diff core/modules/hal/src/LinkManager/RelationLinkManager.php @ 0:c75dbcec494b

Initial commit from drush-created site

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/core/modules/hal/src/LinkManager/RelationLinkManager.php	Thu Jul 05 14:24:15 2018 +0000
@@ -0,0 +1,171 @@
+<?php
+
+namespace Drupal\hal\LinkManager;
+
+use Drupal\Core\Cache\Cache;
+use Drupal\Core\Cache\CacheBackendInterface;
+use Drupal\Core\Config\ConfigFactoryInterface;
+use Drupal\Core\Entity\ContentEntityTypeInterface;
+use Drupal\Core\Entity\EntityManagerInterface;
+use Drupal\Core\Extension\ModuleHandlerInterface;
+use Symfony\Component\HttpFoundation\RequestStack;
+
+class RelationLinkManager extends LinkManagerBase implements RelationLinkManagerInterface {
+
+  /**
+   * @var \Drupal\Core\Cache\CacheBackendInterface;
+   */
+  protected $cache;
+
+  /**
+   * Entity manager.
+   *
+   * @var \Drupal\Core\Entity\EntityManagerInterface
+   */
+  protected $entityManager;
+
+  /**
+   * Module handler service.
+   *
+   * @var \Drupal\Core\Extension\ModuleHandlerInterface
+   */
+  protected $moduleHandler;
+
+  /**
+   * Constructor.
+   *
+   * @param \Drupal\Core\Cache\CacheBackendInterface $cache
+   *   The cache of relation URIs and their associated Typed Data IDs.
+   * @param \Drupal\Core\Entity\EntityManagerInterface $entity_manager
+   *   The entity manager.
+   * @param \Drupal\Core\Extension\ModuleHandlerInterface $module_handler
+   *   The module handler service.
+   * @param \Drupal\Core\Config\ConfigFactoryInterface $config_factory
+   *   The config factory service.
+   * @param \Symfony\Component\HttpFoundation\RequestStack $request_stack
+   *   The request stack.
+   */
+  public function __construct(CacheBackendInterface $cache, EntityManagerInterface $entity_manager, ModuleHandlerInterface $module_handler, ConfigFactoryInterface $config_factory, RequestStack $request_stack) {
+    $this->cache = $cache;
+    $this->entityManager = $entity_manager;
+    $this->configFactory = $config_factory;
+    $this->moduleHandler = $module_handler;
+    $this->requestStack = $request_stack;
+  }
+
+  /**
+   * {@inheritdoc}
+   */
+  public function getRelationUri($entity_type, $bundle, $field_name, $context = []) {
+    // Per the interface documentation of this method, the returned URI may
+    // optionally also serve as the URL of a documentation page about this
+    // field. However, Drupal does not currently implement such a documentation
+    // page. Therefore, we return a URI assembled relative to the site's base
+    // URL, which is sufficient to uniquely identify the site's entity type +
+    // bundle + field for use in hypermedia formats, but we do not take into
+    // account unclean URLs, language prefixing, or anything else that would be
+    // required for Drupal to be able to respond with content at this URL. If a
+    // module is installed that adds such content, but requires this URL to be
+    // different (e.g., include a language prefix), then the module must also
+    // override the RelationLinkManager class/service to return the desired URL.
+    $uri = $this->getLinkDomain($context) . "/rest/relation/$entity_type/$bundle/$field_name";
+    $this->moduleHandler->alter('hal_relation_uri', $uri, $context);
+    // @deprecated in Drupal 8.3.x and will be removed before Drupal 9.0.0. This
+    // hook is invoked to maintain backwards compatibility
+    // @see https://www.drupal.org/node/2830467
+    $this->moduleHandler->alter('rest_relation_uri', $uri, $context);
+    return $uri;
+  }
+
+  /**
+   * {@inheritdoc}
+   */
+  public function getRelationInternalIds($relation_uri, $context = []) {
+    $relations = $this->getRelations($context);
+    if (isset($relations[$relation_uri])) {
+      return $relations[$relation_uri];
+    }
+    return FALSE;
+  }
+
+  /**
+   * Get the array of relation links.
+   *
+   * Any field can be handled as a relation simply by changing how it is
+   * normalized. Therefore, there is no prior knowledge that can be used here
+   * to determine which fields to assign relation URIs. Instead, each field,
+   * even primitives, are given a relation URI. It is up to the caller to
+   * determine which URIs to use.
+   *
+   * @param array $context
+   *   Context from the normalizer/serializer operation.
+   *
+   * @return array
+   *   An array of typed data IDs keyed by corresponding relation URI. The keys
+   *   are:
+   *   - 'entity_type_id'
+   *   - 'bundle'
+   *   - 'field_name'
+   *   - 'entity_type' (deprecated)
+   *   The values for 'entity_type_id', 'bundle' and 'field_name' are strings.
+   *   The 'entity_type' key exists for backwards compatibility and its value is
+   *   the full entity type object. The 'entity_type' key will be removed before
+   *   Drupal 9.0.
+   *
+   * @see https://www.drupal.org/node/2877608
+   */
+  protected function getRelations($context = []) {
+    $cid = 'hal:links:relations';
+    $cache = $this->cache->get($cid);
+    if (!$cache) {
+      $data = $this->writeCache($context);
+    }
+    else {
+      $data = $cache->data;
+    }
+
+    // @todo https://www.drupal.org/node/2716163 Remove this in Drupal 9.0.
+    foreach ($data as $relation_uri => $ids) {
+      $data[$relation_uri]['entity_type'] = $this->entityManager->getDefinition($ids['entity_type_id']);
+    }
+    return $data;
+  }
+
+  /**
+   * Writes the cache of relation links.
+   *
+   * @param array $context
+   *   Context from the normalizer/serializer operation.
+   *
+   * @return array
+   *   An array of typed data IDs keyed by corresponding relation URI. The keys
+   *   are:
+   *   - 'entity_type_id'
+   *   - 'bundle'
+   *   - 'field_name'
+   *   The values for 'entity_type_id', 'bundle' and 'field_name' are strings.
+   */
+  protected function writeCache($context = []) {
+    $data = [];
+
+    foreach ($this->entityManager->getDefinitions() as $entity_type) {
+      if ($entity_type instanceof ContentEntityTypeInterface) {
+        foreach ($this->entityManager->getBundleInfo($entity_type->id()) as $bundle => $bundle_info) {
+          foreach ($this->entityManager->getFieldDefinitions($entity_type->id(), $bundle) as $field_definition) {
+            $relation_uri = $this->getRelationUri($entity_type->id(), $bundle, $field_definition->getName(), $context);
+            $data[$relation_uri] = [
+              'entity_type_id' => $entity_type->id(),
+              'bundle' => $bundle,
+              'field_name' => $field_definition->getName(),
+            ];
+          }
+        }
+      }
+    }
+    // These URIs only change when field info changes, so cache it permanently
+    // and only clear it when the fields cache is cleared.
+    $this->cache->set('hal:links:relations', $data, Cache::PERMANENT, ['entity_field_info']);
+    return $data;
+  }
+
+}