function Fast404ExceptionHtmlSubscriber::on404

Handles a 404 error for HTML.

Parameters

\Symfony\Component\HttpKernel\Event\ExceptionEvent $event: The event to process.

File

core/lib/Drupal/Core/EventSubscriber/Fast404ExceptionHtmlSubscriber.php, line 85

Class

Fast404ExceptionHtmlSubscriber

High-performance 404 exception subscriber.

Namespace

Code

public function on404(ExceptionEvent $event) {
  $request = $event->getRequest();
  $config = $this->configFactory
    ->get('system.performance');
  $exclude_paths = $config->get('fast_404.exclude_paths');
  if ($config->get('fast_404.enabled') && $exclude_paths && !preg_match($exclude_paths, $request->getPathInfo())) {
    $fast_paths = $config->get('fast_404.paths');
    if ($fast_paths && preg_match($fast_paths, $request->getPathInfo())) {
      $fast_404_html = strtr($config->get('fast_404.html'), [
        '@path' => Html::escape($request->getUri()),
      ]);
      $response = new HtmlResponse($fast_404_html, Response::HTTP_NOT_FOUND);
      // Some routes such as system.files conditionally throw a
      // NotFoundHttpException depending on URL parameters instead of just the
      // route and route parameters, so add the URL cache context to account
      // for this.
      $cacheable_metadata = new CacheableMetadata();
      $cacheable_metadata->setCacheContexts([
        'url',
      ]);
      $cacheable_metadata->addCacheTags([
        '4xx-response',
      ]);
      $response->addCacheableDependency($cacheable_metadata);
      $event->setResponse($response);
    }
  }
}