Chris@0: <?php
Chris@0: 
Chris@0: namespace Drupal\Core\Entity;
Chris@0: 
Chris@0: use Drupal\Component\Utility\Crypt;
Chris@0: use Drupal\Core\Cache\Cache;
Chris@18: use Drupal\Core\DependencyInjection\DeprecatedServicePropertyTrait;
Chris@0: use Drupal\Core\Entity\Display\EntityViewDisplayInterface;
Chris@0: use Drupal\Core\Entity\Entity\EntityViewDisplay;
Chris@0: use Drupal\Core\Field\FieldItemInterface;
Chris@0: use Drupal\Core\Field\FieldItemListInterface;
Chris@0: use Drupal\Core\Language\LanguageManagerInterface;
Chris@0: use Drupal\Core\Render\Element;
Chris@0: use Drupal\Core\Theme\Registry;
Chris@14: use Drupal\Core\TypedData\TranslatableInterface as TranslatableDataInterface;
Chris@0: use Symfony\Component\DependencyInjection\ContainerInterface;
Chris@0: 
Chris@0: /**
Chris@0:  * Base class for entity view builders.
Chris@0:  *
Chris@0:  * @ingroup entity_api
Chris@0:  */
Chris@0: class EntityViewBuilder extends EntityHandlerBase implements EntityHandlerInterface, EntityViewBuilderInterface {
Chris@18:   use DeprecatedServicePropertyTrait;
Chris@18: 
Chris@18:   /**
Chris@18:    * {@inheritdoc}
Chris@18:    */
Chris@18:   protected $deprecatedProperties = ['entityManager' => 'entity.manager'];
Chris@0: 
Chris@0:   /**
Chris@0:    * The type of entities for which this view builder is instantiated.
Chris@0:    *
Chris@0:    * @var string
Chris@0:    */
Chris@0:   protected $entityTypeId;
Chris@0: 
Chris@0:   /**
Chris@0:    * Information about the entity type.
Chris@0:    *
Chris@0:    * @var \Drupal\Core\Entity\EntityTypeInterface
Chris@0:    */
Chris@0:   protected $entityType;
Chris@0: 
Chris@0:   /**
Chris@18:    * The entity repository service.
Chris@0:    *
Chris@18:    * @var \Drupal\Core\Entity\EntityRepositoryInterface
Chris@0:    */
Chris@18:   protected $entityRepository;
Chris@18: 
Chris@18:   /**
Chris@18:    * The entity display repository.
Chris@18:    *
Chris@18:    * @var \Drupal\Core\Entity\EntityDisplayRepositoryInterface
Chris@18:    */
Chris@18:   protected $entityDisplayRepository;
Chris@0: 
Chris@0:   /**
Chris@0:    * The cache bin used to store the render cache.
Chris@0:    *
Chris@0:    * @var string
Chris@0:    */
Chris@0:   protected $cacheBin = 'render';
Chris@0: 
Chris@0:   /**
Chris@0:    * The language manager.
Chris@0:    *
Chris@12:    * @var \Drupal\Core\Language\LanguageManagerInterface
Chris@0:    */
Chris@0:   protected $languageManager;
Chris@0: 
Chris@0:   /**
Chris@0:    * The theme registry.
Chris@0:    *
Chris@0:    * @var \Drupal\Core\Theme\Registry
Chris@0:    */
Chris@0:   protected $themeRegistry;
Chris@0: 
Chris@0:   /**
Chris@0:    * The EntityViewDisplay objects created for individual field rendering.
Chris@0:    *
Chris@12:    * @var \Drupal\Core\Entity\Display\EntityViewDisplayInterface[]
Chris@12:    *
Chris@0:    * @see \Drupal\Core\Entity\EntityViewBuilder::getSingleFieldDisplay()
Chris@0:    */
Chris@0:   protected $singleFieldDisplays;
Chris@0: 
Chris@0:   /**
Chris@0:    * Constructs a new EntityViewBuilder.
Chris@0:    *
Chris@0:    * @param \Drupal\Core\Entity\EntityTypeInterface $entity_type
Chris@0:    *   The entity type definition.
Chris@18:    * @param \Drupal\Core\Entity\EntityRepositoryInterface $entity_repository
Chris@18:    *   The entity repository service.
Chris@0:    * @param \Drupal\Core\Language\LanguageManagerInterface $language_manager
Chris@0:    *   The language manager.
Chris@0:    * @param \Drupal\Core\Theme\Registry $theme_registry
Chris@0:    *   The theme registry.
