eventespresso / event-espresso-core

core/libraries/messages/messenger/EE_Email_messenger.class.php

Indentation +643 added lines, -643 removed lines

@@ -5,647 +5,647 @@
  */
 class EE_Email_messenger extends EE_messenger
 {
-    /**
-     * To field for email
-     *
-     * @var string
-     */
-    protected $_to = '';
-
-
-    /**
-     * CC field for email.
-     *
-     * @var string
-     */
-    protected $_cc = '';
-
-    /**
-     * From field for email
-     *
-     * @var string
-     */
-    protected $_from = '';
-
-
-    /**
-     * Subject field for email
-     *
-     * @var string
-     */
-    protected $_subject = '';
-
-
-    /**
-     * Content field for email
-     *
-     * @var string
-     */
-    protected $_content = '';
-
-
-    /**
-     * @throws EE_Error
-     * @throws ReflectionException
-     */
-    public function __construct()
-    {
-        // set name and description properties
-        $this->name                = 'email';
-        $this->description         = sprintf(
-            esc_html__(
-                'This messenger delivers messages via email using the built-in %s function included with WordPress',
-                'event_espresso'
-            ),
-            '<code>wp_mail</code>'
-        );
-        $this->label               = [
-            'singular' => esc_html__('email', 'event_espresso'),
-            'plural'   => esc_html__('emails', 'event_espresso'),
-        ];
-        $this->activate_on_install = true;
-
-        // we're using defaults so let's call parent constructor that will take care of setting up all the other
-        // properties
-        parent::__construct();
-    }
-
-
-    /**
-     * see abstract declaration in parent class for details.
-     */
-    protected function _set_admin_pages()
-    {
-        $this->admin_registered_pages = [
-            'events_edit' => true,
-        ];
-    }
-
-
-    /**
-     * see abstract declaration in parent class for details
-     */
-    protected function _set_valid_shortcodes()
-    {
-        // remember by leaving the other fields not set, those fields will inherit the valid shortcodes from the
-        // message type.
-        $this->_valid_shortcodes = [
-            'to'   => ['email', 'event_author', 'primary_registration_details', 'recipient_details'],
-            'cc'   => ['email', 'event_author', 'primary_registration_details', 'recipient_details'],
-            'from' => ['email', 'event_author', 'primary_registration_details', 'recipient_details'],
-        ];
-    }
-
-
-    /**
-     * see abstract declaration in parent class for details
-     *
-     * @access protected
-     * @return void
-     */
-    protected function _set_validator_config()
-    {
-        $valid_shortcodes = $this->get_valid_shortcodes();
-
-        $this->_validator_config = [
-            'to'            => [
-                'shortcodes' => $valid_shortcodes['to'],
-                'type'       => 'email',
-            ],
-            'cc'            => [
-                'shortcodes' => $valid_shortcodes['to'],
-                'type'       => 'email',
-            ],
-            'from'          => [
-                'shortcodes' => $valid_shortcodes['from'],
-                'type'       => 'email',
-            ],
-            'subject'       => [
-                'shortcodes' => [
-                    'organization',
-                    'primary_registration_details',
-                    'event_author',
-                    'primary_registration_details',
-                    'recipient_details',
-                ],
-            ],
-            'content'       => [
-                'shortcodes' => [
-                    'event_list',
-                    'attendee_list',
-                    'ticket_list',
-                    'organization',
-                    'primary_registration_details',
-                    'primary_registration_list',
-                    'event_author',
-                    'recipient_details',
-                    'recipient_list',
-                    'transaction',
-                    'messenger',
-                ],
-            ],
-            'attendee_list' => [
-                'shortcodes' => ['attendee', 'event_list', 'ticket_list'],
-                'required'   => ['[ATTENDEE_LIST]'],
-            ],
-            'event_list'    => [
-                'shortcodes' => [
-                    'event',
-                    'attendee_list',
-                    'ticket_list',
-                    'venue',
-                    'datetime_list',
-                    'attendee',
-                    'primary_registration_details',
-                    'primary_registration_list',
-                    'event_author',
-                    'recipient_details',
-                    'recipient_list',
-                ],
-                'required'   => ['[EVENT_LIST]'],
-            ],
-            'ticket_list'   => [
-                'shortcodes' => [
-                    'event_list',
-                    'attendee_list',
-                    'ticket',
-                    'datetime_list',
-                    'primary_registration_details',
-                    'recipient_details',
-                ],
-                'required'   => ['[TICKET_LIST]'],
-            ],
-            'datetime_list' => [
-                'shortcodes' => ['datetime', 'venue'],
-                'required'   => ['[DATETIME_LIST]'],
-            ],
-        ];
-    }
-
-
-    /**
-     * @see   parent EE_messenger class for docs
-     * @since 4.5.0
-     */
-    public function do_secondary_messenger_hooks($sending_messenger_name)
-    {
-        if ($sending_messenger_name === 'html') {
-            add_filter('FHEE__EE_Messages_Template_Pack__get_variation', [$this, 'add_email_css'], 10, 8);
-        }
-    }
-
-
-    public function add_email_css(
-        $variation_path,
-        $messenger,
-        $message_type,
-        $type,
-        $variation,
-        $file_extension,
-        $url,
-        EE_Messages_Template_Pack $template_pack
-    ) {
-        // prevent recursion on this callback.
