Prevents an error from being displayed if the user does not enter an email address.

dont-require-email-for-rtb.php

<?php
/**
 * Plugin Name: Don't Require Email Field for Restaurant Reservations
 * Plugin URI: http://themeofthecrop.com
 * Description: Prevents an error from being displayed if the user does not enter an email address.
 * Version: 1.0
 * Author: Theme of the Crop
 * Author URI: http://themeofthecrop.com
 * License:     GNU General Public License v2.0 or later
 * License URI: http://www.gnu.org/licenses/gpl-2.0.html
 * Requires at least: 4.0
 * Tested up to: 4.01
 *
 * Text Domain: rtbdomain
 * Domain Path: /languages/
 *
 * 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.
 *
 * 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 St, Fifth Floor, Boston, MA 02110-1301 USA
 */
if ( ! defined( 'ABSPATH' ) )
	exit;


/**
 * Remove the required attribute for the email field
 */
if ( !function_exists( 'rtbdref_unset_email_required' ) ) {
add_filter( 'rtb_booking_form_fields', 'rtbdref_unset_email_required', 10, 3 );
function rtbdref_unset_email_required( $fields, $request, $args ) {

	foreach( $fields as $fieldsetName => $fieldset) {
		if (!empty($fieldset['fields'])) {
			foreach ($fieldset['fields'] as $fieldName => $field) {
				if ($fieldName === 'email') {
					$fields[$fieldsetName]['fields']['email']['required'] = false;
				}
			}
		}
	}

	return $fields;
}
} // endif

/**
 * Adjust validation results
 */
if ( !function_exists( 'rtbdref_validate_email' ) ) {
add_action( 'rtb_validate_booking_submission', 'rtbdref_validate_email' );
function rtbdref_validate_email( $booking ) {

	// Remove any validation errors attached to the email field
	foreach( $booking->validation_errors as $key => $error ) {
		if ( $error['field'] == 'email' ) {
			unset( $booking->validation_errors[ $key ] );
		}
	}

	// If no email address is provided, add your own email address so
	// you can still send a notification email
	if ( empty( $booking->email ) ) {
		$booking->email = 'your.email@example.org';
	}

}
} // endif