<?php
/*
* This file is part of the Symfony package.
*
* (c) Fabien Potencier <[email protected]>
*
* For the full copyright and license information, please view the LICENSE
* file that was distributed with this source code.
*/
namespace Symfony\Component\HttpKernel\EventListener;
use Symfony\Component\EventDispatcher\EventSubscriberInterface;
use Symfony\Component\HttpKernel\Event\FilterResponseEvent;
use Symfony\Component\HttpKernel\KernelEvents;
/**
* Saves the session, in case it is still open, before sending the response/headers.
*
* This ensures several things in case the developer did not save the session explicitly:
*
* * If a session save handler without locking is used, it ensures the data is available
* on the next request, e.g. after a redirect. PHPs auto-save at script end via
* session_register_shutdown is executed after fastcgi_finish_request. So in this case
* the data could be missing the next request because it might not be saved the moment
* the new request is processed.
* * A locking save handler (e.g. the native 'files') circumvents concurrency problems like
* the one above. But by saving the session before long-running things in the terminate event,
* we ensure the session is not blocked longer than needed.
* * When regenerating the session ID no locking is involved in PHPs session design. See
* https://bugs.php.net/bug.php?id=61470 for a discussion. So in this case, the session must
* be saved anyway before sending the headers with the new session ID. Otherwise session
* data could get lost again for concurrent requests with the new ID. One result could be
* that you get logged out after just logging in.
*
* This listener should be executed as one of the last listeners, so that previous listeners
* can still operate on the open session. This prevents the overhead of restarting it.
* Listeners after closing the session can still work with the session as usual because
* Symfonys session implementation starts the session on demand. So writing to it after
* it is saved will just restart it.
*
* @author Tobias Schultze <http://tobion.de>
*/
class SaveSessionListener implements EventSubscriberInterface
{
public function onKernelResponse(FilterResponseEvent $event)
{
if (!$event->isMasterRequest()) {
return;
}
$session = $event->getRequest()->getSession();
if ($session && $session->isStarted()) {
$session->save();
}
}
public static function getSubscribedEvents()
{
return array(
// low priority but higher than StreamedResponseListener
KernelEvents::RESPONSE => array(array('onKernelResponse', -1000)),
);
}
}