Create additional communication in WPMU Membership2

code.php

<?php

add_filter( 'ms_model_communication_get_communication_types', function( $types ) {
	$types[] = 'my_custom_com_types';
	
	return $types;
}, 10 );

add_filter( 'ms_model_communication_get_communication_type_titles', function( $type_titles ) {
	$type_titles['my_custom_com_types'] = 'My Custom COM Types';
	
	return $type_titles;
}, 10 );

add_filter( 'ms_model_communication_get_communication_type_classes', function( $type_classes ) {
	$type_classes['my_custom_com_types'] = 'MS_Model_My_Custom_COM_Type';
	
	return $type_classes;
}, 10 );

class MS_Model_My_Custom_COM_Type extends MS_Model_Communication{
	/**
	 * Add action to credit card expire event.
	 *
	 * Related Action Hooks:
	 * - ms_model_event_paid
	 *
	 * @since  1.0.0
	 * @var string The communication type.
	 */
	protected $type = 'my_custom_com_types';

	/**
	 * Get communication description.
	 *
	 * @since  1.0.0
	 * @return string The description.
	 */
	public function get_description() {
		return __(
			'My Custom type description.', 'membership2'
		);
	}

	/**
	 * Communication default communication.
	 *
	 * @since  1.0.0
	 */
	public function reset_to_default() {
		parent::reset_to_default();

		$this->subject = sprintf(
			__( 'My Custom Type Subject %s', 'membership2' ),
			self::COMM_VAR_BLOG_NAME
		);
		$this->message = self::get_default_message();
		$this->enabled = false;

		do_action(
			'ms_model_communication_reset_to_default_after',
			$this->type,
			$this
		);
	}

	/**
	 * Get default email message.
	 *
	 * @since  1.0.0
	 * @return string The email message.
	 */
	public static function get_default_message() {
		$subject = sprintf(
			__( 'Hi %1$s,', 'membership2' ),
			self::COMM_VAR_USERNAME
		);
		$body_notice = sprintf(
			__( 'Thank you! Your <strong>%1$s</strong> Membership at %2$s is now activated!', 'membership2' ),
			self::COMM_VAR_MS_NAME,
			self::COMM_VAR_BLOG_NAME
		);
		$body_account = sprintf(
			__( 'You can review and edit your membership details now here: %1$s', 'membership2' ),
			self::COMM_VAR_MS_ACCOUNT_PAGE_URL
		);
		$body_invoice = __( 'Here is the most recent payment information for your subscription:', 'membership2' );

		$html = sprintf(
			'<h2>%1$s</h2><br /><br />%2$s<br /><br />%3$s<br /><br />%4$s<br /><br />%5$s',
			$subject,
			$body_notice,
			$body_account,
			$body_invoice,
			self::COMM_VAR_MS_INVOICE
		);

		return apply_filters(
			'ms_model_communication_my_type_get_default_message',
			$html
		);
	}

	/**
	 * Process communication registration.
	 *
	 * @since  1.0.0
	 */
	public function process_communication( $event, $subscription ) {
		$membership = $subscription->get_membership();

		// Only process Paid memberships here!
		// Email for free memberships is in MS_Model_Communiction_Registration_Free
		if ( $membership->is_free() ) { return; }

		do_action(
			'ms_model_communication_my_type_process_before',
			$subscription,
			$event,
			$this
		);

		$this->send_message( $subscription );

		do_action(
			'ms_model_communication_my_type_process_after',
			$subscription,
			$event,
			$this
		);
	}
}