-        remove_filter('FHEE__EE_Messages_Template_Pack__get_variation', [$this, 'add_email_css'], 10);
-        $variation = $this->get_variation($template_pack, $message_type, $url, 'main', $variation, false);
-
-        add_filter('FHEE__EE_Messages_Template_Pack__get_variation', [$this, 'add_email_css'], 10, 8);
-        return $variation;
-    }
-
-
-    /**
-     * See parent for details
-     *
-     * @access protected
-     * @return void
-     */
-    protected function _set_test_settings_fields()
-    {
-        $this->_test_settings_fields = [
-            'to'      => [
-                'input'      => 'text',
-                'label'      => esc_html__('Send a test email to', 'event_espresso'),
-                'type'       => 'email',
-                'required'   => false,
-                'validation' => true,
-                'css_class'  => 'ee-input-width--big',
-                'format'     => '%s',
-                'default'    => get_bloginfo('admin_email'),
-            ],
-            'subject' => [
-                'input'      => 'hidden',
-                'label'      => '',
-                'type'       => 'string',
-                'required'   => false,
-                'validation' => false,
-                'format'     => '%s',
-                'value'      => sprintf(esc_html__('Test email sent from %s', 'event_espresso'), get_bloginfo('name')),
-                'default'    => '',
-                'css_class'  => '',
-            ],
-        ];
-    }
-
-
-    /**
-     * _set_template_fields
-     * This sets up the fields that a messenger requires for the message to go out.
-     *
-     * @access  protected
-     * @return void
-     */
-    protected function _set_template_fields()
-    {
-        // any extra template fields that are NOT used by the messenger but will get used by a messenger field for
-        // shortcode replacement get added to the 'extra' key in an associated array indexed by the messenger field
-        // they relate to.  This is important for the Messages_admin to know what fields to display to the user.
-        //  Also, notice that the "values" are equal to the field type that messages admin will use to know what
-        // kind of field to display. The values ALSO have one index labeled "shortcode".  the values in that array
-        // indicate which ACTUAL SHORTCODE (i.e. [SHORTCODE]) is required in order for this extra field to be
-        // displayed.  If the required shortcode isn't part of the shortcodes array then the field is not needed and
-        // will not be displayed/parsed.
-        $this->_template_fields = [
-            'to'      => [
-                'input'      => 'text',
-                'label'      => esc_html_x(
-                    'To',
-                    'Label for the "To" field for email addresses',
-                    'event_espresso'
-                ),
-                'type'       => 'string',
-                'required'   => false,
-                'validation' => true,
-                'css_class'  => 'large-text',
-                'format'     => '%s',
-            ],
-            'cc'      => [
-                'input'      => 'text',
-                'label'      => esc_html_x(
-                    'CC',
-                    'Label for the "Carbon Copy" field used for additional email addresses',
-                    'event_espresso'
-                ),
-                'type'       => 'string',
-                'required'   => false,
-                'validation' => true,
-                'css_class'  => 'large-text',
-                'format'     => '%s',
-            ],
-            'from'    => [
-                'input'      => 'text',
-                'label'      => esc_html_x(
-                    'From',
-                    'Label for the "From" field for email addresses.',
-                    'event_espresso'
-                ),
-                'type'       => 'string',
-                'required'   => false,
-                'validation' => true,
-                'css_class'  => 'large-text',
-                'format'     => '%s',
-            ],
-            'subject' => [
-                'input'      => 'text',
-                'label'      => esc_html_x(
-                    'Subject',
-                    'Label for the "Subject" field (short description of contents) for emails.',
-                    'event_espresso'
-                ),
-                'type'       => 'string',
-                'required'   => true,
-                'validation' => true,
-                'css_class'  => 'large-text',
-                'format'     => '%s',
-            ],
-            'content' => '',
-            // left empty b/c it is in the "extra array" but messenger still needs needs to know this is a field.
