[WIP][POC] Add custom xkeys to response

app/Resources/views/default

@@ -0,0 +1 @@
+/var/www/ez/vendor/ezsystems/ezpublish-kernel/eZ/Bundle/EzPublishCoreBundle/Resources/views/default

app/config/views.yml

@@ -0,0 +1,9 @@
+ezpublish:
+    system:
+        site:
+            content_view:
+                full:
+                    default:
+                        controller: AppBundle\Controller\TestController::xKeyAction
+                        template: default/content/full.html.twig
+                        match: true

docker/apache/parameters.yml

@@ -1,5 +1,6 @@
 imports:
     - { resource: cache_pool/cache.redis.yml }
+    - { resource: views.yml }
 
 parameters:
     #TODO: May move all this to .env file or Dockerfile

src/AppBundle/Controller/TestController.php

@@ -0,0 +1,23 @@
+<?php
+
+namespace AppBundle\Controller;
+
+use eZ\Bundle\EzPublishCoreBundle\Controller;
+use eZ\Publish\Core\MVC\Symfony\View\ContentView;
+use Symfony\Component\HttpFoundation\Response;
+
+class TestController extends Controller
+{
+    public function xKeyAction(ContentView $view): ContentView
+    {
+        $response = new Response();
+
+        $locationIds = [123, 456];
+        //$response->headers->set('X-Location-Id', implode(',', $locationIds));
+        $response->headers->set('xkey', 'l'.implode(' l', $locationIds));
+
+        $view->setResponse($response);
+
+        return $view;
+    }
+}