @var EE_Data_Migration_Script_Base[]
+	 */
+	private $_data_migrations_ran = null;
+	/**
+	 * The last ran script. It's nice to store this somewhere accessible, as its easiest
+	 * to know which was the last run by which is the newest wp option; but in most of the code
+	 * we just use the local $_data_migration_ran array, which organized the scripts differently
+	 *
+	 * @var EE_Data_Migration_Script_Base
+	 */
+	private $_last_ran_script = null;
+
+	/**
+	 * Similarly to _last_ran_script, but this is the last INCOMPLETE migration script.
+	 *
+	 * @var EE_Data_Migration_Script_Base
+	 */
+	private $_last_ran_incomplete_script = null;
+	/**
+	 * array where keys are classnames, and values are filepaths of all the known migration scripts
+	 *
+	 * @var array
+	 */
+	private $_data_migration_class_to_filepath_map;
+
+	/**
+	 * the following 4 properties are fully set on construction.
+	 * Note: the first two apply to whether to continue running ALL migration scripts (ie, even though we're finished
+	 * one, we may want to start the next one); whereas the last two indicate whether to continue running a single
+	 * data migration script
+	 *
+	 * @var array
+	 */
+	public $stati_that_indicate_to_continue_migrations = array();
+
+	public $stati_that_indicate_to_stop_migrations = array();
+
+	public $stati_that_indicate_to_continue_single_migration_script = array();
+
+	public $stati_that_indicate_to_stop_single_migration_script = array();
+
+	/**
+	 * @var \EventEspresso\core\services\database\TableManager $table_manager
+	 */
+	protected $_table_manager;
+
+	/**
+	 * @var \EventEspresso\core\services\database\TableAnalysis $table_analysis
+	 */
+	protected $_table_analysis;
+
+	/**
+	 * @var array $script_migration_versions
+	 */
+	protected $script_migration_versions;
+
+	/**
+	 * @var EE_Data_Migration_Manager $_instance
+	 * @access    private
+	 */
+	private static $_instance = null;
+
+
+	/**
+	 * @singleton method used to instantiate class object
+	 * @access    public
+	 * @return EE_Data_Migration_Manager instance
+	 */
+	public static function instance()
+	{
+		// check if class object is instantiated
+		if (! self::$_instance instanceof EE_Data_Migration_Manager) {
+			self::$_instance = new self();
+		}
+		return self::$_instance;
+	}
+
+	/**
+	 * resets the singleton to its brand-new state (but does NOT delete old references to the old singleton. Meaning,
+	 * all new usages of the singleton should be made with Classname::instance()) and returns it
+	 *
+	 * @return EE_Data_Migration_Manager
+	 */
+	public static function reset()
+	{
+		self::$_instance = null;
+		return self::instance();
+	}
+
+
+	/**
+	 * constructor
+	 */
+	private function __construct()
+	{
+		$this->stati_that_indicate_to_continue_migrations = array(
+			self::status_continue,
+			self::status_completed,
+		);
+		$this->stati_that_indicate_to_stop_migrations = array(
+			self::status_fatal_error,
+			self::status_no_more_migration_scripts,
+		);
+		$this->stati_that_indicate_to_continue_single_migration_script = array(
+			self::status_continue,
+		);
+		$this->stati_that_indicate_to_stop_single_migration_script = array(
+			self::status_completed,
+			self::status_fatal_error
+			// note: status_no_more_migration_scripts doesn't apply
+		);
+		// make sure we've included the base migration script, because we may need the EE_DMS_Unknown_1_0_0 class
+		// to be defined, because right now it doesn't get autoloaded on its own
+		EE_Registry::instance()->load_core('Data_Migration_Class_Base', array(), true);
+		EE_Registry::instance()->load_core('Data_Migration_Script_Base', array(), true);
+		EE_Registry::instance()->load_core('DMS_Unknown_1_0_0', array(), true);
+		EE_Registry::instance()->load_core('Data_Migration_Script_Stage', array(), true);
+		EE_Registry::instance()->load_core('Data_Migration_Script_Stage_Table', array(), true);
+		$this->_table_manager = EE_Registry::instance()->create('TableManager', array(), true);
+		$this->_table_analysis = EE_Registry::instance()->create('TableAnalysis', array(), true);
+	}
+
+
+	/**
+	 * Deciphers, from an option's name, what plugin and version it relates to (see _save_migrations_ran to see what
+	 * the option names are like, but generally they're like
+	 * 'ee_data_migration_script_Core.4.1.0' in 4.2 or 'ee_data_migration_script_4.1.0' before that).
+	 * The option name shouldn't ever be like 'ee_data_migration_script_Core.4.1.0.reg' because it's derived,
+	 * indirectly, from the data migration's classname, which should always be like EE_DMS_%s_%d_%d_%d.dms.php (eg
+	 * EE_DMS_Core_4_1_0.dms.php)
+	 *
+	 * @param string $option_name (see EE_Data_Migration_Manage::_save_migrations_ran() where the option name is set)
+	 * @return array where the first item is the plugin slug (eg 'Core','Calendar',etc) and the 2nd is the version of
+	 *               that plugin (eg '4.1.0')
+	 */
+	private function _get_plugin_slug_and_version_string_from_dms_option_name($option_name)
+	{
+		$plugin_slug_and_version_string = str_replace(
+			EE_Data_Migration_Manager::data_migration_script_option_prefix,
+			"",
+			$option_name
+		);
+		// check if $plugin_slug_and_version_string is like '4.1.0' (4.1-style) or 'Core.4.1.0' (4.2-style)
+		$parts = explode(".", $plugin_slug_and_version_string);
+
+		if (count($parts) == 4) {
+			// it's 4.2-style.eg Core.4.1.0
+			$plugin_slug = $parts[0];// eg Core
+			$version_string = $parts[1] . "." . $parts[2] . "." . $parts[3]; // eg 4.1.0
+		} else {
+			// it's 4.1-style: eg 4.1.0
+			$plugin_slug = 'Core';
+			$version_string = $plugin_slug_and_version_string;// eg 4.1.0
+		}
+		return array($plugin_slug, $version_string);
+	}
+
+	/**
+	 * Gets the DMS class from the wordpress option, otherwise throws an EE_Error if it's not
+	 * for a known DMS class.
+	 *
+	 * @param string $dms_option_name
+	 * @param string $dms_option_value (serialized)
+	 * @return EE_Data_Migration_Script_Base
+	 * @throws EE_Error
+	 */
+	private function _get_dms_class_from_wp_option($dms_option_name, $dms_option_value)
+	{
+		$data_migration_data = maybe_unserialize($dms_option_value);
+		if (isset($data_migration_data['class']) && class_exists($data_migration_data['class'])) {
+			$class = LoaderFactory::getLoader()->getShared($data_migration_data['class']);
+			if ($class instanceof EE_Data_Migration_Script_Base) {
+				$class->instantiate_from_array_of_properties($data_migration_data);
+				return $class;
+			} else {
+				// huh, so its an object but not a data migration script?? that shouldn't happen
+				// just leave it as an array (which will probably just get ignored)
+				throw new EE_Error(
+					sprintf(
+						__(
+							"Trying to retrieve DMS class from wp option. No DMS by the name '%s' exists",
+							'event_espresso'
+						),
+						$data_migration_data['class']
+					)
+				);
+			}
+		} else {
+			// so the data doesn't specify a class. So it must either be a legacy array of info or some array (which we'll probably just ignore), or a class that no longer exists
+			throw new EE_Error(
+				sprintf(__("The wp option  with key '%s' does not represent a DMS", 'event_espresso'), $dms_option_name)
+			);
+		}
+	}
+
+	/**
+	 * Gets the array describing what data migrations have run. Also has a side-effect of recording which was the last
+	 * ran, and which was the last ran which hasn't finished yet
+	 *
+	 * @return array where each element should be an array of EE_Data_Migration_Script_Base (but also has a few legacy
+	 *               arrays in there - which should probably be ignored)
+	 */
+	public function get_data_migrations_ran()
+	{
+		if (! $this->_data_migrations_ran) {
+			// setup autoloaders for each of the scripts in there
+			$this->get_all_data_migration_scripts_available();
+			$data_migrations_options = $this->get_all_migration_script_options(
+			);// get_option(EE_Data_Migration_Manager::data_migrations_option_name,get_option('espresso_data_migrations',array()));
+
+			$data_migrations_ran = array();
+			// convert into data migration script classes where possible
+			foreach ($data_migrations_options as $data_migration_option) {
+				list($plugin_slug, $version_string) = $this->_get_plugin_slug_and_version_string_from_dms_option_name(
+					$data_migration_option['option_name']
+				);
+
+				try {
+					$class = $this->_get_dms_class_from_wp_option(
+						$data_migration_option['option_name'],
+						$data_migration_option['option_value']
+					);
+					$data_migrations_ran[ $plugin_slug ][ $version_string ] = $class;
+					// ok so far THIS is the 'last-ran-script'... unless we find another on next iteration
+					$this->_last_ran_script = $class;
+					if (! $class->is_completed()) {
+						// sometimes we also like to know which was the last incomplete script (or if there are any at all)
+						$this->_last_ran_incomplete_script = $class;
+					}
+				} catch (EE_Error $e) {
+					// ok so its not a DMS. We'll just keep it, although other code will need to expect non-DMSs
+					$data_migrations_ran[ $plugin_slug ][ $version_string ] = maybe_unserialize(
+						$data_migration_option['option_value']
+					);
+				}
+			}
+			// so here the array of $data_migrations_ran is actually a mix of classes and a few legacy arrays
+			$this->_data_migrations_ran = $data_migrations_ran;
+			if (! $this->_data_migrations_ran || ! is_array($this->_data_migrations_ran)) {
+				$this->_data_migrations_ran = array();
+			}
+		}
+		return $this->_data_migrations_ran;
+	}
+
+
+	/**
+	 *
+	 * @param string $script_name eg 'DMS_Core_4_1_0'
+	 * @param string $old_table   eg 'wp_events_detail'
+	 * @param string $old_pk      eg 'wp_esp_posts'
+	 * @param        $new_table
+	 * @return mixed string or int
+	 */
+	public function get_mapping_new_pk($script_name, $old_table, $old_pk, $new_table)
+	{
+		$script = EE_Registry::instance()->load_dms($script_name);
+		$mapping = $script->get_mapping_new_pk($old_table, $old_pk, $new_table);
+		return $mapping;
+	}
+
+	/**
+	 * Gets all the options containing migration scripts that have been run. Ordering is important: it's assumed that
+	 * the last option returned in this array is the most-recently ran DMS option
+	 *
+	 * @return array
+	 */
+	public function get_all_migration_script_options()
+	{
+		global $wpdb;
+		return $wpdb->get_results(
+			"SELECT * FROM {$wpdb->options} WHERE option_name like '" . EE_Data_Migration_Manager::data_migration_script_option_prefix . "%' ORDER BY option_id ASC",
+			ARRAY_A
+		);
+	}
+
+	/**
+	 * Gets the array of folders which contain data migration scripts. Also adds them to be auto-loaded
+	 *
+	 * @return array where each value is the full folder path of a folder containing data migration scripts, WITH
+	 *               slashes at the end of the folder name.
+	 */
+	public function get_data_migration_script_folders()
+	{
+		return apply_filters(
+			'FHEE__EE_Data_Migration_Manager__get_data_migration_script_folders',
+			array('Core' => EE_CORE . 'data_migration_scripts')
+		);
+	}
+
+	/**
+	 * Gets the version the migration script upgrades to
+	 *
+	 * @param string $migration_script_name eg 'EE_DMS_Core_4_1_0'
+	 * @return array {
+	 * @type string  $slug                  like 'Core','Calendar',etc
+	 * @type string  $version               like 4.3.0
+	 *                                      }
+	 * @throws EE_Error
+	 */
+	public function script_migrates_to_version($migration_script_name, $eeAddonClass = '')
+	{
+		if (isset($this->script_migration_versions[ $migration_script_name ])) {
+			return $this->script_migration_versions[ $migration_script_name ];
+		}
+		$dms_info = $this->parse_dms_classname($migration_script_name);
+		$this->script_migration_versions[ $migration_script_name ] = array(
+			'slug'    => $eeAddonClass !== '' ? $eeAddonClass : $dms_info['slug'],
+			'version' => $dms_info['major_version'] . "." . $dms_info['minor_version'] . "." . $dms_info['micro_version'],
+		);
+		return $this->script_migration_versions[ $migration_script_name ];
+	}
+
+	/**
+	 * Gets the juicy details out of a dms filename like 'EE_DMS_Core_4_1_0'
+	 *
+	 * @param string $classname
+	 * @return array with keys 'slug','major_version','minor_version', and 'micro_version' (the last 3 are ints)
+	 * @throws EE_Error
+	 */
+	public function parse_dms_classname($classname)
+	{
+		$matches = array();
+		preg_match('~EE_DMS_(.*)_([0-9]*)_([0-9]*)_([0-9]*)~', $classname, $matches);
+		if (! $matches || ! (isset($matches[1]) && isset($matches[2]) && isset($matches[3]))) {
+			throw new EE_Error(
+				sprintf(
+					__(
+						"%s is not a valid Data Migration Script. The classname should be like EE_DMS_w_x_y_z, where w is either 'Core' or the slug of an addon and x, y and z are numbers, ",
+						"event_espresso"
+					),
+					$classname
+				)
+			);
+		}
+		return array(
+			'slug'          => $matches[1],
+			'major_version' => intval($matches[2]),
+			'minor_version' => intval($matches[3]),
+			'micro_version' => intval($matches[4]),
+		);
+	}
+
+	/**
+	 * Ensures that the option indicating the current DB version is set. This should only be
+	 * a concern when activating EE for the first time, THEORETICALLY.
+	 * If we detect that we're activating EE4 over top of EE3.1, then we set the current db state to 3.1.x, otherwise
+	 * to 4.1.x.
+	 *
+	 * @return string of current db state
+	 */
+	public function ensure_current_database_state_is_set()
+	{
+		$espresso_db_core_updates = get_option('espresso_db_update', array());
+		$db_state = get_option(EE_Data_Migration_Manager::current_database_state);
+		if (! $db_state) {
+			// mark the DB as being in the state as the last version in there.
+			// this is done to trigger maintenance mode and do data migration scripts
+			// if the admin installed this version of EE over 3.1.x or 4.0.x
+			// otherwise, the normal maintenance mode code is fine
+			$previous_versions_installed = array_keys($espresso_db_core_updates);
+			$previous_version_installed = end($previous_versions_installed);
+			if (version_compare('4.1.0', $previous_version_installed)) {
+				// last installed version was less than 4.1
+				// so we want the data migrations to happen. SO, we're going to say the DB is at that state
+				$db_state = array('Core' => $previous_version_installed);
+			} else {
+				$db_state = array('Core' => EVENT_ESPRESSO_VERSION);
+			}
+			update_option(EE_Data_Migration_Manager::current_database_state, $db_state);
+		}
+		// in 4.1, $db_state would have only been a simple string like '4.1.0',
+		// but in 4.2+ it should be an array with at least key 'Core' and the value of that plugin's
+		// db, and possibly other keys for other addons like 'Calendar','Permissions',etc
+		if (! is_array($db_state)) {
+			$db_state = array('Core' => $db_state);
+			update_option(EE_Data_Migration_Manager::current_database_state, $db_state);
+		}
+		return $db_state;
+	}
+
+	/**
+	 * Checks if there are any data migration scripts that ought to be run. If found,
+	 * returns the instantiated classes. If none are found (ie, they've all already been run
+	 * or they don't apply), returns an empty array
+	 *
+	 * @return EE_Data_Migration_Script_Base[]
+	 */
+	public function check_for_applicable_data_migration_scripts()
+	{
+		// get the option describing what options have already run
+		$scripts_ran = $this->get_data_migrations_ran();
+		// $scripts_ran = array('4.1.0.core'=>array('monkey'=>null));
+		$script_class_and_filepaths_available = $this->get_all_data_migration_scripts_available();
+
+
+		$current_database_state = $this->ensure_current_database_state_is_set();
+		// determine which have already been run
+		$script_classes_that_should_run_per_iteration = array();
+		$iteration = 0;
+		$next_database_state_to_consider = $current_database_state;
+		$theoretical_database_state = null;
+		do {
+			// the next state after the currently-considered one will start off looking the same as the current, but we may make additions...
+			$theoretical_database_state = $next_database_state_to_consider;
+			// the next db state to consider is "what would the DB be like had we run all the scripts we found that applied last time?)
+			foreach ($script_class_and_filepaths_available as $classname => $filepath) {
+				$migrates_to_version = $this->script_migrates_to_version($classname);
+				$script_converts_plugin_slug = $migrates_to_version['slug'];
+				$script_converts_to_version = $migrates_to_version['version'];
+				// check if this version script is DONE or not; or if it's never been ran
+				if (! $scripts_ran ||
+					! isset($scripts_ran[ $script_converts_plugin_slug ]) ||
+					! isset($scripts_ran[ $script_converts_plugin_slug ][ $script_converts_to_version ])) {
+					// we haven't ran this conversion script before
+					// now check if it applies... note that we've added an autoloader for it on get_all_data_migration_scripts_available
+					$script = LoaderFactory::getLoader()->load($classname);
+					/* @var $script EE_Data_Migration_Script_Base */
+					$can_migrate = $script->can_migrate_from_version($theoretical_database_state);
+					if ($can_migrate) {
+						$script_classes_that_should_run_per_iteration[ $iteration ][ $script->priority() ][] = $script;
+						$migrates_to_version = $script->migrates_to_version();
+						$next_database_state_to_consider[ $migrates_to_version['slug'] ] = $migrates_to_version['version'];
+						unset($script_class_and_filepaths_available[ $classname ]);
+					}
+				} elseif ($scripts_ran[ $script_converts_plugin_slug ][ $script_converts_to_version ] instanceof EE_Data_Migration_Script_Base) {
+					// this script has been ran, or at least started
+					$script = $scripts_ran[ $script_converts_plugin_slug ][ $script_converts_to_version ];
+					if ($script->get_status() != self::status_completed) {
+						// this script is already underway... keep going with it
+						$script_classes_that_should_run_per_iteration[ $iteration ][ $script->priority() ][] = $script;
+						$migrates_to_version = $script->migrates_to_version();
+						$next_database_state_to_consider[ $migrates_to_version['slug'] ] = $migrates_to_version['version'];
+						unset($script_class_and_filepaths_available[ $classname ]);
+					} else {
+						// it must have a status that indicates it has finished, so we don't want to try and run it again
+					}
+				} else {
+					// it exists but it's not  a proper data migration script
+					// maybe the script got renamed? or was simply removed from EE?
+					// either way, its certainly not runnable!
+				}
+			}
+			$iteration++;
+		} while ($next_database_state_to_consider != $theoretical_database_state && $iteration < 6);
+		// ok we have all the scripts that should run, now let's make them into flat array
+		$scripts_that_should_run = array();
+		foreach ($script_classes_that_should_run_per_iteration as $scripts_at_priority) {
+			ksort($scripts_at_priority);
+			foreach ($scripts_at_priority as $scripts) {
+				foreach ($scripts as $script) {
+					$scripts_that_should_run[ get_class($script) ] = $script;
+				}
+			}
+		}
+
+		do_action(
+			'AHEE__EE_Data_Migration_Manager__check_for_applicable_data_migration_scripts__scripts_that_should_run',
+			$scripts_that_should_run
+		);
+		return $scripts_that_should_run;
+	}
+
+
+	/**
+	 * Gets the script which is currently being ran, if there is one. If $include_completed_scripts is set to TRUE
+	 * it will return the last ran script even if its complete.
+	 * This means: if you want to find the currently-executing script, leave it as FALSE.
+	 * If you really just want to find the script which ran most recently, regardless of status, leave it as TRUE.
+	 *
+	 * @param bool $include_completed_scripts
+	 * @return EE_Data_Migration_Script_Base
+	 */
+	public function get_last_ran_script($include_completed_scripts = false)
+	{
+		// make sure we've setup the class properties _last_ran_script and _last_ran_incomplete_script
+		if (! $this->_data_migrations_ran) {
+			$this->get_data_migrations_ran();
+		}
+		if ($include_completed_scripts) {
+			return $this->_last_ran_script;
+		} else {
+			return $this->_last_ran_incomplete_script;
+		}
+	}
+
+
+	/**
+	 * Runs the data migration scripts (well, each request to this method calls one of the
+	 * data migration scripts' migration_step() functions).
+	 *
+	 * @param int   $step_size
+	 * @throws EE_Error
+	 * @return array {
+	 *                                  // where the first item is one EE_Data_Migration_Script_Base's stati,
+	 *                                  //and the second item is a string describing what was done
+	 * @type int    $records_to_migrate from the current migration script
+	 * @type int    $records_migrated
+	 * @type string $status             one of EE_Data_Migration_Manager::status_*
+	 * @type string $script             verbose name of the current DMS
+	 * @type string $message            string describing what was done during this step
+	 *                                  }
+	 */
+	public function migration_step($step_size = 0)
+	{
+
+		// bandaid fix for issue https://events.codebasehq.com/projects/event-espresso/tickets/7535
+		if (class_exists('EE_CPT_Strategy')) {
+			remove_action('pre_get_posts', array(EE_CPT_Strategy::instance(), 'pre_get_posts'), 5);
+		}
+
+		try {
+			$currently_executing_script = $this->get_last_ran_script();
+			if (! $currently_executing_script) {
+				// Find the next script that needs to execute
+				$scripts = $this->check_for_applicable_data_migration_scripts();
+				if (! $scripts) {
+					// huh, no more scripts to run... apparently we're done!