Chris@18:    * @param \Drupal\Core\Entity\EntityDisplayRepositoryInterface $entity_display_repository
Chris@18:    *   The entity display repository.
Chris@0:    */
Chris@18:   public function __construct(EntityTypeInterface $entity_type, EntityRepositoryInterface $entity_repository, LanguageManagerInterface $language_manager, Registry $theme_registry = NULL, EntityDisplayRepositoryInterface $entity_display_repository = NULL) {
Chris@0:     $this->entityTypeId = $entity_type->id();
Chris@0:     $this->entityType = $entity_type;
Chris@18:     $this->entityRepository = $entity_repository;
Chris@0:     $this->languageManager = $language_manager;
Chris@0:     $this->themeRegistry = $theme_registry ?: \Drupal::service('theme.registry');
Chris@18:     if (!$entity_display_repository) {
Chris@18:       @trigger_error('Calling EntityViewBuilder::__construct() with the $entity_repository argument is supported in drupal:8.7.0 and will be required before drupal:9.0.0. See https://www.drupal.org/node/2549139.', E_USER_DEPRECATED);
Chris@18:       $entity_display_repository = \Drupal::service('entity_display.repository');
Chris@18:     }
Chris@18:     $this->entityDisplayRepository = $entity_display_repository;
Chris@0:   }
Chris@0: 
Chris@0:   /**
Chris@0:    * {@inheritdoc}
Chris@0:    */
Chris@0:   public static function createInstance(ContainerInterface $container, EntityTypeInterface $entity_type) {
Chris@0:     return new static(
Chris@0:       $entity_type,
Chris@18:       $container->get('entity.repository'),
Chris@0:       $container->get('language_manager'),
Chris@18:       $container->get('theme.registry'),
Chris@18:       $container->get('entity_display.repository')
Chris@0:     );
Chris@0:   }
Chris@0: 
Chris@0:   /**
Chris@0:    * {@inheritdoc}
Chris@0:    */
Chris@0:   public function view(EntityInterface $entity, $view_mode = 'full', $langcode = NULL) {
Chris@0:     $build_list = $this->viewMultiple([$entity], $view_mode, $langcode);
Chris@0: 
Chris@0:     // The default ::buildMultiple() #pre_render callback won't run, because we
Chris@0:     // extract a child element of the default renderable array. Thus we must
Chris@0:     // assign an alternative #pre_render callback that applies the necessary
Chris@0:     // transformations and then still calls ::buildMultiple().
Chris@0:     $build = $build_list[0];
Chris@0:     $build['#pre_render'][] = [$this, 'build'];
Chris@0: 
Chris@0:     return $build;
Chris@0:   }
Chris@0: 
Chris@0:   /**
Chris@0:    * {@inheritdoc}
Chris@0:    */
Chris@0:   public function viewMultiple(array $entities = [], $view_mode = 'full', $langcode = NULL) {
Chris@0:     $build_list = [
Chris@0:       '#sorted' => TRUE,
Chris@0:       '#pre_render' => [[$this, 'buildMultiple']],
Chris@0:     ];
Chris@0:     $weight = 0;
Chris@0:     foreach ($entities as $key => $entity) {
Chris@0:       // Ensure that from now on we are dealing with the proper translation
Chris@0:       // object.
Chris@18:       $entity = $this->entityRepository->getTranslationFromContext($entity, $langcode);
Chris@0: 
Chris@0:       // Set build defaults.
Chris@0:       $build_list[$key] = $this->getBuildDefaults($entity, $view_mode);
Chris@0:       $entityType = $this->entityTypeId;
Chris@0:       $this->moduleHandler()->alter([$entityType . '_build_defaults', 'entity_build_defaults'], $build_list[$key], $entity, $view_mode);
Chris@0: 
Chris@0:       $build_list[$key]['#weight'] = $weight++;
Chris@0:     }
Chris@0: 
Chris@0:     return $build_list;
Chris@0:   }
Chris@0: 
Chris@0:   /**
Chris@0:    * Provides entity-specific defaults to the build process.
Chris@0:    *
Chris@0:    * @param \Drupal\Core\Entity\EntityInterface $entity
Chris@0:    *   The entity for which the defaults should be provided.
Chris@0:    * @param string $view_mode
Chris@0:    *   The view mode that should be used.
