comment write listener

Author: soyuka

src/EventListener/WriteListener.php

@@ -61,7 +61,9 @@ public function onKernelView(GetResponseForControllerResultEvent $event)
 
                 $event->setControllerResult($persistResult ?? $controllerResult);
 
-                // Comparing the class is necessary because the input might not be readable
+                // Controller result must be immutable for _api_write_item_iri
+                // if it's class changed compared to the base class let's avoid calling the IriConverter
+                // especially that the Output class could be a DTO that's not referencing any route
                 if (null !== $this->iriConverter && \get_class($controllerResult) === \get_class($event->getControllerResult())) {
                     $request->attributes->set('_api_write_item_iri', $this->iriConverter->getIriFromItem($controllerResult));
                 }