Properly injecting the language context.

Author: pmelab

graphql.services.yml

@@ -124,6 +124,7 @@ services:
       - '@container.namespaces'
       - '@module_handler'
       - '@cache.graphql.definitions'
+      - '@graphql.language_context'
       - '\Drupal\graphql\Plugin\FieldPluginInterface'
       - '\Drupal\graphql\Annotation\GraphQLField'
       - '%graphql.config%'

src/Plugin/FieldPluginManager.php

@@ -6,6 +6,7 @@
 use Drupal\Core\Cache\CacheBackendInterface;
 use Drupal\Core\Extension\ModuleHandlerInterface;
 use Drupal\Core\Plugin\DefaultPluginManager;
+use Drupal\graphql\GraphQLLanguageContext;
 
 class FieldPluginManager extends DefaultPluginManager {
 
@@ -16,6 +17,15 @@ class FieldPluginManager extends DefaultPluginManager {
    */
   protected $instances;
 
+  /**
+   * The language context.
+   *
+   * Will be passed on to all plugin instances.
+   *
+   * @var \Drupal\graphql\GraphQLLanguageContext
+   */
+  protected $languageContext;
+
   /**
    * FieldPluginManager constructor.
    *
@@ -28,6 +38,8 @@ class FieldPluginManager extends DefaultPluginManager {
    *   The module handler.
    * @param \Drupal\Core\Cache\CacheBackendInterface $cacheBackend
    *   The cache backend.
+   * @param \Drupal\graphql\GraphQLLanguageContext $languageContext
+   *   The language context.
    * @param string|null $pluginInterface
    *   The interface each plugin should implement.
    * @param string $pluginAnnotationName
@@ -40,10 +52,12 @@ public function __construct(
     \Traversable $namespaces,
     ModuleHandlerInterface $moduleHandler,
     CacheBackendInterface $cacheBackend,
+    GraphQLLanguageContext $languageContext,
     $pluginInterface,
     $pluginAnnotationName,
     array $config
   ) {
+
     parent::__construct(
       $pluginSubdirectory,
       $namespaces,
@@ -52,11 +66,22 @@ public function __construct(
       $pluginAnnotationName
     );
 
+    $this->languageContext = $languageContext;
     $this->alterInfo('graphql_fields');
     $this->useCaches(empty($config['development']));
     $this->setCacheBackend($cacheBackend, 'fields', ['graphql']);
   }
 
+  /**
+   * {@inheritdoc}
+   */
+  public function createInstance($plugin_id, array $configuration = []) {
+    /** @var \Drupal\graphql\Plugin\GraphQL\Fields\FieldPluginBase $plugin */
+    $plugin = parent::createInstance($plugin_id, $configuration);
+    $plugin->setLanguageContext($this->languageContext);
+    return $plugin;
+  }
+
   /**
    * {@inheritdoc}
    */

src/Plugin/GraphQL/Fields/FieldPluginBase.php

@@ -6,8 +6,10 @@
 use Drupal\Component\Render\MarkupInterface;
 use Drupal\Core\Cache\CacheableDependencyInterface;
 use Drupal\Core\Cache\CacheableMetadata;
+use Drupal\Core\Language\LanguageManagerInterface;
 use Drupal\graphql\GraphQL\Execution\ResolveContext;
 use Drupal\graphql\GraphQL\ValueWrapperInterface;
+use Drupal\graphql\GraphQLLanguageContext;
 use Drupal\graphql\Plugin\FieldPluginInterface;
 use Drupal\graphql\Plugin\FieldPluginManager;
 use Drupal\graphql\Plugin\GraphQL\Traits\ArgumentAwarePluginTrait;
@@ -29,6 +31,23 @@ abstract class FieldPluginBase extends PluginBase implements FieldPluginInterfac
   use ArgumentAwarePluginTrait;
   use DeprecatablePluginTrait;
 
+  /**
+   * The language context, for simulating active languages in fields.
+   *
+   * @var \Drupal\graphql\GraphQLLanguageContext
+   */
+  protected $languageContext;
+
+  /**
+   * Set the language context instance.
+   *
+   * @param \Drupal\graphql\GraphQLLanguageContext $languageContext
+   *   The language context instance.
+   */
+  public function setLanguageContext(GraphQLLanguageContext $languageContext) {
+    $this->languageContext = $languageContext;
+  }
+
   /**
    * {@inheritdoc}
    */
@@ -83,7 +102,7 @@ public function resolve($value, array $args, ResolveContext $context, ResolveInf
       }
     }
 
-    return \Drupal::service('graphql.language_context')
+    return $this->languageContext
       ->executeInLanguageContext(function () use ($value, $args, $context, $info) {
         return $this->resolveDeferred([$this, 'resolveValues'], $value, $args, $context, $info);
       }, $context->getContext('language', $info));