Chris@0:    *
Chris@0:    * @return array
Chris@0:    */
Chris@0:   protected function getBuildDefaults(EntityInterface $entity, $view_mode) {
Chris@0:     // Allow modules to change the view mode.
Chris@0:     $context = [];
Chris@0:     $this->moduleHandler()->alter('entity_view_mode', $view_mode, $entity, $context);
Chris@0: 
Chris@0:     $build = [
Chris@0:       "#{$this->entityTypeId}" => $entity,
Chris@0:       '#view_mode' => $view_mode,
Chris@0:       // Collect cache defaults for this entity.
Chris@0:       '#cache' => [
Chris@0:         'tags' => Cache::mergeTags($this->getCacheTags(), $entity->getCacheTags()),
Chris@0:         'contexts' => $entity->getCacheContexts(),
Chris@0:         'max-age' => $entity->getCacheMaxAge(),
Chris@0:       ],
Chris@0:     ];
Chris@0: 
Chris@0:     // Add the default #theme key if a template exists for it.
Chris@0:     if ($this->themeRegistry->getRuntime()->has($this->entityTypeId)) {
Chris@0:       $build['#theme'] = $this->entityTypeId;
Chris@0:     }
Chris@0: 
Chris@0:     // Cache the rendered output if permitted by the view mode and global entity
Chris@0:     // type configuration.
Chris@0:     if ($this->isViewModeCacheable($view_mode) && !$entity->isNew() && $entity->isDefaultRevision() && $this->entityType->isRenderCacheable()) {
Chris@0:       $build['#cache'] += [
Chris@0:         'keys' => [
Chris@0:           'entity_view',
Chris@0:           $this->entityTypeId,
Chris@0:           $entity->id(),
Chris@0:           $view_mode,
Chris@0:         ],
Chris@0:         'bin' => $this->cacheBin,
Chris@0:       ];
Chris@0: 
Chris@14:       if ($entity instanceof TranslatableDataInterface && count($entity->getTranslationLanguages()) > 1) {
Chris@0:         $build['#cache']['keys'][] = $entity->language()->getId();
Chris@0:       }
Chris@0:     }
Chris@0: 
Chris@0:     return $build;
Chris@0:   }
Chris@0: 
Chris@0:   /**
Chris@0:    * Builds an entity's view; augments entity defaults.
Chris@0:    *
Chris@0:    * This function is assigned as a #pre_render callback in ::view().
Chris@0:    *
Chris@0:    * It transforms the renderable array for a single entity to the same
Chris@0:    * structure as if we were rendering multiple entities, and then calls the
Chris@0:    * default ::buildMultiple() #pre_render callback.
Chris@0:    *
Chris@0:    * @param array $build
Chris@0:    *   A renderable array containing build information and context for an entity
Chris@0:    *   view.
Chris@0:    *
Chris@0:    * @return array
Chris@0:    *   The updated renderable array.
Chris@0:    *
Chris@16:    * @see \Drupal\Core\Render\RendererInterface::render()
Chris@0:    */
Chris@0:   public function build(array $build) {
Chris@0:     $build_list = [$build];
Chris@0:     $build_list = $this->buildMultiple($build_list);
Chris@0:     return $build_list[0];
Chris@0:   }
Chris@0: 
Chris@0:   /**
Chris@0:    * Builds multiple entities' views; augments entity defaults.
Chris@0:    *
Chris@0:    * This function is assigned as a #pre_render callback in ::viewMultiple().
Chris@0:    *
Chris@0:    * By delaying the building of an entity until the #pre_render processing in
Chris@0:    * drupal_render(), the processing cost of assembling an entity's renderable
Chris@0:    * array is saved on cache-hit requests.
Chris@0:    *
Chris@0:    * @param array $build_list
Chris@0:    *   A renderable  array containing build information and context for an
Chris@0:    *   entity view.
Chris@0:    *
Chris@0:    * @return array
Chris@0:    *   The updated renderable array.
Chris@0:    *
Chris@16:    * @see \Drupal\Core\Render\RendererInterface::render()
Chris@0:    */
Chris@0:   public function buildMultiple(array $build_list) {
Chris@0:     // Build the view modes and display objects.
Chris@0:     $view_modes = [];
Chris@0:     $entity_type_key = "#{$this->entityTypeId}";
Chris@0:     $view_hook = "{$this->entityTypeId}_view";
Chris@0: 
Chris@0:     // Find the keys for the ContentEntities in the build; Store entities for
Chris@0:     // rendering by view_mode.