+					// but dont forget to make sure initial data is there
+					// we should be good to allow them to exit maintenance mode now
+					EE_Maintenance_Mode::instance()->set_maintenance_level(
+						intval(EE_Maintenance_Mode::level_0_not_in_maintenance)
+					);
+					// saving migrations ran should actually be unnecessary, but leaving in place just in case
+					// remember this migration was finished (even if we timeout initing db for core and plugins)
+					$this->_save_migrations_ran();
+					// make sure DB was updated AFTER we've recorded the migration was done
+					$this->initialize_db_for_enqueued_ee_plugins();
+					return array(
+						'records_to_migrate' => 1,
+						'records_migrated'   => 1,
+						'status'             => self::status_no_more_migration_scripts,
+						'script'             => __("Data Migration Completed Successfully", "event_espresso"),
+						'message'            => __("All done!", "event_espresso"),
+					);
+				}
+				$currently_executing_script = array_shift($scripts);
+				// and add to the array/wp option showing the scripts ran
+
+				$migrates_to = $this->script_migrates_to_version(get_class($currently_executing_script));
+				$plugin_slug = $migrates_to['slug'];
+				$version = $migrates_to['version'];
+				$this->_data_migrations_ran[ $plugin_slug ][ $version ] = $currently_executing_script;
+			}
+			$current_script_name = get_class($currently_executing_script);
+		} catch (Exception $e) {
+			// an exception occurred while trying to get migration scripts
+
+			$message = sprintf(
+				__("Error Message: %sStack Trace:%s", "event_espresso"),
+				$e->getMessage() . '<br>',
+				$e->getTraceAsString()
+			);
+			// record it on the array of data migration scripts ran. This will be overwritten next time we try and try to run data migrations
+			// but that's ok-- it's just an FYI to support that we couldn't even run any data migrations
+			$this->add_error_to_migrations_ran(
+				sprintf(__("Could not run data migrations because: %s", "event_espresso"), $message)
+			);
+			return array(
+				'records_to_migrate' => 1,
+				'records_migrated'   => 0,
+				'status'             => self::status_fatal_error,
+				'script'             => __("Error loading data migration scripts", "event_espresso"),
+				'message'            => $message,
+			);
+		}
+		// ok so we definitely have a data migration script
+		try {
+			// how big of a bite do we want to take? Allow users to easily override via their wp-config
+			if (absint($step_size) < 1) {
+				$step_size = defined('EE_MIGRATION_STEP_SIZE') && absint(EE_MIGRATION_STEP_SIZE)
+					? EE_MIGRATION_STEP_SIZE : EE_Data_Migration_Manager::step_size;
+			}
+			// do what we came to do!
+			$currently_executing_script->migration_step($step_size);
+			// can we wrap it up and verify default data?
+			$init_dbs = false;
+			switch ($currently_executing_script->get_status()) {
+				case EE_Data_Migration_Manager::status_continue:
+					$response_array = array(
+						'records_to_migrate' => $currently_executing_script->count_records_to_migrate(),
+						'records_migrated'   => $currently_executing_script->count_records_migrated(),
+						'status'             => EE_Data_Migration_Manager::status_continue,
+						'message'            => $currently_executing_script->get_feedback_message(),
+						'script'             => $currently_executing_script->pretty_name(),
+					);
+					break;
+				case EE_Data_Migration_Manager::status_completed:
+					// ok so THAT script has completed
+					$this->update_current_database_state_to($this->script_migrates_to_version($current_script_name));
+					$response_array = array(
+						'records_to_migrate' => $currently_executing_script->count_records_to_migrate(),
+						'records_migrated'   => $currently_executing_script->count_records_migrated(),
+						'status'             => EE_Data_Migration_Manager::status_completed,
+						'message'            => $currently_executing_script->get_feedback_message(),
+						'script'             => sprintf(
+							__("%s Completed", 'event_espresso'),
+							$currently_executing_script->pretty_name()
+						),
+					);
+					// check if there are any more after this one.
+					$scripts_remaining = $this->check_for_applicable_data_migration_scripts();
+					if (! $scripts_remaining) {
+						// we should be good to allow them to exit maintenance mode now
+						EE_Maintenance_Mode::instance()->set_maintenance_level(
+							intval(EE_Maintenance_Mode::level_0_not_in_maintenance)
+						);
+						// huh, no more scripts to run... apparently we're done!
+						// but dont forget to make sure initial data is there
+						$init_dbs = true;
+						$response_array['status'] = self::status_no_more_migration_scripts;
+					}
+					break;
+				default:
+					$response_array = array(
+						'records_to_migrate' => $currently_executing_script->count_records_to_migrate(),
+						'records_migrated'   => $currently_executing_script->count_records_migrated(),
+						'status'             => $currently_executing_script->get_status(),
+						'message'            => sprintf(
+							__("Minor errors occurred during %s: %s", "event_espresso"),
+							$currently_executing_script->pretty_name(),
+							implode(", ", $currently_executing_script->get_errors())
+						),
+						'script'             => $currently_executing_script->pretty_name(),
+					);
+					break;
+			}
+		} catch (Exception $e) {
+			// ok so some exception was thrown which killed the data migration script
+			// double-check we have a real script
+			if ($currently_executing_script instanceof EE_Data_Migration_Script_Base) {
+				$script_name = $currently_executing_script->pretty_name();
+				$currently_executing_script->set_broken();
+				$currently_executing_script->add_error($e->getMessage());
+			} else {
+				$script_name = __("Error getting Migration Script", "event_espresso");
+			}
+			$response_array = array(
+				'records_to_migrate' => 1,
+				'records_migrated'   => 0,
+				'status'             => self::status_fatal_error,
+				'message'            => sprintf(
+					__("A fatal error occurred during the migration: %s", "event_espresso"),
+					$e->getMessage()
+				),
+				'script'             => $script_name,
+			);
+		}
+		$successful_save = $this->_save_migrations_ran();
+		if ($successful_save !== true) {
+			// ok so the current wp option didn't save. that's tricky, because we'd like to update it
+			// and mark it as having a fatal error, but remember- WE CAN'T SAVE THIS WP OPTION!
+			// however, if we throw an exception, and return that, then the next request
+			// won't have as much info in it, and it may be able to save
+			throw new EE_Error(
+				sprintf(
+					__(
+						"The error '%s' occurred updating the status of the migration. This is a FATAL ERROR, but the error is preventing the system from remembering that. Please contact event espresso support.",
+						"event_espresso"
+					),
+					$successful_save
+				)
+			);
+		}
+		// if we're all done, initialize EE plugins' default data etc.
+		if ($init_dbs) {
+			$this->initialize_db_for_enqueued_ee_plugins();
+		}
+		return $response_array;
+	}
+
+
+	/**
+	 * Echo out JSON response to migration script AJAX requests. Takes precautions
+	 * to buffer output so that we don't throw junk into our json.
+	 *
+	 * @return array with keys:
+	 * 'records_to_migrate' which counts ALL the records for the current migration, and should remain constant. (ie,
+	 * it's NOT the count of hwo many remain)
+	 * 'records_migrated' which also counts ALL the records which have been migrated (ie, percent_complete =
+	 * records_migrated/records_to_migrate)
+	 * 'status'=>a string, one of EE_Data_migration_Manager::status_*
+	 * 'message'=>a string, containing any message you want to show to the user. We may decide to split this up into
+	 * errors, notifications, and successes
+	 * 'script'=>a pretty name of the script currently running
+	 */
+	public function response_to_migration_ajax_request()
+	{
+		ob_start();
+		try {
+			$response = $this->migration_step();
+		} catch (Exception $e) {
+			$response = array(
+				'records_to_migrate' => 0,
+				'records_migrated'   => 0,
+				'status'             => EE_Data_Migration_Manager::status_fatal_error,
+				'message'            => sprintf(
+					__("Unknown fatal error occurred: %s", "event_espresso"),
+					$e->getMessage()
+				),
+				'script'             => 'Unknown',
+			);
+			$this->add_error_to_migrations_ran($e->getMessage() . "; Stack trace:" . $e->getTraceAsString());
+		}
+		$warnings_etc = @ob_get_contents();
+		ob_end_clean();
+		$response['message'] .= $warnings_etc;
+		return $response;
+	}
+
+	/**
+	 * Updates the wordpress option that keeps track of which which EE version the database
+	 * is at (ie, the code may be at 4.1.0, but the database is still at 3.1.35)
+	 *
+	 * @param array $slug_and_version {
+	 * @type string $slug             like 'Core' or 'Calendar',
+	 * @type string $version          like '4.1.0'
+	 *                                }
+	 * @return void
+	 */
+	public function update_current_database_state_to($slug_and_version = null)
+	{
+		if (! $slug_and_version) {
+			// no version was provided, assume it should be at the current code version
+			$slug_and_version = array('slug' => 'Core', 'version' => espresso_version());
+		}
+		$current_database_state = get_option(self::current_database_state);
+		$current_database_state[ $slug_and_version['slug'] ] = $slug_and_version['version'];
+		update_option(self::current_database_state, $current_database_state);
+	}
+
+	/**
+	 * Determines if the database is currently at a state matching what's indicated in $slug and $version.
+	 *
+	 * @param array $slug_and_version {
+	 * @type string $slug             like 'Core' or 'Calendar',
+	 * @type string $version          like '4.1.0'
+	 *                                }
+	 * @return boolean
+	 */
+	public function database_needs_updating_to($slug_and_version)
+	{
+
+		$slug = $slug_and_version['slug'];
+		$version = $slug_and_version['version'];
+		$current_database_state = get_option(self::current_database_state);
+		if (! isset($current_database_state[ $slug ])) {
+			return true;
+		} else {
+			// just compare the first 3 parts of version string, eg "4.7.1", not "4.7.1.dev.032" because DBs shouldn't change on nano version changes
+			$version_parts_current_db_state = array_slice(explode('.', $current_database_state[ $slug ]), 0, 3);
+			$version_parts_of_provided_db_state = array_slice(explode('.', $version), 0, 3);
+			$needs_updating = false;
+			foreach ($version_parts_current_db_state as $offset => $version_part_in_current_db_state) {
+				if ($version_part_in_current_db_state < $version_parts_of_provided_db_state[ $offset ]) {
+					$needs_updating = true;
+					break;
+				}
+			}
+			return $needs_updating;
+		}
+	}
+
+
+	/**
+	 * Gets all the data migration scripts available in the core folder and folders
+	 * in addons. Has the side effect of adding them for autoloading
+	 *
+	 * @return array keys are expected classnames, values are their filepaths
+	 * @throws InvalidInterfaceException
+	 * @throws InvalidDataTypeException
+	 * @throws EE_Error
+	 * @throws InvalidArgumentException
+	 */
+	public function get_all_data_migration_scripts_available()
+	{
+		if (! $this->_data_migration_class_to_filepath_map) {
+			$this->_data_migration_class_to_filepath_map = array();
+			foreach ($this->get_data_migration_script_folders() as $eeAddonClass => $folder_path) {
+				// strip any placeholders added to classname to make it a unique array key
+				$eeAddonClass = trim($eeAddonClass, '*');
+				$eeAddonClass = $eeAddonClass === 'Core' || class_exists($eeAddonClass)
+					? $eeAddonClass
+					: '';
+				$folder_path = EEH_File::end_with_directory_separator($folder_path);
+				$files = glob($folder_path . '*.dms.php');
+				if (empty($files)) {
+					continue;
+				}
+				foreach ($files as $file) {
+					$pos_of_last_slash = strrpos($file, DS);
+					$classname = str_replace('.dms.php', '', substr($file, $pos_of_last_slash + 1));
+					$migrates_to = $this->script_migrates_to_version($classname, $eeAddonClass);
+					$slug = $migrates_to['slug'];
+					// check that the slug as contained in the DMS is associated with
+					// the slug of an addon or core
+					if ($slug !== 'Core' && EE_Registry::instance()->get_addon_by_name($slug) === null) {
+						EE_Error::doing_it_wrong(
+							__FUNCTION__,
+							sprintf(
+								esc_html__(
+									'The data migration script "%s" migrates the "%s" data, but there is no EE addon with that name. There is only: %s. ',
+									'event_espresso'
+								),
+								$classname,
+								$slug,
+								implode(', ', array_keys(EE_Registry::instance()->get_addons_by_name()))
+							),
+							'4.3.0.alpha.019'
+						);
+					}
+					$this->_data_migration_class_to_filepath_map[ $classname ] = $file;
+				}
+			}
+			EEH_Autoloader::register_autoloader($this->_data_migration_class_to_filepath_map);
+		}
+		return $this->_data_migration_class_to_filepath_map;
+	}
+
+
+	/**
+	 * Once we have an addon that works with EE4.1, we will actually want to fetch the PUE slugs
+	 * from each addon, and check if they need updating,
+	 *
+	 * @return boolean
+	 */
+	public function addons_need_updating()
+	{
+		return false;
+	}
+
+	/**
+	 * Adds this error string to the data_migrations_ran array, but we dont necessarily know
+	 * where to put it, so we just throw it in there... better than nothing...
+	 *
+	 * @param string $error_message
+	 * @throws EE_Error
+	 */
+	public function add_error_to_migrations_ran($error_message)
+	{
+		// get last-ran migration script
+		global $wpdb;
+		$last_migration_script_option = $wpdb->get_row(
+			"SELECT * FROM $wpdb->options WHERE option_name like '" . EE_Data_Migration_Manager::data_migration_script_option_prefix . "%' ORDER BY option_id DESC LIMIT 1",
+			ARRAY_A
+		);
+
+		$last_ran_migration_script_properties = isset($last_migration_script_option['option_value'])
+			? maybe_unserialize($last_migration_script_option['option_value']) : null;
+		// now, tread lightly because we're here because a FATAL non-catchable error
+		// was thrown last time when we were trying to run a data migration script
+		// so the fatal error could have happened while getting the migration script
+		// or doing running it...
+		$versions_migrated_to = isset($last_migration_script_option['option_name']) ? str_replace(
+			EE_Data_Migration_Manager::data_migration_script_option_prefix,
+			"",
+			$last_migration_script_option['option_name']
+		) : null;
+
+		// check if it THINKS its a data migration script and especially if it's one that HASN'T finished yet
+		// because if it has finished, then it obviously couldn't be the cause of this error, right? (because its all done)
+		if (isset($last_ran_migration_script_properties['class']) && isset($last_ran_migration_script_properties['_status']) && $last_ran_migration_script_properties['_status'] != self::status_completed) {
+			// ok then just add this error to its list of errors
+			$last_ran_migration_script_properties['_errors'][] = $error_message;
+			$last_ran_migration_script_properties['_status'] = self::status_fatal_error;
+		} else {
+			// so we don't even know which script was last running
+			// use the data migration error stub, which is designed specifically for this type of thing
+			$general_migration_error = new EE_DMS_Unknown_1_0_0();
+			$general_migration_error->add_error($error_message);
+			$general_migration_error->set_broken();
+			$last_ran_migration_script_properties = $general_migration_error->properties_as_array();
+			$versions_migrated_to = 'Unknown.1.0.0';
+			// now just to make sure appears as last (in case the were previously a fatal error like this)
+			// delete the old one
+			delete_option(self::data_migration_script_option_prefix . $versions_migrated_to);
+		}
+		update_option(
+			self::data_migration_script_option_prefix . $versions_migrated_to,
+			$last_ran_migration_script_properties
+		);
+	}
+
+	/**
+	 * saves what data migrations have ran to the database
+	 *
+	 * @return mixed TRUE if successfully saved migrations ran, string if an error occurred
+	 */
+	protected function _save_migrations_ran()
+	{
+		if ($this->_data_migrations_ran == null) {
+			$this->get_data_migrations_ran();
+		}
+		// now, we don't want to save actual classes to the DB because that's messy
+		$successful_updates = true;
+		foreach ($this->_data_migrations_ran as $plugin_slug => $migrations_ran_for_plugin) {
+			foreach ($migrations_ran_for_plugin as $version_string => $array_or_migration_obj) {
+				$plugin_slug_for_use_in_option_name = $plugin_slug . ".";
+				$option_name = self::data_migration_script_option_prefix . $plugin_slug_for_use_in_option_name . $version_string;
+				$old_option_value = get_option($option_name);
+				if ($array_or_migration_obj instanceof EE_Data_Migration_Script_Base) {
+					$script_array_for_saving = $array_or_migration_obj->properties_as_array();
+					if ($old_option_value != $script_array_for_saving) {
+						$successful_updates = update_option($option_name, $script_array_for_saving);
+					}
+				} else {// we don't know what this array-thing is. So just save it as-is
+					if ($old_option_value != $array_or_migration_obj) {
+						$successful_updates = update_option($option_name, $array_or_migration_obj);
+					}
+				}
+				if (! $successful_updates) {
+					global $wpdb;
+					return $wpdb->last_error;
+				}
+			}
+		}
+		return true;
+		// $updated = update_option(self::data_migrations_option_name, $array_of_migrations);
+		// if ($updated !== true) {
+		//     global $wpdb;
+		//     return $wpdb->last_error;
+		// } else {
+		//     return true;
+		// }
+		// wp_mail(
+		//     "michael@eventespresso.com",
+		//     time() . " price debug info",
+		//     "updated: $updated, last error: $last_error, byte length of option: " . strlen(
+		//         serialize($array_of_migrations)
+		//     )
+		// );
+	}
+
+	/**
+	 * Takes an array of data migration script properties and re-creates the class from
+	 * them. The argument $properties_array is assumed to have been made by
+	 * EE_Data_Migration_Script_Base::properties_as_array()
+	 *
+	 * @param array $properties_array
+	 * @return EE_Data_Migration_Script_Base
+	 * @throws EE_Error
+	 */
+	public function _instantiate_script_from_properties_array($properties_array)
+	{
+		if (! isset($properties_array['class'])) {
+			throw new EE_Error(
+				sprintf(
+					__("Properties array  has no 'class' properties. Here's what it has: %s", "event_espresso"),
+					implode(",", $properties_array)
+				)
+			);
+		}
+		$class_name = $properties_array['class'];
+		if (! class_exists($class_name)) {
+			throw new EE_Error(sprintf(__("There is no migration script named %s", "event_espresso"), $class_name));
+		}
+		$class = new $class_name;
+		if (! $class instanceof EE_Data_Migration_Script_Base) {
+			throw new EE_Error(
+				sprintf(
+					__("Class '%s' is supposed to be a migration script. Its not, its a '%s'", "event_espresso"),
+					$class_name,
+					get_class($class)
+				)
+			);
+		}
+		$class->instantiate_from_array_of_properties($properties_array);
+		return $class;
+	}
+
+	/**
+	 * Gets the classname for the most up-to-date DMS (ie, the one that will finally
+	 * leave the DB in a state usable by the current plugin code).
+	 *
+	 * @param string $plugin_slug the slug for the ee plugin we are searching for. Default is 'Core'
+	 * @return string
+	 */
+	public function get_most_up_to_date_dms($plugin_slug = 'Core')
+	{
+		$class_to_filepath_map = $this->get_all_data_migration_scripts_available();
+		$most_up_to_date_dms_classname = null;
+		foreach ($class_to_filepath_map as $classname => $filepath) {
+			if ($most_up_to_date_dms_classname === null) {
+				$migrates_to = $this->script_migrates_to_version($classname);
+				$this_plugin_slug = $migrates_to['slug'];
+				if ($this_plugin_slug == $plugin_slug) {
+					// if it's for core, it wins
+					$most_up_to_date_dms_classname = $classname;
+				}
+				// if it wasn't for core, we must keep searching for one that is!
+				continue;
+			} else {
+				$champion_migrates_to = $this->script_migrates_to_version($most_up_to_date_dms_classname);
+				$contender_migrates_to = $this->script_migrates_to_version($classname);
+				if ($contender_migrates_to['slug'] == $plugin_slug
+					&& version_compare(
+						$champion_migrates_to['version'],
+						$contender_migrates_to['version'],
+						'<'
+					)) {
+					// so the contenders version is higher and its for Core
+					$most_up_to_date_dms_classname = $classname;
+				}
+			}
+		}
+		return $most_up_to_date_dms_classname;
+	}
+
+	/**
+	 * Gets the migration script specified but ONLY if it has already ran.
+	 *
+	 * Eg, if you wanted to see if 'EE_DMS_Core_4_1_0' has ran, you would run the following code:
+	 * <code> $core_4_1_0_dms_ran = EE_Data_Migration_Manager::instance()->get_migration_ran( '4.1.0', 'Core' ) !==
+	 * NULL;</code> This is especially useful in addons' data migration scripts, this way they can tell if a core (or
+	 * other addon) DMS has ran, in case the current DMS depends on it.
+	 *
+	 * @param string $version     the version the DMS searched for migrates to. Usually just the content before the 3rd
+	 *                            period. Eg '4.1.0'
+	 * @param string $plugin_slug like 'Core', 'Mailchimp', 'Calendar', etc
+	 * @return EE_Data_Migration_Script_Base
+	 */
+	public function get_migration_ran($version, $plugin_slug = 'Core')
+	{
+		$migrations_ran = $this->get_data_migrations_ran();
+		if (isset($migrations_ran[ $plugin_slug ]) && isset($migrations_ran[ $plugin_slug ][ $version ])) {
+			return $migrations_ran[ $plugin_slug ][ $version ];
+		} else {
+			return null;
+		}
+	}
+
+	/**
+	 * Resets the borked data migration scripts so they're no longer borked
+	 * so we can again attempt to migrate
+	 *
+	 * @return bool
+	 * @throws EE_Error
+	 */
+	public function reattempt()
+	{
+		// find if the last-ran script was borked
+		// set it as being non-borked (we shouldn't ever get DMSs that we don't recognize)
+		// add an 'error' saying that we attempted to reset
+		// does it have a stage that was borked too? if so make it no longer borked
+		// add an 'error' saying we attempted to reset
+		$last_ran_script = $this->get_last_ran_script();
+		if ($last_ran_script instanceof EE_DMS_Unknown_1_0_0) {
+			// if it was an error DMS, just mark it as complete (if another error occurs it will overwrite it)
+			$last_ran_script->set_completed();
+		} elseif ($last_ran_script instanceof EE_Data_Migration_Script_Base) {
+			$last_ran_script->reattempt();
+		} else {
+			throw new EE_Error(
+				sprintf(
+					__(
+						'Unable to reattempt the last ran migration script because it was not a valid migration script. || It was %s',
+						'event_espresso'
+					),
+					print_r($last_ran_script, true)
+				)
+			);
+		}
+		return $this->_save_migrations_ran();
+	}
+
+	/**
+	 * Gets whether or not this particular migration has run or not
+	 *
+	 * @param string $version     the version the DMS searched for migrates to. Usually just the content before the 3rd
+	 *                            period. Eg '4.1.0'
+	 * @param string $plugin_slug like 'Core', 'Mailchimp', 'Calendar', etc
+	 * @return boolean
+	 */
+	public function migration_has_ran($version, $plugin_slug = 'Core')
+	{
+		return $this->get_migration_ran($version, $plugin_slug) !== null;
+	}
+
+	/**
+	 * Enqueues this ee plugin to have its data initialized
+	 *
+	 * @param string $plugin_slug either 'Core' or EE_Addon::name()'s return value
+	 */
+	public function enqueue_db_initialization_for($plugin_slug)
+	{
+		$queue = $this->get_db_initialization_queue();
+		if (! in_array($plugin_slug, $queue)) {
+			$queue[] = $plugin_slug;
+		}
+		update_option(self::db_init_queue_option_name, $queue);
+	}
+
+	/**
+	 * Calls EE_Addon::initialize_db_if_no_migrations_required() on each addon
+	 * specified in EE_Data_Migration_Manager::get_db_init_queue(), and if 'Core' is
+	 * in the queue, calls EE_System::initialize_db_if_no_migrations_required().
