Add custom member application fields as substitution variables for email messages from the OEIS Member Application Management

oeis-substitution-variables.php

<?php
/*
Plugin Name: OEIS Member Application Management: Custom Substitution Variables
Plugin URI: https://eighty20results.com/paid-memberships-pro/do-it-for-me/
Description: Add custom, pre-defined Register Helper fields, as email substitution variables for the messages sent by the OEIS Member Application Management plugin
Version: 1.1
Requires at least: 4.9
Tested up to: 4.9.8
Author: Eighty / 20 Results by Wicked Strong Chicks, LLC <thomas@eighty20results.com>
Author URI: https://eighty20results.com/thomas-sjolshagen/
License URI: https://www.gnu.org/licenses/old-licenses/gpl-2.0.html
License: GPLv2 or later

 * Copyright (C) 2018  Thomas Sjolshagen - Eighty / 20 Results by Wicked Strong Chicks, LLC
 *
 * This program is free software; you can redistribute it and/or
 * modify it under the terms of the GNU General Public License
 * as published by the Free Software Foundation; either version 2
 * of the License, or (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA.
 */

namespace E20R\Customizations\Custom_Filters;

use OEIS\Application_Management\Models\OEIS_Data;

/**
 * Adds a defined Register Helper field as a substitution variable for the OEIS Member Application Management plugin
 *
 * @param array $keys_by_type
 * @param int   $msg_type
 *
 * @return array
 */
function oeisCustomSubstitutionVars( $keys_by_type, $msg_type ) {
	
	// OEIS Member Application Management plugin isn't active...
	if ( ! isset( OEIS_DATA::PEER_SUPPORT ) ) {
		return $keys_by_type;
	}
	
	$types = array();
	
	if ( empty( $type ) ) {
		
		// No type(s) specified so add them all
		foreach (
			array(
				OEIS_Data::PEER_SUPPORT,
				OEIS_Data::MEMBER_SUPPORT,
				OEIS_Data::MEMBER_COMMITTEE,
			) as $msg_type
		) {
			$types[] = $msg_type;
		}
	}
	
	// Type specified, but not as a list. Converting to a single element list
	if ( ! is_array( $type ) ) {
		$types[] = $type;
	}
	
	// Process all types and add variables for each of them
	foreach ( $types as $msg_type ) {
		
		/**
		 * TODO: To add/extend/change the list, add a new `$keys_by_type[ $msg_type ][] = '...';` line for the Register Helper field you need to include
		 *
		 * This will be available to _all_ notification types
		 */
		$keys_by_type[ $msg_type ][] = 'active_mbr_support_type';
		$keys_by_type[ $msg_type ][] = 'current_mbr_sup_name';
		$keys_by_type[ $msg_type ][] = 'current_mbr_sup_email';
		$keys_by_type[ $msg_type ][] = 'ext_phys_1_sup_name';
		$keys_by_type[ $msg_type ][] = 'ext_phys_1_sup_email';
		$keys_by_type[ $msg_type ][] = 'ext_phys_2_sup_name';
		$keys_by_type[ $msg_type ][] = 'ext_phys_1_sup_email';
	}
	
	return $keys_by_type;
}

add_filter( 'oeis_substitution_variable_names', 'oeisCustomSubstitutionVars', 10, 2 );