Adds a minimum party size setting to the Restaurant Reservations plugin.

party-limits-for-rtb.php

<?php
/**
 * Plugin Name: Party Limits for Restaurant Reservations
 * Plugin URI: http://themeofthecrop.com
 * Description: Adds a minimum party size setting to the Restaurant Reservations plugin.
 * Version: 0.3
 * 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
 *
 * Text Domain: party-limits-for-rtb
 * 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;

if ( !class_exists( 'plrtbInit' ) ) {
class plrtbInit {

	/**
	 * The single instance of this class
	 */
	private static $instance;

	/**
	 * Path to the plugin directory
	 */
	static $plugin_dir;

	/**
	 * URL to the plugin
	 */
	static $plugin_url;

	/**
	 * Create or retrieve the single instance of the class
	 *
	 * @since 0.1
	 */
	public static function instance() {

		if ( !isset( self::$instance ) ) {

			self::$instance = new plrtbInit;

			self::$plugin_dir = untrailingslashit( plugin_dir_path( __FILE__ ) );
			self::$plugin_url = untrailingslashit( plugin_dir_url( __FILE__ ) );

			self::$instance->init();
		}

		return self::$instance;
	}

	/**
	 * Initialize the plugin and register hooks
	 */
	public function init() {

		// Load the textdomain
		add_action( 'init', array( $this, 'load_textdomain' ) );

		if ( !defined( 'RTB_BOOKING_POST_TYPE' ) ) {
			return;
		}

		// Modify party field options
		add_filter( 'rtb_form_party_options', array( $this, 'modify_form_party_options' ) );

		// Validate party field submission
		add_action( 'rtb_validate_booking_submission', array( $this, 'validate_booking_submission' ) );

		// Add min party size setting
		add_filter( 'rtb_settings_page', array( $this, 'add_settings' ) );

	}

	/**
	 * Load the plugin textdomain for localistion
	 * @since 0.0.1
	 */
	public function load_textdomain() {
		load_plugin_textdomain( 'party-limits-for-rtb', false, plugin_basename( dirname( __FILE__ ) ) . '/languages/' );
	}

	/**
	 * Modify the select options in the booking form's party field
	 *
	 * @since 0.0.1
	 */
	public function modify_form_party_options( $options ) {

		global $rtb_controller;
		$min = (int) $rtb_controller->settings->get_setting( 'party-size-min' );

		$new_options = array();
		for( $i = $min; $i < count( $options ); $i++ ) {
			$new_options[$i] = $i;
		}

		return $new_options;
	}

	/**
	 * Only allow valid party sizes
	 */
	public function validate_booking_submission( $booking ) {

		global $rtb_controller;
		$max = $rtb_controller->settings->get_setting( 'party-size' );
		$min = $rtb_controller->settings->get_setting( 'party-size-min' );

		$party = absint( $booking->party );
		if ( $party < $min || $party > $max ) {

			// Remove any existing errors on the party field so we
			// don't end up with duplicates
			for( $i = 0; $i < count( $booking->validation_errors ); $i++ ) {
				if ( $booking->validation_errors[$i]['field'] === 'party' ) {
					unset( $booking->validation_errors[$i] );
				}
			}

			$booking->validation_errors[] = array(
				'field'		=> 'party',
				'error_msg'	=> 'Booking request party is invalid',
				'message'	=> sprintf( __( 'Sorry, we only take bookings for parties of %s to %s people.', 'party-limits-for-rtb' ), $min, $max ),
			);

			$booking->validation_errors = array_filter( $booking->validation_errors );
		}
	}

	/**
	 * Add a min party size setting
	 */
	public function add_settings( $sap ) {

		global $rtb_controller;

		$sap->add_setting(
			'rtb-settings',
			'rtb-general',
			'select',
			array(
				'id'            => 'party-size-min',
				'title'         => __( 'Min Party Size', 'party-limits-for-rtb' ),
				'description'   => __( 'Set a minimum allowed party size for bookings.', 'party-limits-for-rtb' ),
				'blank_option'  => false,
				'options'       => $rtb_controller->settings->get_party_size_setting_options(),
			)
		);

		return $sap;
	}
}
} // endif;

/**
 * This function returns one plrtbInit instance everywhere
 * and can be used like a global, without needing to declare the global.
 *
 * Example: $plrtb = plrtbInit();
 */
if ( !function_exists( 'plrtbInit' ) ) {
function plrtbInit() {
	return plrtbInit::instance();
}
add_action( 'plugins_loaded', 'plrtbInit' );
} // endif;