+	 */
+	public function initialize_db_for_enqueued_ee_plugins()
+	{
+		$queue = $this->get_db_initialization_queue();
+		foreach ($queue as $plugin_slug) {
+			$most_up_to_date_dms = $this->get_most_up_to_date_dms($plugin_slug);
+			if (! $most_up_to_date_dms) {
+				// if there is NO DMS for this plugin, obviously there's no schema to verify anyways
+				$verify_db = false;
+			} else {
+				$most_up_to_date_dms_migrates_to = $this->script_migrates_to_version($most_up_to_date_dms);
+				$verify_db = $this->database_needs_updating_to($most_up_to_date_dms_migrates_to);
+			}
+			if ($plugin_slug == 'Core') {
+				EE_System::instance()->initialize_db_if_no_migrations_required(
+					false,
+					$verify_db
+				);
+			} else {
+				// just loop through the addons to make sure their database is setup
+				foreach (EE_Registry::instance()->addons as $addon) {
+					if ($addon->name() == $plugin_slug) {
+						$addon->initialize_db_if_no_migrations_required($verify_db);
+						break;
+					}
+				}
+			}
+		}
+		// because we just initialized the DBs for the enqueued ee plugins
+		// we don't need to keep remembering which ones needed to be initialized
+		delete_option(self::db_init_queue_option_name);
+	}
+
+	/**
+	 * Gets a numerically-indexed array of plugin slugs that need to have their databases
+	 * (re-)initialized after migrations are complete. ie, each element should be either
+	 * 'Core', or the return value of EE_Addon::name() for an addon
+	 *
+	 * @return array
+	 */
+	public function get_db_initialization_queue()
+	{
+		return get_option(self::db_init_queue_option_name, array());
+	}
+
+	/**
+	 * 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 $this->_table_analysis;
+		} else {
+			throw new EE_Error(
+				sprintf(
+					__('Table analysis class on class %1$s is not set properly.', 'event_espresso'),
+					get_class($this)
+				)
+			);
+		}
+	}
+
+	/**
+	 * Gets the injected table manager, or throws an exception
+	 *
+	 * @return TableManager
+	 * @throws EE_Error
+	 */
+	protected function _get_table_manager()
+	{
+		if ($this->_table_manager instanceof TableManager) {
+			return $this->_table_manager;
+		} else {
+			throw new EE_Error(
+				sprintf(
+					__('Table manager class on class %1$s is not set properly.', 'event_espresso'),
+					get_class($this)
+				)
+			);
+		}
+	}
 }

Spacing +61 added lines, -61 removed lines

@@ -158,7 +158,7 @@ 
     public static function instance()
     {
         // check if class object is instantiated
-        if (! self::$_instance instanceof EE_Data_Migration_Manager) {
+        if ( ! self::$_instance instanceof EE_Data_Migration_Manager) {
             self::$_instance = new self();
         }
         return self::$_instance;
@@ -234,12 +234,12 @@ 
 
         if (count($parts) == 4) {
             // it's 4.2-style.eg Core.4.1.0
-            $plugin_slug = $parts[0];// eg Core
-            $version_string = $parts[1] . "." . $parts[2] . "." . $parts[3]; // eg 4.1.0
+            $plugin_slug = $parts[0]; // eg Core
+            $version_string = $parts[1].".".$parts[2].".".$parts[3]; // eg 4.1.0
         } else {
             // it's 4.1-style: eg 4.1.0
             $plugin_slug = 'Core';
-            $version_string = $plugin_slug_and_version_string;// eg 4.1.0
+            $version_string = $plugin_slug_and_version_string; // eg 4.1.0
         }
         return array($plugin_slug, $version_string);
     }
@@ -291,11 +291,11 @@ 
      */
     public function get_data_migrations_ran()
     {
-        if (! $this->_data_migrations_ran) {
+        if ( ! $this->_data_migrations_ran) {
             // setup autoloaders for each of the scripts in there
             $this->get_all_data_migration_scripts_available();
             $data_migrations_options = $this->get_all_migration_script_options(
-            );// get_option(EE_Data_Migration_Manager::data_migrations_option_name,get_option('espresso_data_migrations',array()));
+            ); // get_option(EE_Data_Migration_Manager::data_migrations_option_name,get_option('espresso_data_migrations',array()));
 
             $data_migrations_ran = array();
             // convert into data migration script classes where possible
@@ -309,23 +309,23 @@ 
                         $data_migration_option['option_name'],
                         $data_migration_option['option_value']
                     );
-                    $data_migrations_ran[ $plugin_slug ][ $version_string ] = $class;
+                    $data_migrations_ran[$plugin_slug][$version_string] = $class;
                     // ok so far THIS is the 'last-ran-script'... unless we find another on next iteration
                     $this->_last_ran_script = $class;
-                    if (! $class->is_completed()) {
+                    if ( ! $class->is_completed()) {
                         // sometimes we also like to know which was the last incomplete script (or if there are any at all)
                         $this->_last_ran_incomplete_script = $class;
                     }
                 } catch (EE_Error $e) {
                     // ok so its not a DMS. We'll just keep it, although other code will need to expect non-DMSs
-                    $data_migrations_ran[ $plugin_slug ][ $version_string ] = maybe_unserialize(
+                    $data_migrations_ran[$plugin_slug][$version_string] = maybe_unserialize(
                         $data_migration_option['option_value']
                     );
                 }
             }
             // so here the array of $data_migrations_ran is actually a mix of classes and a few legacy arrays
             $this->_data_migrations_ran = $data_migrations_ran;
-            if (! $this->_data_migrations_ran || ! is_array($this->_data_migrations_ran)) {
+            if ( ! $this->_data_migrations_ran || ! is_array($this->_data_migrations_ran)) {
                 $this->_data_migrations_ran = array();
             }
         }
@@ -358,7 +358,7 @@ 
     {
         global $wpdb;
         return $wpdb->get_results(
-            "SELECT * FROM {$wpdb->options} WHERE option_name like '" . EE_Data_Migration_Manager::data_migration_script_option_prefix . "%' ORDER BY option_id ASC",
+            "SELECT * FROM {$wpdb->options} WHERE option_name like '".EE_Data_Migration_Manager::data_migration_script_option_prefix."%' ORDER BY option_id ASC",
             ARRAY_A
         );
     }
@@ -373,7 +373,7 @@ 
     {
         return apply_filters(
             'FHEE__EE_Data_Migration_Manager__get_data_migration_script_folders',
-            array('Core' => EE_CORE . 'data_migration_scripts')
+            array('Core' => EE_CORE.'data_migration_scripts')
         );
     }
 
@@ -389,15 +389,15 @@ 
      */
     public function script_migrates_to_version($migration_script_name, $eeAddonClass = '')
     {
-        if (isset($this->script_migration_versions[ $migration_script_name ])) {
-            return $this->script_migration_versions[ $migration_script_name ];
+        if (isset($this->script_migration_versions[$migration_script_name])) {
+            return $this->script_migration_versions[$migration_script_name];
         }
         $dms_info = $this->parse_dms_classname($migration_script_name);
-        $this->script_migration_versions[ $migration_script_name ] = array(
+        $this->script_migration_versions[$migration_script_name] = array(
             'slug'    => $eeAddonClass !== '' ? $eeAddonClass : $dms_info['slug'],
-            'version' => $dms_info['major_version'] . "." . $dms_info['minor_version'] . "." . $dms_info['micro_version'],
+            'version' => $dms_info['major_version'].".".$dms_info['minor_version'].".".$dms_info['micro_version'],
         );
-        return $this->script_migration_versions[ $migration_script_name ];
+        return $this->script_migration_versions[$migration_script_name];
     }
 
     /**
@@ -411,7 +411,7 @@ 
     {
         $matches = array();
         preg_match('~EE_DMS_(.*)_([0-9]*)_([0-9]*)_([0-9]*)~', $classname, $matches);
-        if (! $matches || ! (isset($matches[1]) && isset($matches[2]) && isset($matches[3]))) {
+        if ( ! $matches || ! (isset($matches[1]) && isset($matches[2]) && isset($matches[3]))) {
             throw new EE_Error(
                 sprintf(
                     __(
@@ -442,7 +442,7 @@ 
     {
         $espresso_db_core_updates = get_option('espresso_db_update', array());
         $db_state = get_option(EE_Data_Migration_Manager::current_database_state);
-        if (! $db_state) {
+        if ( ! $db_state) {
             // mark the DB as being in the state as the last version in there.
             // this is done to trigger maintenance mode and do data migration scripts
             // if the admin installed this version of EE over 3.1.x or 4.0.x
@@ -461,7 +461,7 @@ 
         // in 4.1, $db_state would have only been a simple string like '4.1.0',
         // but in 4.2+ it should be an array with at least key 'Core' and the value of that plugin's
         // db, and possibly other keys for other addons like 'Calendar','Permissions',etc
-        if (! is_array($db_state)) {
+        if ( ! is_array($db_state)) {
             $db_state = array('Core' => $db_state);
             update_option(EE_Data_Migration_Manager::current_database_state, $db_state);
         }
@@ -498,29 +498,29 @@ 
                 $script_converts_plugin_slug = $migrates_to_version['slug'];
                 $script_converts_to_version = $migrates_to_version['version'];
                 // check if this version script is DONE or not; or if it's never been ran
-                if (! $scripts_ran ||
-                    ! isset($scripts_ran[ $script_converts_plugin_slug ]) ||
-                    ! isset($scripts_ran[ $script_converts_plugin_slug ][ $script_converts_to_version ])) {
+                if ( ! $scripts_ran ||
+                    ! isset($scripts_ran[$script_converts_plugin_slug]) ||
+                    ! isset($scripts_ran[$script_converts_plugin_slug][$script_converts_to_version])) {
                     // we haven't ran this conversion script before
                     // now check if it applies... note that we've added an autoloader for it on get_all_data_migration_scripts_available
                     $script = LoaderFactory::getLoader()->load($classname);
                     /* @var $script EE_Data_Migration_Script_Base */
                     $can_migrate = $script->can_migrate_from_version($theoretical_database_state);
                     if ($can_migrate) {
-                        $script_classes_that_should_run_per_iteration[ $iteration ][ $script->priority() ][] = $script;
+                        $script_classes_that_should_run_per_iteration[$iteration][$script->priority()][] = $script;
                         $migrates_to_version = $script->migrates_to_version();
-                        $next_database_state_to_consider[ $migrates_to_version['slug'] ] = $migrates_to_version['version'];
-                        unset($script_class_and_filepaths_available[ $classname ]);
+                        $next_database_state_to_consider[$migrates_to_version['slug']] = $migrates_to_version['version'];
+                        unset($script_class_and_filepaths_available[$classname]);
                     }
-                } elseif ($scripts_ran[ $script_converts_plugin_slug ][ $script_converts_to_version ] instanceof EE_Data_Migration_Script_Base) {
+                } elseif ($scripts_ran[$script_converts_plugin_slug][$script_converts_to_version] instanceof EE_Data_Migration_Script_Base) {
                     // this script has been ran, or at least started
-                    $script = $scripts_ran[ $script_converts_plugin_slug ][ $script_converts_to_version ];
+                    $script = $scripts_ran[$script_converts_plugin_slug][$script_converts_to_version];
                     if ($script->get_status() != self::status_completed) {
                         // this script is already underway... keep going with it
-                        $script_classes_that_should_run_per_iteration[ $iteration ][ $script->priority() ][] = $script;
+                        $script_classes_that_should_run_per_iteration[$iteration][$script->priority()][] = $script;
                         $migrates_to_version = $script->migrates_to_version();
-                        $next_database_state_to_consider[ $migrates_to_version['slug'] ] = $migrates_to_version['version'];
-                        unset($script_class_and_filepaths_available[ $classname ]);
+                        $next_database_state_to_consider[$migrates_to_version['slug']] = $migrates_to_version['version'];
+                        unset($script_class_and_filepaths_available[$classname]);
                     } else {
                         // it must have a status that indicates it has finished, so we don't want to try and run it again
                     }
@@ -531,14 +531,14 @@ 
                 }
             }
             $iteration++;
-        } while ($next_database_state_to_consider != $theoretical_database_state && $iteration < 6);
+        }while ($next_database_state_to_consider != $theoretical_database_state && $iteration < 6);
         // ok we have all the scripts that should run, now let's make them into flat array
         $scripts_that_should_run = array();
         foreach ($script_classes_that_should_run_per_iteration as $scripts_at_priority) {
             ksort($scripts_at_priority);
             foreach ($scripts_at_priority as $scripts) {
                 foreach ($scripts as $script) {
-                    $scripts_that_should_run[ get_class($script) ] = $script;
+                    $scripts_that_should_run[get_class($script)] = $script;
                 }
             }
         }
@@ -563,7 +563,7 @@ 
     public function get_last_ran_script($include_completed_scripts = false)
     {
         // make sure we've setup the class properties _last_ran_script and _last_ran_incomplete_script
-        if (! $this->_data_migrations_ran) {
+        if ( ! $this->_data_migrations_ran) {
             $this->get_data_migrations_ran();
         }
         if ($include_completed_scripts) {
@@ -600,10 +600,10 @@ 
 
         try {
             $currently_executing_script = $this->get_last_ran_script();
-            if (! $currently_executing_script) {
+            if ( ! $currently_executing_script) {
                 // Find the next script that needs to execute
                 $scripts = $this->check_for_applicable_data_migration_scripts();
-                if (! $scripts) {
+                if ( ! $scripts) {
                     // huh, no more scripts to run... apparently we're done!
                     // but dont forget to make sure initial data is there
                     // we should be good to allow them to exit maintenance mode now
@@ -629,7 +629,7 @@ 
                 $migrates_to = $this->script_migrates_to_version(get_class($currently_executing_script));
                 $plugin_slug = $migrates_to['slug'];
                 $version = $migrates_to['version'];
-                $this->_data_migrations_ran[ $plugin_slug ][ $version ] = $currently_executing_script;
+                $this->_data_migrations_ran[$plugin_slug][$version] = $currently_executing_script;
             }
             $current_script_name = get_class($currently_executing_script);
         } catch (Exception $e) {
@@ -637,7 +637,7 @@ 
 
             $message = sprintf(
                 __("Error Message: %sStack Trace:%s", "event_espresso"),
-                $e->getMessage() . '<br>',
+                $e->getMessage().'<br>',
                 $e->getTraceAsString()
             );
             // record it on the array of data migration scripts ran. This will be overwritten next time we try and try to run data migrations
@@ -689,7 +689,7 @@ 
                     );
                     // check if there are any more after this one.
                     $scripts_remaining = $this->check_for_applicable_data_migration_scripts();
-                    if (! $scripts_remaining) {
+                    if ( ! $scripts_remaining) {
                         // we should be good to allow them to exit maintenance mode now
                         EE_Maintenance_Mode::instance()->set_maintenance_level(
                             intval(EE_Maintenance_Mode::level_0_not_in_maintenance)
@@ -789,7 +789,7 @@ 
                 ),
                 'script'             => 'Unknown',
             );
-            $this->add_error_to_migrations_ran($e->getMessage() . "; Stack trace:" . $e->getTraceAsString());
+            $this->add_error_to_migrations_ran($e->getMessage()."; Stack trace:".$e->getTraceAsString());
         }
         $warnings_etc = @ob_get_contents();
         ob_end_clean();
@@ -809,12 +809,12 @@ 
      */
     public function update_current_database_state_to($slug_and_version = null)
     {
-        if (! $slug_and_version) {
+        if ( ! $slug_and_version) {
             // no version was provided, assume it should be at the current code version
             $slug_and_version = array('slug' => 'Core', 'version' => espresso_version());
         }
         $current_database_state = get_option(self::current_database_state);
-        $current_database_state[ $slug_and_version['slug'] ] = $slug_and_version['version'];
+        $current_database_state[$slug_and_version['slug']] = $slug_and_version['version'];
         update_option(self::current_database_state, $current_database_state);
     }
 
@@ -833,15 +833,15 @@ 
         $slug = $slug_and_version['slug'];
         $version = $slug_and_version['version'];
         $current_database_state = get_option(self::current_database_state);
-        if (! isset($current_database_state[ $slug ])) {
+        if ( ! isset($current_database_state[$slug])) {
             return true;
         } else {
             // just compare the first 3 parts of version string, eg "4.7.1", not "4.7.1.dev.032" because DBs shouldn't change on nano version changes
-            $version_parts_current_db_state = array_slice(explode('.', $current_database_state[ $slug ]), 0, 3);
+            $version_parts_current_db_state = array_slice(explode('.', $current_database_state[$slug]), 0, 3);
             $version_parts_of_provided_db_state = array_slice(explode('.', $version), 0, 3);
             $needs_updating = false;
             foreach ($version_parts_current_db_state as $offset => $version_part_in_current_db_state) {
-                if ($version_part_in_current_db_state < $version_parts_of_provided_db_state[ $offset ]) {
+                if ($version_part_in_current_db_state < $version_parts_of_provided_db_state[$offset]) {
                     $needs_updating = true;
                     break;
                 }
@@ -863,7 +863,7 @@ 
      */
     public function get_all_data_migration_scripts_available()
     {
-        if (! $this->_data_migration_class_to_filepath_map) {
+        if ( ! $this->_data_migration_class_to_filepath_map) {
             $this->_data_migration_class_to_filepath_map = array();
             foreach ($this->get_data_migration_script_folders() as $eeAddonClass => $folder_path) {
                 // strip any placeholders added to classname to make it a unique array key
@@ -872,7 +872,7 @@ 
                     ? $eeAddonClass
                     : '';
                 $folder_path = EEH_File::end_with_directory_separator($folder_path);
-                $files = glob($folder_path . '*.dms.php');
+                $files = glob($folder_path.'*.dms.php');
                 if (empty($files)) {
                     continue;
                 }
@@ -898,7 +898,7 @@ 
                             '4.3.0.alpha.019'
                         );
                     }
-                    $this->_data_migration_class_to_filepath_map[ $classname ] = $file;
+                    $this->_data_migration_class_to_filepath_map[$classname] = $file;
                 }
             }
             EEH_Autoloader::register_autoloader($this->_data_migration_class_to_filepath_map);
@@ -930,7 +930,7 @@ 
         // get last-ran migration script
         global $wpdb;
         $last_migration_script_option = $wpdb->get_row(
-            "SELECT * FROM $wpdb->options WHERE option_name like '" . EE_Data_Migration_Manager::data_migration_script_option_prefix . "%' ORDER BY option_id DESC LIMIT 1",
+            "SELECT * FROM $wpdb->options WHERE option_name like '".EE_Data_Migration_Manager::data_migration_script_option_prefix."%' ORDER BY option_id DESC LIMIT 1",
             ARRAY_A
         );
 
@@ -962,10 +962,10 @@ 
             $versions_migrated_to = 'Unknown.1.0.0';
             // now just to make sure appears as last (in case the were previously a fatal error like this)
             // delete the old one
-            delete_option(self::data_migration_script_option_prefix . $versions_migrated_to);
+            delete_option(self::data_migration_script_option_prefix.$versions_migrated_to);
         }
         update_option(
-            self::data_migration_script_option_prefix . $versions_migrated_to,
+            self::data_migration_script_option_prefix.$versions_migrated_to,
             $last_ran_migration_script_properties
         );
     }
@@ -984,8 +984,8 @@ 
         $successful_updates = true;
         foreach ($this->_data_migrations_ran as $plugin_slug => $migrations_ran_for_plugin) {
             foreach ($migrations_ran_for_plugin as $version_string => $array_or_migration_obj) {
-                $plugin_slug_for_use_in_option_name = $plugin_slug . ".";
-                $option_name = self::data_migration_script_option_prefix . $plugin_slug_for_use_in_option_name . $version_string;
+                $plugin_slug_for_use_in_option_name = $plugin_slug.".";
+                $option_name = self::data_migration_script_option_prefix.$plugin_slug_for_use_in_option_name.$version_string;
                 $old_option_value = get_option($option_name);
                 if ($array_or_migration_obj instanceof EE_Data_Migration_Script_Base) {
                     $script_array_for_saving = $array_or_migration_obj->properties_as_array();
@@ -997,7 +997,7 @@ 
                         $successful_updates = update_option($option_name, $array_or_migration_obj);
                     }
                 }
-                if (! $successful_updates) {
+                if ( ! $successful_updates) {
                     global $wpdb;
                     return $wpdb->last_error;
                 }
@@ -1031,7 +1031,7 @@ 
      */
     public function _instantiate_script_from_properties_array($properties_array)
     {
-        if (! isset($properties_array['class'])) {
+        if ( ! isset($properties_array['class'])) {
             throw new EE_Error(
                 sprintf(
                     __("Properties array  has no 'class' properties. Here's what it has: %s", "event_espresso"),
@@ -1040,11 +1040,11 @@ 
             );
         }
         $class_name = $properties_array['class'];
-        if (! class_exists($class_name)) {
+        if ( ! class_exists($class_name)) {
             throw new EE_Error(sprintf(__("There is no migration script named %s", "event_espresso"), $class_name));
         }
         $class = new $class_name;
-        if (! $class instanceof EE_Data_Migration_Script_Base) {
+        if ( ! $class instanceof EE_Data_Migration_Script_Base) {
             throw new EE_Error(
                 sprintf(
                     __("Class '%s' is supposed to be a migration script. Its not, its a '%s'", "event_espresso"),
@@ -1111,8 +1111,8 @@ 
     public function get_migration_ran($version, $plugin_slug = 'Core')
     {
         $migrations_ran = $this->get_data_migrations_ran();
-        if (isset($migrations_ran[ $plugin_slug ]) && isset($migrations_ran[ $plugin_slug ][ $version ])) {
-            return $migrations_ran[ $plugin_slug ][ $version ];
+        if (isset($migrations_ran[$plugin_slug]) && isset($migrations_ran[$plugin_slug][$version])) {
+            return $migrations_ran[$plugin_slug][$version];
         } else {
             return null;
         }
@@ -1173,7 +1173,7 @@ 
     public function enqueue_db_initialization_for($plugin_slug)
     {
         $queue = $this->get_db_initialization_queue();
-        if (! in_array($plugin_slug, $queue)) {
+        if ( ! in_array($plugin_slug, $queue)) {
             $queue[] = $plugin_slug;
         }
         update_option(self::db_init_queue_option_name, $queue);
@@ -1189,7 +1189,7 @@ 
         $queue = $this->get_db_initialization_queue();
         foreach ($queue as $plugin_slug) {
             $most_up_to_date_dms = $this->get_most_up_to_date_dms($plugin_slug);
-            if (! $most_up_to_date_dms) {
+            if ( ! $most_up_to_date_dms) {
                 // if there is NO DMS for this plugin, obviously there's no schema to verify anyways
                 $verify_db = false;
             } else {

core/EE_Dependency_Map.core.php

Indentation +1103 added lines, -1103 removed lines

@@ -20,1107 +20,1107 @@
 class EE_Dependency_Map
 {
 
-    /**
-     * This means that the requested class dependency is not present in the dependency map
-     */
-    const not_registered = 0;
-
-    /**
-     * This instructs class loaders to ALWAYS return a newly instantiated object for the requested class.
