private function onHasRelationException(GetResponseForExceptionEvent $event)
{
$request = $this->requestStack->getMasterRequest();
/** @var HasRelationException $exception */
$exception = $event->getException();
$errorText = $exception->getErrorMessage();
if ($request->get('_format') == 'json') {
$response = new JsonResponse(['error' => $errorText]);
$event->setResponse($response);
return;
}
$routeArr = $this->getRefererParams($event->getRequest());
$route = $routeArr['_route'];
unset($routeArr['_route']);
unset($routeArr['__controller']);
$this->session->getFlashBag()->add('danger', $errorText);
$url = $this->router->generate($route, $routeArr);
$response = new RedirectResponse($url);
$event->setResponse($response);
}