felixarntz/plugin-lib

<?php
/**
 * AJAX handler class
 *
 * @package Leaves_And_Love\Plugin_Lib
 * @since 1.0.0
 */

namespace Leaves_And_Love\Plugin_Lib;

use Leaves_And_Love\Plugin_Lib\Traits\Hook_Service_Trait;
use Leaves_And_Love\Plugin_Lib\Traits\Translations_Service_Trait;
use Leaves_And_Love\Plugin_Lib\Translations\Translations_AJAX;
use WP_Error;

if ( ! class_exists( 'Leaves_And_Love\Plugin_Lib\AJAX' ) ) :

    /**
     * Class for handling AJAX requests.
     *
     * @since 1.0.0
     */
    class AJAX extends Service {
        use Hook_Service_Trait, Translations_Service_Trait;

        /**
         * Registered AJAX actions, as `$name => $args` pairs.
         *
         * @since 1.0.0
         * @var array
         */
        protected $ajax_actions = array();

        /**
         * Constructor.
         *
         * @since 1.0.0
         *
         * @param string            $prefix       The prefix for all AJAX actions.
         * @param Translations_AJAX $translations Translations instance.
         */
        public function __construct( $prefix, $translations ) {
            $this->set_prefix( $prefix );
            $this->set_translations( $translations );

            $this->setup_hooks();
        }

        /**
         * Registers an action.
         *
         * @since 1.0.0
         *
         * @param string   $name     Action name.
         * @param callable $callback Callback to handle the action. Must return a response or an error object.
         *                           Instead of a fully qualified function name, a string referencing to a method
         *                           inside this class can be passed as well. The method must then have the same
         *                           name prefixed with 'ajax_' in order to work properly.
         * @param array    $args     Optional. Additional arguments. 'nopriv' is the only supported key.
         * @return bool|WP_Error True on success, error object on failure.
         */
        public function register_action( $name, $callback, $args = array() ) {
            if ( doing_action( 'admin_init' ) || did_action( 'admin_init' ) ) {
                return new WP_Error( 'ajax_registered_too_late', sprintf( $this->get_translation( 'ajax_registered_too_late' ), '<code>admin_init</code>' ) );
            }

            if ( ! $name || isset( $this->ajax_actions[ $name ] ) ) {
                return new WP_Error( 'ajax_invalid_action_name', $this->get_translation( 'ajax_invalid_action_name' ) );
            }

            $nonce = function_exists( 'wp_create_nonce' ) ? wp_create_nonce( $this->get_nonce_action( $name ) ) : '';

            $args = wp_parse_args(
                $args,
                array(
                    'callback' => $callback,
                    'nopriv'   => false,
                    'nonce'    => $nonce,
                )
            );

            $this->ajax_actions[ $name ] = $args;

            return true;
        }

        /**
         * Handles an AJAX request.
         *
         * @since 1.0.0
         */
        public function request() {
            $request_data = wp_unslash( $_REQUEST ); // phpcs:ignore WordPress.Security.NonceVerification

            $name = str_replace( $this->get_prefix(), '', $request_data['action'] );

            if ( ! isset( $this->ajax_actions[ $name ] ) ) {
                wp_send_json_error( $this->get_translation( 'ajax_request_invalid_action' ) );
            }

            $callback = $this->ajax_actions[ $name ]['callback'];
            if ( is_string( $callback ) && ! is_callable( $callback ) ) {
                $callback = array( $this, 'ajax_' . $this->ajax_actions[ $name ]['callback'] );
            }

            if ( ! is_callable( $callback ) ) {
                wp_send_json_error( $this->get_translation( 'ajax_request_invalid_callback' ) );
            }

            $nonce_field = isset( $request_data['nonce'] ) ? 'nonce' : '_wpnonce';

            if ( ! check_ajax_referer( $this->get_nonce_action( $name ), $nonce_field, false ) ) {
                wp_send_json_error( $this->get_translation( 'ajax_request_invalid_nonce' ) );
            }

            $response = call_user_func( $callback, $request_data );

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

            wp_send_json_success( $response );
        }

        /**
         * Returns a nonce for a specific AJAX action.
         *
         * @since 1.0.0
         *
         * @param string $action Action name.
         * @return string Nonce for the action, or empty string if action not registered.
         */
        public function get_nonce( $action ) {
            if ( ! isset( $this->ajax_actions[ $action ] ) ) {
                return '';
            }

            if ( empty( $this->ajax_actions[ $action ]['nonce'] ) ) {
                if ( ! function_exists( 'wp_create_nonce' ) ) {
                    return '';
                }

                $this->ajax_actions[ $action ]['nonce'] = wp_create_nonce( $this->get_nonce_action( $action ) );
            }

            return $this->ajax_actions[ $action ]['nonce'];
        }

        /**
         * Adds AJAX action hooks.
         *
         * @since 1.0.0
         */
        protected function add_ajax_actions() {
            if ( ! wp_doing_ajax() ) {
                return;
            }

            $prefix = $this->get_prefix();

            foreach ( $this->ajax_actions as $name => $args ) {
                add_action( 'wp_ajax_' . $prefix . $name, array( $this, 'request' ) );

                if ( $args['nopriv'] ) {
                    add_action( 'wp_ajax_nopriv_' . $prefix . $name, array( $this, 'request' ) );
                }
            }
        }

        /**
         * Returns the action name to use when working with nonces.
         *
         * @since 1.0.0
         *
         * @param string $action Action name.
         * @return string Nonce action.
         */
        protected function get_nonce_action( $action ) {
            return $this->get_prefix() . 'ajax_' . $action;
        }

        /**
         * Sets up all action and filter hooks for the service.
         *
         * This method must be implemented and then be called from the constructor.
         *
         * @since 1.0.0
         */
        protected function setup_hooks() {
            $this->actions = array(
                array(
                    'name'     => 'admin_init',
                    'callback' => array( $this, 'add_ajax_actions' ),
                    'priority' => 10,
                    'num_args' => 0,
                ),
            );
        }
    }

endif;