Chris@0:     $children = Element::children($build_list);
Chris@0:     foreach ($children as $key) {
Chris@0:       if (isset($build_list[$key][$entity_type_key])) {
Chris@0:         $entity = $build_list[$key][$entity_type_key];
Chris@0:         if ($entity instanceof FieldableEntityInterface) {
Chris@0:           $view_modes[$build_list[$key]['#view_mode']][$key] = $entity;
Chris@0:         }
Chris@0:       }
Chris@0:     }
Chris@0: 
Chris@0:     // Build content for the displays represented by the entities.
Chris@0:     foreach ($view_modes as $view_mode => $view_mode_entities) {
Chris@0:       $displays = EntityViewDisplay::collectRenderDisplays($view_mode_entities, $view_mode);
Chris@0:       $this->buildComponents($build_list, $view_mode_entities, $displays, $view_mode);
Chris@0:       foreach (array_keys($view_mode_entities) as $key) {
Chris@0:         // Allow for alterations while building, before rendering.
Chris@0:         $entity = $build_list[$key][$entity_type_key];
Chris@0:         $display = $displays[$entity->bundle()];
Chris@0: 
Chris@0:         $this->moduleHandler()->invokeAll($view_hook, [&$build_list[$key], $entity, $display, $view_mode]);
Chris@0:         $this->moduleHandler()->invokeAll('entity_view', [&$build_list[$key], $entity, $display, $view_mode]);
Chris@0: 
Chris@14:         $this->addContextualLinks($build_list[$key], $entity);
Chris@0:         $this->alterBuild($build_list[$key], $entity, $display, $view_mode);
Chris@0: 
Chris@0:         // Assign the weights configured in the display.
Chris@0:         // @todo: Once https://www.drupal.org/node/1875974 provides the missing
Chris@0:         //   API, only do it for 'extra fields', since other components have
Chris@0:         //   been taken care of in EntityViewDisplay::buildMultiple().
Chris@0:         foreach ($display->getComponents() as $name => $options) {
Chris@0:           if (isset($build_list[$key][$name])) {
Chris@0:             $build_list[$key][$name]['#weight'] = $options['weight'];
Chris@0:           }
Chris@0:         }
Chris@0: 
Chris@0:         // Allow modules to modify the render array.
Chris@0:         $this->moduleHandler()->alter([$view_hook, 'entity_view'], $build_list[$key], $entity, $display);
Chris@0:       }
Chris@0:     }
Chris@0: 
Chris@0:     return $build_list;
Chris@0:   }
Chris@0: 
Chris@0:   /**
Chris@0:    * {@inheritdoc}
Chris@0:    */
Chris@0:   public function buildComponents(array &$build, array $entities, array $displays, $view_mode) {
Chris@0:     $entities_by_bundle = [];
Chris@0:     foreach ($entities as $id => $entity) {
Chris@0:       // Initialize the field item attributes for the fields being displayed.
Chris@0:       // The entity can include fields that are not displayed, and the display
Chris@0:       // can include components that are not fields, so we want to act on the
Chris@0:       // intersection. However, the entity can have many more fields than are
Chris@0:       // displayed, so we avoid the cost of calling $entity->getProperties()
Chris@0:       // by iterating the intersection as follows.
Chris@0:       foreach ($displays[$entity->bundle()]->getComponents() as $name => $options) {
Chris@0:         if ($entity->hasField($name)) {
Chris@0:           foreach ($entity->get($name) as $item) {
Chris@0:             $item->_attributes = [];
Chris@0:           }
Chris@0:         }
Chris@0:       }
Chris@0:       // Group the entities by bundle.
Chris@0:       $entities_by_bundle[$entity->bundle()][$id] = $entity;
Chris@0:     }
Chris@0: 
Chris@0:     // Invoke hook_entity_prepare_view().
Chris@0:     $this->moduleHandler()->invokeAll('entity_prepare_view', [$this->entityTypeId, $entities, $displays, $view_mode]);
Chris@0: 
Chris@0:     // Let the displays build their render arrays.
Chris@0:     foreach ($entities_by_bundle as $bundle => $bundle_entities) {
Chris@0:       $display_build = $displays[$bundle]->buildMultiple($bundle_entities);
Chris@0:       foreach ($bundle_entities as $id => $entity) {
Chris@0:         $build[$id] += $display_build[$id];
Chris@0:       }
Chris@0:     }
Chris@0:   }
Chris@0: 
Chris@0:   /**
Chris@14:    * Add contextual links.