-            'extra'   => [
-                'content' => [
-                    'main'          => [
-                        'input'      => 'wp_editor',
-                        'label'      => esc_html__('Main Content', 'event_espresso'),
-                        'type'       => 'string',
-                        'required'   => false,
-                        'validation' => true,
-                        'format'     => '%s',
-                        'rows'       => '15',
-                    ],
-                    'event_list'    => [
-                        'input'               => 'wp_editor',
-                        'label'               => '[EVENT_LIST]',
-                        'type'                => 'string',
-                        'required'            => false,
-                        'validation'          => true,
-                        'format'              => '%s',
-                        'rows'                => '15',
-                        'shortcodes_required' => ['[EVENT_LIST]'],
-                    ],
-                    'attendee_list' => [
-                        'input'               => 'textarea',
-                        'label'               => '[ATTENDEE_LIST]',
-                        'type'                => 'string',
-                        'required'            => false,
-                        'validation'          => true,
-                        'format'              => '%s',
-                        'css_class'           => 'large-text',
-                        'rows'                => '5',
-                        'shortcodes_required' => ['[ATTENDEE_LIST]'],
-                    ],
-                    'ticket_list'   => [
-                        'input'               => 'textarea',
-                        'label'               => '[TICKET_LIST]',
-                        'type'                => 'string',
-                        'required'            => false,
-                        'validation'          => true,
-                        'format'              => '%s',
-                        'css_class'           => 'large-text',
-                        'rows'                => '10',
-                        'shortcodes_required' => ['[TICKET_LIST]'],
-                    ],
-                    'datetime_list' => [
-                        'input'               => 'textarea',
-                        'label'               => '[DATETIME_LIST]',
-                        'type'                => 'string',
-                        'required'            => false,
-                        'validation'          => true,
-                        'format'              => '%s',
-                        'css_class'           => 'large-text',
-                        'rows'                => '10',
-                        'shortcodes_required' => ['[DATETIME_LIST]'],
-                    ],
-                ],
-            ],
-        ];
-    }
-
-
-    /**
-     * See definition of this class in parent
-     */
-    protected function _set_default_message_types()
-    {
-        $this->_default_message_types = [
-            'payment',
-            'payment_refund',
-            'registration',
-            'not_approved_registration',
-            'pending_approval',
-        ];
-    }
-
-
-    /**
-     * @see   definition of this class in parent
-     * @since 4.5.0
-     */
-    protected function _set_valid_message_types()
-    {
-        $this->_valid_message_types = [
-            'payment',
-            'registration',
-            'not_approved_registration',
-            'declined_registration',
-            'cancelled_registration',
-            'pending_approval',
-            'registration_summary',
-            'payment_reminder',
-            'payment_declined',
-            'payment_refund',
-        ];
-    }
-
-
-    /**
-     * setting up admin_settings_fields for messenger.
-     */
-    protected function _set_admin_settings_fields()
-    {
-    }
-
-
-    /**
-     * We just deliver the messages don't kill us!!
-     *
-     * @return bool|WP_Error true if message delivered, false if it didn't deliver OR bubble up any error object if
-     *              present.
-     * @throws EE_Error
-     * @throws Exception
-     */
-    protected function _send_message()
-    {
-        $success = wp_mail(
-            $this->_to,
-            // some old values for subject may be expecting HTML entities to be decoded in the subject
-            // and subjects aren't interpreted as HTML, so there should be no HTML in them
-            wp_strip_all_tags(wp_specialchars_decode($this->_subject, ENT_QUOTES)),
-            $this->_body(),
-            $this->_headers()
-        );
-        if (! $success) {
-            EE_Error::add_error(
-                sprintf(
-                    esc_html__(
-                        'The email did not send successfully.%3$sThe WordPress wp_mail function is used for sending mails but does not give any useful information when an email fails to send.%3$sIt is possible the "to" address (%1$s) or "from" address (%2$s) is invalid.%3$s',
-                        'event_espresso'
-                    ),
-                    $this->_to,
-                    $this->_from,
-                    '<br />'
-                ),
-                __FILE__,
-                __FUNCTION__,
-                __LINE__
-            );
-        }
-        return $success;
-    }
-
-
-    /**
-     * see parent for definition
-     *
-     * @return string html body of the message content and the related css.
-     * @throws EE_Error
-     * @throws Exception
-     */
-    protected function _preview()
-    {
-        return $this->_body(true);
-    }
-
-
-    /**
-     * Setup headers for email
-     *
-     * @access protected
-     * @return string formatted header for email
-     */
-    protected function _headers()
-    {
-        $this->_ensure_has_from_email_address();
-        $from    = $this->_from;
-        $headers = [
-            'From:' . $from,
-            'Reply-To:' . $from,
-            'Content-Type:text/html; charset=utf-8',
-        ];
-
-        /**
-         * Second condition added as a result of https://events.codebasehq.com/projects/event-espresso/tickets/11416 to
-         * cover back compat where there may be users who have saved cc values in their db for the newsletter message
-         * type which they are no longer able to change.
-         */
-        if (! empty($this->_cc) && ! $this->_incoming_message_type instanceof EE_Newsletter_message_type) {
-            $headers[] = 'cc: ' . $this->_cc;
-        }
-
-        // but wait!  Header's for the from is NOT reliable because some plugins don't respect From: as set in the
-        // header.
