我有一个插件作为一个类，其中我使用一个shortcode属性来填充$outlet变量。然而，尽管sanitize_text_field($atts[\'outlet\']) 返回所需字符串，$this->outlet = sanitize_text_field($atts[\'outlet\']) 未更新的值$outlet. 如果我为类的$outlet 最初，它在example_callback(). 插件的所有其他功能都按预期工作。只是wp_news_shortcode() 未分配$attr 价值

总之，我需要在ajax_callback() 功能是否有我忽略的东西？

class Example _Search {
       
        private static $instance = null;

        public $outlet;

        public function __construct() {
            $this->settings = array(
                \'plugin_path\' => plugin_dir_path(__FILE__),
                \'plugin_url\' => plugin_dir_url(__FILE__),
                \'plugin_base\' => dirname(plugin_basename(__FILE__)),
                \'plugin_base_url\' => plugin_basename(__FILE__),
                \'plugin_file\' => __FILE__,
                \'plugin_version\' => \'1.0.0\',
            );

            $this->run_plugin();
        }

         /**
         * Singleton.
         *
         * @return self Main instance.
         */
        public static function init() {
            if (is_null(self::$instance)) {
                self::$instance = new self();
            }
            return self::$instance;
        }

        /**
         * Main plugin function.
         *
         * @since 1.0.0
         */
        public function run_plugin() {
            add_action(\'wp_ajax_example_callback\', array($this, \'example_callback\'));
            add_action(\'wp_ajax_nopriv_example_callback\', array($this, \'example_callback\'));
            add_shortcode(\'wp_example_search\', array($this, \'wp_example_shortcode\'));
        }

       

        /**
         * Example Search shortcode. Adds form to page and stores "outlet" attribute to options.
         *
         * @since 1.0.0
         * @param array $atts An associative array of attributes.
         * @return string
         */
        public function wp_example_shortcode($atts) {
            $atts = shortcode_atts(
                array(
                    \'outlet\' => \'google\',
                ),
                $atts
            );
            $this->outlet = sanitize_text_field($atts[\'outlet\']);

            $content = \'\';
            $view = $this->get_view_path(\'form.php\');
            if (file_exists($view)) {
                ob_start();
                include $view;
                $content = ob_get_clean();
            }
            return $content;
        }

        /**
         * Get the path to view.
         *
         * @param string $view_name View name.
         * @param string|boolean $sub_dir_name The sub-directory.
         * @return string
         */
        public function get_view_path($view_name, $sub_dir_name = false) {
            $path = $rel_path = \'\';
            $plugin_base = \'wp-example-search\';
            if (!empty($sub_dir_name)) {
                $rel_path .= "/{$sub_dir_name}";
            }
            $rel_path .= "/{$view_name}";
            $path = $this->settings[\'plugin_path\'] . \'views\' . $rel_path;
            return $path;
        }

        /**
         * Handle AJAX request.
         */
        public function example_callback() {

            $_POST = filter_input_array(INPUT_POST, FILTER_SANITIZE_STRING);

            if (isset($_POST[\'data\'])) {
                $form_data = ($_POST[\'data\']);
                $keyword = trim($form_data[\'keyword\']);

                $endpoint = \'https://example.com?q=\' . rawurlencode($keyword) . \'&domains=\' . 
                $this->outlet . \'.com\';
                
                ];
                $response = wp_remote_get($endpoint);
                $response_body = wp_remote_retrieve_body($response);
                $result = json_decode($response_body);
                $result_items = $result->items;

                if (is_array($result) && !is_wp_error($result)) {
                    $error_message = $result->get_error_message();
                    echo "Something went wrong: $error_message";
                }  else {
                    $content = \'\';
                    $view = $this->get_view_path(\'article.php\');
                    if (file_exists($view)) {
                        ob_start();
                        include $view;
                        $content = ob_get_clean();
                    }
                    echo $content;
                }
            }

            die();

        }
    }

    Example_Search::init();