-     */
-    const load_new_object = 1;
-
-    /**
-     * This instructs class loaders to return a previously instantiated and cached object for the requested class.
-     * IF a previously instantiated object does not exist, a new one will be created and added to the cache.
-     */
-    const load_from_cache = 2;
-
-    /**
-     * When registering a dependency,
-     * this indicates to keep any existing dependencies that already exist,
-     * and simply discard any new dependencies declared in the incoming data
-     */
-    const KEEP_EXISTING_DEPENDENCIES = 0;
-
-    /**
-     * When registering a dependency,
-     * this indicates to overwrite any existing dependencies that already exist using the incoming data
-     */
-    const OVERWRITE_DEPENDENCIES = 1;
-
-
-    /**
-     * @type EE_Dependency_Map $_instance
-     */
-    protected static $_instance;
-
-    /**
-     * @var ClassInterfaceCache $class_cache
-     */
-    private $class_cache;
-
-    /**
-     * @type RequestInterface $request
-     */
-    protected $request;
-
-    /**
-     * @type LegacyRequestInterface $legacy_request
-     */
-    protected $legacy_request;
-
-    /**
-     * @type ResponseInterface $response
-     */
-    protected $response;
-
-    /**
-     * @type LoaderInterface $loader
-     */
-    protected $loader;
-
-    /**
-     * @type array $_dependency_map
-     */
-    protected $_dependency_map = array();
-
-    /**
-     * @type array $_class_loaders
-     */
-    protected $_class_loaders = array();
-
-
-    /**
-     * EE_Dependency_Map constructor.
-     *
-     * @param ClassInterfaceCache $class_cache
-     */
-    protected function __construct(ClassInterfaceCache $class_cache)
-    {
-        $this->class_cache = $class_cache;
-        do_action('EE_Dependency_Map____construct', $this);
-    }
-
-
-    /**
-     * @return void
-     */
-    public function initialize()
-    {
-        $this->_register_core_dependencies();
-        $this->_register_core_class_loaders();
-        $this->_register_core_aliases();
-    }
-
-
-    /**
-     * @singleton method used to instantiate class object
-     * @param ClassInterfaceCache|null $class_cache
-     * @return EE_Dependency_Map
-     */
-    public static function instance(ClassInterfaceCache $class_cache = null)
-    {
-        // check if class object is instantiated, and instantiated properly
-        if (! self::$_instance instanceof EE_Dependency_Map
-            && $class_cache instanceof ClassInterfaceCache
-        ) {
-            self::$_instance = new EE_Dependency_Map($class_cache);
-        }
-        return self::$_instance;
-    }
-
-
-    /**
-     * @param RequestInterface $request
-     */
-    public function setRequest(RequestInterface $request)
-    {
-        $this->request = $request;
-    }
-
-
-    /**
-     * @param LegacyRequestInterface $legacy_request
-     */
-    public function setLegacyRequest(LegacyRequestInterface $legacy_request)
-    {
-        $this->legacy_request = $legacy_request;
-    }
-
-
-    /**
-     * @param ResponseInterface $response
-     */
-    public function setResponse(ResponseInterface $response)
-    {
-        $this->response = $response;
-    }
-
-
-    /**
-     * @param LoaderInterface $loader
-     */
-    public function setLoader(LoaderInterface $loader)
-    {
-        $this->loader = $loader;
-    }
-
-
-    /**
-     * @param string $class
-     * @param array  $dependencies
-     * @param int    $overwrite
-     * @return bool
-     */
-    public static function register_dependencies(
-        $class,
-        array $dependencies,
-        $overwrite = EE_Dependency_Map::KEEP_EXISTING_DEPENDENCIES
-    ) {
-        return self::$_instance->registerDependencies($class, $dependencies, $overwrite);
-    }
-
-
-    /**
-     * Assigns an array of class names and corresponding load sources (new or cached)
-     * to the class specified by the first parameter.
-     * IMPORTANT !!!
-     * The order of elements in the incoming $dependencies array MUST match
-     * the order of the constructor parameters for the class in question.
-     * This is especially important when overriding any existing dependencies that are registered.
-     * the third parameter controls whether any duplicate dependencies are overwritten or not.
-     *
-     * @param string $class
-     * @param array  $dependencies
-     * @param int    $overwrite
-     * @return bool
-     */
-    public function registerDependencies(
-        $class,
-        array $dependencies,
-        $overwrite = EE_Dependency_Map::KEEP_EXISTING_DEPENDENCIES
-    ) {
-        $class = trim($class, '\\');
-        $registered = false;
-        if (empty(self::$_instance->_dependency_map[ $class ])) {
-            self::$_instance->_dependency_map[ $class ] = array();
-        }
-        // we need to make sure that any aliases used when registering a dependency
-        // get resolved to the correct class name
-        foreach ($dependencies as $dependency => $load_source) {
-            $alias = self::$_instance->getFqnForAlias($dependency);
-            if ($overwrite === EE_Dependency_Map::OVERWRITE_DEPENDENCIES
-                || ! isset(self::$_instance->_dependency_map[ $class ][ $alias ])
-            ) {
-                unset($dependencies[ $dependency ]);
-                $dependencies[ $alias ] = $load_source;
-                $registered = true;
-            }
-        }
-        // now add our two lists of dependencies together.
-        // using Union (+=) favours the arrays in precedence from left to right,
-        // so $dependencies is NOT overwritten because it is listed first
-        // ie: with A = B + C, entries in B take precedence over duplicate entries in C
-        // Union is way faster than array_merge() but should be used with caution...
-        // especially with numerically indexed arrays
-        $dependencies += self::$_instance->_dependency_map[ $class ];
-        // now we need to ensure that the resulting dependencies
-        // array only has the entries that are required for the class
-        // so first count how many dependencies were originally registered for the class
-        $dependency_count = count(self::$_instance->_dependency_map[ $class ]);
-        // if that count is non-zero (meaning dependencies were already registered)
-        self::$_instance->_dependency_map[ $class ] = $dependency_count
-            // then truncate the  final array to match that count
-            ? array_slice($dependencies, 0, $dependency_count)
-            // otherwise just take the incoming array because nothing previously existed
-            : $dependencies;
-        return $registered;
-    }
-
-
-    /**
-     * @param string $class_name
-     * @param string $loader
-     * @return bool
-     * @throws DomainException
-     */
-    public static function register_class_loader($class_name, $loader = 'load_core')
-    {
-        if (! $loader instanceof Closure && strpos($class_name, '\\') !== false) {
-            throw new DomainException(
-                esc_html__('Don\'t use class loaders for FQCNs.', 'event_espresso')
-            );
-        }
-        // check that loader is callable or method starts with "load_" and exists in EE_Registry
-        if (! is_callable($loader)
-            && (
-                strpos($loader, 'load_') !== 0
-                || ! method_exists('EE_Registry', $loader)
-            )
-        ) {
-            throw new DomainException(
-                sprintf(
-                    esc_html__(
-                        '"%1$s" is not a valid loader method on EE_Registry.',
-                        'event_espresso'
-                    ),
-                    $loader
-                )
-            );
-        }
-        $class_name = self::$_instance->getFqnForAlias($class_name);
-        if (! isset(self::$_instance->_class_loaders[ $class_name ])) {
-            self::$_instance->_class_loaders[ $class_name ] = $loader;
-            return true;
-        }
-        return false;
-    }
-
-
-    /**
-     * @return array
-     */
-    public function dependency_map()
-    {
-        return $this->_dependency_map;
-    }
-
-
-    /**
-     * returns TRUE if dependency map contains a listing for the provided class name
-     *
-     * @param string $class_name
-     * @return boolean
-     */
-    public function has($class_name = '')
-    {
-        // all legacy models have the same dependencies
-        if (strpos($class_name, 'EEM_') === 0) {
-            $class_name = 'LEGACY_MODELS';
-        }
-        return isset($this->_dependency_map[ $class_name ]) ? true : false;
-    }
-
-
-    /**
-     * returns TRUE if dependency map contains a listing for the provided class name AND dependency
-     *
-     * @param string $class_name
-     * @param string $dependency
-     * @return bool
-     */
-    public function has_dependency_for_class($class_name = '', $dependency = '')
-    {
-        // all legacy models have the same dependencies
-        if (strpos($class_name, 'EEM_') === 0) {
-            $class_name = 'LEGACY_MODELS';
-        }
-        $dependency = $this->getFqnForAlias($dependency, $class_name);
-        return isset($this->_dependency_map[ $class_name ][ $dependency ])
-            ? true
-            : false;
-    }
-
-
-    /**
-     * returns loading strategy for whether a previously cached dependency should be loaded or a new instance returned
-     *
-     * @param string $class_name
-     * @param string $dependency
-     * @return int
-     */
-    public function loading_strategy_for_class_dependency($class_name = '', $dependency = '')
-    {
-        // all legacy models have the same dependencies
-        if (strpos($class_name, 'EEM_') === 0) {
-            $class_name = 'LEGACY_MODELS';
-        }
-        $dependency = $this->getFqnForAlias($dependency);
-        return $this->has_dependency_for_class($class_name, $dependency)
-            ? $this->_dependency_map[ $class_name ][ $dependency ]
-            : EE_Dependency_Map::not_registered;
-    }
-
-
-    /**
-     * @param string $class_name
-     * @return string | Closure
-     */
-    public function class_loader($class_name)
-    {
-        // all legacy models use load_model()
-        if (strpos($class_name, 'EEM_') === 0) {
-            return 'load_model';
-        }
-        // EE_CPT_*_Strategy classes like EE_CPT_Event_Strategy, EE_CPT_Venue_Strategy, etc
-        // perform strpos() first to avoid loading regex every time we load a class
-        if (strpos($class_name, 'EE_CPT_') === 0
-            && preg_match('/^EE_CPT_([a-zA-Z]+)_Strategy$/', $class_name)
-        ) {
-            return 'load_core';
-        }
-        $class_name = $this->getFqnForAlias($class_name);
-        return isset($this->_class_loaders[ $class_name ]) ? $this->_class_loaders[ $class_name ] : '';
-    }
-
-
-    /**
-     * @return array
-     */
-    public function class_loaders()
-    {
-        return $this->_class_loaders;
-    }
-
-
-    /**
-     * adds an alias for a classname
-     *
-     * @param string $fqcn      the class name that should be used (concrete class to replace interface)
-     * @param string $alias     the class name that would be type hinted for (abstract parent or interface)
-     * @param string $for_class the class that has the dependency (is type hinting for the interface)
-     */
-    public function add_alias($fqcn, $alias, $for_class = '')
-    {
-        $this->class_cache->addAlias($fqcn, $alias, $for_class);
-    }
-
-
-    /**
-     * Returns TRUE if the provided fully qualified name IS an alias
-     * WHY?
-     * Because if a class is type hinting for a concretion,
-     * then why would we need to find another class to supply it?
-     * ie: if a class asks for `Fully/Qualified/Namespace/SpecificClassName`,
-     * then give it an instance of `Fully/Qualified/Namespace/SpecificClassName`.
-     * Don't go looking for some substitute.
-     * Whereas if a class is type hinting for an interface...
-     * then we need to find an actual class to use.
-     * So the interface IS the alias for some other FQN,
-     * and we need to find out if `Fully/Qualified/Namespace/SomeInterface`
-     * represents some other class.
-     *
-     * @param string $fqn
-     * @param string $for_class
-     * @return bool
-     */
-    public function isAlias($fqn = '', $for_class = '')
-    {
-        return $this->class_cache->isAlias($fqn, $for_class);
-    }
-
-
-    /**
-     * Returns a FQN for provided alias if one exists, otherwise returns the original $alias
-     * functions recursively, so that multiple aliases can be used to drill down to a FQN
-     *  for example:
-     *      if the following two entries were added to the _aliases array:
-     *          array(
-     *              'interface_alias'           => 'some\namespace\interface'
-     *              'some\namespace\interface'  => 'some\namespace\classname'
-     *          )
-     *      then one could use EE_Registry::instance()->create( 'interface_alias' )
-     *      to load an instance of 'some\namespace\classname'
-     *
-     * @param string $alias
-     * @param string $for_class
-     * @return string
-     */
-    public function getFqnForAlias($alias = '', $for_class = '')
-    {
-        return (string) $this->class_cache->getFqnForAlias($alias, $for_class);
-    }
-
-
-    /**
-     * Registers the core dependencies and whether a previously instantiated object should be loaded from the cache,
-     * if one exists, or whether a new object should be generated every time the requested class is loaded.
-     * This is done by using the following class constants:
-     *        EE_Dependency_Map::load_from_cache - loads previously instantiated object
-     *        EE_Dependency_Map::load_new_object - generates a new object every time
-     */
-    protected function _register_core_dependencies()
-    {
-        $this->_dependency_map = array(
-            'EE_Request_Handler'                                                                                          => array(
-                'EE_Request' => EE_Dependency_Map::load_from_cache,
-            ),
-            'EE_System'                                                                                                   => array(
-                'EE_Registry'                                 => EE_Dependency_Map::load_from_cache,
-                'EventEspresso\core\services\loaders\Loader'  => EE_Dependency_Map::load_from_cache,
-                'EventEspresso\core\services\request\Request' => EE_Dependency_Map::load_from_cache,
-                'EE_Maintenance_Mode'                         => EE_Dependency_Map::load_from_cache,
-            ),
-            'EE_Session'                                                                                                  => array(
-                'EventEspresso\core\services\cache\TransientCacheStorage'  => EE_Dependency_Map::load_from_cache,
-                'EventEspresso\core\domain\values\session\SessionLifespan' => EE_Dependency_Map::load_from_cache,
-                'EventEspresso\core\services\request\Request'              => EE_Dependency_Map::load_from_cache,
-                'EventEspresso\core\services\session\SessionStartHandler'  => EE_Dependency_Map::load_from_cache,
-                'EE_Encryption'                                            => EE_Dependency_Map::load_from_cache,
-            ),
-            'EE_Cart'                                                                                                     => array(
-                'EE_Session' => EE_Dependency_Map::load_from_cache,
-            ),
-            'EE_Front_Controller'                                                                                         => array(
-                'EE_Registry'              => EE_Dependency_Map::load_from_cache,
-                'EE_Request_Handler'       => EE_Dependency_Map::load_from_cache,
-                'EE_Module_Request_Router' => EE_Dependency_Map::load_from_cache,
-            ),
-            'EE_Messenger_Collection_Loader'                                                                              => array(
-                'EE_Messenger_Collection' => EE_Dependency_Map::load_new_object,
-            ),
-            'EE_Message_Type_Collection_Loader'                                                                           => array(
-                'EE_Message_Type_Collection' => EE_Dependency_Map::load_new_object,
-            ),
-            'EE_Message_Resource_Manager'                                                                                 => array(
-                'EE_Messenger_Collection_Loader'    => EE_Dependency_Map::load_new_object,
-                'EE_Message_Type_Collection_Loader' => EE_Dependency_Map::load_new_object,
-                'EEM_Message_Template_Group'        => EE_Dependency_Map::load_from_cache,
-            ),
-            'EE_Message_Factory'                                                                                          => array(
-                'EE_Message_Resource_Manager' => EE_Dependency_Map::load_from_cache,
-            ),
-            'EE_messages'                                                                                                 => array(
-                'EE_Message_Resource_Manager' => EE_Dependency_Map::load_from_cache,
-            ),
-            'EE_Messages_Generator'                                                                                       => array(
-                'EE_Messages_Queue'                    => EE_Dependency_Map::load_new_object,
-                'EE_Messages_Data_Handler_Collection'  => EE_Dependency_Map::load_new_object,
-                'EE_Message_Template_Group_Collection' => EE_Dependency_Map::load_new_object,
-                'EEH_Parse_Shortcodes'                 => EE_Dependency_Map::load_from_cache,
-            ),
-            'EE_Messages_Processor'                                                                                       => array(
-                'EE_Message_Resource_Manager' => EE_Dependency_Map::load_from_cache,
-            ),
-            'EE_Messages_Queue'                                                                                           => array(
-                'EE_Message_Repository' => EE_Dependency_Map::load_new_object,
-            ),
-            'EE_Messages_Template_Defaults'                                                                               => array(
-                'EEM_Message_Template_Group' => EE_Dependency_Map::load_from_cache,
-                'EEM_Message_Template'       => EE_Dependency_Map::load_from_cache,
-            ),
-            'EE_Message_To_Generate_From_Request'                                                                         => array(
-                'EE_Message_Resource_Manager' => EE_Dependency_Map::load_from_cache,
-                'EE_Request_Handler'          => EE_Dependency_Map::load_from_cache,
-            ),
-            'EventEspresso\core\services\commands\CommandBus'                                                             => array(
-                'EventEspresso\core\services\commands\CommandHandlerManager' => EE_Dependency_Map::load_from_cache,
-            ),
-            'EventEspresso\services\commands\CommandHandler'                                                              => array(
-                'EE_Registry'         => EE_Dependency_Map::load_from_cache,
-                'CommandBusInterface' => EE_Dependency_Map::load_from_cache,
-            ),
-            'EventEspresso\core\services\commands\CommandHandlerManager'                                                  => array(
-                'EventEspresso\core\services\loaders\Loader' => EE_Dependency_Map::load_from_cache,
-            ),
-            'EventEspresso\core\services\commands\CompositeCommandHandler'                                                => array(
-                'EventEspresso\core\services\commands\CommandBus'     => EE_Dependency_Map::load_from_cache,
-                'EventEspresso\core\services\commands\CommandFactory' => EE_Dependency_Map::load_from_cache,
-            ),
-            'EventEspresso\core\services\commands\CommandFactory'                                                         => array(
-                'EventEspresso\core\services\loaders\Loader' => EE_Dependency_Map::load_from_cache,
-            ),
-            'EventEspresso\core\services\commands\middleware\CapChecker'                                                  => array(
-                'EventEspresso\core\domain\services\capabilities\CapabilitiesChecker' => EE_Dependency_Map::load_from_cache,
-            ),
-            'EventEspresso\core\domain\services\capabilities\CapabilitiesChecker'                                         => array(
-                'EE_Capabilities' => EE_Dependency_Map::load_from_cache,
-            ),
-            'EventEspresso\core\domain\services\capabilities\RegistrationsCapChecker'                                     => array(
-                'EE_Capabilities' => EE_Dependency_Map::load_from_cache,
-            ),
-            'EventEspresso\core\services\commands\registration\CreateRegistrationCommandHandler'                          => array(
-                'EventEspresso\core\domain\services\registration\CreateRegistrationService' => EE_Dependency_Map::load_from_cache,
-            ),
-            'EventEspresso\core\services\commands\registration\CopyRegistrationDetailsCommandHandler'                     => array(
-                'EventEspresso\core\domain\services\registration\CopyRegistrationService' => EE_Dependency_Map::load_from_cache,
-            ),
-            'EventEspresso\core\services\commands\registration\CopyRegistrationPaymentsCommandHandler'                    => array(
-                'EventEspresso\core\domain\services\registration\CopyRegistrationService' => EE_Dependency_Map::load_from_cache,
-            ),
-            'EventEspresso\core\services\commands\registration\CancelRegistrationAndTicketLineItemCommandHandler'         => array(
-                'EventEspresso\core\domain\services\registration\CancelTicketLineItemService' => EE_Dependency_Map::load_from_cache,
-            ),
-            'EventEspresso\core\services\commands\registration\UpdateRegistrationAndTransactionAfterChangeCommandHandler' => array(
-                'EventEspresso\core\domain\services\registration\UpdateRegistrationService' => EE_Dependency_Map::load_from_cache,
-            ),
-            'EventEspresso\core\services\commands\ticket\CreateTicketLineItemCommandHandler'                              => array(
-                'EventEspresso\core\domain\services\ticket\CreateTicketLineItemService' => EE_Dependency_Map::load_from_cache,
-            ),
-            'EventEspresso\core\services\commands\ticket\CancelTicketLineItemCommandHandler'                              => array(
-                'EventEspresso\core\domain\services\ticket\CancelTicketLineItemService' => EE_Dependency_Map::load_from_cache,
-            ),
-            'EventEspresso\core\domain\services\registration\CancelRegistrationService'                                   => array(
-                'EventEspresso\core\domain\services\ticket\CancelTicketLineItemService' => EE_Dependency_Map::load_from_cache,
-            ),
-            'EventEspresso\core\services\commands\attendee\CreateAttendeeCommandHandler'                                  => array(
-                'EEM_Attendee' => EE_Dependency_Map::load_from_cache,
-            ),
-            'EventEspresso\core\services\database\TableManager'                                                           => array(
-                'EventEspresso\core\services\database\TableAnalysis' => EE_Dependency_Map::load_from_cache,
-            ),
-            'EE_Data_Migration_Class_Base'                                                                                => array(
-                'EventEspresso\core\services\database\TableAnalysis' => EE_Dependency_Map::load_from_cache,
-                'EventEspresso\core\services\database\TableManager'  => EE_Dependency_Map::load_from_cache,