-        add_filter('wp_mail_from', [$this, 'set_from_address'], 100);
-        add_filter('wp_mail_from_name', [$this, 'set_from_name'], 100);
-        return apply_filters('FHEE__EE_Email_messenger___headers', $headers, $this->_incoming_message_type, $this);
-    }
-
-
-    /**
-     * This simply ensures that the from address is not empty.  If it is, then we use whatever is set as the site email
-     * address for the from address to avoid problems with sending emails.
-     */
-    protected function _ensure_has_from_email_address()
-    {
-        if (empty($this->_from)) {
-            $this->_from = get_bloginfo('admin_email');
-        }
-    }
-
-
-    /**
-     * This simply parses whatever is set as the $_from address and determines if it is in the format {name} <{email}>
-     * or just {email} and returns an array with the "from_name" and "from_email" as the values. Note from_name *MAY*
-     * be empty
-     *
-     * @return array
-     * @since 4.3.1
-     */
-    private function _parse_from()
-    {
-        if (strpos($this->_from, '<') !== false) {
-            $from_name = substr($this->_from, 0, strpos($this->_from, '<') - 1);
-            $from_name = str_replace('"', '', $from_name);
-            $from_name = trim($from_name);
-
-            $from_email = substr($this->_from, strpos($this->_from, '<') + 1);
-            $from_email = str_replace('>', '', $from_email);
-            $from_email = trim($from_email);
-        } elseif (trim($this->_from) !== '') {
-            $from_name  = '';
-            $from_email = trim($this->_from);
-        } else {
-            $from_name = $from_email = '';
-        }
-        return [$from_name, $from_email];
-    }
-
-
-    /**
-     * Callback for the wp_mail_from filter.
-     *
-     * @param string $from_email What the original from_email is.
-     * @return string
-     * @since 4.3.1
-     */
-    public function set_from_address($from_email)
-    {
-        $parsed_from = $this->_parse_from();
-        // includes fallback if the parsing failed.
-        return is_array($parsed_from) && ! empty($parsed_from[1])
-            ? $parsed_from[1]
-            : get_bloginfo('admin_email');
-    }
-
-
-    /**
-     * Callback for the wp_mail_from_name filter.
-     *
-     * @param string $from_name The original from_name.
-     * @return string
-     * @since 4.3.1
-     */
-    public function set_from_name($from_name)
-    {
-        $parsed_from = $this->_parse_from();
-        if (is_array($parsed_from) && ! empty($parsed_from[0])) {
-            $from_name = $parsed_from[0];
-        }
-
-        // if from name is "WordPress" let's sub in the site name instead (more friendly!)
-        // but realize the default name is HTML entity-encoded
-        return $from_name == 'WordPress' ? wp_specialchars_decode(get_bloginfo(), ENT_QUOTES) : $from_name;
-    }
-
-
-    /**
-     * setup body for email
-     *
-     * @param bool $preview will determine whether this is preview template or not.
-     * @return string formatted body for email.
-     * @throws EE_Error
-     * @throws Exception
-     */
-    protected function _body($preview = false)
-    {
-        // setup template args!
-        $this->_template_args = [
-            'subject'   => $this->_subject,
-            'from'      => $this->_from,
-            'main_body' => wpautop($this->_content),
-        ];
-        $body                 = $this->_get_main_template($preview);
-
-        /**
-         * This filter allows one to bypass the CSSToInlineStyles tool and leave the body untouched.
-         *
-         * @type    bool $preview Indicates whether a preview is being generated or not.
-         * @return  bool    true  indicates to use the inliner, false bypasses it.
-         */
-        if (apply_filters('FHEE__EE_Email_messenger__apply_CSSInliner ', true, $preview)) {
-            // now if this isn't a preview, let's set up the body so it has inline styles
-            if (! $preview || (defined('DOING_AJAX') && DOING_AJAX)) {
-                $style = file_get_contents(
-                    $this->get_variation(
-                        $this->_tmp_pack,
-                        $this->_incoming_message_type->name,
-                        false,
-                        'main',
-                        $this->_variation
-                    ),
-                    true
-                );
-                $CSS   = new TijsVerkoyen\CssToInlineStyles\CssToInlineStyles();
-                $body  = $CSS->convert($body, $style);
-            }
-        }
-        return $body;
-    }
-
-
-    /**
-     * This just returns any existing test settings that might be saved in the database
-     *
-     * @access public
-     * @return array
-     * @throws EE_Error
-     * @throws ReflectionException
-     */
-    public function get_existing_test_settings()
-    {
-        $settings = parent::get_existing_test_settings();
-        // override subject if present because we always want it to be fresh.
