class BlockViewBuilder in Drupal 8

Same name and namespace in other branches

9 core/modules/block/src/BlockViewBuilder.php \Drupal\block\BlockViewBuilder

Provides a Block view builder.

Hierarchy

class \Drupal\Core\Entity\EntityHandlerBase uses DependencySerializationTrait, StringTranslationTrait
- class \Drupal\Core\Entity\EntityViewBuilder implements EntityHandlerInterface, EntityViewBuilderInterface, TrustedCallbackInterface uses DeprecatedServicePropertyTrait
  - class \Drupal\block\BlockViewBuilder implements TrustedCallbackInterface

Expanded class hierarchy of BlockViewBuilder

File

core/modules/block/src/BlockViewBuilder.php, line 20

Namespace

Drupal\block

View source

class BlockViewBuilder extends EntityViewBuilder implements TrustedCallbackInterface {

  /**
   * {@inheritdoc}
   */
  public function buildComponents(array &$build, array $entities, array $displays, $view_mode) {
  }

  /**
   * {@inheritdoc}
   */
  public function view(EntityInterface $entity, $view_mode = 'full', $langcode = NULL) {
    $build = $this
      ->viewMultiple([
      $entity,
    ], $view_mode, $langcode);
    return reset($build);
  }

  /**
   * {@inheritdoc}
   */
  public function viewMultiple(array $entities = [], $view_mode = 'full', $langcode = NULL) {

    /** @var \Drupal\block\BlockInterface[] $entities */
    $build = [];
    foreach ($entities as $entity) {
      $entity_id = $entity
        ->id();
      $plugin = $entity
        ->getPlugin();
      $cache_tags = Cache::mergeTags($this
        ->getCacheTags(), $entity
        ->getCacheTags());
      $cache_tags = Cache::mergeTags($cache_tags, $plugin
        ->getCacheTags());

      // Create the render array for the block as a whole.
      // @see template_preprocess_block().
      $build[$entity_id] = [
        '#cache' => [
          'keys' => [
            'entity_view',
            'block',
            $entity
              ->id(),
          ],
          'contexts' => Cache::mergeContexts($entity
            ->getCacheContexts(), $plugin
            ->getCacheContexts()),
          'tags' => $cache_tags,
          'max-age' => $plugin
            ->getCacheMaxAge(),
        ],
        '#weight' => $entity
          ->getWeight(),
      ];

      // Allow altering of cacheability metadata or setting #create_placeholder.
      $this->moduleHandler
        ->alter([
        'block_build',
        "block_build_" . $plugin
          ->getBaseId(),
      ], $build[$entity_id], $plugin);
      if ($plugin instanceof MainContentBlockPluginInterface || $plugin instanceof TitleBlockPluginInterface) {

        // Immediately build a #pre_render-able block, since this block cannot
        // be built lazily.
        $build[$entity_id] += static::buildPreRenderableBlock($entity, $this
          ->moduleHandler());
      }
      else {

        // Assign a #lazy_builder callback, which will generate a #pre_render-
        // able block lazily (when necessary).
        $build[$entity_id] += [
          '#lazy_builder' => [
            static::class . '::lazyBuilder',
            [
              $entity_id,
              $view_mode,
              $langcode,
            ],
          ],
        ];
      }
    }
    return $build;
  }

  /**
   * Builds a #pre_render-able block render array.
   *
   * @param \Drupal\block\BlockInterface $entity
   *   A block config entity.
   * @param \Drupal\Core\Extension\ModuleHandlerInterface $module_handler
   *   The module handler service.
   *
   * @return array
   *   A render array with a #pre_render callback to render the block.
   */
  protected static function buildPreRenderableBlock($entity, ModuleHandlerInterface $module_handler) {
    $plugin = $entity
      ->getPlugin();
    $plugin_id = $plugin
      ->getPluginId();
    $base_id = $plugin
      ->getBaseId();
    $derivative_id = $plugin
      ->getDerivativeId();
    $configuration = $plugin
      ->getConfiguration();

    // Inject runtime contexts.
    if ($plugin instanceof ContextAwarePluginInterface) {
      $contexts = \Drupal::service('context.repository')
        ->getRuntimeContexts($plugin
        ->getContextMapping());
      \Drupal::service('context.handler')
        ->applyContextMapping($plugin, $contexts);
    }

