Remove the party field from your Restaurant Reservations booking form.

remove-party-for-rtb.php

<?php
/**
 * Plugin Name: Remove Party Field for Restaurant Reservations
 * Plugin URI: http://themeofthecrop.com
 * Description: Removes the party field and prevents the associated errors from occurring.
 * 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 party field from the reservation fieldset
 */
if ( !function_exists( 'rtbrpf_remove_party' ) ) {
add_filter( 'rtb_booking_form_fields', 'rtbrpf_remove_party', 10, 2 );
function rtbrpf_remove_party( $fields, $request ) {

	$fields['reservation']['fields']['party']['callback'] = '__return_false';

	return $fields;
}
} // endif;

/**
 * Adjust validation results so the party is not required
 */
if ( !function_exists( 'rtbrpf_allow_empty_party' ) ) {
add_action( 'rtb_validate_booking_submission', 'rtbrpf_allow_empty_party', 100 );
function rtbrpf_allow_empty_party( $booking ) {

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

}
} // endif