How to register a new Request Format and Mime Type¶
Every Request
has a “format” (e.g. html
, json
), which is used
to determine what type of content to return in the Response
. In fact,
the request format, accessible via
:method:`Symfony\\Component\\HttpFoundation\\Request::getRequestFormat`,
is used to set the MIME type of the Content-Type
header on the Response
object. Internally, Symfony contains a map of the most common formats (e.g.
html
, json
) and their associated MIME types (e.g. text/html
,
application/json
). Of course, additional format-MIME type entries can
easily be added. This document will show how you can add the jsonp
format
and corresponding MIME type.
Create an kernel.request
Listener¶
The key to defining a new MIME type is to create a class that will “listen” to
the kernel.request
event dispatched by the Symfony kernel. The
kernel.request
event is dispatched early in Symfony’s request handling
process and allows you to modify the request object.
Create the following class, replacing the path with a path to a bundle in your project:
// src/Acme/DemoBundle/RequestListener.php
namespace Acme\DemoBundle;
use Symfony\Component\HttpKernel\HttpKernelInterface;
use Symfony\Component\HttpKernel\Event\GetResponseEvent;
class RequestListener
{
public function onKernelRequest(GetResponseEvent $event)
{
$event->getRequest()->setFormat('jsonp', 'application/javascript');
}
}
Registering your Listener¶
As for any other listener, you need to add it in one of your configuration
file and register it as a listener by adding the kernel.event_listener
tag:
- XML
<!-- app/config/config.xml --> <?xml version="1.0" ?> <container xmlns="http://symfony.com/schema/dic/services" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://symfony.com/schema/dic/services http://symfony.com/schema/dic/services/services-1.0.xsd"> <services> <service id="acme.demobundle.listener.request" class="Acme\DemoBundle\RequestListener"> <tag name="kernel.event_listener" event="kernel.request" method="onKernelRequest" /> </service> </services> </container>
- YAML
# app/config/config.yml services: acme.demobundle.listener.request: class: Acme\DemoBundle\RequestListener tags: - { name: kernel.event_listener, event: kernel.request, method: onKernelRequest }
- PHP
# app/config/config.php $definition = new Definition('Acme\DemoBundle\RequestListener'); $definition->addTag('kernel.event_listener', array('event' => 'kernel.request', 'method' => 'onKernelRequest')); $container->setDefinition('acme.demobundle.listener.request', $definition);
At this point, the acme.demobundle.listener.request
service has been
configured and will be notified when the Symfony kernel dispatches the
kernel.request
event.
Tip
You can also register the listener in a configuration extension class (see Importing Configuration via Container Extensions for more information).