aleph1.co.uk Git - yaffs-website/blob - web/core/lib/Drupal/Core/EventSubscriber/CustomPageExceptionHtmlSubscriber.php

   1 <?php
   2
   3 namespace Drupal\Core\EventSubscriber;
   4
   5 use Drupal\Core\Access\AccessManagerInterface;
   6 use Drupal\Core\Cache\RefinableCacheableDependencyInterface;
   7 use Drupal\Core\Config\ConfigFactoryInterface;
   8 use Drupal\Core\Routing\AccessAwareRouterInterface;
   9 use Drupal\Core\Routing\RedirectDestinationInterface;
  10 use Drupal\Core\Url;
  11 use Psr\Log\LoggerInterface;
  12 use Symfony\Component\HttpFoundation\Response;
  13 use Symfony\Component\HttpKernel\Event\GetResponseForExceptionEvent;
  14 use Symfony\Component\HttpKernel\HttpKernelInterface;
  15 use Symfony\Component\Routing\Matcher\UrlMatcherInterface;
  16
  17 /**
  18  * Exception subscriber for handling core custom HTML error pages.
  19  */
  20 class CustomPageExceptionHtmlSubscriber extends DefaultExceptionHtmlSubscriber {
  21
  22   /**
  23    * The configuration factory.
  24    *
  25    * @var \Drupal\Core\Config\ConfigFactoryInterface
  26    */
  27   protected $configFactory;
  28
  29   /**
  30    * The access manager.
  31    *
  32    * @var \Drupal\Core\Access\AccessManagerInterface
  33    */
  34   protected $accessManager;
  35
  36   /**
  37    * Constructs a new CustomPageExceptionHtmlSubscriber.
  38    *
  39    * @param \Drupal\Core\Config\ConfigFactoryInterface $config_factory
  40    *   The configuration factory.
  41    * @param \Symfony\Component\HttpKernel\HttpKernelInterface $http_kernel
  42    *   The HTTP Kernel service.
  43    * @param \Psr\Log\LoggerInterface $logger
  44    *   The logger service.
  45    * @param \Drupal\Core\Routing\RedirectDestinationInterface $redirect_destination
  46    *   The redirect destination service.
  47    * @param \Symfony\Component\Routing\Matcher\UrlMatcherInterface $access_unaware_router
  48    *   A router implementation which does not check access.
  49    * @param \Drupal\Core\Access\AccessManagerInterface $access_manager
  50    *   The access manager.
  51    */
  52   public function __construct(ConfigFactoryInterface $config_factory, HttpKernelInterface $http_kernel, LoggerInterface $logger, RedirectDestinationInterface $redirect_destination, UrlMatcherInterface $access_unaware_router, AccessManagerInterface $access_manager) {
  53     parent::__construct($http_kernel, $logger, $redirect_destination, $access_unaware_router);
  54     $this->configFactory = $config_factory;
  55     $this->accessManager = $access_manager;
  56   }
  57
  58   /**
  59    * {@inheritdoc}
  60    */
  61   protected static function getPriority() {
  62     return -50;
  63   }
  64
  65   /**
  66    * {@inheritdoc}
  67    */
  68   public function on403(GetResponseForExceptionEvent $event) {
  69     $custom_403_path = $this->configFactory->get('system.site')->get('page.403');
  70     if (!empty($custom_403_path)) {
  71       $this->makeSubrequestToCustomPath($event, $custom_403_path, Response::HTTP_FORBIDDEN);
  72     }
  73   }
  74
  75   /**
  76    * {@inheritdoc}
  77    */
  78   public function on404(GetResponseForExceptionEvent $event) {
  79     $custom_404_path = $this->configFactory->get('system.site')->get('page.404');
  80     if (!empty($custom_404_path)) {
  81       $this->makeSubrequestToCustomPath($event, $custom_404_path, Response::HTTP_NOT_FOUND);
  82     }
  83   }
  84
  85   /**
  86    * Makes a subrequest to retrieve the custom error page.
  87    *
  88    * @param \Symfony\Component\HttpKernel\Event\GetResponseForExceptionEvent $event
  89    *   The event to process.
  90    * @param string $custom_path
  91    *   The custom path to which to make a subrequest for this error message.
  92    * @param int $status_code
  93    *   The status code for the error being handled.
  94    */
  95   protected function makeSubrequestToCustomPath(GetResponseForExceptionEvent $event, $custom_path, $status_code) {
  96     $url = Url::fromUserInput($custom_path);
  97     if ($url->isRouted()) {
  98       $access_result = $this->accessManager->checkNamedRoute($url->getRouteName(), $url->getRouteParameters(), NULL, TRUE);
  99       $request = $event->getRequest();
 100
 101       // Merge the custom path's route's access result's cacheability metadata
 102       // with the existing one (from the master request), otherwise create it.
 103       if (!$request->attributes->has(AccessAwareRouterInterface::ACCESS_RESULT)) {
 104         $request->attributes->set(AccessAwareRouterInterface::ACCESS_RESULT, $access_result);
 105       }
 106       else {
 107         $existing_access_result = $request->attributes->get(AccessAwareRouterInterface::ACCESS_RESULT);
 108         if ($existing_access_result instanceof RefinableCacheableDependencyInterface) {
 109           $existing_access_result->addCacheableDependency($access_result);
 110         }
 111       }
 112
 113       // Only perform the subrequest if the custom path is actually accessible.
 114       if (!$access_result->isAllowed()) {
 115         return;
 116       }
 117     }
 118
 119     $this->makeSubrequest($event, $custom_path, $status_code);
 120   }
 121
 122 }