-            ),
-            'EE_DMS_Core_4_1_0'                                                                                           => array(
-                'EventEspresso\core\services\database\TableAnalysis' => EE_Dependency_Map::load_from_cache,
-                'EventEspresso\core\services\database\TableManager'  => EE_Dependency_Map::load_from_cache,
-            ),
-            'EE_DMS_Core_4_2_0'                                                                                           => array(
-                'EventEspresso\core\services\database\TableAnalysis' => EE_Dependency_Map::load_from_cache,
-                'EventEspresso\core\services\database\TableManager'  => EE_Dependency_Map::load_from_cache,
-            ),
-            'EE_DMS_Core_4_3_0'                                                                                           => array(
-                'EventEspresso\core\services\database\TableAnalysis' => EE_Dependency_Map::load_from_cache,
-                'EventEspresso\core\services\database\TableManager'  => EE_Dependency_Map::load_from_cache,
-            ),
-            'EE_DMS_Core_4_4_0'                                                                                           => array(
-                'EventEspresso\core\services\database\TableAnalysis' => EE_Dependency_Map::load_from_cache,
-                'EventEspresso\core\services\database\TableManager'  => EE_Dependency_Map::load_from_cache,
-            ),
-            'EE_DMS_Core_4_5_0'                                                                                           => array(
-                'EventEspresso\core\services\database\TableAnalysis' => EE_Dependency_Map::load_from_cache,
-                'EventEspresso\core\services\database\TableManager'  => EE_Dependency_Map::load_from_cache,
-            ),
-            'EE_DMS_Core_4_6_0'                                                                                           => array(
-                'EventEspresso\core\services\database\TableAnalysis' => EE_Dependency_Map::load_from_cache,
-                'EventEspresso\core\services\database\TableManager'  => EE_Dependency_Map::load_from_cache,
-            ),
-            'EE_DMS_Core_4_7_0'                                                                                           => array(
-                'EventEspresso\core\services\database\TableAnalysis' => EE_Dependency_Map::load_from_cache,
-                'EventEspresso\core\services\database\TableManager'  => EE_Dependency_Map::load_from_cache,
-            ),
-            'EE_DMS_Core_4_8_0'                                                                                           => array(
-                'EventEspresso\core\services\database\TableAnalysis' => EE_Dependency_Map::load_from_cache,
-                'EventEspresso\core\services\database\TableManager'  => EE_Dependency_Map::load_from_cache,
-            ),
-            'EE_DMS_Core_4_9_0' => array(
-                'EventEspresso\core\services\database\TableAnalysis' => EE_Dependency_Map::load_from_cache,
-                'EventEspresso\core\services\database\TableManager'  => EE_Dependency_Map::load_from_cache,
-            ),
-            'EE_DMS_Core_4_10_0' => array(
-                'EventEspresso\core\services\database\TableAnalysis' => EE_Dependency_Map::load_from_cache,
-                'EventEspresso\core\services\database\TableManager'  => EE_Dependency_Map::load_from_cache,
-                'EE_DMS_Core_4_9_0'                                  => EE_Dependency_Map::load_from_cache,
-            ),
-            'EventEspresso\core\services\assets\I18nRegistry'                                                             => array(
-                array(),
-                'EventEspresso\core\domain\Domain' => EE_Dependency_Map::load_from_cache,
-            ),
-            'EventEspresso\core\services\assets\Registry'                                                                 => array(
-                'EventEspresso\core\services\assets\AssetCollection' => EE_Dependency_Map::load_from_cache,
-                'EventEspresso\core\services\assets\I18nRegistry'    => EE_Dependency_Map::load_from_cache,
-            ),
-            'EventEspresso\core\domain\entities\shortcodes\EspressoCancelled'                                             => array(
-                'EventEspresso\core\services\cache\PostRelatedCacheManager' => EE_Dependency_Map::load_from_cache,
-            ),
-            'EventEspresso\core\domain\entities\shortcodes\EspressoCheckout'                                              => array(
-                'EventEspresso\core\services\cache\PostRelatedCacheManager' => EE_Dependency_Map::load_from_cache,
-            ),
-            'EventEspresso\core\domain\entities\shortcodes\EspressoEventAttendees'                                        => array(
-                'EventEspresso\core\services\cache\PostRelatedCacheManager' => EE_Dependency_Map::load_from_cache,
-            ),
-            'EventEspresso\core\domain\entities\shortcodes\EspressoEvents'                                                => array(
-                'EventEspresso\core\services\cache\PostRelatedCacheManager' => EE_Dependency_Map::load_from_cache,
-            ),
-            'EventEspresso\core\domain\entities\shortcodes\EspressoThankYou'                                              => array(
-                'EventEspresso\core\services\cache\PostRelatedCacheManager' => EE_Dependency_Map::load_from_cache,
-            ),
-            'EventEspresso\core\domain\entities\shortcodes\EspressoTicketSelector'                                        => array(
-                'EventEspresso\core\services\cache\PostRelatedCacheManager' => EE_Dependency_Map::load_from_cache,
-            ),
-            'EventEspresso\core\domain\entities\shortcodes\EspressoTxnPage'                                               => array(
-                'EventEspresso\core\services\cache\PostRelatedCacheManager' => EE_Dependency_Map::load_from_cache,
-            ),
-            'EventEspresso\core\services\cache\BasicCacheManager'                                                         => array(
-                'EventEspresso\core\services\cache\TransientCacheStorage' => EE_Dependency_Map::load_from_cache,
-            ),
-            'EventEspresso\core\services\cache\PostRelatedCacheManager'                                                   => array(
-                'EventEspresso\core\services\cache\TransientCacheStorage' => EE_Dependency_Map::load_from_cache,
-            ),
-            'EventEspresso\core\domain\services\validation\email\EmailValidationService'                                  => array(
-                'EE_Registration_Config'                     => EE_Dependency_Map::load_from_cache,
-                'EventEspresso\core\services\loaders\Loader' => EE_Dependency_Map::load_from_cache,
-            ),
-            'EventEspresso\core\domain\values\EmailAddress'                                                               => array(
-                null,
-                'EventEspresso\core\domain\services\validation\email\EmailValidationService' => EE_Dependency_Map::load_from_cache,
-            ),
-            'EventEspresso\core\services\orm\ModelFieldFactory'                                                           => array(
-                'EventEspresso\core\services\loaders\Loader' => EE_Dependency_Map::load_from_cache,
-            ),
-            'LEGACY_MODELS'                                                                                               => array(
-                null,
-                'EventEspresso\core\services\database\ModelFieldFactory' => EE_Dependency_Map::load_from_cache,
-            ),
-            'EE_Module_Request_Router'                                                                                    => array(
-                'EE_Request' => EE_Dependency_Map::load_from_cache,
-            ),
-            'EE_Registration_Processor'                                                                                   => array(
-                'EE_Request' => EE_Dependency_Map::load_from_cache,
-            ),
-            'EventEspresso\core\services\notifications\PersistentAdminNoticeManager'                                      => array(
-                null,
-                'EventEspresso\core\domain\services\capabilities\CapabilitiesChecker' => EE_Dependency_Map::load_from_cache,
-                'EventEspresso\core\services\request\Request'                         => EE_Dependency_Map::load_from_cache,
-            ),
-            'EventEspresso\core\services\licensing\LicenseService'                                                        => array(
-                'EventEspresso\core\domain\services\pue\Stats'  => EE_Dependency_Map::load_from_cache,
-                'EventEspresso\core\domain\services\pue\Config' => EE_Dependency_Map::load_from_cache,
-            ),
-            'EE_Admin_Transactions_List_Table'                                                                            => array(
-                null,
-                'EventEspresso\core\domain\values\session\SessionLifespan' => EE_Dependency_Map::load_from_cache,
-            ),
-            'EventEspresso\core\domain\services\pue\Stats'                                                                => array(
-                'EventEspresso\core\domain\services\pue\Config'        => EE_Dependency_Map::load_from_cache,
-                'EE_Maintenance_Mode'                                  => EE_Dependency_Map::load_from_cache,
-                'EventEspresso\core\domain\services\pue\StatsGatherer' => EE_Dependency_Map::load_from_cache,
-            ),
-            'EventEspresso\core\domain\services\pue\Config'                                                               => array(
-                'EE_Network_Config' => EE_Dependency_Map::load_from_cache,
-                'EE_Config'         => EE_Dependency_Map::load_from_cache,
-            ),
-            'EventEspresso\core\domain\services\pue\StatsGatherer'                                                        => array(
-                'EEM_Payment_Method' => EE_Dependency_Map::load_from_cache,
-                'EEM_Event'          => EE_Dependency_Map::load_from_cache,
-                'EEM_Datetime'       => EE_Dependency_Map::load_from_cache,
-                'EEM_Ticket'         => EE_Dependency_Map::load_from_cache,
-                'EEM_Registration'   => EE_Dependency_Map::load_from_cache,
-                'EEM_Transaction'    => EE_Dependency_Map::load_from_cache,
-                'EE_Config'          => EE_Dependency_Map::load_from_cache,
-            ),
-            'EventEspresso\core\domain\services\admin\ExitModal'                                                          => array(
-                'EventEspresso\core\services\assets\Registry' => EE_Dependency_Map::load_from_cache,
-            ),
-            'EventEspresso\core\domain\services\admin\PluginUpsells'                                                      => array(
-                'EventEspresso\core\domain\Domain' => EE_Dependency_Map::load_from_cache,
-            ),
-            'EventEspresso\caffeinated\modules\recaptcha_invisible\InvisibleRecaptcha'                                    => array(
-                'EE_Registration_Config' => EE_Dependency_Map::load_from_cache,
-                'EE_Session'             => EE_Dependency_Map::load_from_cache,
-            ),
-            'EventEspresso\caffeinated\modules\recaptcha_invisible\RecaptchaAdminSettings'                                => array(
-                'EE_Registration_Config' => EE_Dependency_Map::load_from_cache,
-            ),
-            'EventEspresso\modules\ticket_selector\ProcessTicketSelector'                                                 => array(
-                'EE_Core_Config'                                                          => EE_Dependency_Map::load_from_cache,
-                'EventEspresso\core\services\request\Request'                             => EE_Dependency_Map::load_from_cache,
-                'EE_Session'                                                              => EE_Dependency_Map::load_from_cache,
-                'EEM_Ticket'                                                              => EE_Dependency_Map::load_from_cache,
-                'EventEspresso\modules\ticket_selector\TicketDatetimeAvailabilityTracker' => EE_Dependency_Map::load_from_cache,
-            ),
-            'EventEspresso\modules\ticket_selector\TicketDatetimeAvailabilityTracker'                                     => array(
-                'EEM_Datetime' => EE_Dependency_Map::load_from_cache,
-            ),
-            'EventEspresso\core\domain\entities\custom_post_types\CustomPostTypeDefinitions'                              => array(
-                'EE_Core_Config'                             => EE_Dependency_Map::load_from_cache,
-                'EventEspresso\core\services\loaders\Loader' => EE_Dependency_Map::load_from_cache,
-            ),
-            'EventEspresso\core\domain\services\custom_post_types\RegisterCustomPostTypes'                                => array(
-                'EventEspresso\core\domain\entities\custom_post_types\CustomPostTypeDefinitions' => EE_Dependency_Map::load_from_cache,
-            ),
-            'EventEspresso\core\domain\services\custom_post_types\RegisterCustomTaxonomies'                               => array(
-                'EventEspresso\core\domain\entities\custom_post_types\CustomTaxonomyDefinitions' => EE_Dependency_Map::load_from_cache,
-            ),
-            'EE_CPT_Strategy'                                                                                             => array(
-                'EventEspresso\core\domain\entities\custom_post_types\CustomPostTypeDefinitions' => EE_Dependency_Map::load_from_cache,
-                'EventEspresso\core\domain\entities\custom_post_types\CustomTaxonomyDefinitions' => EE_Dependency_Map::load_from_cache,
-            ),
-            'EventEspresso\core\services\loaders\ObjectIdentifier'                                                        => array(
-                'EventEspresso\core\services\loaders\ClassInterfaceCache' => EE_Dependency_Map::load_from_cache,
-            ),
-            'EventEspresso\core\domain\services\assets\CoreAssetManager'                                                  => array(
-                'EventEspresso\core\services\assets\AssetCollection' => EE_Dependency_Map::load_from_cache,
-                'EE_Currency_Config'                                 => EE_Dependency_Map::load_from_cache,
-                'EE_Template_Config'                                 => EE_Dependency_Map::load_from_cache,
-                'EventEspresso\core\domain\Domain'                   => EE_Dependency_Map::load_from_cache,
-                'EventEspresso\core\services\assets\Registry'        => EE_Dependency_Map::load_from_cache,
-            ),
-            'EventEspresso\core\domain\services\admin\privacy\policy\PrivacyPolicy' => array(
-                'EEM_Payment_Method' => EE_Dependency_Map::load_from_cache,
-                'EventEspresso\core\domain\values\session\SessionLifespan' => EE_Dependency_Map::load_from_cache
-            ),
-            'EventEspresso\core\domain\services\admin\privacy\export\ExportAttendee' => array(
-                'EEM_Attendee' => EE_Dependency_Map::load_from_cache,
-            ),
-            'EventEspresso\core\domain\services\admin\privacy\export\ExportAttendeeBillingData' => array(
-                'EEM_Attendee' => EE_Dependency_Map::load_from_cache,
-                'EEM_Payment_Method' => EE_Dependency_Map::load_from_cache
-            ),
-            'EventEspresso\core\domain\services\admin\privacy\export\ExportCheckins' => array(
-                'EEM_Checkin' => EE_Dependency_Map::load_from_cache,
-            ),
-            'EventEspresso\core\domain\services\admin\privacy\export\ExportRegistration' => array(
-                'EEM_Registration' => EE_Dependency_Map::load_from_cache,
-            ),
-            'EventEspresso\core\domain\services\admin\privacy\export\ExportTransaction' => array(
-                'EEM_Transaction' => EE_Dependency_Map::load_from_cache,
-            ),
-            'EventEspresso\core\domain\services\admin\privacy\erasure\EraseAttendeeData' => array(
-                'EEM_Attendee' => EE_Dependency_Map::load_from_cache,
-            ),
-            'EventEspresso\core\domain\services\admin\privacy\erasure\EraseAnswers' => array(
-                'EEM_Answer' => EE_Dependency_Map::load_from_cache,
-                'EEM_Question' => EE_Dependency_Map::load_from_cache,
-            ),
-            'EventEspresso\core\CPTs\CptQueryModifier' => array(
-                null,
-                null,
-                null,
-                'EE_Request_Handler'                          => EE_Dependency_Map::load_from_cache,
-                'EventEspresso\core\services\request\Request' => EE_Dependency_Map::load_from_cache,
-                'EventEspresso\core\services\loaders\Loader'  => EE_Dependency_Map::load_from_cache,
-            ),
-            'EventEspresso\core\domain\services\admin\privacy\forms\PrivacySettingsFormHandler' => array(
-                'EE_Registry' => EE_Dependency_Map::load_from_cache,
-                'EE_Config' => EE_Dependency_Map::load_from_cache
-            ),
-            'EventEspresso\core\services\editor\BlockRegistrationManager'                                                 => array(
-                'EventEspresso\core\services\assets\BlockAssetManagerCollection' => EE_Dependency_Map::load_from_cache,
-                'EventEspresso\core\domain\entities\editor\BlockCollection'      => EE_Dependency_Map::load_from_cache,
-                'EventEspresso\core\services\route_match\RouteMatchSpecificationManager' => EE_Dependency_Map::load_from_cache,
-                'EventEspresso\core\services\request\Request'                    => EE_Dependency_Map::load_from_cache,
-            ),
-            'EventEspresso\core\domain\entities\editor\CoreBlocksAssetManager' => array(
-                'EventEspresso\core\domain\Domain'                   => EE_Dependency_Map::load_from_cache,
-                'EventEspresso\core\services\assets\AssetCollection' => EE_Dependency_Map::load_from_cache,
-                'EventEspresso\core\services\assets\Registry'        => EE_Dependency_Map::load_from_cache,
-            ),
-            'EventEspresso\core\domain\services\blocks\EventAttendeesBlockRenderer' => array(
-                'EventEspresso\core\domain\Domain' => EE_Dependency_Map::load_from_cache,
-                'EEM_Attendee' => EE_Dependency_Map::load_from_cache,
-            ),
-            'EventEspresso\core\domain\entities\editor\blocks\EventAttendees' => array(
-                'EventEspresso\core\domain\entities\editor\CoreBlocksAssetManager' => self::load_from_cache,
-                'EventEspresso\core\services\request\Request' => EE_Dependency_Map::load_from_cache,
-                'EventEspresso\core\domain\services\blocks\EventAttendeesBlockRenderer' => self::load_from_cache,
-            ),
-            'EventEspresso\core\services\route_match\RouteMatchSpecificationDependencyResolver' => array(
-                'EventEspresso\core\services\container\Mirror' => EE_Dependency_Map::load_from_cache,
-                'EventEspresso\core\services\loaders\ClassInterfaceCache' => EE_Dependency_Map::load_from_cache,
-                'EE_Dependency_Map' => EE_Dependency_Map::load_from_cache,
-            ),
-            'EventEspresso\core\services\route_match\RouteMatchSpecificationFactory' => array(
-                'EventEspresso\core\services\route_match\RouteMatchSpecificationDependencyResolver' => EE_Dependency_Map::load_from_cache,
-                'EventEspresso\core\services\loaders\Loader' => EE_Dependency_Map::load_from_cache,
-            ),
-            'EventEspresso\core\services\route_match\RouteMatchSpecificationManager' => array(
-                'EventEspresso\core\services\route_match\RouteMatchSpecificationCollection' => EE_Dependency_Map::load_from_cache,
-                'EventEspresso\core\services\route_match\RouteMatchSpecificationFactory' => EE_Dependency_Map::load_from_cache,
-            ),
-            'EventEspresso\core\libraries\rest_api\CalculatedModelFields' => array(
-                'EventEspresso\core\libraries\rest_api\calculations\CalculatedModelFieldsFactory' => EE_Dependency_Map::load_from_cache
-            ),
-            'EventEspresso\core\libraries\rest_api\calculations\CalculatedModelFieldsFactory' => array(
-                'EventEspresso\core\services\loaders\Loader'  => EE_Dependency_Map::load_from_cache,
-            ),
-            'EventEspresso\core\libraries\rest_api\controllers\model\Read' => array(
-                'EventEspresso\core\libraries\rest_api\CalculatedModelFields' => EE_Dependency_Map::load_from_cache
-            ),
-            'EventEspresso\core\libraries\rest_api\calculations\Datetime' => array(
-                'EEM_Datetime' => EE_Dependency_Map::load_from_cache,
-                'EEM_Registration' => EE_Dependency_Map::load_from_cache
-            ),
-            'EventEspresso\core\libraries\rest_api\calculations\Event' => array(
-                'EEM_Event' => EE_Dependency_Map::load_from_cache,
-                'EEM_Registration' => EE_Dependency_Map::load_from_cache
-            ),
-            'EventEspresso\core\libraries\rest_api\calculations\Registration' => array(
-                'EEM_Registration' => EE_Dependency_Map::load_from_cache
-            ),
-            'EventEspresso\core\services\session\SessionStartHandler' => array(
-                'EventEspresso\core\services\request\Request' => EE_Dependency_Map::load_from_cache,
-            ),
-            'EE_URL_Validation_Strategy' => array(
-                null,
-                null,
-                'EventEspresso\core\services\validators\URLValidator' => EE_Dependency_Map::load_from_cache
-            ),
-            'EventEspresso\admin_pages\general_settings\OrganizationSettings' => array(
-                'EE_Registry'                                             => EE_Dependency_Map::load_from_cache,
-                'EE_Organization_Config'                                  => EE_Dependency_Map::load_from_cache,
-                'EE_Core_Config'                                          => EE_Dependency_Map::load_from_cache,
-                'EE_Network_Core_Config'                                  => EE_Dependency_Map::load_from_cache,
-                'EventEspresso\core\services\address\CountrySubRegionDao' => EE_Dependency_Map::load_from_cache,
-            ),
-            'EventEspresso\core\services\address\CountrySubRegionDao' => array(
-                'EEM_State'                                            => EE_Dependency_Map::load_from_cache,
-                'EventEspresso\core\services\validators\JsonValidator' => EE_Dependency_Map::load_from_cache
-            ),
-            'EventEspresso\core\domain\services\admin\ajax\WordpressHeartbeat' => array(
-                'EventEspresso\core\services\loaders\Loader'  => EE_Dependency_Map::load_from_cache,
-                'EventEspresso\core\services\request\Request' => EE_Dependency_Map::load_from_cache,
-            ),
-            'EventEspresso\core\domain\services\admin\ajax\EventEditorHeartbeat' => array(
-                'EventEspresso\core\domain\Domain' => EE_Dependency_Map::load_from_cache,
-                'EE_Environment_Config'            => EE_Dependency_Map::load_from_cache,
-            ),
-            'EventEspresso\core\services\request\files\FilesDataHandler' => array(
-                'EventEspresso\core\services\request\Request' => EE_Dependency_Map::load_from_cache,
-            ),
-            'EventEspressoBatchRequest\BatchRequestProcessor' => [
-                'EventEspresso\core\services\loaders\Loader'  => EE_Dependency_Map::load_from_cache,
-            ]
-        );
-    }
-
-
-    /**
-     * Registers how core classes are loaded.
