class DefaultExceptionSubscriber in Drupal 8

Handles default error responses in serialization formats.

Hierarchy

• class \Drupal\Core\EventSubscriber\HttpExceptionSubscriberBase implements \Symfony\Component\EventDispatcher\EventSubscriberInterface
  • class \Drupal\serialization\EventSubscriber\DefaultExceptionSubscriber

2 files declare their use of DefaultExceptionSubscriber

DefaultExceptionSubscriber.php in core/modules/jsonapi/src/EventSubscriber/DefaultExceptionSubscriber.php

DefaultExceptionSubscriberTest.php in core/modules/serialization/tests/src/Unit/EventSubscriber/DefaultExceptionSubscriberTest.php

1 string reference to 'DefaultExceptionSubscriber'

serialization.services.yml in core/modules/serialization/serialization.services.yml

core/modules/serialization/serialization.services.yml

1 service uses DefaultExceptionSubscriber

serialization.exception.default in core/modules/serialization/serialization.services.yml

Drupal\serialization\EventSubscriber\DefaultExceptionSubscriber

File

core/modules/serialization/src/EventSubscriber/DefaultExceptionSubscriber.php, line 15

Namespace

Drupal\serialization\EventSubscriber

class DefaultExceptionSubscriber extends HttpExceptionSubscriberBase {

  /**
   * The serializer.
   *
   * @var \Symfony\Component\Serializer\Serializer
   */
  protected $serializer;

  /**
   * The available serialization formats.
   *
   * @var array
   */
  protected $serializerFormats = [];

  /**
   * DefaultExceptionSubscriber constructor.
   *
   * @param \Symfony\Component\Serializer\SerializerInterface $serializer
   *   The serializer service.
   * @param array $serializer_formats
   *   The available serialization formats.
   */
  public function __construct(SerializerInterface $serializer, array $serializer_formats) {
    $this->serializer = $serializer;
    $this->serializerFormats = $serializer_formats;
  }

  /**
   * {@inheritdoc}
   */
  protected function getHandledFormats() {
    return $this->serializerFormats;
  }

  /**
   * {@inheritdoc}
   */
  protected static function getPriority() {

    // This will fire after the most common HTML handler, since HTML requests
    // are still more common than HTTP requests. But it has a lower priority
    // than \Drupal\Core\EventSubscriber\ExceptionJsonSubscriber::on4xx(), so
    // that this also handles the 'json' format. Then all serialization formats
    // (::getHandledFormats()) are handled by this exception subscriber, which
    // results in better consistency.
    return -70;
  }

  /**
   * Handles all 4xx errors for all serialization failures.
   *
   * @param \Symfony\Component\HttpKernel\Event\GetResponseForExceptionEvent $event
   *   The event to process.
   */
  public function on4xx(GetResponseForExceptionEvent $event) {

    /** @var \Symfony\Component\HttpKernel\Exception\HttpExceptionInterface $exception */
    $exception = $event
      ->getException();
    $request = $event
      ->getRequest();
    $format = $request
      ->getRequestFormat();
    $content = [
      'message' => $exception
        ->getMessage(),
    ];
    $encoded_content = $this->serializer
      ->serialize($content, $format);
    $headers = $exception
      ->getHeaders();

    // Add the MIME type from the request to send back in the header.
    $headers['Content-Type'] = $request
      ->getMimeType($format);

    // If the exception is cacheable, generate a cacheable response.
    if ($exception instanceof CacheableDependencyInterface) {
      $response = new CacheableResponse($encoded_content, $exception
        ->getStatusCode(), $headers);
      $response
        ->addCacheableDependency($exception);
    }
    else {
      $response = new Response($encoded_content, $exception
        ->getStatusCode(), $headers);
    }
    $event
      ->setResponse($response);
  }

}

Members

Name	Modifiers	Type	Description	Overrides
DefaultExceptionSubscriber::$serializer	protected	property	The serializer.
DefaultExceptionSubscriber::$serializerFormats	protected	property	The available serialization formats.
DefaultExceptionSubscriber::getHandledFormats	protected	function	Specifies the request formats this subscriber will respond to. Overrides HttpExceptionSubscriberBase::getHandledFormats
DefaultExceptionSubscriber::getPriority	protected static	function	Specifies the priority of all listeners in this class. Overrides HttpExceptionSubscriberBase::getPriority
DefaultExceptionSubscriber::on4xx	public	function	Handles all 4xx errors for all serialization failures.
DefaultExceptionSubscriber::__construct	public	function	DefaultExceptionSubscriber constructor.
HttpExceptionSubscriberBase::getSubscribedEvents	public static	function	Registers the methods in this class that should be listeners.
HttpExceptionSubscriberBase::onException	public	function	Handles errors for this subscriber.