common\components\Controller::message PHP Method

    public function message($message, $type = 'info', $redirect = null, $resultType = null)
    {
        $resultType === null && ($resultType = Yii::$app->getRequest()->getIsAjax() ? 'json' : 'html');
        is_array($redirect) && ($redirect = Url::to($redirect));
        $data = ['type' => $type, 'message' => $message, 'redirect' => $redirect];
        if ($resultType === 'json') {
            Yii::$app->getResponse()->format = Response::FORMAT_JSON;
            return $data;
        } elseif ($resultType === 'html') {
            return $this->render('/common/message', $data);
        }
    }