-     * This can either be done by simply providing the name of one of the EE_Registry loader methods such as:
-     *        'EE_Request_Handler' => 'load_core'
-     *        'EE_Messages_Queue'  => 'load_lib'
-     *        'EEH_Debug_Tools'    => 'load_helper'
-     * or, if greater control is required, by providing a custom closure. For example:
-     *        'Some_Class' => function () {
-     *            return new Some_Class();
-     *        },
-     * This is required for instantiating dependencies
-     * where an interface has been type hinted in a class constructor. For example:
-     *        'Required_Interface' => function () {
-     *            return new A_Class_That_Implements_Required_Interface();
-     *        },
-     */
-    protected function _register_core_class_loaders()
-    {
-        $this->_class_loaders = array(
-            // load_core
-            'EE_Dependency_Map'                            => function () {
-                return $this;
-            },
-            'EE_Capabilities'                              => 'load_core',
-            'EE_Encryption'                                => 'load_core',
-            'EE_Front_Controller'                          => 'load_core',
-            'EE_Module_Request_Router'                     => 'load_core',
-            'EE_Registry'                                  => 'load_core',
-            'EE_Request'                                   => function () {
-                return $this->legacy_request;
-            },
-            'EventEspresso\core\services\request\Request'  => function () {
-                return $this->request;
-            },
-            'EventEspresso\core\services\request\Response' => function () {
-                return $this->response;
-            },
-            'EE_Base'                                      => 'load_core',
-            'EE_Request_Handler'                           => 'load_core',
-            'EE_Session'                                   => 'load_core',
-            'EE_Cron_Tasks'                                => 'load_core',
-            'EE_System'                                    => 'load_core',
-            'EE_Maintenance_Mode'                          => 'load_core',
-            'EE_Register_CPTs'                             => 'load_core',
-            'EE_Admin'                                     => 'load_core',
-            'EE_CPT_Strategy'                              => 'load_core',
-            // load_class
-            'EE_Registration_Processor'                    => 'load_class',
-            // load_lib
-            'EE_Message_Resource_Manager'                  => 'load_lib',
-            'EE_Message_Type_Collection'                   => 'load_lib',
-            'EE_Message_Type_Collection_Loader'            => 'load_lib',
-            'EE_Messenger_Collection'                      => 'load_lib',
-            'EE_Messenger_Collection_Loader'               => 'load_lib',
-            'EE_Messages_Processor'                        => 'load_lib',
-            'EE_Message_Repository'                        => 'load_lib',
-            'EE_Messages_Queue'                            => 'load_lib',
-            'EE_Messages_Data_Handler_Collection'          => 'load_lib',
-            'EE_Message_Template_Group_Collection'         => 'load_lib',
-            'EE_Payment_Method_Manager'                    => 'load_lib',
-            'EE_DMS_Core_4_1_0'                            => 'load_dms',
-            'EE_DMS_Core_4_2_0'                            => 'load_dms',
-            'EE_DMS_Core_4_3_0'                            => 'load_dms',
-            'EE_DMS_Core_4_5_0'                            => 'load_dms',
-            'EE_DMS_Core_4_6_0'                            => 'load_dms',
-            'EE_DMS_Core_4_7_0'                            => 'load_dms',
-            'EE_DMS_Core_4_8_0'                            => 'load_dms',
-            'EE_DMS_Core_4_9_0'                            => 'load_dms',
-            'EE_DMS_Core_4_10_0'                            => 'load_dms',
-            'EE_Messages_Generator'                        => function () {
-                return EE_Registry::instance()->load_lib(
-                    'Messages_Generator',
-                    array(),
-                    false,
-                    false
-                );
-            },
-            'EE_Messages_Template_Defaults'                => function ($arguments = array()) {
-                return EE_Registry::instance()->load_lib(
-                    'Messages_Template_Defaults',
-                    $arguments,
-                    false,
-                    false
-                );
-            },
-            // load_helper
-            'EEH_Parse_Shortcodes'                         => function () {
-                if (EE_Registry::instance()->load_helper('Parse_Shortcodes')) {
-                    return new EEH_Parse_Shortcodes();
-                }
-                return null;
-            },
-            'EE_Template_Config'                           => function () {
-                return EE_Config::instance()->template_settings;
-            },
-            'EE_Currency_Config'                           => function () {
-                return EE_Config::instance()->currency;
-            },
-            'EE_Registration_Config'                       => function () {
-                return EE_Config::instance()->registration;
-            },
-            'EE_Core_Config'                               => function () {
-                return EE_Config::instance()->core;
-            },
-            'EventEspresso\core\services\loaders\Loader'   => function () {
-                return LoaderFactory::getLoader();
-            },
-            'EE_Network_Config'                            => function () {
-                return EE_Network_Config::instance();
-            },
-            'EE_Config'                                    => function () {
-                return EE_Config::instance();
-            },
-            'EventEspresso\core\domain\Domain'             => function () {
-                return DomainFactory::getEventEspressoCoreDomain();
-            },
-            'EE_Admin_Config'                              => function () {
-                return EE_Config::instance()->admin;
-            },
-            'EE_Organization_Config'                       => function () {
-                return EE_Config::instance()->organization;
-            },
-            'EE_Network_Core_Config'                       => function () {
-                return EE_Network_Config::instance()->core;
-            },
-            'EE_Environment_Config'                        => function () {
-                return EE_Config::instance()->environment;
-            },
-        );
-    }
-
-
-    /**
-     * can be used for supplying alternate names for classes,
-     * or for connecting interface names to instantiable classes
-     */
-    protected function _register_core_aliases()
-    {
-        $aliases = array(
-            'CommandBusInterface'                                                          => 'EventEspresso\core\services\commands\CommandBusInterface',
-            'EventEspresso\core\services\commands\CommandBusInterface'                     => 'EventEspresso\core\services\commands\CommandBus',
-            'CommandHandlerManagerInterface'                                               => 'EventEspresso\core\services\commands\CommandHandlerManagerInterface',
-            'EventEspresso\core\services\commands\CommandHandlerManagerInterface'          => 'EventEspresso\core\services\commands\CommandHandlerManager',
-            'CapChecker'                                                                   => 'EventEspresso\core\services\commands\middleware\CapChecker',
-            'AddActionHook'                                                                => 'EventEspresso\core\services\commands\middleware\AddActionHook',
-            'CapabilitiesChecker'                                                          => 'EventEspresso\core\domain\services\capabilities\CapabilitiesChecker',
-            'CapabilitiesCheckerInterface'                                                 => 'EventEspresso\core\domain\services\capabilities\CapabilitiesCheckerInterface',
-            'EventEspresso\core\domain\services\capabilities\CapabilitiesCheckerInterface' => 'EventEspresso\core\domain\services\capabilities\CapabilitiesChecker',
-            'CreateRegistrationService'                                                    => 'EventEspresso\core\domain\services\registration\CreateRegistrationService',
-            'CreateRegistrationCommandHandler'                                             => 'EventEspresso\core\services\commands\registration\CreateRegistrationCommand',
-            'CopyRegistrationDetailsCommandHandler'                                        => 'EventEspresso\core\services\commands\registration\CopyRegistrationDetailsCommand',
-            'CopyRegistrationPaymentsCommandHandler'                                       => 'EventEspresso\core\services\commands\registration\CopyRegistrationPaymentsCommand',
-            'CancelRegistrationAndTicketLineItemCommandHandler'                            => 'EventEspresso\core\services\commands\registration\CancelRegistrationAndTicketLineItemCommandHandler',
-            'UpdateRegistrationAndTransactionAfterChangeCommandHandler'                    => 'EventEspresso\core\services\commands\registration\UpdateRegistrationAndTransactionAfterChangeCommandHandler',
-            'CreateTicketLineItemCommandHandler'                                           => 'EventEspresso\core\services\commands\ticket\CreateTicketLineItemCommand',
-            'CreateTransactionCommandHandler'                                              => 'EventEspresso\core\services\commands\transaction\CreateTransactionCommandHandler',
-            'CreateAttendeeCommandHandler'                                                 => 'EventEspresso\core\services\commands\attendee\CreateAttendeeCommandHandler',
-            'TableManager'                                                                 => 'EventEspresso\core\services\database\TableManager',
-            'TableAnalysis'                                                                => 'EventEspresso\core\services\database\TableAnalysis',
-            'EspressoShortcode'                                                            => 'EventEspresso\core\services\shortcodes\EspressoShortcode',
-            'ShortcodeInterface'                                                           => 'EventEspresso\core\services\shortcodes\ShortcodeInterface',
-            'EventEspresso\core\services\shortcodes\ShortcodeInterface'                    => 'EventEspresso\core\services\shortcodes\EspressoShortcode',
-            'EventEspresso\core\services\cache\CacheStorageInterface'                      => 'EventEspresso\core\services\cache\TransientCacheStorage',
-            'LoaderInterface'                                                              => 'EventEspresso\core\services\loaders\LoaderInterface',
-            'EventEspresso\core\services\loaders\LoaderInterface'                          => 'EventEspresso\core\services\loaders\Loader',
-            'CommandFactoryInterface'                                                      => 'EventEspresso\core\services\commands\CommandFactoryInterface',
-            'EventEspresso\core\services\commands\CommandFactoryInterface'                 => 'EventEspresso\core\services\commands\CommandFactory',
-            'EmailValidatorInterface'                                                      => 'EventEspresso\core\domain\services\validation\email\EmailValidatorInterface',
-            'EventEspresso\core\domain\services\validation\email\EmailValidatorInterface'  => 'EventEspresso\core\domain\services\validation\email\EmailValidationService',
-            'NoticeConverterInterface'                                                     => 'EventEspresso\core\services\notices\NoticeConverterInterface',
-            'EventEspresso\core\services\notices\NoticeConverterInterface'                 => 'EventEspresso\core\services\notices\ConvertNoticesToEeErrors',
-            'NoticesContainerInterface'                                                    => 'EventEspresso\core\services\notices\NoticesContainerInterface',
-            'EventEspresso\core\services\notices\NoticesContainerInterface'                => 'EventEspresso\core\services\notices\NoticesContainer',
-            'EventEspresso\core\services\request\RequestInterface'                         => 'EventEspresso\core\services\request\Request',
-            'EventEspresso\core\services\request\ResponseInterface'                        => 'EventEspresso\core\services\request\Response',
-            'EventEspresso\core\domain\DomainInterface'                                    => 'EventEspresso\core\domain\Domain',
-            'Registration_Processor'                                                       => 'EE_Registration_Processor',
-        );
-        foreach ($aliases as $alias => $fqn) {
-            if (is_array($fqn)) {
-                foreach ($fqn as $class => $for_class) {
-                    $this->class_cache->addAlias($class, $alias, $for_class);
-                }
-                continue;
-            }
-            $this->class_cache->addAlias($fqn, $alias);
-        }
-        if (! (defined('DOING_AJAX') && DOING_AJAX) && is_admin()) {
-            $this->class_cache->addAlias(
-                'EventEspresso\core\services\notices\ConvertNoticesToAdminNotices',
-                'EventEspresso\core\services\notices\NoticeConverterInterface'
-            );
-        }
-    }
-
-
-    /**
-     * This is used to reset the internal map and class_loaders to their original default state at the beginning of the
-     * request Primarily used by unit tests.
-     */
-    public function reset()
-    {
-        $this->_register_core_class_loaders();
-        $this->_register_core_dependencies();
-    }
-
-
-    /**
-     * PLZ NOTE: a better name for this method would be is_alias()
-     * because it returns TRUE if the provided fully qualified name IS an alias
-     * WHY?
-     * Because if a class is type hinting for a concretion,
-     * then why would we need to find another class to supply it?
-     * ie: if a class asks for `Fully/Qualified/Namespace/SpecificClassName`,
-     * then give it an instance of `Fully/Qualified/Namespace/SpecificClassName`.
-     * Don't go looking for some substitute.
-     * Whereas if a class is type hinting for an interface...
-     * then we need to find an actual class to use.
-     * So the interface IS the alias for some other FQN,
-     * and we need to find out if `Fully/Qualified/Namespace/SomeInterface`
-     * represents some other class.
-     *
-     * @deprecated 4.9.62.p
-     * @param string $fqn
-     * @param string $for_class
-     * @return bool
-     */
-    public function has_alias($fqn = '', $for_class = '')
-    {
-        return $this->isAlias($fqn, $for_class);
-    }
-
-
-    /**
-     * PLZ NOTE: a better name for this method would be get_fqn_for_alias()
-     * because it returns a FQN for provided alias if one exists, otherwise returns the original $alias
-     * functions recursively, so that multiple aliases can be used to drill down to a FQN
-     *  for example:
-     *      if the following two entries were added to the _aliases array:
-     *          array(
-     *              'interface_alias'           => 'some\namespace\interface'
-     *              'some\namespace\interface'  => 'some\namespace\classname'
-     *          )
-     *      then one could use EE_Registry::instance()->create( 'interface_alias' )
-     *      to load an instance of 'some\namespace\classname'
-     *
-     * @deprecated 4.9.62.p
-     * @param string $alias
-     * @param string $for_class
-     * @return string
-     */
-    public function get_alias($alias = '', $for_class = '')
-    {
-        return $this->getFqnForAlias($alias, $for_class);
-    }
+	/**
+	 * This means that the requested class dependency is not present in the dependency map
+	 */
+	const not_registered = 0;
+
+	/**
+	 * This instructs class loaders to ALWAYS return a newly instantiated object for the requested class.
+	 */
+	const load_new_object = 1;
+
+	/**
+	 * This instructs class loaders to return a previously instantiated and cached object for the requested class.
+	 * IF a previously instantiated object does not exist, a new one will be created and added to the cache.
+	 */
+	const load_from_cache = 2;
+
+	/**
+	 * When registering a dependency,
+	 * this indicates to keep any existing dependencies that already exist,
+	 * and simply discard any new dependencies declared in the incoming data
+	 */
+	const KEEP_EXISTING_DEPENDENCIES = 0;
+
+	/**
+	 * When registering a dependency,
+	 * this indicates to overwrite any existing dependencies that already exist using the incoming data
+	 */
+	const OVERWRITE_DEPENDENCIES = 1;
+
+
+	/**
+	 * @type EE_Dependency_Map $_instance
+	 */
+	protected static $_instance;
+
+	/**
+	 * @var ClassInterfaceCache $class_cache
+	 */
+	private $class_cache;
+
+	/**
+	 * @type RequestInterface $request
+	 */
+	protected $request;
+
+	/**
+	 * @type LegacyRequestInterface $legacy_request
+	 */
+	protected $legacy_request;
+
+	/**
+	 * @type ResponseInterface $response
+	 */
+	protected $response;
+
+	/**
+	 * @type LoaderInterface $loader
+	 */
+	protected $loader;
+
+	/**
+	 * @type array $_dependency_map
+	 */
+	protected $_dependency_map = array();
+
+	/**
+	 * @type array $_class_loaders
+	 */
+	protected $_class_loaders = array();
+
+
+	/**
+	 * EE_Dependency_Map constructor.
+	 *
+	 * @param ClassInterfaceCache $class_cache
+	 */
+	protected function __construct(ClassInterfaceCache $class_cache)
+	{
+		$this->class_cache = $class_cache;
+		do_action('EE_Dependency_Map____construct', $this);
+	}
+
+
+	/**
+	 * @return void
+	 */
+	public function initialize()
+	{
+		$this->_register_core_dependencies();
+		$this->_register_core_class_loaders();
+		$this->_register_core_aliases();
+	}
+
+
+	/**
+	 * @singleton method used to instantiate class object
+	 * @param ClassInterfaceCache|null $class_cache
+	 * @return EE_Dependency_Map
+	 */
+	public static function instance(ClassInterfaceCache $class_cache = null)
+	{
+		// check if class object is instantiated, and instantiated properly
+		if (! self::$_instance instanceof EE_Dependency_Map
+			&& $class_cache instanceof ClassInterfaceCache
+		) {
+			self::$_instance = new EE_Dependency_Map($class_cache);
+		}
+		return self::$_instance;
+	}
+
+
+	/**
+	 * @param RequestInterface $request
+	 */
+	public function setRequest(RequestInterface $request)
+	{
+		$this->request = $request;
+	}
+
+
+	/**
+	 * @param LegacyRequestInterface $legacy_request
+	 */
+	public function setLegacyRequest(LegacyRequestInterface $legacy_request)
+	{
+		$this->legacy_request = $legacy_request;
+	}
+
+
+	/**
+	 * @param ResponseInterface $response
+	 */
+	public function setResponse(ResponseInterface $response)
+	{
+		$this->response = $response;
+	}
+
+
+	/**
+	 * @param LoaderInterface $loader
+	 */
+	public function setLoader(LoaderInterface $loader)
+	{
+		$this->loader = $loader;
+	}
+
+
+	/**
+	 * @param string $class
+	 * @param array  $dependencies
+	 * @param int    $overwrite
+	 * @return bool
+	 */
+	public static function register_dependencies(
+		$class,
+		array $dependencies,
+		$overwrite = EE_Dependency_Map::KEEP_EXISTING_DEPENDENCIES
+	) {
+		return self::$_instance->registerDependencies($class, $dependencies, $overwrite);
+	}
+
+
+	/**
+	 * Assigns an array of class names and corresponding load sources (new or cached)
+	 * to the class specified by the first parameter.
+	 * IMPORTANT !!!
+	 * The order of elements in the incoming $dependencies array MUST match
+	 * the order of the constructor parameters for the class in question.
+	 * This is especially important when overriding any existing dependencies that are registered.
+	 * the third parameter controls whether any duplicate dependencies are overwritten or not.
+	 *
+	 * @param string $class
+	 * @param array  $dependencies
+	 * @param int    $overwrite
+	 * @return bool
+	 */
+	public function registerDependencies(
+		$class,
+		array $dependencies,
+		$overwrite = EE_Dependency_Map::KEEP_EXISTING_DEPENDENCIES
+	) {
+		$class = trim($class, '\\');
+		$registered = false;
+		if (empty(self::$_instance->_dependency_map[ $class ])) {
+			self::$_instance->_dependency_map[ $class ] = array();
+		}
+		// we need to make sure that any aliases used when registering a dependency
+		// get resolved to the correct class name
+		foreach ($dependencies as $dependency => $load_source) {
+			$alias = self::$_instance->getFqnForAlias($dependency);
+			if ($overwrite === EE_Dependency_Map::OVERWRITE_DEPENDENCIES
+				|| ! isset(self::$_instance->_dependency_map[ $class ][ $alias ])
+			) {
+				unset($dependencies[ $dependency ]);
+				$dependencies[ $alias ] = $load_source;
+				$registered = true;
+			}
+		}
+		// now add our two lists of dependencies together.
+		// using Union (+=) favours the arrays in precedence from left to right,
+		// so $dependencies is NOT overwritten because it is listed first
+		// ie: with A = B + C, entries in B take precedence over duplicate entries in C
+		// Union is way faster than array_merge() but should be used with caution...
+		// especially with numerically indexed arrays
+		$dependencies += self::$_instance->_dependency_map[ $class ];
+		// now we need to ensure that the resulting dependencies
+		// array only has the entries that are required for the class
+		// so first count how many dependencies were originally registered for the class
+		$dependency_count = count(self::$_instance->_dependency_map[ $class ]);
+		// if that count is non-zero (meaning dependencies were already registered)
+		self::$_instance->_dependency_map[ $class ] = $dependency_count
+			// then truncate the  final array to match that count
+			? array_slice($dependencies, 0, $dependency_count)
+			// otherwise just take the incoming array because nothing previously existed
+			: $dependencies;
+		return $registered;
+	}
+
+
+	/**
+	 * @param string $class_name
+	 * @param string $loader
+	 * @return bool
+	 * @throws DomainException
+	 */
+	public static function register_class_loader($class_name, $loader = 'load_core')
+	{
+		if (! $loader instanceof Closure && strpos($class_name, '\\') !== false) {
+			throw new DomainException(
+				esc_html__('Don\'t use class loaders for FQCNs.', 'event_espresso')
+			);
+		}
+		// check that loader is callable or method starts with "load_" and exists in EE_Registry
+		if (! is_callable($loader)
+			&& (
+				strpos($loader, 'load_') !== 0
+				|| ! method_exists('EE_Registry', $loader)
+			)
+		) {
+			throw new DomainException(
+				sprintf(
+					esc_html__(
+						'"%1$s" is not a valid loader method on EE_Registry.',
+						'event_espresso'
+					),
+					$loader
+				)
+			);
+		}
+		$class_name = self::$_instance->getFqnForAlias($class_name);
+		if (! isset(self::$_instance->_class_loaders[ $class_name ])) {
+			self::$_instance->_class_loaders[ $class_name ] = $loader;
+			return true;
+		}
+		return false;
+	}
+
+
+	/**
+	 * @return array
+	 */
+	public function dependency_map()
+	{
+		return $this->_dependency_map;
+	}
+
+
+	/**
+	 * returns TRUE if dependency map contains a listing for the provided class name
+	 *
+	 * @param string $class_name
+	 * @return boolean
+	 */
+	public function has($class_name = '')
+	{
+		// all legacy models have the same dependencies
+		if (strpos($class_name, 'EEM_') === 0) {
+			$class_name = 'LEGACY_MODELS';
+		}
+		return isset($this->_dependency_map[ $class_name ]) ? true : false;
+	}
+
+
+	/**
+	 * returns TRUE if dependency map contains a listing for the provided class name AND dependency
+	 *
+	 * @param string $class_name
+	 * @param string $dependency
+	 * @return bool
+	 */
+	public function has_dependency_for_class($class_name = '', $dependency = '')
+	{
+		// all legacy models have the same dependencies
+		if (strpos($class_name, 'EEM_') === 0) {
+			$class_name = 'LEGACY_MODELS';
+		}
+		$dependency = $this->getFqnForAlias($dependency, $class_name);
+		return isset($this->_dependency_map[ $class_name ][ $dependency ])
+			? true
+			: false;
+	}
+
+
+	/**
+	 * returns loading strategy for whether a previously cached dependency should be loaded or a new instance returned
+	 *
+	 * @param string $class_name
+	 * @param string $dependency
+	 * @return int
+	 */
+	public function loading_strategy_for_class_dependency($class_name = '', $dependency = '')
+	{
+		// all legacy models have the same dependencies
+		if (strpos($class_name, 'EEM_') === 0) {
+			$class_name = 'LEGACY_MODELS';
+		}
+		$dependency = $this->getFqnForAlias($dependency);
+		return $this->has_dependency_for_class($class_name, $dependency)
+			? $this->_dependency_map[ $class_name ][ $dependency ]
+			: EE_Dependency_Map::not_registered;
+	}
+
+
+	/**
+	 * @param string $class_name
+	 * @return string | Closure
+	 */
+	public function class_loader($class_name)
+	{
+		// all legacy models use load_model()
+		if (strpos($class_name, 'EEM_') === 0) {
+			return 'load_model';
+		}
+		// EE_CPT_*_Strategy classes like EE_CPT_Event_Strategy, EE_CPT_Venue_Strategy, etc
+		// perform strpos() first to avoid loading regex every time we load a class
+		if (strpos($class_name, 'EE_CPT_') === 0
+			&& preg_match('/^EE_CPT_([a-zA-Z]+)_Strategy$/', $class_name)
+		) {
+			return 'load_core';
+		}
+		$class_name = $this->getFqnForAlias($class_name);
+		return isset($this->_class_loaders[ $class_name ]) ? $this->_class_loaders[ $class_name ] : '';
+	}
+
+
+	/**
+	 * @return array
+	 */
+	public function class_loaders()
+	{
+		return $this->_class_loaders;
+	}
+
+
+	/**
+	 * adds an alias for a classname
+	 *
+	 * @param string $fqcn      the class name that should be used (concrete class to replace interface)
+	 * @param string $alias     the class name that would be type hinted for (abstract parent or interface)
+	 * @param string $for_class the class that has the dependency (is type hinting for the interface)
+	 */
+	public function add_alias($fqcn, $alias, $for_class = '')
+	{
+		$this->class_cache->addAlias($fqcn, $alias, $for_class);
+	}
+
+
+	/**
+	 * Returns TRUE if the provided fully qualified name IS an alias
+	 * WHY?
