yii\base\Controller::renderPartial PHP Method

    public function renderPartial($view, $params = [])
    {
        return $this->getView()->render($view, $params, $this);
    }

 public function actionGet_product_view()
 {
     if (Yii::$app->request->isAjax) {
         $id = $_POST['id'];
         $response['update_view'] = \yii\base\Controller::renderPartial('view', ['model' => $this->findModel($id)]);
         return json_encode($response);
     }
 }