--- /dev/null
+<?php
+
+namespace Drupal\block;
+
+use Drupal\Core\Block\MainContentBlockPluginInterface;
+use Drupal\Core\Block\TitleBlockPluginInterface;
+use Drupal\Core\Cache\Cache;
+use Drupal\Core\Cache\CacheableMetadata;
+use Drupal\Core\Entity\EntityManagerInterface;
+use Drupal\Core\Entity\EntityTypeInterface;
+use Drupal\Core\Entity\EntityViewBuilder;
+use Drupal\Core\Entity\EntityInterface;
+use Drupal\Core\Extension\ModuleHandlerInterface;
+use Drupal\Core\Language\LanguageManagerInterface;
+use Drupal\Core\Plugin\ContextAwarePluginInterface;
+use Drupal\Core\Render\Element;
+use Drupal\block\Entity\Block;
+use Symfony\Component\DependencyInjection\ContainerInterface;
+
+/**
+ * Provides a Block view builder.
+ */
+class BlockViewBuilder extends EntityViewBuilder {
+
+ /**
+ * The module handler.
+ *
+ * @var \Drupal\Core\Extension\ModuleHandlerInterface
+ */
+ protected $moduleHandler;
+
+ /**
+ * Constructs a new BlockViewBuilder.
+ *
+ * @param \Drupal\Core\Entity\EntityTypeInterface $entity_type
+ * The entity type definition.
+ * @param \Drupal\Core\Entity\EntityManagerInterface $entity_manager
+ * The entity manager service.
+ * @param \Drupal\Core\Language\LanguageManagerInterface $language_manager
+ * The language manager.
+ * @param \Drupal\Core\Extension\ModuleHandlerInterface $module_handler
+ * The module handler.
+ */
+ public function __construct(EntityTypeInterface $entity_type, EntityManagerInterface $entity_manager, LanguageManagerInterface $language_manager, ModuleHandlerInterface $module_handler) {
+ parent::__construct($entity_type, $entity_manager, $language_manager);
+ $this->moduleHandler = $module_handler;
+ }
+
+ /**
+ * {@inheritdoc}
+ */
+ public static function createInstance(ContainerInterface $container, EntityTypeInterface $entity_type) {
+ return new static(
+ $entity_type,
+ $container->get('entity.manager'),
+ $container->get('language_manager'),
+ $container->get('module_handler')
+ );
+ }
+
+ /**
+ * {@inheritdoc}
+ */
+ public function buildComponents(array &$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;
+ }
+
+ /**
+ * #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;
+ }
+ // Either the block's content is completely empty, or it consists only of
+ // cacheability metadata.
+ 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;
+ }
+
+}
projects / yaffs-website / blobdiff