Appointments+ Cancel Link

wpmudev-app-notification-cancel-link.php

<?php
/*
Plugin Name: Appointments+ Cancel Link
Description: Adds a cancel link in notifications. *Please read the instructions in plugin file before usage
Plugin URI: http://premium.wpmudev.org/
Version: 1.0.0
Author: Panos Lyrakis
Author URI: https://premium.wpmudev.org/profile/panoskatws
*/


/**
*   ==========  INSTRUCTIONS  ==========
*
*   1. In your wp-config file add: define( 'APP_ALLOW_CANCEL', true );
*   2. Create a new page in your admin and add this shortcode: [app_cancel_page]
*   3. Get the page id that you add the shortcode and replace 'null' at line 45 of this file with that id
*   4. Use the APP_RM_LINK placeholder in your notification messages instead of CANCEL
*/



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

		private static $_instance = null;
        public static $post_type = null;
        var $cancel_page;


        public static function get_instance() {
            if ( is_null( self::$_instance ) ) {
                self::$_instance = new WPMUDEV_APP_Notification_Cancel_Link();
            }

            return self::$_instance;
        }



        private function __construct() {

            //Please replace "null" with the id of your cancelation page in following line:
            $this->cancel_page = null;


            if( $this->cancel_page == null ) return false;

        	add_filter( 'app_confirmation_message', array( $this, 'add_cancel_link' ), 10 , 3   );
            add_filter( 'app_reminder_message',     array( $this, 'add_cancel_link' ), 10 , 3   ); 

        	add_filter( 'query_vars',               array( $this, 'query_vars' ), 10            );

            add_shortcode( 'app_cancel_page',       array( $this, 'cancel_page_sh' )            );

        }


        public function add_cancel_link( $text, $r, $app_id ){

            global $appointments;

            if ( defined( "APP_ALLOW_CANCEL" ) && APP_ALLOW_CANCEL ) {

                    $app = appointments_get_appointment( $app_id );

                    if ( $app )
                        return str_replace( 'APP_RM_LINK', add_query_arg( array( 'app_cancel'=>1, 'app_id'=>$app_id, 'app_nonce'=>md5( $app_id . $appointments->salt . strtotime( $app->created ) ) ), get_permalink( $this->cancel_page ) ), $text);
                    else
                        return str_replace( 'APP_RM_LINK', '', $text );
                }
                else
                    return str_replace( 'APP_RM_LINK', '', $text );

        }


        public function cancel_page_sh( $atts ){

            global $appointments, $post;

            if( ! is_object( $post ) || ! isset( $post->ID ) ){
                return false;
            }
            
            if ( ! defined( "APP_ALLOW_CANCEL" ) || ! APP_ALLOW_CANCEL ){

                return 'This action is not allowed! Please contact site administrator';

            }

            if( get_query_var( 'app_cancel' ) == ''
                || get_query_var( 'app_cancel' ) != 1
                || get_query_var( 'app_id' ) == ''
                || get_query_var( 'app_nonce' ) == ''
             ){
                 return 'Cheating huh?';
             }

            if( ! is_user_logged_in() ){

                $redirect = add_query_arg( array( 
                    'app_cancel'=>1, 
                    'app_id'=>get_query_var( 'app_id' ), 
                    'app_nonce'=> get_query_var( 'app_nonce' )
                ), get_permalink( $this->cancel_page ) );

                $login_page = wp_login_url( $redirect );

                return sprintf( 'You need to be logged in to cancel this Appointment. Please log in <a href="%s">here</a> ', $login_page );
            }
            

            $app = appointments_get_appointment( get_query_var( 'app_id' ) );

            if( get_current_user_id() != $app->user ){
                return 'You are not allowed to cancel this Appointment. Please contact site administrator.';
            }

            if ( appointments_update_appointment_status( $app->ID, 'removed' ) ) {
                $appointments->log( sprintf( __('Client %s cancelled appointment with ID: %s','appointments'), $appointments->get_client_name( $app->ID ), $app->ID ) );
                appointments_send_cancel_notification( $app->ID );

                do_action('app-appointments-appointment_cancelled', $app->ID);

                return 'Appointment has been canceled succesfully!';

            }
            
            do_action( 'app_cancel_failed', $app->ID );

        }


        public function query_vars( $vars ){

            $vars[] = "app_cancel";
            $vars[] = "app_id";
            $vars[] = "app_nonce";

            return $vars;

        }


    }
    
    add_action( 'plugins_loaded', function(){
        WPMUDEV_APP_Notification_Cancel_Link::get_instance();
    },10 );
}

Adds a cancel link in notifications. *Please read the instructions in plugin file before usage

/**

• ========== INSTRUCTIONS ==========
• 1. In your wp-config file add: define( 'APP_ALLOW_CANCEL', true );
• 2. Create a new page in your admin and add this shortcode: [app_cancel_page]
• 3. Get the page id that you add the shortcode and replace 'null' at line 45 of this file with that id
• 4. Use the APP_RM_LINK placeholder in your notification messages instead of CANCEL
     */