feat: make server errors visible to the user for htmx requests

2026-07-02 10:02:05 +02:00
parent 4d3fc69faa
commit de37186706
2 changed files with 65 additions and 0 deletions
@@ -0,0 +1,53 @@
 <?php
 declare(strict_types=1);
 namespace App\EventListener;
 use Symfony\Component\EventDispatcher\EventSubscriberInterface;
 use Symfony\Component\HttpFoundation\Response;
 use Symfony\Component\HttpKernel\Event\ExceptionEvent;
 use Symfony\Component\HttpKernel\KernelEvents;
 use Twig\Environment;
 /**
 * Returns an error modal for unhandled exceptions on HTMX requests.
 *
 * Without this, a 500 from an HTMX endpoint is silently discarded by the browser
 * and the user sees nothing. This listener intercepts those exceptions and returns
 * a 200 with the error modal HTML, using HX-Retarget/HX-Reswap to append it to
 * <body> regardless of the original hx-target.
 */
 class HtmxExceptionListener implements EventSubscriberInterface
 {
    public function __construct(private readonly Environment $twig)
    {
    }
    public static function getSubscribedEvents(): array
    {
        return [
            KernelEvents::EXCEPTION => ['onKernelException', -10],
        ];
    }
    public function onKernelException(ExceptionEvent $event): void
    {
        if (false === $event->getRequest()->headers->has('HX-Request')) {
            return;
        }
        if ($event->hasResponse()) {
            return;
        }
        $html = $this->twig->render('htmx_error_modal.html.twig');
        $response = new Response($html, Response::HTTP_OK);
        $response->headers->set('HX-Retarget', 'body');
        $response->headers->set('HX-Reswap', 'beforeend');
        $event->setResponse($response);
        $event->allowCustomResponseCode();
    }
 }
@@ -0,0 +1,12 @@
 {% embed '_partials/_modal.html.twig' with { 'level': 'error' } %}
    {% block title %}
        Oops...
    {% endblock %}
    {% block content %}
        {% include '_partials/_alert.html.twig' with {
            level: 'error',
            modal: true,
            messages: ['Da ist etwas schiefgelaufen. Wir haben uns Notizen gemacht und kümmern uns schnellstmöglich darum.']
        } %}
    {% endblock %}
 {% endembed %}