-        if (is_array($settings) && ! empty($settings['subject'])) {
-            $settings['subject'] =
-                sprintf(esc_html__('Test email sent from %s', 'event_espresso'), get_bloginfo('name'));
-        }
-        return $settings;
-    }
+	/**
+	 * To field for email
+	 *
+	 * @var string
+	 */
+	protected $_to = '';
+
+
+	/**
+	 * CC field for email.
+	 *
+	 * @var string
+	 */
+	protected $_cc = '';
+
+	/**
+	 * From field for email
+	 *
+	 * @var string
+	 */
+	protected $_from = '';
+
+
+	/**
+	 * Subject field for email
+	 *
+	 * @var string
+	 */
+	protected $_subject = '';
+
+
+	/**
+	 * Content field for email
+	 *
+	 * @var string
+	 */
+	protected $_content = '';
+
+
+	/**
+	 * @throws EE_Error
+	 * @throws ReflectionException
+	 */
+	public function __construct()
+	{
+		// set name and description properties
+		$this->name                = 'email';
+		$this->description         = sprintf(
+			esc_html__(
+				'This messenger delivers messages via email using the built-in %s function included with WordPress',
+				'event_espresso'
+			),
+			'<code>wp_mail</code>'
+		);
+		$this->label               = [
+			'singular' => esc_html__('email', 'event_espresso'),
+			'plural'   => esc_html__('emails', 'event_espresso'),
+		];
+		$this->activate_on_install = true;
+
+		// we're using defaults so let's call parent constructor that will take care of setting up all the other
+		// properties
+		parent::__construct();
+	}
+
+
+	/**
+	 * see abstract declaration in parent class for details.
+	 */
+	protected function _set_admin_pages()
+	{
+		$this->admin_registered_pages = [
+			'events_edit' => true,
+		];
+	}
+
+
+	/**
+	 * see abstract declaration in parent class for details
+	 */
+	protected function _set_valid_shortcodes()
+	{
+		// remember by leaving the other fields not set, those fields will inherit the valid shortcodes from the
+		// message type.
+		$this->_valid_shortcodes = [
+			'to'   => ['email', 'event_author', 'primary_registration_details', 'recipient_details'],
+			'cc'   => ['email', 'event_author', 'primary_registration_details', 'recipient_details'],
+			'from' => ['email', 'event_author', 'primary_registration_details', 'recipient_details'],
+		];
+	}
+
+
+	/**
+	 * see abstract declaration in parent class for details
+	 *
+	 * @access protected
+	 * @return void
+	 */
+	protected function _set_validator_config()
+	{
+		$valid_shortcodes = $this->get_valid_shortcodes();
+
+		$this->_validator_config = [
+			'to'            => [
+				'shortcodes' => $valid_shortcodes['to'],
+				'type'       => 'email',
+			],
+			'cc'            => [
+				'shortcodes' => $valid_shortcodes['to'],
+				'type'       => 'email',
+			],
+			'from'          => [
+				'shortcodes' => $valid_shortcodes['from'],
+				'type'       => 'email',
+			],
+			'subject'       => [
+				'shortcodes' => [
+					'organization',
+					'primary_registration_details',
+					'event_author',
+					'primary_registration_details',
+					'recipient_details',
+				],
+			],
+			'content'       => [
+				'shortcodes' => [
+					'event_list',
+					'attendee_list',
+					'ticket_list',
+					'organization',
+					'primary_registration_details',
+					'primary_registration_list',
+					'event_author',
+					'recipient_details',
+					'recipient_list',
+					'transaction',
+					'messenger',
+				],
+			],
+			'attendee_list' => [
+				'shortcodes' => ['attendee', 'event_list', 'ticket_list'],
+				'required'   => ['[ATTENDEE_LIST]'],
+			],
+			'event_list'    => [
+				'shortcodes' => [
+					'event',
+					'attendee_list',
+					'ticket_list',
+					'venue',
+					'datetime_list',
+					'attendee',
+					'primary_registration_details',
+					'primary_registration_list',
+					'event_author',
+					'recipient_details',
+					'recipient_list',
+				],
+				'required'   => ['[EVENT_LIST]'],
+			],
+			'ticket_list'   => [
+				'shortcodes' => [
+					'event_list',
+					'attendee_list',
+					'ticket',
+					'datetime_list',
+					'primary_registration_details',
+					'recipient_details',
+				],
+				'required'   => ['[TICKET_LIST]'],
+			],
+			'datetime_list' => [
+				'shortcodes' => ['datetime', 'venue'],
+				'required'   => ['[DATETIME_LIST]'],
+			],
+		];
+	}
+
+
+	/**
+	 * @see   parent EE_messenger class for docs
+	 * @since 4.5.0
+	 */
+	public function do_secondary_messenger_hooks($sending_messenger_name)
+	{
+		if ($sending_messenger_name === 'html') {
+			add_filter('FHEE__EE_Messages_Template_Pack__get_variation', [$this, 'add_email_css'], 10, 8);
+		}
+	}
+
+
+	public function add_email_css(
+		$variation_path,
+		$messenger,
+		$message_type,
+		$type,
+		$variation,
+		$file_extension,
+		$url,
+		EE_Messages_Template_Pack $template_pack
+	) {
+		// prevent recursion on this callback.
