Chris@0: <?php
Chris@0: 
Chris@0: namespace Drupal\Core\EventSubscriber;
Chris@0: 
Chris@0: use Drupal\Core\Config\ConfigFactoryInterface;
Chris@0: use Drupal\Component\Utility\Html;
Chris@0: use Symfony\Component\HttpFoundation\Response;
Chris@0: use Symfony\Component\HttpKernel\Event\GetResponseForExceptionEvent;
Chris@0: use Symfony\Component\HttpKernel\HttpKernelInterface;
Chris@0: 
Chris@0: /**
Chris@0:  * High-performance 404 exception subscriber.
Chris@0:  *
Chris@0:  * This subscriber will return a minimalist 404 response for HTML requests
Chris@0:  * without running a full page theming operation.
Chris@0:  */
Chris@0: class Fast404ExceptionHtmlSubscriber extends HttpExceptionSubscriberBase {
Chris@0: 
Chris@0:   /**
Chris@0:    * The HTTP kernel.
Chris@0:    *
Chris@0:    * @var \Symfony\Component\HttpKernel\HttpKernelInterface
Chris@0:    */
Chris@0:   protected $httpKernel;
Chris@0: 
Chris@0:   /**
Chris@0:    * The config factory.
Chris@0:    *
Chris@0:    * @var \Drupal\Core\Config\ConfigFactoryInterface
Chris@0:    */
Chris@0:   protected $configFactory;
Chris@0: 
Chris@0:   /**
Chris@0:    * Constructs a new Fast404ExceptionHtmlSubscriber.
Chris@0:    *
Chris@0:    * @param \Drupal\Core\Config\ConfigFactoryInterface $config_factory
Chris@0:    *   The configuration factory.
Chris@0:    * @param \Symfony\Component\HttpKernel\HttpKernelInterface $http_kernel
Chris@0:    *   The HTTP Kernel service.
Chris@0:    */
Chris@0:   public function __construct(ConfigFactoryInterface $config_factory, HttpKernelInterface $http_kernel) {
Chris@0:     $this->configFactory = $config_factory;
Chris@0:     $this->httpKernel = $http_kernel;
Chris@0:   }
Chris@0: 
Chris@0:   /**
Chris@0:    * {@inheritdoc}
Chris@0:    */
Chris@0:   protected static function getPriority() {
Chris@0:     // A very high priority so that it can take precedent over anything else,
Chris@0:     // and thus be fast.
Chris@0:     return 200;
Chris@0:   }
Chris@0: 
Chris@0:   /**
Chris@0:    * {@inheritdoc}
Chris@0:    */
Chris@0:   protected function getHandledFormats() {
Chris@0:     return ['html'];
Chris@0:   }
Chris@0: 
Chris@0:   /**
Chris@0:    * Handles a 404 error for HTML.
Chris@0:    *
Chris@0:    * @param \Symfony\Component\HttpKernel\Event\GetResponseForExceptionEvent $event
Chris@0:    *   The event to process.
Chris@0:    */
Chris@0:   public function on404(GetResponseForExceptionEvent $event) {
Chris@0:     $request = $event->getRequest();
Chris@0: 
Chris@0:     $config = $this->configFactory->get('system.performance');
Chris@0:     $exclude_paths = $config->get('fast_404.exclude_paths');
Chris@0:     if ($config->get('fast_404.enabled') && $exclude_paths && !preg_match($exclude_paths, $request->getPathInfo())) {
Chris@0:       $fast_paths = $config->get('fast_404.paths');
Chris@0:       if ($fast_paths && preg_match($fast_paths, $request->getPathInfo())) {
Chris@0:         $fast_404_html = strtr($config->get('fast_404.html'), ['@path' => Html::escape($request->getUri())]);
Chris@0:         $response = new Response($fast_404_html, Response::HTTP_NOT_FOUND);
Chris@0:         $event->setResponse($response);
Chris@0:       }
Chris@0:     }
Chris@0:   }
Chris@0: 
Chris@0: }