Chris@14:    *
Chris@14:    * @param array $build
Chris@14:    *   The render array that is being created.
Chris@14:    * @param \Drupal\Core\Entity\EntityInterface $entity
Chris@14:    *   The entity to be prepared.
Chris@14:    */
Chris@14:   protected function addContextualLinks(array &$build, EntityInterface $entity) {
Chris@14:     if ($entity->isNew()) {
Chris@14:       return;
Chris@14:     }
Chris@14:     $key = $entity->getEntityTypeId();
Chris@14:     $rel = 'canonical';
Chris@14:     if ($entity instanceof ContentEntityInterface && !$entity->isDefaultRevision()) {
Chris@14:       $rel = 'revision';
Chris@14:       $key .= '_revision';
Chris@14:     }
Chris@14:     if ($entity->hasLinkTemplate($rel)) {
Chris@14:       $build['#contextual_links'][$key] = [
Chris@14:         'route_parameters' => $entity->toUrl($rel)->getRouteParameters(),
Chris@14:       ];
Chris@14:       if ($entity instanceof EntityChangedInterface) {
Chris@14:         $build['#contextual_links'][$key]['metadata'] = [
Chris@14:           'changed' => $entity->getChangedTime(),
Chris@14:         ];
Chris@14:       }
Chris@14:     }
Chris@14:   }
Chris@14: 
Chris@14:   /**
Chris@0:    * Specific per-entity building.
Chris@0:    *
Chris@0:    * @param array $build
Chris@0:    *   The render array that is being created.
Chris@0:    * @param \Drupal\Core\Entity\EntityInterface $entity
Chris@0:    *   The entity to be prepared.
Chris@0:    * @param \Drupal\Core\Entity\Display\EntityViewDisplayInterface $display
Chris@0:    *   The entity view display holding the display options configured for the
Chris@0:    *   entity components.
Chris@0:    * @param string $view_mode
Chris@0:    *   The view mode that should be used to prepare the entity.
Chris@0:    */
Chris@0:   protected function alterBuild(array &$build, EntityInterface $entity, EntityViewDisplayInterface $display, $view_mode) {}
Chris@0: 
Chris@0:   /**
Chris@0:    * {@inheritdoc}
Chris@0:    */
Chris@0:   public function getCacheTags() {
Chris@0:     return [$this->entityTypeId . '_view'];
Chris@0:   }
Chris@0: 
Chris@0:   /**
Chris@0:    * {@inheritdoc}
Chris@0:    */
Chris@0:   public function resetCache(array $entities = NULL) {
Chris@0:     // If no set of specific entities is provided, invalidate the entity view
Chris@0:     // builder's cache tag. This will invalidate all entities rendered by this
Chris@0:     // view builder.
Chris@0:     // Otherwise, if a set of specific entities is provided, invalidate those
Chris@0:     // specific entities only, plus their list cache tags, because any lists in
Chris@0:     // which these entities are rendered, must be invalidated as well. However,
Chris@0:     // even in this case, we might invalidate more cache items than necessary.
Chris@0:     // When we have a way to invalidate only those cache items that have both
Chris@0:     // the individual entity's cache tag and the view builder's cache tag, we'll
Chris@0:     // be able to optimize this further.
Chris@0:     if (isset($entities)) {
Chris@0:       $tags = [];
Chris@0:       foreach ($entities as $entity) {
Chris@0:         $tags = Cache::mergeTags($tags, $entity->getCacheTags());
Chris@0:         $tags = Cache::mergeTags($tags, $entity->getEntityType()->getListCacheTags());
Chris@0:       }
Chris@0:       Cache::invalidateTags($tags);
Chris@0:     }
Chris@0:     else {
Chris@0:       Cache::invalidateTags($this->getCacheTags());
Chris@0:     }
Chris@0:   }
Chris@0: 
Chris@0:   /**
Chris@0:    * Determines whether the view mode is cacheable.
Chris@0:    *
Chris@0:    * @param string $view_mode
Chris@0:    *   Name of the view mode that should be rendered.
Chris@0:    *
Chris@0:    * @return bool
Chris@0:    *   TRUE if the view mode can be cached, FALSE otherwise.
Chris@0:    */
Chris@0:   protected function isViewModeCacheable($view_mode) {
Chris@0:     if ($view_mode == 'default') {
Chris@0:       // The 'default' is not an actual view mode.