+		remove_filter('FHEE__EE_Messages_Template_Pack__get_variation', [$this, 'add_email_css'], 10);
+		$variation = $this->get_variation($template_pack, $message_type, $url, 'main', $variation, false);
+
+		add_filter('FHEE__EE_Messages_Template_Pack__get_variation', [$this, 'add_email_css'], 10, 8);
+		return $variation;
+	}
+
+
+	/**
+	 * See parent for details
+	 *
+	 * @access protected
+	 * @return void
+	 */
+	protected function _set_test_settings_fields()
+	{
+		$this->_test_settings_fields = [
+			'to'      => [
+				'input'      => 'text',
+				'label'      => esc_html__('Send a test email to', 'event_espresso'),
+				'type'       => 'email',
+				'required'   => false,
+				'validation' => true,
+				'css_class'  => 'ee-input-width--big',
+				'format'     => '%s',
+				'default'    => get_bloginfo('admin_email'),
+			],
+			'subject' => [
+				'input'      => 'hidden',
+				'label'      => '',
+				'type'       => 'string',
+				'required'   => false,
+				'validation' => false,
+				'format'     => '%s',
+				'value'      => sprintf(esc_html__('Test email sent from %s', 'event_espresso'), get_bloginfo('name')),
+				'default'    => '',
+				'css_class'  => '',
+			],
+		];
+	}
+
+
+	/**
+	 * _set_template_fields
+	 * This sets up the fields that a messenger requires for the message to go out.
+	 *
+	 * @access  protected
+	 * @return void
+	 */
+	protected function _set_template_fields()
+	{
+		// any extra template fields that are NOT used by the messenger but will get used by a messenger field for
+		// shortcode replacement get added to the 'extra' key in an associated array indexed by the messenger field
+		// they relate to.  This is important for the Messages_admin to know what fields to display to the user.
+		//  Also, notice that the "values" are equal to the field type that messages admin will use to know what
+		// kind of field to display. The values ALSO have one index labeled "shortcode".  the values in that array
+		// indicate which ACTUAL SHORTCODE (i.e. [SHORTCODE]) is required in order for this extra field to be
+		// displayed.  If the required shortcode isn't part of the shortcodes array then the field is not needed and
+		// will not be displayed/parsed.
+		$this->_template_fields = [
+			'to'      => [
+				'input'      => 'text',
+				'label'      => esc_html_x(
+					'To',
+					'Label for the "To" field for email addresses',
+					'event_espresso'
+				),
+				'type'       => 'string',
+				'required'   => false,
+				'validation' => true,
+				'css_class'  => 'large-text',
+				'format'     => '%s',
+			],
+			'cc'      => [
+				'input'      => 'text',
+				'label'      => esc_html_x(
+					'CC',
+					'Label for the "Carbon Copy" field used for additional email addresses',
+					'event_espresso'
+				),
+				'type'       => 'string',
+				'required'   => false,
+				'validation' => true,
+				'css_class'  => 'large-text',
+				'format'     => '%s',
+			],
+			'from'    => [
+				'input'      => 'text',
+				'label'      => esc_html_x(
+					'From',
+					'Label for the "From" field for email addresses.',
+					'event_espresso'
+				),
+				'type'       => 'string',
+				'required'   => false,
+				'validation' => true,
+				'css_class'  => 'large-text',
+				'format'     => '%s',
+			],
+			'subject' => [
+				'input'      => 'text',
+				'label'      => esc_html_x(
+					'Subject',
+					'Label for the "Subject" field (short description of contents) for emails.',
+					'event_espresso'
+				),
+				'type'       => 'string',
+				'required'   => true,
+				'validation' => true,
+				'css_class'  => 'large-text',
+				'format'     => '%s',
+			],
+			'content' => '',
+			// left empty b/c it is in the "extra array" but messenger still needs needs to know this is a field.