+	 * Because if a class is type hinting for a concretion,
+	 * then why would we need to find another class to supply it?
+	 * ie: if a class asks for `Fully/Qualified/Namespace/SpecificClassName`,
+	 * then give it an instance of `Fully/Qualified/Namespace/SpecificClassName`.
+	 * Don't go looking for some substitute.
+	 * Whereas if a class is type hinting for an interface...
+	 * then we need to find an actual class to use.
+	 * So the interface IS the alias for some other FQN,
+	 * and we need to find out if `Fully/Qualified/Namespace/SomeInterface`
+	 * represents some other class.
+	 *
+	 * @param string $fqn
+	 * @param string $for_class
+	 * @return bool
+	 */
+	public function isAlias($fqn = '', $for_class = '')
+	{
+		return $this->class_cache->isAlias($fqn, $for_class);
+	}
+
+
+	/**
+	 * Returns a FQN for provided alias if one exists, otherwise returns the original $alias
+	 * functions recursively, so that multiple aliases can be used to drill down to a FQN
+	 *  for example:
+	 *      if the following two entries were added to the _aliases array:
+	 *          array(
+	 *              'interface_alias'           => 'some\namespace\interface'
+	 *              'some\namespace\interface'  => 'some\namespace\classname'
+	 *          )
+	 *      then one could use EE_Registry::instance()->create( 'interface_alias' )
+	 *      to load an instance of 'some\namespace\classname'
+	 *
+	 * @param string $alias
+	 * @param string $for_class
+	 * @return string
+	 */
+	public function getFqnForAlias($alias = '', $for_class = '')
+	{
+		return (string) $this->class_cache->getFqnForAlias($alias, $for_class);
+	}
+
+
+	/**
+	 * Registers the core dependencies and whether a previously instantiated object should be loaded from the cache,
+	 * if one exists, or whether a new object should be generated every time the requested class is loaded.
+	 * This is done by using the following class constants:
+	 *        EE_Dependency_Map::load_from_cache - loads previously instantiated object
+	 *        EE_Dependency_Map::load_new_object - generates a new object every time
+	 */
+	protected function _register_core_dependencies()
+	{
+		$this->_dependency_map = array(
+			'EE_Request_Handler'                                                                                          => array(
+				'EE_Request' => EE_Dependency_Map::load_from_cache,
+			),
+			'EE_System'                                                                                                   => array(
+				'EE_Registry'                                 => EE_Dependency_Map::load_from_cache,
+				'EventEspresso\core\services\loaders\Loader'  => EE_Dependency_Map::load_from_cache,
+				'EventEspresso\core\services\request\Request' => EE_Dependency_Map::load_from_cache,
+				'EE_Maintenance_Mode'                         => EE_Dependency_Map::load_from_cache,
+			),
+			'EE_Session'                                                                                                  => array(
+				'EventEspresso\core\services\cache\TransientCacheStorage'  => EE_Dependency_Map::load_from_cache,
+				'EventEspresso\core\domain\values\session\SessionLifespan' => EE_Dependency_Map::load_from_cache,
+				'EventEspresso\core\services\request\Request'              => EE_Dependency_Map::load_from_cache,
+				'EventEspresso\core\services\session\SessionStartHandler'  => EE_Dependency_Map::load_from_cache,
+				'EE_Encryption'                                            => EE_Dependency_Map::load_from_cache,
+			),
+			'EE_Cart'                                                                                                     => array(
+				'EE_Session' => EE_Dependency_Map::load_from_cache,
+			),
+			'EE_Front_Controller'                                                                                         => array(
+				'EE_Registry'              => EE_Dependency_Map::load_from_cache,
+				'EE_Request_Handler'       => EE_Dependency_Map::load_from_cache,
+				'EE_Module_Request_Router' => EE_Dependency_Map::load_from_cache,
+			),
+			'EE_Messenger_Collection_Loader'                                                                              => array(
+				'EE_Messenger_Collection' => EE_Dependency_Map::load_new_object,
+			),
+			'EE_Message_Type_Collection_Loader'                                                                           => array(
+				'EE_Message_Type_Collection' => EE_Dependency_Map::load_new_object,
+			),
+			'EE_Message_Resource_Manager'                                                                                 => array(
+				'EE_Messenger_Collection_Loader'    => EE_Dependency_Map::load_new_object,
+				'EE_Message_Type_Collection_Loader' => EE_Dependency_Map::load_new_object,
+				'EEM_Message_Template_Group'        => EE_Dependency_Map::load_from_cache,
+			),
+			'EE_Message_Factory'                                                                                          => array(
+				'EE_Message_Resource_Manager' => EE_Dependency_Map::load_from_cache,
+			),
+			'EE_messages'                                                                                                 => array(
+				'EE_Message_Resource_Manager' => EE_Dependency_Map::load_from_cache,
+			),
+			'EE_Messages_Generator'                                                                                       => array(
+				'EE_Messages_Queue'                    => EE_Dependency_Map::load_new_object,
+				'EE_Messages_Data_Handler_Collection'  => EE_Dependency_Map::load_new_object,
+				'EE_Message_Template_Group_Collection' => EE_Dependency_Map::load_new_object,
+				'EEH_Parse_Shortcodes'                 => EE_Dependency_Map::load_from_cache,
+			),
+			'EE_Messages_Processor'                                                                                       => array(
+				'EE_Message_Resource_Manager' => EE_Dependency_Map::load_from_cache,
+			),
+			'EE_Messages_Queue'                                                                                           => array(
+				'EE_Message_Repository' => EE_Dependency_Map::load_new_object,
+			),
+			'EE_Messages_Template_Defaults'                                                                               => array(
+				'EEM_Message_Template_Group' => EE_Dependency_Map::load_from_cache,
+				'EEM_Message_Template'       => EE_Dependency_Map::load_from_cache,
+			),
+			'EE_Message_To_Generate_From_Request'                                                                         => array(
+				'EE_Message_Resource_Manager' => EE_Dependency_Map::load_from_cache,
+				'EE_Request_Handler'          => EE_Dependency_Map::load_from_cache,
+			),
+			'EventEspresso\core\services\commands\CommandBus'                                                             => array(
+				'EventEspresso\core\services\commands\CommandHandlerManager' => EE_Dependency_Map::load_from_cache,
+			),
+			'EventEspresso\services\commands\CommandHandler'                                                              => array(
+				'EE_Registry'         => EE_Dependency_Map::load_from_cache,
+				'CommandBusInterface' => EE_Dependency_Map::load_from_cache,
+			),
+			'EventEspresso\core\services\commands\CommandHandlerManager'                                                  => array(
+				'EventEspresso\core\services\loaders\Loader' => EE_Dependency_Map::load_from_cache,
+			),
+			'EventEspresso\core\services\commands\CompositeCommandHandler'                                                => array(
+				'EventEspresso\core\services\commands\CommandBus'     => EE_Dependency_Map::load_from_cache,
+				'EventEspresso\core\services\commands\CommandFactory' => EE_Dependency_Map::load_from_cache,
+			),
+			'EventEspresso\core\services\commands\CommandFactory'                                                         => array(
+				'EventEspresso\core\services\loaders\Loader' => EE_Dependency_Map::load_from_cache,
+			),
+			'EventEspresso\core\services\commands\middleware\CapChecker'                                                  => array(
+				'EventEspresso\core\domain\services\capabilities\CapabilitiesChecker' => EE_Dependency_Map::load_from_cache,
+			),
+			'EventEspresso\core\domain\services\capabilities\CapabilitiesChecker'                                         => array(
+				'EE_Capabilities' => EE_Dependency_Map::load_from_cache,
+			),
+			'EventEspresso\core\domain\services\capabilities\RegistrationsCapChecker'                                     => array(
+				'EE_Capabilities' => EE_Dependency_Map::load_from_cache,
+			),
+			'EventEspresso\core\services\commands\registration\CreateRegistrationCommandHandler'                          => array(
+				'EventEspresso\core\domain\services\registration\CreateRegistrationService' => EE_Dependency_Map::load_from_cache,
+			),
+			'EventEspresso\core\services\commands\registration\CopyRegistrationDetailsCommandHandler'                     => array(
+				'EventEspresso\core\domain\services\registration\CopyRegistrationService' => EE_Dependency_Map::load_from_cache,
+			),
+			'EventEspresso\core\services\commands\registration\CopyRegistrationPaymentsCommandHandler'                    => array(
+				'EventEspresso\core\domain\services\registration\CopyRegistrationService' => EE_Dependency_Map::load_from_cache,
+			),
+			'EventEspresso\core\services\commands\registration\CancelRegistrationAndTicketLineItemCommandHandler'         => array(
+				'EventEspresso\core\domain\services\registration\CancelTicketLineItemService' => EE_Dependency_Map::load_from_cache,
+			),
+			'EventEspresso\core\services\commands\registration\UpdateRegistrationAndTransactionAfterChangeCommandHandler' => array(
+				'EventEspresso\core\domain\services\registration\UpdateRegistrationService' => EE_Dependency_Map::load_from_cache,
+			),
+			'EventEspresso\core\services\commands\ticket\CreateTicketLineItemCommandHandler'                              => array(
+				'EventEspresso\core\domain\services\ticket\CreateTicketLineItemService' => EE_Dependency_Map::load_from_cache,
+			),
+			'EventEspresso\core\services\commands\ticket\CancelTicketLineItemCommandHandler'                              => array(
+				'EventEspresso\core\domain\services\ticket\CancelTicketLineItemService' => EE_Dependency_Map::load_from_cache,
+			),
+			'EventEspresso\core\domain\services\registration\CancelRegistrationService'                                   => array(
+				'EventEspresso\core\domain\services\ticket\CancelTicketLineItemService' => EE_Dependency_Map::load_from_cache,
+			),
+			'EventEspresso\core\services\commands\attendee\CreateAttendeeCommandHandler'                                  => array(
+				'EEM_Attendee' => EE_Dependency_Map::load_from_cache,
+			),
+			'EventEspresso\core\services\database\TableManager'                                                           => array(
+				'EventEspresso\core\services\database\TableAnalysis' => EE_Dependency_Map::load_from_cache,
+			),
+			'EE_Data_Migration_Class_Base'                                                                                => array(
+				'EventEspresso\core\services\database\TableAnalysis' => EE_Dependency_Map::load_from_cache,
+				'EventEspresso\core\services\database\TableManager'  => EE_Dependency_Map::load_from_cache,
+			),
+			'EE_DMS_Core_4_1_0'                                                                                           => array(
+				'EventEspresso\core\services\database\TableAnalysis' => EE_Dependency_Map::load_from_cache,
+				'EventEspresso\core\services\database\TableManager'  => EE_Dependency_Map::load_from_cache,
+			),
+			'EE_DMS_Core_4_2_0'                                                                                           => array(
+				'EventEspresso\core\services\database\TableAnalysis' => EE_Dependency_Map::load_from_cache,
+				'EventEspresso\core\services\database\TableManager'  => EE_Dependency_Map::load_from_cache,
+			),
+			'EE_DMS_Core_4_3_0'                                                                                           => array(
+				'EventEspresso\core\services\database\TableAnalysis' => EE_Dependency_Map::load_from_cache,
+				'EventEspresso\core\services\database\TableManager'  => EE_Dependency_Map::load_from_cache,
+			),
+			'EE_DMS_Core_4_4_0'                                                                                           => array(
+				'EventEspresso\core\services\database\TableAnalysis' => EE_Dependency_Map::load_from_cache,
+				'EventEspresso\core\services\database\TableManager'  => EE_Dependency_Map::load_from_cache,
+			),
+			'EE_DMS_Core_4_5_0'                                                                                           => array(
+				'EventEspresso\core\services\database\TableAnalysis' => EE_Dependency_Map::load_from_cache,
+				'EventEspresso\core\services\database\TableManager'  => EE_Dependency_Map::load_from_cache,
+			),
+			'EE_DMS_Core_4_6_0'                                                                                           => array(
+				'EventEspresso\core\services\database\TableAnalysis' => EE_Dependency_Map::load_from_cache,
+				'EventEspresso\core\services\database\TableManager'  => EE_Dependency_Map::load_from_cache,
+			),
+			'EE_DMS_Core_4_7_0'                                                                                           => array(
+				'EventEspresso\core\services\database\TableAnalysis' => EE_Dependency_Map::load_from_cache,
+				'EventEspresso\core\services\database\TableManager'  => EE_Dependency_Map::load_from_cache,
+			),
+			'EE_DMS_Core_4_8_0'                                                                                           => array(
+				'EventEspresso\core\services\database\TableAnalysis' => EE_Dependency_Map::load_from_cache,
+				'EventEspresso\core\services\database\TableManager'  => EE_Dependency_Map::load_from_cache,
+			),
+			'EE_DMS_Core_4_9_0' => array(
+				'EventEspresso\core\services\database\TableAnalysis' => EE_Dependency_Map::load_from_cache,
+				'EventEspresso\core\services\database\TableManager'  => EE_Dependency_Map::load_from_cache,
+			),
+			'EE_DMS_Core_4_10_0' => array(
+				'EventEspresso\core\services\database\TableAnalysis' => EE_Dependency_Map::load_from_cache,
+				'EventEspresso\core\services\database\TableManager'  => EE_Dependency_Map::load_from_cache,
+				'EE_DMS_Core_4_9_0'                                  => EE_Dependency_Map::load_from_cache,
+			),
+			'EventEspresso\core\services\assets\I18nRegistry'                                                             => array(
+				array(),
+				'EventEspresso\core\domain\Domain' => EE_Dependency_Map::load_from_cache,
+			),
+			'EventEspresso\core\services\assets\Registry'                                                                 => array(
+				'EventEspresso\core\services\assets\AssetCollection' => EE_Dependency_Map::load_from_cache,
+				'EventEspresso\core\services\assets\I18nRegistry'    => EE_Dependency_Map::load_from_cache,
+			),
+			'EventEspresso\core\domain\entities\shortcodes\EspressoCancelled'                                             => array(
+				'EventEspresso\core\services\cache\PostRelatedCacheManager' => EE_Dependency_Map::load_from_cache,
+			),
+			'EventEspresso\core\domain\entities\shortcodes\EspressoCheckout'                                              => array(
+				'EventEspresso\core\services\cache\PostRelatedCacheManager' => EE_Dependency_Map::load_from_cache,
+			),
+			'EventEspresso\core\domain\entities\shortcodes\EspressoEventAttendees'                                        => array(
+				'EventEspresso\core\services\cache\PostRelatedCacheManager' => EE_Dependency_Map::load_from_cache,
+			),
+			'EventEspresso\core\domain\entities\shortcodes\EspressoEvents'                                                => array(
+				'EventEspresso\core\services\cache\PostRelatedCacheManager' => EE_Dependency_Map::load_from_cache,
+			),
+			'EventEspresso\core\domain\entities\shortcodes\EspressoThankYou'                                              => array(
+				'EventEspresso\core\services\cache\PostRelatedCacheManager' => EE_Dependency_Map::load_from_cache,
+			),
+			'EventEspresso\core\domain\entities\shortcodes\EspressoTicketSelector'                                        => array(
+				'EventEspresso\core\services\cache\PostRelatedCacheManager' => EE_Dependency_Map::load_from_cache,
+			),
+			'EventEspresso\core\domain\entities\shortcodes\EspressoTxnPage'                                               => array(
+				'EventEspresso\core\services\cache\PostRelatedCacheManager' => EE_Dependency_Map::load_from_cache,
+			),
+			'EventEspresso\core\services\cache\BasicCacheManager'                                                         => array(
+				'EventEspresso\core\services\cache\TransientCacheStorage' => EE_Dependency_Map::load_from_cache,
+			),
+			'EventEspresso\core\services\cache\PostRelatedCacheManager'                                                   => array(
+				'EventEspresso\core\services\cache\TransientCacheStorage' => EE_Dependency_Map::load_from_cache,
+			),
+			'EventEspresso\core\domain\services\validation\email\EmailValidationService'                                  => array(
+				'EE_Registration_Config'                     => EE_Dependency_Map::load_from_cache,
+				'EventEspresso\core\services\loaders\Loader' => EE_Dependency_Map::load_from_cache,
+			),
+			'EventEspresso\core\domain\values\EmailAddress'                                                               => array(
+				null,
+				'EventEspresso\core\domain\services\validation\email\EmailValidationService' => EE_Dependency_Map::load_from_cache,
+			),
+			'EventEspresso\core\services\orm\ModelFieldFactory'                                                           => array(
+				'EventEspresso\core\services\loaders\Loader' => EE_Dependency_Map::load_from_cache,
+			),
+			'LEGACY_MODELS'                                                                                               => array(
+				null,
+				'EventEspresso\core\services\database\ModelFieldFactory' => EE_Dependency_Map::load_from_cache,
+			),
+			'EE_Module_Request_Router'                                                                                    => array(
+				'EE_Request' => EE_Dependency_Map::load_from_cache,
+			),
+			'EE_Registration_Processor'                                                                                   => array(
+				'EE_Request' => EE_Dependency_Map::load_from_cache,
+			),
+			'EventEspresso\core\services\notifications\PersistentAdminNoticeManager'                                      => array(
+				null,
+				'EventEspresso\core\domain\services\capabilities\CapabilitiesChecker' => EE_Dependency_Map::load_from_cache,
+				'EventEspresso\core\services\request\Request'                         => EE_Dependency_Map::load_from_cache,
+			),
+			'EventEspresso\core\services\licensing\LicenseService'                                                        => array(
+				'EventEspresso\core\domain\services\pue\Stats'  => EE_Dependency_Map::load_from_cache,
+				'EventEspresso\core\domain\services\pue\Config' => EE_Dependency_Map::load_from_cache,
+			),
+			'EE_Admin_Transactions_List_Table'                                                                            => array(
+				null,
+				'EventEspresso\core\domain\values\session\SessionLifespan' => EE_Dependency_Map::load_from_cache,
+			),
+			'EventEspresso\core\domain\services\pue\Stats'                                                                => array(
+				'EventEspresso\core\domain\services\pue\Config'        => EE_Dependency_Map::load_from_cache,
+				'EE_Maintenance_Mode'                                  => EE_Dependency_Map::load_from_cache,
+				'EventEspresso\core\domain\services\pue\StatsGatherer' => EE_Dependency_Map::load_from_cache,
+			),
+			'EventEspresso\core\domain\services\pue\Config'                                                               => array(
+				'EE_Network_Config' => EE_Dependency_Map::load_from_cache,
+				'EE_Config'         => EE_Dependency_Map::load_from_cache,
+			),
+			'EventEspresso\core\domain\services\pue\StatsGatherer'                                                        => array(
+				'EEM_Payment_Method' => EE_Dependency_Map::load_from_cache,
+				'EEM_Event'          => EE_Dependency_Map::load_from_cache,
+				'EEM_Datetime'       => EE_Dependency_Map::load_from_cache,
+				'EEM_Ticket'         => EE_Dependency_Map::load_from_cache,
+				'EEM_Registration'   => EE_Dependency_Map::load_from_cache,
+				'EEM_Transaction'    => EE_Dependency_Map::load_from_cache,
+				'EE_Config'          => EE_Dependency_Map::load_from_cache,
+			),
+			'EventEspresso\core\domain\services\admin\ExitModal'                                                          => array(
+				'EventEspresso\core\services\assets\Registry' => EE_Dependency_Map::load_from_cache,
+			),
+			'EventEspresso\core\domain\services\admin\PluginUpsells'                                                      => array(
+				'EventEspresso\core\domain\Domain' => EE_Dependency_Map::load_from_cache,
+			),
+			'EventEspresso\caffeinated\modules\recaptcha_invisible\InvisibleRecaptcha'                                    => array(
+				'EE_Registration_Config' => EE_Dependency_Map::load_from_cache,
+				'EE_Session'             => EE_Dependency_Map::load_from_cache,
+			),
+			'EventEspresso\caffeinated\modules\recaptcha_invisible\RecaptchaAdminSettings'                                => array(
+				'EE_Registration_Config' => EE_Dependency_Map::load_from_cache,
+			),
+			'EventEspresso\modules\ticket_selector\ProcessTicketSelector'                                                 => array(
+				'EE_Core_Config'                                                          => EE_Dependency_Map::load_from_cache,
+				'EventEspresso\core\services\request\Request'                             => EE_Dependency_Map::load_from_cache,
+				'EE_Session'                                                              => EE_Dependency_Map::load_from_cache,
+				'EEM_Ticket'                                                              => EE_Dependency_Map::load_from_cache,
+				'EventEspresso\modules\ticket_selector\TicketDatetimeAvailabilityTracker' => EE_Dependency_Map::load_from_cache,
+			),
+			'EventEspresso\modules\ticket_selector\TicketDatetimeAvailabilityTracker'                                     => array(
+				'EEM_Datetime' => EE_Dependency_Map::load_from_cache,
+			),
+			'EventEspresso\core\domain\entities\custom_post_types\CustomPostTypeDefinitions'                              => array(
+				'EE_Core_Config'                             => EE_Dependency_Map::load_from_cache,
+				'EventEspresso\core\services\loaders\Loader' => EE_Dependency_Map::load_from_cache,
+			),
+			'EventEspresso\core\domain\services\custom_post_types\RegisterCustomPostTypes'                                => array(
+				'EventEspresso\core\domain\entities\custom_post_types\CustomPostTypeDefinitions' => EE_Dependency_Map::load_from_cache,
+			),
+			'EventEspresso\core\domain\services\custom_post_types\RegisterCustomTaxonomies'                               => array(
+				'EventEspresso\core\domain\entities\custom_post_types\CustomTaxonomyDefinitions' => EE_Dependency_Map::load_from_cache,
+			),
+			'EE_CPT_Strategy'                                                                                             => array(
