feat: invalid form returns http 422

Fixes sulu#383

Event/RequestListener.php

@@ -17,7 +17,9 @@
 use Sulu\Bundle\FormBundle\Form\HandlerInterface;
 use Symfony\Component\EventDispatcher\EventDispatcherInterface;
 use Symfony\Component\HttpFoundation\RedirectResponse;
+use Symfony\Component\HttpFoundation\Response;
 use Symfony\Component\HttpKernel\Event\RequestEvent;
+use Symfony\Component\HttpKernel\Event\ResponseEvent;
 
 class RequestListener
 {
@@ -41,6 +43,14 @@ class RequestListener
      */
     protected $eventDispatcher;
 
+    /**
+     * Flag set to true when an invalid form is submitted,
+     * so we can set the http return code to 422.
+     *
+     * @var bool
+     */
+    protected $invalidSubmittedForm = false;
+
     /**
      * RequestListener constructor.
      */
@@ -73,10 +83,16 @@ public function onKernelRequest(RequestEvent $event): void
         try {
             $form = $this->formBuilder->buildByRequest($request);
 
-            if (!$form || !$form->isSubmitted() || !$form->isValid()) {
+            if (!$form || !$form->isSubmitted()) {
                 // do nothing when no form was found or not valid
                 return;
             }
+
+            if ($form && $form->isSubmitted() && !$form->isValid()) {
+                $this->invalidSubmittedForm = true;
+
+                return;
+            }
         } catch (\Exception $e) {
             // Catch all exception on build form by request
             return;
@@ -96,4 +112,19 @@ public function onKernelRequest(RequestEvent $event): void
             $event->setResponse($response);
         }
     }
+
+    public function onKernelResponse(ResponseEvent $event): void
+    {
+        if (\method_exists($event, 'isMainRequest') ? !$event->isMainRequest() : !$event->isMasterRequest()) {
+            // do nothing if it's not the master request
+            return;
+        }
+
+        if ($this->invalidSubmittedForm) {
+            $response = $event->getResponse() ?? new Response();
+            $response->setStatusCode(Response::HTTP_UNPROCESSABLE_ENTITY);
+
+            $event->setResponse($response);
+        }
+    }
 }

Resources/config/services.xml

@@ -104,6 +104,7 @@
             <argument type="service" id="event_dispatcher" />
 
             <tag name="kernel.event_listener" event="kernel.request" method="onKernelRequest" />
+            <tag name="kernel.event_listener" event="kernel.response" method="onKernelResponse" />
         </service>
 
         <!-- List Builder -->