+			'extra'   => [
+				'content' => [
+					'main'          => [
+						'input'      => 'wp_editor',
+						'label'      => esc_html__('Main Content', 'event_espresso'),
+						'type'       => 'string',
+						'required'   => false,
+						'validation' => true,
+						'format'     => '%s',
+						'rows'       => '15',
+					],
+					'event_list'    => [
+						'input'               => 'wp_editor',
+						'label'               => '[EVENT_LIST]',
+						'type'                => 'string',
+						'required'            => false,
+						'validation'          => true,
+						'format'              => '%s',
+						'rows'                => '15',
+						'shortcodes_required' => ['[EVENT_LIST]'],
+					],
+					'attendee_list' => [
+						'input'               => 'textarea',
+						'label'               => '[ATTENDEE_LIST]',
+						'type'                => 'string',
+						'required'            => false,
+						'validation'          => true,
+						'format'              => '%s',
+						'css_class'           => 'large-text',
+						'rows'                => '5',
+						'shortcodes_required' => ['[ATTENDEE_LIST]'],
+					],
+					'ticket_list'   => [
+						'input'               => 'textarea',
+						'label'               => '[TICKET_LIST]',
+						'type'                => 'string',
+						'required'            => false,
+						'validation'          => true,
+						'format'              => '%s',
+						'css_class'           => 'large-text',
+						'rows'                => '10',
+						'shortcodes_required' => ['[TICKET_LIST]'],
+					],
+					'datetime_list' => [
+						'input'               => 'textarea',
+						'label'               => '[DATETIME_LIST]',
+						'type'                => 'string',
+						'required'            => false,
+						'validation'          => true,
+						'format'              => '%s',
+						'css_class'           => 'large-text',
+						'rows'                => '10',
+						'shortcodes_required' => ['[DATETIME_LIST]'],
+					],
+				],
+			],
+		];
+	}
+
+
+	/**
+	 * See definition of this class in parent
+	 */
+	protected function _set_default_message_types()
+	{
+		$this->_default_message_types = [
+			'payment',
+			'payment_refund',
+			'registration',
+			'not_approved_registration',
+			'pending_approval',
+		];
+	}
+
+
+	/**
+	 * @see   definition of this class in parent
+	 * @since 4.5.0
+	 */
+	protected function _set_valid_message_types()
+	{
+		$this->_valid_message_types = [
+			'payment',
+			'registration',
+			'not_approved_registration',
+			'declined_registration',
+			'cancelled_registration',
+			'pending_approval',
+			'registration_summary',
+			'payment_reminder',
+			'payment_declined',
+			'payment_refund',
+		];
+	}
+
+
+	/**
+	 * setting up admin_settings_fields for messenger.
+	 */
+	protected function _set_admin_settings_fields()
+	{
+	}
+
+
+	/**
+	 * We just deliver the messages don't kill us!!
+	 *
+	 * @return bool|WP_Error true if message delivered, false if it didn't deliver OR bubble up any error object if
+	 *              present.
+	 * @throws EE_Error
+	 * @throws Exception
+	 */
+	protected function _send_message()
+	{
+		$success = wp_mail(
+			$this->_to,
+			// some old values for subject may be expecting HTML entities to be decoded in the subject
+			// and subjects aren't interpreted as HTML, so there should be no HTML in them
+			wp_strip_all_tags(wp_specialchars_decode($this->_subject, ENT_QUOTES)),
+			$this->_body(),
+			$this->_headers()
+		);
+		if (! $success) {
+			EE_Error::add_error(
+				sprintf(
+					esc_html__(
+						'The email did not send successfully.%3$sThe WordPress wp_mail function is used for sending mails but does not give any useful information when an email fails to send.%3$sIt is possible the "to" address (%1$s) or "from" address (%2$s) is invalid.%3$s',
+						'event_espresso'
+					),
+					$this->_to,
+					$this->_from,
+					'<br />'
+				),
+				__FILE__,
+				__FUNCTION__,
+				__LINE__
+			);
+		}
+		return $success;
+	}
+
+
+	/**
+	 * see parent for definition
+	 *
+	 * @return string html body of the message content and the related css.
+	 * @throws EE_Error
+	 * @throws Exception
+	 */
+	protected function _preview()
+	{
+		return $this->_body(true);
+	}
+
+
+	/**
+	 * Setup headers for email
+	 *
+	 * @access protected
+	 * @return string formatted header for email
+	 */
+	protected function _headers()
+	{
+		$this->_ensure_has_from_email_address();
+		$from    = $this->_from;
+		$headers = [
+			'From:' . $from,
+			'Reply-To:' . $from,
+			'Content-Type:text/html; charset=utf-8',
+		];
+
+		/**
+		 * Second condition added as a result of https://events.codebasehq.com/projects/event-espresso/tickets/11416 to
+		 * cover back compat where there may be users who have saved cc values in their db for the newsletter message
+		 * type which they are no longer able to change.
+		 */
+		if (! empty($this->_cc) && ! $this->_incoming_message_type instanceof EE_Newsletter_message_type) {
+			$headers[] = 'cc: ' . $this->_cc;
+		}
+
+		// but wait!  Header's for the from is NOT reliable because some plugins don't respect From: as set in the
+		// header.
