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