Merge caching for entity fields (#996)

I noticed an issue with missing caching tags when requesting long text fields (wysiwyg editor-enabled) with inline media. The cache tags of the inline media were not available in the response. I traced it down to this file (EntityFieldBase.php) in the graphql_core sub-module.

With this small change, the caching tags set by the entity fields will be used in the response. And it solves the issue that a change of an image in a media item does not invalidate the cache of the pages where it is used in the long text fields.

Co-authored-by: Luis Gil <luis.gil@biko2.com>

Author: SpadXIII

modules/graphql_core/src/Plugin/GraphQL/Fields/EntityFieldBase.php

@@ -3,6 +3,8 @@
 namespace Drupal\graphql_core\Plugin\GraphQL\Fields;
 
 use Drupal\Component\Render\MarkupInterface;
+use Drupal\Core\Cache\CacheableDependencyInterface;
+use Drupal\Core\Cache\CacheableMetadata;
 use Drupal\Core\Entity\ContentEntityInterface;
 use Drupal\Core\Entity\Entity;
 use Drupal\Core\Entity\EntityInterface;
@@ -25,7 +27,8 @@ protected function resolveItem($item, array $args, ResolveContext $context, Reso
     if ($item instanceof FieldItemInterface) {
       $definition = $this->getPluginDefinition();
       $property = $definition['property'];
-      $result = $item->get($property)->getValue();
+      $itemProperty = $item->get($property);
+      $result = $itemProperty->getValue();
       $result = $result instanceof MarkupInterface ? $result->__toString() : $result;
 
       $type = $info->returnType;
@@ -40,6 +43,12 @@ protected function resolveItem($item, array $args, ResolveContext $context, Reso
         }
       }
 
+      if ($itemProperty instanceof CacheableDependencyInterface) {
+        $context->addCacheTags($itemProperty->getCacheTags());
+        $context->addCacheContexts($itemProperty->getCacheContexts());
+        $context->mergeCacheMaxAge($itemProperty->getCacheMaxAge());
+      }
+
       return $result;
     }
   }