diff core/modules/jsonapi/src/Revisions/NegotiatorBase.php @ 18:af1871eacc83

Update to Drupal core 8.7.1

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/core/modules/jsonapi/src/Revisions/NegotiatorBase.php	Thu May 09 15:33:08 2019 +0100
@@ -0,0 +1,106 @@
+<?php
+
+namespace Drupal\jsonapi\Revisions;
+
+use Drupal\Core\Entity\EntityInterface;
+use Drupal\Core\Entity\EntityTypeManagerInterface;
+
+/**
+ * Base implementation for version negotiators.
+ *
+ * @internal JSON:API maintains no PHP API since its API is the HTTP API. This
+ *   class may change at any time and this will break any dependencies on it.
+ *
+ * @see https://www.drupal.org/project/jsonapi/issues/3032787
+ * @see jsonapi.api.php
+ */
+abstract class NegotiatorBase implements VersionNegotiatorInterface {
+
+  /**
+   * The entity type manager to load the revision.
+   *
+   * @var \Drupal\Core\Entity\EntityTypeManagerInterface
+   */
+  protected $entityTypeManager;
+
+  /**
+   * Constructs a version negotiator instance.
+   *
+   * @param \Drupal\Core\Entity\EntityTypeManagerInterface $entity_type_manager
+   *   The entity type manager.
+   */
+  public function __construct(EntityTypeManagerInterface $entity_type_manager) {
+    $this->entityTypeManager = $entity_type_manager;
+  }
+
+  /**
+   * Gets the revision ID.
+   *
+   * @param \Drupal\Core\Entity\EntityInterface $entity
+   *   The entity.
+   * @param string $version_argument
+   *   A value used to derive a revision ID for the given entity.
+   *
+   * @return int
+   *   The revision ID.
+   *
+   * @throws \Drupal\jsonapi\Revisions\VersionNotFoundException
+   *   When the revision does not exist.
+   * @throws \Drupal\jsonapi\Revisions\InvalidVersionIdentifierException
+   *   When the revision ID is not valid.
+   */
+  abstract protected function getRevisionId(EntityInterface $entity, $version_argument);
+
+  /**
+   * {@inheritdoc}
+   */
+  public function getRevision(EntityInterface $entity, $version_argument) {
+    return $this->loadRevision($entity, $this->getRevisionId($entity, $version_argument));
+  }
+
+  /**
+   * Loads an entity revision.
+   *
+   * @param \Drupal\Core\Entity\EntityInterface $entity
+   *   The entity for which to load a revision.
+   * @param int $revision_id
+   *   The revision ID to be loaded.
+   *
+   * @return \Drupal\Core\Entity\EntityInterface|null
+   *   The revision or NULL if the revision does not exists.
+   *
+   * @throws \Drupal\Component\Plugin\Exception\PluginNotFoundException
+   *   Thrown if the entity type doesn't exist.
+   * @throws \Drupal\Component\Plugin\Exception\InvalidPluginDefinitionException
+   *   Thrown if the storage handler couldn't be loaded.
+   */
+  protected function loadRevision(EntityInterface $entity, $revision_id) {
+    $storage = $this->entityTypeManager->getStorage($entity->getEntityTypeId());
+    $revision = static::ensureVersionExists($storage->loadRevision($revision_id));
+    if ($revision->id() !== $entity->id()) {
+      throw new VersionNotFoundException(sprintf('The requested resource does not have a version with ID %s.', $revision_id));
+    }
+    return $revision;
+  }
+
+  /**
+   * Helper method that ensures that a version exists.
+   *
+   * @param int|\Drupal\Core\Entity\EntityInterface $revision
+   *   A revision ID, or NULL if one was not found.
+   *
+   * @return int|\Drupal\Core\Entity\EntityInterface
+   *   A revision or revision ID, if one was found.
+   *
+   * @throws \Drupal\jsonapi\Revisions\VersionNotFoundException
+   *   Thrown if the given value is NULL, meaning the requested version was not
+   *   found.
+   */
+  protected static function ensureVersionExists($revision) {
+    if (is_null($revision)) {
+      throw new VersionNotFoundException();
+    }
+    return $revision;
+  }
+
+}