/**
  * Validate ActiveRecord model and generate error & warning
  * If validation is successful then it will display all other buttons in form
  * @param integer $id
  * @return mixed
  */
 public function actionValidate($id = 0)
 {
     $model = $this->findModel($id);
     $data = $model->checkError(true);
     if (isset($data['errors'])) {
         $data['html'] = '';
         foreach ($data['errors'] as $type => $errordata) {
             if ($type == 'error') {
                 $class = 'alert-danger';
                 $icon = 'fa fa-ban';
             } elseif ($type == 'warning') {
                 $class = 'alert-warning';
                 $icon = 'fa fa-warning';
             } else {
                 $class = 'alert-info';
                 $icon = 'fa fa-info';
             }
             foreach ($errordata as $field => $message) {
                 $data['html'] .= \yii\adminUi\widget\Alert::widget(['options' => ['class' => $class . ' alert-dismissable'], 'icon' => $icon, 'closeButton' => [], 'body' => $field . ': ' . $message]);
             }
         }
     }
     header("content-type:application/json");
     echo \yii\helpers\Json::encode($data);
     Yii::$app->end();
 }
    <p><?php 
    echo $flash;
    ?>
</p>
    <?php 
    Alert::end();
}
if ($flash = Yii::$app->session->getFlash("restaurant_chian_notification_error")) {
    Alert::begin(['options' => ['class' => 'alert-danger alert-dismissable'], 'icon' => 'fa fa-info', 'closeButton' => []]);
    ?>
    <p><?php 
    echo $flash;
    ?>
</p>
    <?php 
    Alert::end();
}
Row::begin();
Column::begin();
Box::begin(['type' => Box::TYPE_INFO, 'header' => $this->title, 'headerIcon' => 'fa fa-gear']);
echo $this->render('_restaurant_search', ['model' => $searchModel, 'restaurantDetails' => $restaurantDetails]);
$queryArray = yii::$app->getRequest()->getQueryParams();
if ($queryArray['RestaurantSearch']) {
    $form = ActiveForm::begin(['action' => ['tag'], 'method' => 'post']);
    echo Html::submitButton('Allocate', ['class' => 'btn btn-success']);
    echo GridView::widget(['filterPosition' => false, 'dataProvider' => $dataProvider, 'filterModel' => $searchModel, 'tableOptions' => ['class' => 'table table-bordered'], 'columns' => ['Id', 'name', 1 ? ['class' => 'yii\\grid\\CheckboxColumn', 'multiple' => false] : []]]);
    echo Html::input('hidden', 'chainId', $restaurantDetails->Id);
    ActiveForm::end();
}
Box::end();
Column::end();