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Symfony2 – Franz Jordán 2011
$session->setLocale('fr');
These attributes will remain on the user for the remainder of that user's session.
Flash Messages
You can also store small messages that will be stored on the user's session for exactly one
additional request. This is useful when processing a form: you want to redirect and have a
special message shown on the next request. These types of messages are called "flash"
messages.
For example, imagine you're processing a form submit:
public function updateAction()
{
$form = $this->createForm(...);
$form->bindRequest($this->getRequest());
if ($form->isValid()) {
// do some sort of processing
$this->get('session')->setFlash('notice', 'Your changes were saved!');
return $this->redirect($this->generateUrl(...));
}
return $this->render(...);
}
After processing the request, the controller sets a notice flash message and then redirects.
The name (notice) isn't significant - it's just what you're using to identify the type of the
message.
In the template of the next action, the following code could be used to render
the notice message:
Twig
{% if app.session.hasFlash('notice') %}
{{ app.session.flash('notice') }}
{% endif %}
By design, flash messages are meant to live for exactly one request (they're "gone in a flash").
They're designed to be used across redirects exactly as you've done in this example.
The Response Object
The only requirement for a controller is to return a Response object. The Response class is a
PHP abstraction around the HTTP response - the text-based message filled with HTTP headers
and content that's sent back to the client:
// create a simple Response with a 200 status code (the default)
$response = new Response('Hello '.$name, 200);
// create a JSON-response with a 200 status code
$response = new Response(json_encode(array('name' => $name)));
$response->headers->set('Content-Type', 'application/json');
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