class EnforcedFormResponseSubscriber

class EnforcedFormResponseSubscriber implements EventSubscriberInterface {
  
  /**
   * Replaces the response in case an EnforcedResponseException was thrown.
   */
  public function onKernelException(ExceptionEvent $event) {
    if ($response = EnforcedResponse::createFromException($event->getThrowable())) {
      // Setting the response stops the event propagation.
      $event->setResponse($response);
    }
  }
  
  /**
   * Unwraps an enforced response.
   */
  public function onKernelResponse(ResponseEvent $event) {
    $response = $event->getResponse();
    if ($response instanceof EnforcedResponse && $event->isMainRequest()) {
      $event->setResponse($response->getResponse());
    }
  }
  
  /**
   * {@inheritdoc}
   */
  public static function getSubscribedEvents() : array {
    $events[KernelEvents::EXCEPTION] = [
      'onKernelException',
      128,
    ];
    $events[KernelEvents::RESPONSE] = [
      'onKernelResponse',
      128,
    ];
    return $events;
  }

}