    // Create the render array for the block as a whole.
    // @see template_preprocess_block().
    $build = [
      '#theme' => 'block',
      '#attributes' => [],
      // All blocks get a "Configure block" contextual link.
      '#contextual_links' => [
        'block' => [
          'route_parameters' => [
            'block' => $entity
              ->id(),
          ],
        ],
      ],
      '#weight' => $entity
        ->getWeight(),
      '#configuration' => $configuration,
      '#plugin_id' => $plugin_id,
      '#base_plugin_id' => $base_id,
      '#derivative_plugin_id' => $derivative_id,
      '#id' => $entity
        ->id(),
      '#pre_render' => [
        static::class . '::preRender',
      ],
      // Add the entity so that it can be used in the #pre_render method.
      '#block' => $entity,
    ];

    // If an alter hook wants to modify the block contents, it can append
    // another #pre_render hook.
    $module_handler
      ->alter([
      'block_view',
      "block_view_{$base_id}",
    ], $build, $plugin);
    return $build;
  }

  /**
   * {@inheritdoc}
   */
  public static function trustedCallbacks() {
    return [
      'preRender',
      'lazyBuilder',
    ];
  }

  /**
   * #lazy_builder callback; builds a #pre_render-able block.
   *
   * @param $entity_id
   *   A block config entity ID.
   * @param $view_mode
   *   The view mode the block is being viewed in.
   *
   * @return array
   *   A render array with a #pre_render callback to render the block.
   */
  public static function lazyBuilder($entity_id, $view_mode) {
    return static::buildPreRenderableBlock(Block::load($entity_id), \Drupal::service('module_handler'));
  }

  /**
   * #pre_render callback for building a block.
   *
   * Renders the content using the provided block plugin, and then:
   * - if there is no content, aborts rendering, and makes sure the block won't
   *   be rendered.
   * - if there is content, moves the contextual links from the block content to
   *   the block itself.
   */
  public static function preRender($build) {
    $content = $build['#block']
      ->getPlugin()
      ->build();

    // Remove the block entity from the render array, to ensure that blocks
    // can be rendered without the block config entity.
    unset($build['#block']);
    if ($content !== NULL && !Element::isEmpty($content)) {

      // Place the $content returned by the block plugin into a 'content' child
      // element, as a way to allow the plugin to have complete control of its
      // properties and rendering (for instance, its own #theme) without
      // conflicting with the properties used above, or alternate ones used by
      // alternate block rendering approaches in contrib (for instance, Panels).
      // However, the use of a child element is an implementation detail of this
      // particular block rendering approach. Semantically, the content returned
      // by the plugin "is the" block, and in particular, #attributes and
      // #contextual_links is information about the *entire* block. Therefore,
      // we must move these properties from $content and merge them into the
      // top-level element.
      foreach ([
        '#attributes',
        '#contextual_links',
      ] as $property) {
        if (isset($content[$property])) {
          $build[$property] += $content[$property];
          unset($content[$property]);
        }
      }
      $build['content'] = $content;
    }
    else {

      // Abort rendering: render as the empty string and ensure this block is
      // render cached, so we can avoid the work of having to repeatedly
      // determine whether the block is empty. For instance, modifying or adding
      // entities could cause the block to no longer be empty.
      $build = [
        '#markup' => '',
        '#cache' => $build['#cache'],
      ];

      // If $content is not empty, then it contains cacheability metadata, and
      // we must merge it with the existing cacheability metadata. This allows
      // blocks to be empty, yet still bubble cacheability metadata, to indicate
      // why they are empty.
      if (!empty($content)) {
        CacheableMetadata::createFromRenderArray($build)
          ->merge(CacheableMetadata::createFromRenderArray($content))
          ->applyTo($build);
      }
    }
    return $build;
  }

