public function actionAddChild()
 {
     $parent_id = Yii::$app->request->post('parent_id');
     $category_name = Yii::$app->request->post('node_name');
     $category_type_id = Yii::$app->request->post('cur_cat_type_id');
     if (Yii::$app->getRequest()->isAjax && $parent_id && $category_name && $category_type_id) {
         return Categories::addChildCategory($parent_id, $category_name, $category_type_id);
     }
 }