felixarntz/wp-gcs-offload

<?php
/**
 * WPGCSOffload\Core\AjaxHandler class
 *
 * @package WPGCSOffload
 * @subpackage Core
 * @author Felix Arntz <felix-arntz@leaves-and-love.net>
 * @since 0.5.0
 */

namespace WPGCSOffload\Core;

use WPGCSOffload\Admin\Settings as Settings;

if ( ! defined( 'ABSPATH' ) ) {
    die();
}

if ( ! class_exists( 'WPGCSOffload\Core\AjaxHandler' ) ) {
    /**
     * This class handles AJAX calls.
     *
     * @since 0.5.0
     */
    class AjaxHandler {
        private static $instance = null;

        public static function instance() {
            if ( null === self::$instance ) {
                self::$instance = new self();
            }

            return self::$instance;
        }

        private $actions = array();
        private $nonces = array();

        private function __construct() {
            // empty
        }

        public function register_action( $name, $callback, $nopriv = false ) {
            if ( isset( $this->actions[ $name ] ) ) {
                return false;
            }

            $this->actions[ $name ] = array(
                'callback'        => $callback,
                'nopriv'        => $nopriv,
            );

            return true;
        }

        public function add_actions() {
            if ( ! defined( 'DOING_AJAX' ) || ! DOING_AJAX ) {
                return;
            }

            foreach ( $this->actions as $action => $data ) {
                add_action( 'wp_ajax_wpgcso_' . $action, array( $this, 'request' ) );
                if ( $data['nopriv'] ) {
                    add_action( 'wp_ajax_nopriv_wpgcso_' . $action, array( $this, 'request' ) );
                }
            }
        }

        public function request() {
            $name = str_replace( 'wpgcso_', '', $_REQUEST['action'] );

            if ( ! isset( $this->actions[ $name ] ) ) {
                wp_send_json_error( __( 'Invalid action.', 'wp-gcs-offload' ) );
            }

            if ( ! is_callable( $this->actions[ $name ]['callback'] ) ) {
                wp_send_json_error( __( 'Invalid action callback.', 'wp-gcs-offload' ) );
            }

            if ( ! isset( $_REQUEST['nonce'] ) ) {
                wp_send_json_error( __( 'Missing nonce.', 'wp-gcs-offload' ) );
            }

            if ( ! check_ajax_referer( $this->get_nonce_action( $name ), 'nonce', false ) ) {
                wp_send_json_error( __( 'Invalid nonce.', 'wp-gcs-offload' ) );
            }

            $response = call_user_func( $this->actions[ $name ]['callback'], $_REQUEST );

            if ( is_wp_error( $response ) ) {
                wp_send_json_error( $response->get_error_message() );
            }

            wp_send_json_success( $response );
        }

        public function get_action_nonce( $name ) {
            if ( ! isset( $this->nonces[ $name ] ) ) {
                $this->nonces[ $name ] = wp_create_nonce( $this->get_nonce_action( $name ) );
            }
            return $this->nonces[ $name ];
        }

        private function get_nonce_action( $name ) {
            return 'wpgcso_ajax_' . $name;
        }
    }
}