+				'EventEspresso\core\domain\entities\custom_post_types\CustomPostTypeDefinitions' => EE_Dependency_Map::load_from_cache,
+				'EventEspresso\core\domain\entities\custom_post_types\CustomTaxonomyDefinitions' => EE_Dependency_Map::load_from_cache,
+			),
+			'EventEspresso\core\services\loaders\ObjectIdentifier'                                                        => array(
+				'EventEspresso\core\services\loaders\ClassInterfaceCache' => EE_Dependency_Map::load_from_cache,
+			),
+			'EventEspresso\core\domain\services\assets\CoreAssetManager'                                                  => array(
+				'EventEspresso\core\services\assets\AssetCollection' => EE_Dependency_Map::load_from_cache,
+				'EE_Currency_Config'                                 => EE_Dependency_Map::load_from_cache,
+				'EE_Template_Config'                                 => EE_Dependency_Map::load_from_cache,
+				'EventEspresso\core\domain\Domain'                   => EE_Dependency_Map::load_from_cache,
+				'EventEspresso\core\services\assets\Registry'        => EE_Dependency_Map::load_from_cache,
+			),
+			'EventEspresso\core\domain\services\admin\privacy\policy\PrivacyPolicy' => array(
+				'EEM_Payment_Method' => EE_Dependency_Map::load_from_cache,
+				'EventEspresso\core\domain\values\session\SessionLifespan' => EE_Dependency_Map::load_from_cache
+			),
+			'EventEspresso\core\domain\services\admin\privacy\export\ExportAttendee' => array(
+				'EEM_Attendee' => EE_Dependency_Map::load_from_cache,
+			),
+			'EventEspresso\core\domain\services\admin\privacy\export\ExportAttendeeBillingData' => array(
+				'EEM_Attendee' => EE_Dependency_Map::load_from_cache,
+				'EEM_Payment_Method' => EE_Dependency_Map::load_from_cache
+			),
+			'EventEspresso\core\domain\services\admin\privacy\export\ExportCheckins' => array(
+				'EEM_Checkin' => EE_Dependency_Map::load_from_cache,
+			),
+			'EventEspresso\core\domain\services\admin\privacy\export\ExportRegistration' => array(
+				'EEM_Registration' => EE_Dependency_Map::load_from_cache,
+			),
+			'EventEspresso\core\domain\services\admin\privacy\export\ExportTransaction' => array(
+				'EEM_Transaction' => EE_Dependency_Map::load_from_cache,
+			),
+			'EventEspresso\core\domain\services\admin\privacy\erasure\EraseAttendeeData' => array(
+				'EEM_Attendee' => EE_Dependency_Map::load_from_cache,
+			),
+			'EventEspresso\core\domain\services\admin\privacy\erasure\EraseAnswers' => array(
+				'EEM_Answer' => EE_Dependency_Map::load_from_cache,
+				'EEM_Question' => EE_Dependency_Map::load_from_cache,
+			),
+			'EventEspresso\core\CPTs\CptQueryModifier' => array(
+				null,
+				null,
+				null,
+				'EE_Request_Handler'                          => EE_Dependency_Map::load_from_cache,
+				'EventEspresso\core\services\request\Request' => EE_Dependency_Map::load_from_cache,
+				'EventEspresso\core\services\loaders\Loader'  => EE_Dependency_Map::load_from_cache,
+			),
+			'EventEspresso\core\domain\services\admin\privacy\forms\PrivacySettingsFormHandler' => array(
+				'EE_Registry' => EE_Dependency_Map::load_from_cache,
+				'EE_Config' => EE_Dependency_Map::load_from_cache
+			),
+			'EventEspresso\core\services\editor\BlockRegistrationManager'                                                 => array(
+				'EventEspresso\core\services\assets\BlockAssetManagerCollection' => EE_Dependency_Map::load_from_cache,
+				'EventEspresso\core\domain\entities\editor\BlockCollection'      => EE_Dependency_Map::load_from_cache,
+				'EventEspresso\core\services\route_match\RouteMatchSpecificationManager' => EE_Dependency_Map::load_from_cache,
+				'EventEspresso\core\services\request\Request'                    => EE_Dependency_Map::load_from_cache,
+			),
+			'EventEspresso\core\domain\entities\editor\CoreBlocksAssetManager' => array(
+				'EventEspresso\core\domain\Domain'                   => EE_Dependency_Map::load_from_cache,
+				'EventEspresso\core\services\assets\AssetCollection' => EE_Dependency_Map::load_from_cache,
+				'EventEspresso\core\services\assets\Registry'        => EE_Dependency_Map::load_from_cache,
+			),
+			'EventEspresso\core\domain\services\blocks\EventAttendeesBlockRenderer' => array(
+				'EventEspresso\core\domain\Domain' => EE_Dependency_Map::load_from_cache,
+				'EEM_Attendee' => EE_Dependency_Map::load_from_cache,
+			),
+			'EventEspresso\core\domain\entities\editor\blocks\EventAttendees' => array(
+				'EventEspresso\core\domain\entities\editor\CoreBlocksAssetManager' => self::load_from_cache,
+				'EventEspresso\core\services\request\Request' => EE_Dependency_Map::load_from_cache,
+				'EventEspresso\core\domain\services\blocks\EventAttendeesBlockRenderer' => self::load_from_cache,
+			),
+			'EventEspresso\core\services\route_match\RouteMatchSpecificationDependencyResolver' => array(
+				'EventEspresso\core\services\container\Mirror' => EE_Dependency_Map::load_from_cache,
+				'EventEspresso\core\services\loaders\ClassInterfaceCache' => EE_Dependency_Map::load_from_cache,
+				'EE_Dependency_Map' => EE_Dependency_Map::load_from_cache,
+			),
+			'EventEspresso\core\services\route_match\RouteMatchSpecificationFactory' => array(
+				'EventEspresso\core\services\route_match\RouteMatchSpecificationDependencyResolver' => EE_Dependency_Map::load_from_cache,
+				'EventEspresso\core\services\loaders\Loader' => EE_Dependency_Map::load_from_cache,
+			),
+			'EventEspresso\core\services\route_match\RouteMatchSpecificationManager' => array(
+				'EventEspresso\core\services\route_match\RouteMatchSpecificationCollection' => EE_Dependency_Map::load_from_cache,
+				'EventEspresso\core\services\route_match\RouteMatchSpecificationFactory' => EE_Dependency_Map::load_from_cache,
+			),
+			'EventEspresso\core\libraries\rest_api\CalculatedModelFields' => array(
+				'EventEspresso\core\libraries\rest_api\calculations\CalculatedModelFieldsFactory' => EE_Dependency_Map::load_from_cache
+			),
+			'EventEspresso\core\libraries\rest_api\calculations\CalculatedModelFieldsFactory' => array(
+				'EventEspresso\core\services\loaders\Loader'  => EE_Dependency_Map::load_from_cache,
+			),
+			'EventEspresso\core\libraries\rest_api\controllers\model\Read' => array(
+				'EventEspresso\core\libraries\rest_api\CalculatedModelFields' => EE_Dependency_Map::load_from_cache
+			),
+			'EventEspresso\core\libraries\rest_api\calculations\Datetime' => array(
+				'EEM_Datetime' => EE_Dependency_Map::load_from_cache,
+				'EEM_Registration' => EE_Dependency_Map::load_from_cache
+			),
+			'EventEspresso\core\libraries\rest_api\calculations\Event' => array(
+				'EEM_Event' => EE_Dependency_Map::load_from_cache,
+				'EEM_Registration' => EE_Dependency_Map::load_from_cache
+			),
+			'EventEspresso\core\libraries\rest_api\calculations\Registration' => array(
+				'EEM_Registration' => EE_Dependency_Map::load_from_cache
+			),
+			'EventEspresso\core\services\session\SessionStartHandler' => array(
+				'EventEspresso\core\services\request\Request' => EE_Dependency_Map::load_from_cache,
+			),
+			'EE_URL_Validation_Strategy' => array(
+				null,
+				null,
+				'EventEspresso\core\services\validators\URLValidator' => EE_Dependency_Map::load_from_cache
+			),
+			'EventEspresso\admin_pages\general_settings\OrganizationSettings' => array(
+				'EE_Registry'                                             => EE_Dependency_Map::load_from_cache,
+				'EE_Organization_Config'                                  => EE_Dependency_Map::load_from_cache,
+				'EE_Core_Config'                                          => EE_Dependency_Map::load_from_cache,
+				'EE_Network_Core_Config'                                  => EE_Dependency_Map::load_from_cache,
+				'EventEspresso\core\services\address\CountrySubRegionDao' => EE_Dependency_Map::load_from_cache,
+			),
+			'EventEspresso\core\services\address\CountrySubRegionDao' => array(
+				'EEM_State'                                            => EE_Dependency_Map::load_from_cache,
+				'EventEspresso\core\services\validators\JsonValidator' => EE_Dependency_Map::load_from_cache
+			),
+			'EventEspresso\core\domain\services\admin\ajax\WordpressHeartbeat' => array(
+				'EventEspresso\core\services\loaders\Loader'  => EE_Dependency_Map::load_from_cache,
+				'EventEspresso\core\services\request\Request' => EE_Dependency_Map::load_from_cache,
+			),
+			'EventEspresso\core\domain\services\admin\ajax\EventEditorHeartbeat' => array(
+				'EventEspresso\core\domain\Domain' => EE_Dependency_Map::load_from_cache,
+				'EE_Environment_Config'            => EE_Dependency_Map::load_from_cache,
+			),
+			'EventEspresso\core\services\request\files\FilesDataHandler' => array(
+				'EventEspresso\core\services\request\Request' => EE_Dependency_Map::load_from_cache,
+			),
+			'EventEspressoBatchRequest\BatchRequestProcessor' => [
+				'EventEspresso\core\services\loaders\Loader'  => EE_Dependency_Map::load_from_cache,
+			]
+		);
+	}
+
+
+	/**
+	 * Registers how core classes are loaded.
+	 * This can either be done by simply providing the name of one of the EE_Registry loader methods such as:
+	 *        'EE_Request_Handler' => 'load_core'
+	 *        'EE_Messages_Queue'  => 'load_lib'
+	 *        'EEH_Debug_Tools'    => 'load_helper'
+	 * or, if greater control is required, by providing a custom closure. For example:
+	 *        'Some_Class' => function () {
+	 *            return new Some_Class();
+	 *        },
+	 * This is required for instantiating dependencies
+	 * where an interface has been type hinted in a class constructor. For example:
+	 *        'Required_Interface' => function () {
+	 *            return new A_Class_That_Implements_Required_Interface();
+	 *        },
+	 */
+	protected function _register_core_class_loaders()
+	{
+		$this->_class_loaders = array(
+			// load_core
+			'EE_Dependency_Map'                            => function () {
+				return $this;
+			},
+			'EE_Capabilities'                              => 'load_core',
+			'EE_Encryption'                                => 'load_core',
+			'EE_Front_Controller'                          => 'load_core',
+			'EE_Module_Request_Router'                     => 'load_core',
+			'EE_Registry'                                  => 'load_core',
+			'EE_Request'                                   => function () {
+				return $this->legacy_request;
+			},
+			'EventEspresso\core\services\request\Request'  => function () {
+				return $this->request;
+			},
+			'EventEspresso\core\services\request\Response' => function () {
+				return $this->response;
+			},
+			'EE_Base'                                      => 'load_core',
+			'EE_Request_Handler'                           => 'load_core',
+			'EE_Session'                                   => 'load_core',
+			'EE_Cron_Tasks'                                => 'load_core',
+			'EE_System'                                    => 'load_core',
+			'EE_Maintenance_Mode'                          => 'load_core',
+			'EE_Register_CPTs'                             => 'load_core',
+			'EE_Admin'                                     => 'load_core',
+			'EE_CPT_Strategy'                              => 'load_core',
+			// load_class
+			'EE_Registration_Processor'                    => 'load_class',
+			// load_lib
+			'EE_Message_Resource_Manager'                  => 'load_lib',
+			'EE_Message_Type_Collection'                   => 'load_lib',
+			'EE_Message_Type_Collection_Loader'            => 'load_lib',
+			'EE_Messenger_Collection'                      => 'load_lib',
+			'EE_Messenger_Collection_Loader'               => 'load_lib',
+			'EE_Messages_Processor'                        => 'load_lib',
+			'EE_Message_Repository'                        => 'load_lib',
+			'EE_Messages_Queue'                            => 'load_lib',
+			'EE_Messages_Data_Handler_Collection'          => 'load_lib',
+			'EE_Message_Template_Group_Collection'         => 'load_lib',
+			'EE_Payment_Method_Manager'                    => 'load_lib',
+			'EE_DMS_Core_4_1_0'                            => 'load_dms',
+			'EE_DMS_Core_4_2_0'                            => 'load_dms',
+			'EE_DMS_Core_4_3_0'                            => 'load_dms',
+			'EE_DMS_Core_4_5_0'                            => 'load_dms',
+			'EE_DMS_Core_4_6_0'                            => 'load_dms',
+			'EE_DMS_Core_4_7_0'                            => 'load_dms',
+			'EE_DMS_Core_4_8_0'                            => 'load_dms',
+			'EE_DMS_Core_4_9_0'                            => 'load_dms',
+			'EE_DMS_Core_4_10_0'                            => 'load_dms',
+			'EE_Messages_Generator'                        => function () {
+				return EE_Registry::instance()->load_lib(
+					'Messages_Generator',
+					array(),
+					false,
+					false
+				);
+			},
+			'EE_Messages_Template_Defaults'                => function ($arguments = array()) {
+				return EE_Registry::instance()->load_lib(
+					'Messages_Template_Defaults',
+					$arguments,
+					false,
+					false
+				);
+			},
+			// load_helper
+			'EEH_Parse_Shortcodes'                         => function () {
+				if (EE_Registry::instance()->load_helper('Parse_Shortcodes')) {
+					return new EEH_Parse_Shortcodes();
+				}
+				return null;
+			},
+			'EE_Template_Config'                           => function () {
+				return EE_Config::instance()->template_settings;
+			},
+			'EE_Currency_Config'                           => function () {
+				return EE_Config::instance()->currency;
+			},
+			'EE_Registration_Config'                       => function () {
+				return EE_Config::instance()->registration;
+			},
+			'EE_Core_Config'                               => function () {
+				return EE_Config::instance()->core;
+			},
+			'EventEspresso\core\services\loaders\Loader'   => function () {
+				return LoaderFactory::getLoader();
+			},
+			'EE_Network_Config'                            => function () {
+				return EE_Network_Config::instance();
+			},
+			'EE_Config'                                    => function () {
+				return EE_Config::instance();
+			},
+			'EventEspresso\core\domain\Domain'             => function () {
+				return DomainFactory::getEventEspressoCoreDomain();
+			},
+			'EE_Admin_Config'                              => function () {
+				return EE_Config::instance()->admin;
+			},
+			'EE_Organization_Config'                       => function () {
+				return EE_Config::instance()->organization;
+			},
+			'EE_Network_Core_Config'                       => function () {
+				return EE_Network_Config::instance()->core;
+			},
+			'EE_Environment_Config'                        => function () {
+				return EE_Config::instance()->environment;
+			},
+		);
+	}
+
+
+	/**
+	 * can be used for supplying alternate names for classes,
+	 * or for connecting interface names to instantiable classes
+	 */
+	protected function _register_core_aliases()
+	{
+		$aliases = array(
+			'CommandBusInterface'                                                          => 'EventEspresso\core\services\commands\CommandBusInterface',
+			'EventEspresso\core\services\commands\CommandBusInterface'                     => 'EventEspresso\core\services\commands\CommandBus',
+			'CommandHandlerManagerInterface'                                               => 'EventEspresso\core\services\commands\CommandHandlerManagerInterface',
+			'EventEspresso\core\services\commands\CommandHandlerManagerInterface'          => 'EventEspresso\core\services\commands\CommandHandlerManager',
+			'CapChecker'                                                                   => 'EventEspresso\core\services\commands\middleware\CapChecker',
+			'AddActionHook'                                                                => 'EventEspresso\core\services\commands\middleware\AddActionHook',
+			'CapabilitiesChecker'                                                          => 'EventEspresso\core\domain\services\capabilities\CapabilitiesChecker',
+			'CapabilitiesCheckerInterface'                                                 => 'EventEspresso\core\domain\services\capabilities\CapabilitiesCheckerInterface',
+			'EventEspresso\core\domain\services\capabilities\CapabilitiesCheckerInterface' => 'EventEspresso\core\domain\services\capabilities\CapabilitiesChecker',
+			'CreateRegistrationService'                                                    => 'EventEspresso\core\domain\services\registration\CreateRegistrationService',
+			'CreateRegistrationCommandHandler'                                             => 'EventEspresso\core\services\commands\registration\CreateRegistrationCommand',
+			'CopyRegistrationDetailsCommandHandler'                                        => 'EventEspresso\core\services\commands\registration\CopyRegistrationDetailsCommand',
+			'CopyRegistrationPaymentsCommandHandler'                                       => 'EventEspresso\core\services\commands\registration\CopyRegistrationPaymentsCommand',
+			'CancelRegistrationAndTicketLineItemCommandHandler'                            => 'EventEspresso\core\services\commands\registration\CancelRegistrationAndTicketLineItemCommandHandler',
+			'UpdateRegistrationAndTransactionAfterChangeCommandHandler'                    => 'EventEspresso\core\services\commands\registration\UpdateRegistrationAndTransactionAfterChangeCommandHandler',
+			'CreateTicketLineItemCommandHandler'                                           => 'EventEspresso\core\services\commands\ticket\CreateTicketLineItemCommand',
+			'CreateTransactionCommandHandler'                                              => 'EventEspresso\core\services\commands\transaction\CreateTransactionCommandHandler',
+			'CreateAttendeeCommandHandler'                                                 => 'EventEspresso\core\services\commands\attendee\CreateAttendeeCommandHandler',
+			'TableManager'                                                                 => 'EventEspresso\core\services\database\TableManager',
+			'TableAnalysis'                                                                => 'EventEspresso\core\services\database\TableAnalysis',
+			'EspressoShortcode'                                                            => 'EventEspresso\core\services\shortcodes\EspressoShortcode',
+			'ShortcodeInterface'                                                           => 'EventEspresso\core\services\shortcodes\ShortcodeInterface',
+			'EventEspresso\core\services\shortcodes\ShortcodeInterface'                    => 'EventEspresso\core\services\shortcodes\EspressoShortcode',
+			'EventEspresso\core\services\cache\CacheStorageInterface'                      => 'EventEspresso\core\services\cache\TransientCacheStorage',
+			'LoaderInterface'                                                              => 'EventEspresso\core\services\loaders\LoaderInterface',
+			'EventEspresso\core\services\loaders\LoaderInterface'                          => 'EventEspresso\core\services\loaders\Loader',
+			'CommandFactoryInterface'                                                      => 'EventEspresso\core\services\commands\CommandFactoryInterface',
+			'EventEspresso\core\services\commands\CommandFactoryInterface'                 => 'EventEspresso\core\services\commands\CommandFactory',
+			'EmailValidatorInterface'                                                      => 'EventEspresso\core\domain\services\validation\email\EmailValidatorInterface',
+			'EventEspresso\core\domain\services\validation\email\EmailValidatorInterface'  => 'EventEspresso\core\domain\services\validation\email\EmailValidationService',
+			'NoticeConverterInterface'                                                     => 'EventEspresso\core\services\notices\NoticeConverterInterface',
+			'EventEspresso\core\services\notices\NoticeConverterInterface'                 => 'EventEspresso\core\services\notices\ConvertNoticesToEeErrors',
+			'NoticesContainerInterface'                                                    => 'EventEspresso\core\services\notices\NoticesContainerInterface',
+			'EventEspresso\core\services\notices\NoticesContainerInterface'                => 'EventEspresso\core\services\notices\NoticesContainer',
+			'EventEspresso\core\services\request\RequestInterface'                         => 'EventEspresso\core\services\request\Request',
+			'EventEspresso\core\services\request\ResponseInterface'                        => 'EventEspresso\core\services\request\Response',
+			'EventEspresso\core\domain\DomainInterface'                                    => 'EventEspresso\core\domain\Domain',
+			'Registration_Processor'                                                       => 'EE_Registration_Processor',
+		);
+		foreach ($aliases as $alias => $fqn) {
+			if (is_array($fqn)) {
+				foreach ($fqn as $class => $for_class) {
+					$this->class_cache->addAlias($class, $alias, $for_class);
+				}
+				continue;
+			}
+			$this->class_cache->addAlias($fqn, $alias);
+		}
+		if (! (defined('DOING_AJAX') && DOING_AJAX) && is_admin()) {
+			$this->class_cache->addAlias(
+				'EventEspresso\core\services\notices\ConvertNoticesToAdminNotices',
+				'EventEspresso\core\services\notices\NoticeConverterInterface'
+			);
+		}
+	}
+
+
+	/**
+	 * This is used to reset the internal map and class_loaders to their original default state at the beginning of the
+	 * request Primarily used by unit tests.
+	 */
+	public function reset()
+	{
+		$this->_register_core_class_loaders();
+		$this->_register_core_dependencies();
+	}
+
+
+	/**
+	 * PLZ NOTE: a better name for this method would be is_alias()
+	 * because it returns TRUE if the provided fully qualified name IS an alias
+	 * WHY?
+	 * Because if a class is type hinting for a concretion,
+	 * then why would we need to find another class to supply it?
+	 * ie: if a class asks for `Fully/Qualified/Namespace/SpecificClassName`,
+	 * then give it an instance of `Fully/Qualified/Namespace/SpecificClassName`.
+	 * Don't go looking for some substitute.
+	 * Whereas if a class is type hinting for an interface...
+	 * then we need to find an actual class to use.
+	 * So the interface IS the alias for some other FQN,
+	 * and we need to find out if `Fully/Qualified/Namespace/SomeInterface`
+	 * represents some other class.
+	 *
+	 * @deprecated 4.9.62.p
+	 * @param string $fqn
+	 * @param string $for_class
+	 * @return bool
+	 */
+	public function has_alias($fqn = '', $for_class = '')
+	{
+		return $this->isAlias($fqn, $for_class);
+	}
+
+
+	/**
+	 * PLZ NOTE: a better name for this method would be get_fqn_for_alias()
+	 * because it returns a FQN for provided alias if one exists, otherwise returns the original $alias
+	 * functions recursively, so that multiple aliases can be used to drill down to a FQN
+	 *  for example:
+	 *      if the following two entries were added to the _aliases array:
+	 *          array(
+	 *              'interface_alias'           => 'some\namespace\interface'
+	 *              'some\namespace\interface'  => 'some\namespace\classname'
+	 *          )
+	 *      then one could use EE_Registry::instance()->create( 'interface_alias' )
+	 *      to load an instance of 'some\namespace\classname'
+	 *
+	 * @deprecated 4.9.62.p
+	 * @param string $alias
+	 * @param string $for_class
+	 * @return string
+	 */
+	public function get_alias($alias = '', $for_class = '')
+	{
+		return $this->getFqnForAlias($alias, $for_class);
+	}
 }