Provide a version parameter to entity by id queries to provide the latest or...

Provide a version parameter to entity by id queries to provide the latest or working copy of content

Closes #3446883

src/Plugin/GraphQL/DataProducer/EntityVersionFallback.php

+<?php
+
+declare(strict_types=1);
+
+namespace Drupal\graphql_compose\Plugin\GraphQL\DataProducer;
+
+use Drupal\Core\Entity\EntityInterface;
+use Drupal\Core\Entity\EntityTypeManagerInterface;
+use Drupal\Core\Entity\RevisionableInterface;
+use Drupal\Core\Entity\RevisionableStorageInterface;
+use Drupal\Core\Entity\TranslatableInterface;
+use Drupal\Core\Entity\TranslatableRevisionableStorageInterface;
+use Drupal\Core\Language\LanguageManagerInterface;
+use Drupal\Core\Plugin\ContainerFactoryPluginInterface;
+use Drupal\graphql\GraphQL\Execution\FieldContext;
+use Drupal\graphql\Plugin\GraphQL\DataProducer\DataProducerPluginBase;
+use Drupal\graphql_compose\Plugin\GraphQLCompose\SchemaType\VersionType;
+use Symfony\Component\DependencyInjection\ContainerInterface;
+
+/**
+ * The entity version fallback.
+ *
+ * @DataProducer(
+ *   id = "entity_version_fallback",
+ *   name = @Translation("Entity revision fallback"),
+ *   description = @Translation("Returns the entity by version (i.e. latest or working-copy) with optional fallback."),
+ *   produces = @ContextDefinition("entity",
+ *     label = @Translation("Versioned entity")
+ *   ),
+ *   consumes = {
+ *     "entity" = @ContextDefinition("entity",
+ *       label = @Translation("Entity")
+ *     ),
+ *     "version" = @ContextDefinition("string",
+ *       label = @Translation("version"),
+ *       required = FALSE
+ *     ),
+ *     "langcode" = @ContextDefinition("string",
+ *       label = @Translation("langcode"),
+ *       required = FALSE
+ *     ),
+ *     "fallback" = @ContextDefinition("boolean",
+ *       label = @Translation("Return same entity as fallback"),
+ *       required = FALSE
+ *     )
+ *   }
+ * )
+ */
+class EntityVersionFallback extends DataProducerPluginBase implements ContainerFactoryPluginInterface {
+
+  /**
+   * The entity type manager.
+   *
+   * @var \Drupal\Core\Entity\EntityTypeManagerInterface
+   */
+  protected $entityTypeManager;
+
+  /**
+   * The language manager.
+   *
+   * @var \Drupal\Core\Language\LanguageManagerInterface
+   */
+  protected $languageManager;
+
+  /**
+   * Constructs a EntityTranslationRevisionFallback.
+   *
+   * @param array $configuration
+   *   The plugin configuration.
+   * @param string $plugin_id
+   *   The plugin id.
+   * @param array $plugin_definition
+   *   The plugin definition.
+   * @param \Drupal\Core\Entity\EntityTypeManagerInterface $entity_type_manager
+   *   The entity type manager.
+   * @param \Drupal\Core\Language\LanguageManagerInterface $language_manager
+   *   The language manager.
+   */
+  public function __construct(array $configuration, $plugin_id, array $plugin_definition, EntityTypeManagerInterface $entity_type_manager, LanguageManagerInterface $language_manager) {
+    parent::__construct($configuration, $plugin_id, $plugin_definition);
+
+    $this->entityTypeManager = $entity_type_manager;
+    $this->languageManager = $language_manager;
+  }
+
+  /**
+   * {@inheritDoc}
+   */
+  public static function create(ContainerInterface $container, array $configuration, $plugin_id, $plugin_definition) {
+    return new static(
+      $configuration,
+      $plugin_id,
+      $plugin_definition,
+      $container->get('entity_type.manager'),
+      $container->get('language_manager')
+    );
+  }
+
+  /**
+   * Returns the entity for a given revision and translation.
+   *
+   * @param \Drupal\Core\Entity\EntityInterface $entity
+   *   The entity.
+   * @param string|null $version
+   *   The version.
+   * @param string|null $langcode
+   *   The entity langcode.
+   * @param bool|null $fallback
+   *   Flag to indicate whether to fallback to original entity.
+   * @param \Drupal\graphql\GraphQL\Execution\FieldContext $context
+   *   The GraphQL context.
+   *
+   * @return \Drupal\Core\Entity\EntityInterface|null
+   *   The revised entity.
+   */
+  public function resolve(EntityInterface $entity, ?string $version, ?string $langcode, ?bool $fallback, FieldContext $context) {
+    // If the version value is null or 'working-copy' just return the entity.
+    if ($version !== VersionType::WORKING_COPY) {
+      return $entity;
+    }
+
+    if ($entity instanceof RevisionableInterface && $entity->getEntityType()->isRevisionable()) {
+      if ($version_id = $this->getRevisionId($entity, $langcode)) {
+        $entity = $this->getRevisionStorage($entity)->loadRevision($version_id);
+        if ($langcode && $entity instanceof TranslatableInterface && $entity->hasTranslation($langcode)) {
+          $entity = $entity->getTranslation($langcode);
+        }
+        $entity->addCacheContexts(["static:version:{$version_id}"]);
+        /** @var \Drupal\Core\Access\AccessResultInterface $accessResult */
+        $accessResult = $entity->access('view', NULL, TRUE);
+        $context->addCacheableDependency($accessResult);
+        if (!$accessResult->isAllowed()) {
+          return NULL;
+        }
+        $context->setContextValue('version', $version_id);
+        return $entity;
+      }
+    }
+
+    // Fallback to the current entity.
+    if ($fallback) {
+      return $entity;
+    }
+
+    return NULL;
+  }
+
+  /**
+   * Get the revision id for an entity.
+   *
+   * @param \Drupal\Core\Entity\EntityInterface $entity
+   *   The revisable entity.
+   * @param string|null $langcode
+   *   The entity langcode.
+   *
+   * @return int|string|null
+   *   Returns the revision id OTHERWISE null.
+   */
+  protected function getRevisionId(EntityInterface $entity, ?string $langcode) : int|string|null {
+    $entity_storage = $this->getRevisionStorage($entity);
+    $version_id = NULL;
+    if ($entity_storage instanceof RevisionableStorageInterface) {
+      $entity_id = $entity->id();
+      if ($entity_storage instanceof TranslatableRevisionableStorageInterface) {
+        $version_id = $entity_storage->getLatestTranslationAffectedRevisionId(
+          $entity_id,
+          $langcode ?? $this->languageManager->getDefaultLanguage()->getId(),
+        );
+      }
+      else {
+        $version_id = $entity_storage->getLatestRevisionId($entity_id);
+      }
+    }
+
+    return $version_id;
+  }
+
+  /**
+   * Provides the storage interface.
+   *
+   * @param \Drupal\Core\Entity\RevisionableInterface $entity
+   *   The entity.
+   *
+   * @return \Drupal\Core\Entity\RevisionableStorageInterface
+   *   The revisionable storage interface.
+   */
+  protected function getRevisionStorage(RevisionableInterface $entity) : RevisionableStorageInterface {
+    return $this->entityTypeManager->getStorage($entity->getEntityTypeId());
+  }
+
+}