We often need to display a success page after the user has submitted a form without problem. We may show some welcome message after a user registers a new account. There are many ways to implement this workflow. In this article, I will explain a method that exploits flash messages.

As we know, a flash message is a message that is available on the current and the next page request. Yii provides [CWebUser::getFlash()] and [CWebUser::setFlash()] to support this feature.

In order to implement a success page, we can have the following action code.

public function actionRegister()
{
	// display the success page if the register form was previously
	// submitted successfully
	if (Yii::app()->user->hasFlash('register.success'))
	{
		$this->render('registerSuccess', Yii::app()->user->getFlash('register.success'));
		return;
	}
	
	$model = new User('register');
	if (isset($_POST['User']))
	{
		$model->attributes = $_POST['User'];
		if ($model->save())
		{
			Yii::app()->user->setFlash('register.success', array(
				'username' => $model->username,
				'email' => $model->email,
			));
			$this->refresh();
		}
	}
	$this->render('register', array('model'=>$model));
}

We also need to create two views named register.php and registerSuccess.php, respectively. I will not give more details about these two views since they are very straightforward: one is to display the register form, the other is to display the success message.

Let me explain a bit more about the action code.

In the register action, we first check if there is a flash message named register.success. If so, it means the user has just finished registration and we should display a success page to him. We render the registerSuccess view with the register.success flash message. As I will explain shortly, the register.success flash message is an array, instead of a string. As a result, all data in this array will be available in the registerSuccess view. In this example, we will be able to use $username and $email about the new user.

Next, we see a typical model create/update action code. When the model is successfully saved, we set the flash messages with an array (NOT a string). The array contains the data that will be used to render in the success page. We call [CController::refresh()] to refresh the current page, which will discard the post data and prevent the user from resubmitting the data by reloading/refreshing the page.

So what are new stuff here?

• First, instead of saving a string as flash message, we save an array of data that will persist to the next page request.

• Second, we use the action code to control which view to render. The code conforms better to the MVC pattern.