From 98346f28c2bdcc47aff35ffc7725b12cda69059a Mon Sep 17 00:00:00 2001
From: stollr <christian.stoller@mail.de>
Date: Fri, 31 Mar 2023 08:58:23 +0200
Subject: [PATCH] Trigger event to allow updating the response based on view
 data at one central place

---
 DependencyInjection/FOSRestExtension.php |  1 +
 Resources/doc/2-the-view-layer.rst       | 27 ++++++++++++++
 View/ViewHandler.php                     | 12 ++++++
 View/ViewResponseEvent.php               | 47 ++++++++++++++++++++++++
 4 files changed, 87 insertions(+)
 create mode 100644 View/ViewResponseEvent.php

diff --git a/DependencyInjection/FOSRestExtension.php b/DependencyInjection/FOSRestExtension.php
index 8d54fbcad..f1bb1a397 100644
--- a/DependencyInjection/FOSRestExtension.php
+++ b/DependencyInjection/FOSRestExtension.php
@@ -293,6 +293,7 @@ private function loadView(array $config, XmlFileLoader $loader, ContainerBuilder
             $config['view']['empty_content'],
             $config['view']['serialize_null'],
         ]);
+        $defaultViewHandler->addMethodCall('setEventDispatcher', [new Reference('event_dispatcher')]);
     }
 
     private function loadException(array $config, XmlFileLoader $loader, ContainerBuilder $container): void
diff --git a/Resources/doc/2-the-view-layer.rst b/Resources/doc/2-the-view-layer.rst
index 17260a7b1..dea01e998 100644
--- a/Resources/doc/2-the-view-layer.rst
+++ b/Resources/doc/2-the-view-layer.rst
@@ -198,6 +198,33 @@ data transformer. Fortunately, the FOSRestBundle comes with an
 This way, the data structure remains untouched and the person can be assigned to
 the task without any client modifications.
 
+Update the Response based on View Data
+--------------------------------------
+
+If you have the need to globally modify the response depending on the view data
+you can use the ``ViewResponseEvent``. It allows you to do some custom stuff
+at one central place and reduce repetitive work.
+
+Here's an example how to use it:
+
+.. code-block:: php
+    namespace App\EventListener;
+
+    use FOS\RestBundle\View\ViewResponseEvent;
+    use Symfony\Component\EventDispatcher\Attribute\AsEventListener;
+
+    #[AsEventListener]
+    class PaginationViewResponseListener
+    {
+        public function __invoke(ViewResponseEvent $event): void
+        {
+            $view = $event->getView(); // you have access to the view and the response
+            $response = $event->getResponse();
+            // ...
+        }
+    }
+
+
 Configuration
 -------------
 
diff --git a/View/ViewHandler.php b/View/ViewHandler.php
index 6e638fbb2..a5db50e64 100644
--- a/View/ViewHandler.php
+++ b/View/ViewHandler.php
@@ -19,6 +19,7 @@
 use Symfony\Component\HttpFoundation\Response;
 use Symfony\Component\HttpKernel\Exception\UnsupportedMediaTypeHttpException;
 use Symfony\Component\Routing\Generator\UrlGeneratorInterface;
+use Symfony\Contracts\EventDispatcher\EventDispatcherInterface;
 
 /**
  * View may be used in controllers to build up a response in a format agnostic way
@@ -52,6 +53,7 @@ final class ViewHandler implements ConfigurableViewHandlerInterface
     private $urlGenerator;
     private $serializer;
     private $requestStack;
+    private $dispatcher = null;
     private $options;
 
     private function __construct(
@@ -198,9 +200,19 @@ public function createResponse(View $view, Request $request, string $format): Re
             $response->headers->set('Content-Type', $mimeType);
         }
 
+        if (null !== $this->dispatcher) {
+            $event = new ViewResponseEvent($view, $response, $request);
+            $this->dispatcher->dispatch($event);
+        }
+
         return $response;
     }
 
+    public function setEventDispatcher(EventDispatcherInterface $dispatcher): void
+    {
+        $this->dispatcher = $dispatcher;
+    }
+
     /**
      * Gets a response HTTP status code from a View instance.
      *
diff --git a/View/ViewResponseEvent.php b/View/ViewResponseEvent.php
new file mode 100644
index 000000000..cefd07cc8
--- /dev/null
+++ b/View/ViewResponseEvent.php
@@ -0,0 +1,47 @@
+<?php
+
+/*
+ * This file is part of the FOSRestBundle package.
+ *
+ * (c) FriendsOfSymfony <http://friendsofsymfony.github.com/>
+ *
+ * For the full copyright and license information, please view the LICENSE
+ * file that was distributed with this source code.
+ */
+
+namespace FOS\RestBundle\View;
+
+use Symfony\Component\HttpFoundation\Request;
+use Symfony\Component\HttpFoundation\Response;
+
+/**
+ * Allows to update the Response an the basis of view data.
+ */
+class ViewResponseEvent
+{
+    private $view;
+    private $response;
+    private $request;
+
+    public function __construct(View $view, Response $response, Request $request)
+    {
+        $this->view = $view;
+        $this->response = $response;
+        $this->request = $request;
+    }
+
+    public function getView(): View
+    {
+        return $this->view;
+    }
+
+    public function getResponse(): Response
+    {
+        return $this->response;
+    }
+
+    public function getRequest(): Request
+    {
+        return $this->request;
+    }
+}