+		add_filter('wp_mail_from', [$this, 'set_from_address'], 100);
+		add_filter('wp_mail_from_name', [$this, 'set_from_name'], 100);
+		return apply_filters('FHEE__EE_Email_messenger___headers', $headers, $this->_incoming_message_type, $this);
+	}
+
+
+	/**
+	 * This simply ensures that the from address is not empty.  If it is, then we use whatever is set as the site email
+	 * address for the from address to avoid problems with sending emails.
+	 */
+	protected function _ensure_has_from_email_address()
+	{
+		if (empty($this->_from)) {
+			$this->_from = get_bloginfo('admin_email');
+		}
+	}
+
+
+	/**
+	 * This simply parses whatever is set as the $_from address and determines if it is in the format {name} <{email}>
+	 * or just {email} and returns an array with the "from_name" and "from_email" as the values. Note from_name *MAY*
+	 * be empty
+	 *
+	 * @return array
+	 * @since 4.3.1
+	 */
+	private function _parse_from()
+	{
+		if (strpos($this->_from, '<') !== false) {
+			$from_name = substr($this->_from, 0, strpos($this->_from, '<') - 1);
+			$from_name = str_replace('"', '', $from_name);
+			$from_name = trim($from_name);
+
+			$from_email = substr($this->_from, strpos($this->_from, '<') + 1);
+			$from_email = str_replace('>', '', $from_email);
+			$from_email = trim($from_email);
+		} elseif (trim($this->_from) !== '') {
+			$from_name  = '';
+			$from_email = trim($this->_from);
+		} else {
+			$from_name = $from_email = '';
+		}
+		return [$from_name, $from_email];
+	}
+
+
+	/**
+	 * Callback for the wp_mail_from filter.
+	 *
+	 * @param string $from_email What the original from_email is.
+	 * @return string
+	 * @since 4.3.1
+	 */
+	public function set_from_address($from_email)
+	{
+		$parsed_from = $this->_parse_from();
+		// includes fallback if the parsing failed.
+		return is_array($parsed_from) && ! empty($parsed_from[1])
+			? $parsed_from[1]
+			: get_bloginfo('admin_email');
+	}
+
+
+	/**
+	 * Callback for the wp_mail_from_name filter.
+	 *
+	 * @param string $from_name The original from_name.
+	 * @return string
+	 * @since 4.3.1
+	 */
+	public function set_from_name($from_name)
+	{
+		$parsed_from = $this->_parse_from();
+		if (is_array($parsed_from) && ! empty($parsed_from[0])) {
+			$from_name = $parsed_from[0];
+		}
+
+		// if from name is "WordPress" let's sub in the site name instead (more friendly!)
+		// but realize the default name is HTML entity-encoded
+		return $from_name == 'WordPress' ? wp_specialchars_decode(get_bloginfo(), ENT_QUOTES) : $from_name;
+	}
+
+
+	/**
+	 * setup body for email
+	 *
+	 * @param bool $preview will determine whether this is preview template or not.
+	 * @return string formatted body for email.
+	 * @throws EE_Error
+	 * @throws Exception
+	 */
+	protected function _body($preview = false)
+	{
+		// setup template args!
+		$this->_template_args = [
+			'subject'   => $this->_subject,
+			'from'      => $this->_from,
+			'main_body' => wpautop($this->_content),
+		];
+		$body                 = $this->_get_main_template($preview);
+
+		/**
+		 * This filter allows one to bypass the CSSToInlineStyles tool and leave the body untouched.
+		 *
+		 * @type    bool $preview Indicates whether a preview is being generated or not.
+		 * @return  bool    true  indicates to use the inliner, false bypasses it.
+		 */
+		if (apply_filters('FHEE__EE_Email_messenger__apply_CSSInliner ', true, $preview)) {
+			// now if this isn't a preview, let's set up the body so it has inline styles
+			if (! $preview || (defined('DOING_AJAX') && DOING_AJAX)) {
+				$style = file_get_contents(
+					$this->get_variation(
+						$this->_tmp_pack,
+						$this->_incoming_message_type->name,
+						false,
+						'main',
+						$this->_variation
+					),
+					true
+				);
+				$CSS   = new TijsVerkoyen\CssToInlineStyles\CssToInlineStyles();
+				$body  = $CSS->convert($body, $style);
+			}
+		}
+		return $body;
+	}
+
+
+	/**
+	 * This just returns any existing test settings that might be saved in the database
+	 *
+	 * @access public
+	 * @return array
+	 * @throws EE_Error
+	 * @throws ReflectionException
+	 */
+	public function get_existing_test_settings()
+	{
+		$settings = parent::get_existing_test_settings();
+		// override subject if present because we always want it to be fresh.
+		if (is_array($settings) && ! empty($settings['subject'])) {
+			$settings['subject'] =
+				sprintf(esc_html__('Test email sent from %s', 'event_espresso'), get_bloginfo('name'));
+		}
+		return $settings;
+	}
 }