public function actionConfig()
    {
        // valid keys
        $keys = [Config::HTTP_EXCEPTION_NAV_ID];
        
        foreach (Yii::$app->request->bodyParams as $key => $value) {
            if (in_array($key, $keys)) {
                Config::set($key, $value);
            }
        }
        
        $data = [];
        $data[Config::HTTP_EXCEPTION_NAV_ID] = Config::get(Config::HTTP_EXCEPTION_NAV_ID, 0);
        $data['previewUrl'] = $this->module->previewUrl;
        return $data;
    }