Using flash messages_Yii 1.1 Application Development Cookbook-QQ阅读男生都市网

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Using flash messages

When you are editing a model with a form, when you are deleting a model, or doing any other operation, it is good to tell users if it went fine or if there was an error. Typically, after some kind of action, such as editing a form, a redirect will happen and we need to display a message on the page we want to go to. However, how to pass it from the current page to the redirect target and clean afterwards? Flash messages will help us.

Getting ready

Set up a new application using yiic webapp.

How to do it...

Let's create a protected/controllers/WebsiteController.php controller as follows:

class WebsiteController extends CController
{
   function actionOk()
   {
      Yii::app()->user->setFlash('success', 'Everything went fine!');
      $this->redirect('index');
   }

   function actionBad()
   {
      Yii::app()->user->setFlash('error', 'Everything went wrong!');
      $this->redirect('index');
   }

   function actionIndex()
   {
      $this->render('index');
   }
}

Additionally, create the protected/views/website/index.php view as follows:

<?php if(Yii::app()->user->hasFlash('success')):?>
<div class="flash-notice">
   <?php echo Yii::app()->user->getFlash('success')?>
</div>
<?php endif?>
<?php if(Yii::app()->user->hasFlash('error')):?>
<div class="flash-error">
   <?php echo Yii::app()->user->getFlash('error')?>
</div>
<?php endif?>

Now, if we go to http://example.com/website/ok, we'll be redirected to http://example.com/website/index and a success message will be displayed. Moreover, if we go to http://example.com/website/bad, we will be redirected to the same page, but with an error message. Refreshing the index page will hide the message.

How it works...

We are setting a flash message with Yii::app()->user->setFlash('success', 'Everything went fine!'), for example, calling CWebUser::setFlash. Internally, it is saving a message into a user state, so in the lowest level, our message is being kept in $_SESSION until Yii::app()->user->getFlash('success') is called and the $_SESSION key is deleted.

There's more…

The following URL contains an API reference of CWebUser and will help you to understand flash messages better:

http://www.yiiframework.com/doc/api/CWebUser