}

Members

Name	Modifiers	Type	Description	Overrides
BlockViewBuilder::buildComponents	public	function	Builds the component fields and properties of a set of entities. Overrides EntityViewBuilder::buildComponents
BlockViewBuilder::buildPreRenderableBlock	protected static	function	Builds a #pre_render-able block render array.
BlockViewBuilder::lazyBuilder	public static	function	#lazy_builder callback; builds a #pre_render-able block.
BlockViewBuilder::preRender	public static	function	#pre_render callback for building a block.
BlockViewBuilder::trustedCallbacks	public static	function	Lists the trusted callbacks provided by the implementing class. Overrides EntityViewBuilder::trustedCallbacks
BlockViewBuilder::view	public	function	Builds the render array for the provided entity. Overrides EntityViewBuilder::view
BlockViewBuilder::viewMultiple	public	function	Builds the render array for the provided entities. Overrides EntityViewBuilder::viewMultiple
DependencySerializationTrait::$_entityStorages	protected	property	An array of entity type IDs keyed by the property name of their storages.
DependencySerializationTrait::$_serviceIds	protected	property	An array of service IDs keyed by property name used for serialization.
DependencySerializationTrait::__sleep	public	function		1
DependencySerializationTrait::__wakeup	public	function		2
DeprecatedServicePropertyTrait::__get	public	function	Allows to access deprecated/removed properties.
EntityHandlerBase::$moduleHandler	protected	property	The module handler to invoke hooks on.	2
EntityHandlerBase::moduleHandler	protected	function	Gets the module handler.	2
EntityHandlerBase::setModuleHandler	public	function	Sets the module handler for this handler.
EntityViewBuilder::$cacheBin	protected	property	The cache bin used to store the render cache.
EntityViewBuilder::$deprecatedProperties	protected	property
EntityViewBuilder::$entityDisplayRepository	protected	property	The entity display repository.
EntityViewBuilder::$entityRepository	protected	property	The entity repository service.
EntityViewBuilder::$entityType	protected	property	Information about the entity type.
EntityViewBuilder::$entityTypeId	protected	property	The type of entities for which this view builder is instantiated.
EntityViewBuilder::$languageManager	protected	property	The language manager.
EntityViewBuilder::$singleFieldDisplays	protected	property	The EntityViewDisplay objects created for individual field rendering.
EntityViewBuilder::$themeRegistry	protected	property	The theme registry.
EntityViewBuilder::addContextualLinks	protected	function	Add contextual links.
EntityViewBuilder::alterBuild	protected	function	Specific per-entity building.	1
EntityViewBuilder::build	public	function	Builds an entity's view; augments entity defaults.
EntityViewBuilder::buildMultiple	public	function	Builds multiple entities' views; augments entity defaults.
EntityViewBuilder::createInstance	public static	function	Instantiates a new instance of this entity handler. Overrides EntityHandlerInterface::createInstance	2
EntityViewBuilder::getBuildDefaults	protected	function	Provides entity-specific defaults to the build process.	4
EntityViewBuilder::getCacheTags	public	function	The cache tag associated with this entity view builder. Overrides EntityViewBuilderInterface::getCacheTags
EntityViewBuilder::getSingleFieldDisplay	protected	function	Gets an EntityViewDisplay for rendering an individual field.
EntityViewBuilder::isViewModeCacheable	protected	function	Determines whether the view mode is cacheable.
EntityViewBuilder::resetCache	public	function	Resets the entity render cache. Overrides EntityViewBuilderInterface::resetCache
EntityViewBuilder::viewField	public	function	Builds a renderable array for the value of a single field in an entity. Overrides EntityViewBuilderInterface::viewField
EntityViewBuilder::viewFieldItem	public	function	Builds a renderable array for a single field item. Overrides EntityViewBuilderInterface::viewFieldItem
EntityViewBuilder::__construct	public	function	Constructs a new EntityViewBuilder.	2
StringTranslationTrait::$stringTranslation	protected	property	The string translation service.	1
StringTranslationTrait::formatPlural	protected	function	Formats a string containing a count of items.
StringTranslationTrait::getNumberOfPlurals	protected	function	Returns the number of plurals supported by a given language.
StringTranslationTrait::getStringTranslation	protected	function	Gets the string translation service.
StringTranslationTrait::setStringTranslation	public	function	Sets the string translation service to use.	2
StringTranslationTrait::t	protected	function	Translates a string to the current language or to a given language.
TrustedCallbackInterface::THROW_EXCEPTION		constant	Untrusted callbacks throw exceptions.
TrustedCallbackInterface::TRIGGER_SILENCED_DEPRECATION		constant	Untrusted callbacks trigger silenced E_USER_DEPRECATION errors.
TrustedCallbackInterface::TRIGGER_WARNING		constant	Untrusted callbacks trigger E_USER_WARNING errors.

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class BlockViewBuilder in Drupal 8

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