SetInlineBlockDependency.php

<?php

namespace Drupal\layout_builder\EventSubscriber;

use Drupal\block_content\BlockContentEvents;
use Drupal\block_content\BlockContentInterface;
use Drupal\block_content\Event\BlockContentGetDependencyEvent;
use Drupal\Core\Database\Connection;
use Drupal\Core\Entity\EntityInterface;
use Drupal\Core\Entity\EntityTypeManagerInterface;
use Drupal\layout_builder\InlineBlockUsageInterface;
use Drupal\layout_builder\LayoutEntityHelperTrait;
use Drupal\layout_builder\SectionStorage\SectionStorageManagerInterface;
use Symfony\Component\EventDispatcher\EventSubscriberInterface;

/**
 * An event subscriber that returns an access dependency for inline blocks.
 *
 * When used within the layout builder the access dependency for inline blocks
 * will be explicitly set but if access is evaluated outside of the layout
 * builder then the dependency may not have been set.
 *
 * A known example of when the access dependency will not have been set is when
 * determining 'view' or 'download' access to a file entity that is attached
 * to a content block via a field that is using the private file system. The
 * file access handler will evaluate access on the content block without setting
 * the dependency.
 *
 * @internal
 *   Tagged services are internal.
 *
 * @see \Drupal\file\FileAccessControlHandler::checkAccess()
 * @see \Drupal\block_content\BlockContentAccessControlHandler::checkAccess()
 */
class SetInlineBlockDependency implements EventSubscriberInterface {
    use LayoutEntityHelperTrait;
    
    /**
     * The entity type manager.
     *
     * @var \Drupal\Core\Entity\EntityTypeManagerInterface
     */
    protected $entityTypeManager;
    
    /**
     * The database connection.
     *
     * @var \Drupal\Core\Database\Connection
     */
    protected $database;
    
    /**
     * The inline block usage service.
     *
     * @var \Drupal\layout_builder\InlineBlockUsageInterface
     */
    protected $usage;
    
    /**
     * Constructs SetInlineBlockDependency object.
     *
     * @param \Drupal\Core\Entity\EntityTypeManagerInterface $entity_type_manager
     *   The entity type manager.
     * @param \Drupal\Core\Database\Connection $database
     *   The database connection.
     * @param \Drupal\layout_builder\InlineBlockUsageInterface $usage
     *   The inline block usage service.
     * @param \Drupal\layout_builder\SectionStorage\SectionStorageManagerInterface $section_storage_manager
     *   The section storage manager.
     */
    public function __construct(EntityTypeManagerInterface $entity_type_manager, Connection $database, InlineBlockUsageInterface $usage, SectionStorageManagerInterface $section_storage_manager) {
        $this->entityTypeManager = $entity_type_manager;
        $this->database = $database;
        $this->usage = $usage;
        $this->sectionStorageManager = $section_storage_manager;
    }
    
    /**
     * {@inheritdoc}
     */
    public static function getSubscribedEvents() : array {
        return [
            BlockContentEvents::BLOCK_CONTENT_GET_DEPENDENCY => 'onGetDependency',
        ];
    }
    
    /**
     * Handles the BlockContentEvents::INLINE_BLOCK_GET_DEPENDENCY event.
     *
     * @param \Drupal\block_content\Event\BlockContentGetDependencyEvent $event
     *   The event.
     */
    public function onGetDependency(BlockContentGetDependencyEvent $event) {
        if ($dependency = $this->getInlineBlockDependency($event->getBlockContentEntity())) {
            $event->setAccessDependency($dependency);
        }
    }
    
    /**
     * Get the access dependency of an inline block.
     *
     * If the block is used in an entity that entity will be returned as the
     * dependency.
     *
     * For revisionable entities the entity will only be returned if it is used in
     * the latest revision of the entity. For inline blocks that are not used in
     * the latest revision but are used in a previous revision the entity will not
     * be returned because calling
     * \Drupal\Core\Access\AccessibleInterface::access() will only check access on
     * the latest revision. Therefore if the previous revision of the entity was
     * returned as the dependency access would be granted to inline block
     * regardless of whether the user has access to the revision in which the
     * inline block was used.
     *
     * @param \Drupal\block_content\BlockContentInterface $block_content
     *   The block content entity.
     *
     * @return \Drupal\Core\Entity\EntityInterface|null
     *   Returns the layout dependency.
     *
     * @see \Drupal\block_content\BlockContentAccessControlHandler::checkAccess()
     * @see \Drupal\layout_builder\EventSubscriber\BlockComponentRenderArray::onBuildRender()
     */
    protected function getInlineBlockDependency(BlockContentInterface $block_content) {
        $layout_entity_info = $this->usage
            ->getUsage($block_content->id());
        if (empty($layout_entity_info)) {
            // If the block does not have usage information then we cannot set a
            // dependency. It may be used by another module besides layout builder.
            return NULL;
        }
        $layout_entity_storage = $this->entityTypeManager
            ->getStorage($layout_entity_info->layout_entity_type);
        $layout_entity = $layout_entity_storage->load($layout_entity_info->layout_entity_id);
        if ($this->isLayoutCompatibleEntity($layout_entity)) {
            if ($this->isBlockRevisionUsedInEntity($layout_entity, $block_content)) {
                return $layout_entity;
            }
        }
        return NULL;
    }
    
    /**
     * Determines if a block content revision is used in an entity.
     *
     * @param \Drupal\Core\Entity\EntityInterface $layout_entity
     *   The layout entity.
     * @param \Drupal\block_content\BlockContentInterface $block_content
     *   The block content revision.
     *
     * @return bool
     *   TRUE if the block content revision is used as an inline block in the
     *   layout entity.
     */
    protected function isBlockRevisionUsedInEntity(EntityInterface $layout_entity, BlockContentInterface $block_content) {
        $sections_blocks_revision_ids = $this->getInlineBlockRevisionIdsInSections($this->getEntitySections($layout_entity));
        return in_array($block_content->getRevisionId(), $sections_blocks_revision_ids);
    }

}