vendor/sensio/framework-extra-bundle/EventListener/HttpCacheListener.php line 82

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  1. <?php
  3. /*
  4.  * This file is part of the Symfony framework.
  5.  *
  6.  * (c) Fabien Potencier <fabien@symfony.com>
  7.  *
  8.  * This source file is subject to the MIT license that is bundled
  9.  * with this source code in the file LICENSE.
  10.  */
  12. namespace Sensio\Bundle\FrameworkExtraBundle\EventListener;
  14. use Symfony\Component\HttpKernel\Event\FilterControllerEvent;
  15. use Symfony\Component\HttpKernel\Event\FilterResponseEvent;
  16. use Symfony\Component\HttpKernel\KernelEvents;
  17. use Symfony\Component\HttpFoundation\Response;
  18. use Symfony\Component\EventDispatcher\EventSubscriberInterface;
  19. use Symfony\Component\ExpressionLanguage\ExpressionLanguage;
  21. /**
  22.  * HttpCacheListener handles HTTP cache headers.
  23.  *
  24.  * It can be configured via the Cache annotation.
  25.  *
  26.  * @author Fabien Potencier <fabien@symfony.com>
  27.  */
  28. class HttpCacheListener implements EventSubscriberInterface
  29. {
  30.     private $lastModifiedDates;
  31.     private $etags;
  32.     private $expressionLanguage;
  34.     public function __construct()
  35.     {
  36.         $this->lastModifiedDates = new \SplObjectStorage();
  37.         $this->etags = new \SplObjectStorage();
  38.     }
  40.     /**
  41.      * Handles HTTP validation headers.
  42.      */
  43.     public function onKernelController(FilterControllerEvent $event)
  44.     {
  45.         $request = $event->getRequest();
  46.         if (!$configuration = $request->attributes->get('_cache')) {
  47.             return;
  48.         }
  50.         $response = new Response();
  52.         $lastModifiedDate = '';
  53.         if ($configuration->getLastModified()) {
  54.             $lastModifiedDate = $this->getExpressionLanguage()->evaluate($configuration->getLastModified(), $request->attributes->all());
  55.             $response->setLastModified($lastModifiedDate);
  56.         }
  58.         $etag = '';
  59.         if ($configuration->getETag()) {
  60.             $etag = hash('sha256', $this->getExpressionLanguage()->evaluate($configuration->getETag(), $request->attributes->all()));
  61.             $response->setETag($etag);
  62.         }
  64.         if ($response->isNotModified($request)) {
  65.             $event->setController(function () use ($response) {
  66.                 return $response;
  67.             });
  68.             $event->stopPropagation();
  69.         } else {
  70.             if ($etag) {
  71.                 $this->etags[$request] = $etag;
  72.             }
  73.             if ($lastModifiedDate) {
  74.                 $this->lastModifiedDates[$request] = $lastModifiedDate;
  75.             }
  76.         }
  77.     }
  79.     /**
  80.      * Modifies the response to apply HTTP cache headers when needed.
  81.      */
  82.     public function onKernelResponse(FilterResponseEvent $event)
  83.     {
  84.         $request = $event->getRequest();
  86.         if (!$configuration = $request->attributes->get('_cache')) {
  87.             return;
  88.         }
  90.         $response = $event->getResponse();
  92.         // http://tools.ietf.org/html/draft-ietf-httpbis-p4-conditional-12#section-3.1
  93.         if (!in_array($response->getStatusCode(), array(200, 203, 300, 301, 302, 304, 404, 410))) {
  94.             return;
  95.         }
  97.         if (null !== $age = $configuration->getSMaxAge()) {
  98.             if (!is_numeric($age)) {
  99.                 $now = microtime(true);
  101.                 $age = ceil(strtotime($configuration->getSMaxAge(), $now) - $now);
  102.             }
  104.             $response->setSharedMaxAge($age);
  105.         }
  107.         if (null !== $age = $configuration->getMaxAge()) {
  108.             if (!is_numeric($age)) {
  109.                 $now = microtime(true);
  111.                 $age = ceil(strtotime($configuration->getMaxAge(), $now) - $now);
  112.             }
  114.             $response->setMaxAge($age);
  115.         }
  117.         if (null !== $configuration->getExpires()) {
  118.             $date = \DateTime::createFromFormat('U', strtotime($configuration->getExpires()), new \DateTimeZone('UTC'));
  119.             $response->setExpires($date);
  120.         }
  122.         if (null !== $configuration->getVary()) {
  123.             $response->setVary($configuration->getVary());
  124.         }
  126.         if ($configuration->isPublic()) {
  127.             $response->setPublic();
  128.         }
  130.         if ($configuration->isPrivate()) {
  131.             $response->setPrivate();
  132.         }
  134.         if (isset($this->lastModifiedDates[$request])) {
  135.             $response->setLastModified($this->lastModifiedDates[$request]);
  137.             unset($this->lastModifiedDates[$request]);
  138.         }
  140.         if (isset($this->etags[$request])) {
  141.             $response->setETag($this->etags[$request]);
  143.             unset($this->etags[$request]);
  144.         }
  145.     }
  147.     public static function getSubscribedEvents()
  148.     {
  149.         return array(
  150.             KernelEvents::CONTROLLER => 'onKernelController',
  151.             KernelEvents::RESPONSE => 'onKernelResponse',
  152.         );
  153.     }
  155.     private function getExpressionLanguage()
  156.     {
  157.         if (null === $this->expressionLanguage) {
  158.             if (!class_exists('Symfony\Component\ExpressionLanguage\ExpressionLanguage')) {
  159.                 throw new \RuntimeException('Unable to use expressions as the Symfony ExpressionLanguage component is not installed.');
  160.             }
  161.             $this->expressionLanguage = new ExpressionLanguage();
  162.         }
  164.         return $this->expressionLanguage;
  165.     }
  166. }