made cachable edlp_agenda home

sites/all/modules/figli/edlp_agenda/src/Controller/AgendaController.php

@@ -5,7 +5,9 @@ namespace Drupal\edlp_agenda\Controller;
 use Drupal\Core\Controller\ControllerBase;
 use Drupal\Core\Datetime\DrupalDateTime;
 use Symfony\Component\HttpFoundation\JsonResponse;
-
+use Drupal\Core\Cache\CacheableJsonResponse;
+use Drupal\Core\Cache\CacheableMetadata;
+use Drupal\core\render\RenderContext;
 
 class AgendaController extends ControllerBase {
 
@@ -66,16 +68,29 @@ class AgendaController extends ControllerBase {
    */
   public function agendajson() {
 
-    $response = new JsonResponse();
     $renderable = $this->toRenderable();
-    $rendered = render($renderable);
+    // $rendered = render($renderable);
+    // We can't render directly the entity as it throw an exception with cachable data
+    //http://blog.dcycle.com/blog/2018-01-24/caching-drupal-8-rest-resource/#the-dreaded-leaked-metadata-error
+    $rendered = \Drupal::service('renderer')->executeInRenderContext(new RenderContext(), function () use ($renderable) {
+      return render($renderable);
+    });
 
-    $response->setData([
-      'test'=>'hello',
+    $data = [
       'rendered'=> $rendered
-    ]);
+    ];
+
+    $data['#cache'] = [
+      'max-age' => \Drupal\Core\Cache\Cache::PERMANENT,
+      'tags' => ['edlp-agenda-cache']
+    ];
+
+    // $response = new JsonResponse();
+    // $response->setData($data);
+    $response = new CacheableJsonResponse($data);
+    $response->addCacheableDependency(CacheableMetadata::createFromRenderArray($data));
+    $response->addCacheableDependency(CacheableMetadata::createFromRenderArray($renderable));
 
     return $response;
   }
-
 }