<?php

/*

* This file is part of the FOSHttpCacheBundle package.

*

* (c) FriendsOfSymfony <http://friendsofsymfony.github.com/>

*

* For the full copyright and license information, please view the LICENSE

* file that was distributed with this source code.

*/

namespace FOS\HttpCacheBundle\EventListener;

use FOS\HttpCache\UserContext\HashGenerator;

use Symfony\Component\EventDispatcher\EventSubscriberInterface;

use Symfony\Component\HttpFoundation\RequestMatcherInterface;

use Symfony\Component\HttpKernel\Event\FilterResponseEvent;

use Symfony\Component\HttpKernel\Event\GetResponseEvent;

use Symfony\Component\HttpFoundation\Response;

use Symfony\Component\HttpKernel\HttpKernelInterface;

use Symfony\Component\HttpKernel\KernelEvents;

/**

* Check requests and responses with the matcher.

*

* Abort context hash requests immediately and return the hash.

* Add the vary information on responses to normal requests.

*

* @author Stefan Paschke <[email protected]>

* @author Joel Wurtz <[email protected]>

*/

class UserContextSubscriber implements EventSubscriberInterface

{

/**

* @var RequestMatcherInterface

*/

private $requestMatcher;

/**

* @var HashGenerator

*/

private $hashGenerator;

/**

* @var string[]

*/

private $userIdentifierHeaders;

/**

* @var string

*/

private $hashHeader;

/**

* @var integer

*/

private $ttl;

public function __construct(

RequestMatcherInterface $requestMatcher,

HashGenerator $hashGenerator,

array $userIdentifierHeaders = array('Cookie', 'Authorization'),

$hashHeader = "X-User-Context-Hash",

$ttl = 0

) {

if (!count($userIdentifierHeaders)) {

throw new \InvalidArgumentException('The user context must vary on some request headers');

}

$this->requestMatcher = $requestMatcher;

$this->hashGenerator = $hashGenerator;

$this->userIdentifierHeaders = $userIdentifierHeaders;

$this->hashHeader = $hashHeader;

$this->ttl = $ttl;

}

/**

* Return the response to the context hash request with a header containing

* the generated hash.

*

* If the ttl is bigger than 0, cache headers will be set for this response.

*

* @param GetResponseEvent $event

*/

public function onKernelRequest(GetResponseEvent $event)

{

if ($event->getRequestType() != HttpKernelInterface::MASTER_REQUEST) {

return;

}

if (!$this->requestMatcher->matches($event->getRequest())) {

return;

}

$hash = $this->hashGenerator->generateHash();

// status needs to be 200 as otherwise varnish will not cache the response.

$response = new Response('', 200, array(

$this->hashHeader => $hash,

'Content-Type' => 'application/vnd.fos.user-context-hash',

));

if ($this->ttl > 0) {

$response->setClientTtl($this->ttl);

$response->setVary($this->userIdentifierHeaders);

$response->setPublic();

} else {

$response->setClientTtl(0);

$response->headers->addCacheControlDirective('no-cache');

}

$event->setResponse($response);

}

/**

* Add the context hash header to the headers to vary on if the header was

* present in the request.

*

* @param FilterResponseEvent $event

*/

public function onKernelResponse(FilterResponseEvent $event)

{

if ($event->getRequestType() != HttpKernelInterface::MASTER_REQUEST) {

return;

}

$response = $event->getResponse();

$vary = $response->getVary();

if ($event->getRequest()->headers->has($this->hashHeader)) {

if (!in_array($this->hashHeader, $vary)) {

$vary[] = $this->hashHeader;

}

} else {

foreach ($this->userIdentifierHeaders as $header) {

if (!in_array($header, $vary)) {

$vary[] = $header;

}

}

}

$response->setVary($vary, true);

}

/**

* {@inheritdoc}

*/

public static function getSubscribedEvents()

{

return array(

KernelEvents::RESPONSE => 'onKernelResponse',

KernelEvents::REQUEST => array('onKernelRequest', 7),

);

}

}