Chris@0:       return TRUE;
Chris@0:     }
Chris@18:     $view_modes_info = $this->entityDisplayRepository->getViewModes($this->entityTypeId);
Chris@0:     return !empty($view_modes_info[$view_mode]['cache']);
Chris@0:   }
Chris@0: 
Chris@0:   /**
Chris@0:    * {@inheritdoc}
Chris@0:    */
Chris@0:   public function viewField(FieldItemListInterface $items, $display_options = []) {
Chris@0:     $entity = $items->getEntity();
Chris@0:     $field_name = $items->getFieldDefinition()->getName();
Chris@0:     $display = $this->getSingleFieldDisplay($entity, $field_name, $display_options);
Chris@0: 
Chris@0:     $output = [];
Chris@0:     $build = $display->build($entity);
Chris@0:     if (isset($build[$field_name])) {
Chris@0:       $output = $build[$field_name];
Chris@0:     }
Chris@0: 
Chris@0:     return $output;
Chris@0:   }
Chris@0: 
Chris@0:   /**
Chris@0:    * {@inheritdoc}
Chris@0:    */
Chris@0:   public function viewFieldItem(FieldItemInterface $item, $display = []) {
Chris@0:     $entity = $item->getEntity();
Chris@0:     $field_name = $item->getFieldDefinition()->getName();
Chris@0: 
Chris@0:     // Clone the entity since we are going to modify field values.
Chris@0:     $clone = clone $entity;
Chris@0: 
Chris@0:     // Push the item as the single value for the field, and defer to viewField()
Chris@0:     // to build the render array for the whole list.
Chris@0:     $clone->{$field_name}->setValue([$item->getValue()]);
Chris@0:     $elements = $this->viewField($clone->{$field_name}, $display);
Chris@0: 
Chris@0:     // Extract the part of the render array we need.
Chris@0:     $output = isset($elements[0]) ? $elements[0] : [];
Chris@0:     if (isset($elements['#access'])) {
Chris@0:       $output['#access'] = $elements['#access'];
Chris@0:     }
Chris@0: 
Chris@0:     return $output;
Chris@0:   }
Chris@0: 
Chris@0:   /**
Chris@0:    * Gets an EntityViewDisplay for rendering an individual field.
Chris@0:    *
Chris@0:    * @param \Drupal\Core\Entity\EntityInterface $entity
Chris@0:    *   The entity.
Chris@0:    * @param string $field_name
Chris@0:    *   The field name.
Chris@0:    * @param string|array $display_options
Chris@0:    *   The display options passed to the viewField() method.
Chris@0:    *
Chris@0:    * @return \Drupal\Core\Entity\Display\EntityViewDisplayInterface
Chris@0:    */
Chris@0:   protected function getSingleFieldDisplay($entity, $field_name, $display_options) {
Chris@0:     if (is_string($display_options)) {
Chris@0:       // View mode: use the Display configured for the view mode.
Chris@0:       $view_mode = $display_options;
Chris@0:       $display = EntityViewDisplay::collectRenderDisplay($entity, $view_mode);
Chris@0:       // Hide all fields except the current one.
Chris@0:       foreach (array_keys($entity->getFieldDefinitions()) as $name) {
Chris@0:         if ($name != $field_name) {
Chris@0:           $display->removeComponent($name);
Chris@0:         }
Chris@0:       }
Chris@0:     }
Chris@0:     else {
Chris@0:       // Array of custom display options: use a runtime Display for the
Chris@0:       // '_custom' view mode. Persist the displays created, to reduce the number
Chris@0:       // of objects (displays and formatter plugins) created when rendering a
Chris@0:       // series of fields individually for cases such as views tables.
Chris@0:       $entity_type_id = $entity->getEntityTypeId();
Chris@0:       $bundle = $entity->bundle();
Chris@0:       $key = $entity_type_id . ':' . $bundle . ':' . $field_name . ':' . Crypt::hashBase64(serialize($display_options));
Chris@0:       if (!isset($this->singleFieldDisplays[$key])) {
Chris@0:         $this->singleFieldDisplays[$key] = EntityViewDisplay::create([
Chris@0:           'targetEntityType' => $entity_type_id,
Chris@0:           'bundle' => $bundle,
Chris@0:           'status' => TRUE,
Chris@0:         ])->setComponent($field_name, $display_options);
Chris@0:       }
Chris@0:       $display = $this->singleFieldDisplays[$key];
Chris@0:     }
Chris@0: 
Chris@0:     return $display;
Chris@0:   }
Chris@0: 
Chris@0: }