EntityRevisionViewController.php

<?php

namespace Drupal\Core\Entity\Controller;

use Drupal\Core\Datetime\DateFormatterInterface;
use Drupal\Core\DependencyInjection\ContainerInjectionInterface;
use Drupal\Core\Entity\EntityRepositoryInterface;
use Drupal\Core\Entity\EntityTypeManagerInterface;
use Drupal\Core\Entity\RevisionableInterface;
use Drupal\Core\Entity\RevisionLogInterface;
use Drupal\Core\StringTranslation\StringTranslationTrait;
use Drupal\Core\StringTranslation\TranslatableMarkup;
use Drupal\Core\StringTranslation\TranslationInterface;
use Symfony\Component\DependencyInjection\ContainerInterface;

/**
 * Defines a controller to view an entity revision.
 */
class EntityRevisionViewController implements ContainerInjectionInterface {
    use StringTranslationTrait;
    
    /**
     * Creates a new EntityRevisionViewController.
     *
     * @param \Drupal\Core\Entity\EntityTypeManagerInterface $entityTypeManager
     *   The entity type manager.
     * @param \Drupal\Core\Entity\EntityRepositoryInterface $entityRepository
     *   The entity repository.
     * @param \Drupal\Core\Datetime\DateFormatterInterface $dateFormatter
     *   The date formatter.
     * @param \Drupal\Core\StringTranslation\TranslationInterface $translation
     *   The string translation manager.
     */
    public function __construct(EntityTypeManagerInterface $entityTypeManager, EntityRepositoryInterface $entityRepository, DateFormatterInterface $dateFormatter, TranslationInterface $translation) {
        $this->setStringTranslation($translation);
    }
    
    /**
     * {@inheritdoc}
     */
    public static function create(ContainerInterface $container) {
        return new static($container->get('entity_type.manager'), $container->get('entity.repository'), $container->get('date.formatter'), $container->get('string_translation'));
    }
    
    /**
     * Provides a page to render a single entity revision.
     *
     * @param \Drupal\Core\Entity\RevisionableInterface $_entity_revision
     *   The Entity to be rendered. Note this variable is named $_entity_revision
     *   rather than $entity to prevent collisions with other named placeholders
     *   in the route.
     * @param string $view_mode
     *   (optional) The view mode that should be used to display the entity.
     *   Defaults to 'full'.
     *
     * @return array
     *   A render array.
     */
    public function __invoke(RevisionableInterface $_entity_revision, string $view_mode = 'full') : array {
        $entityTypeId = $_entity_revision->getEntityTypeId();
        $page = $this->entityTypeManager
            ->getViewBuilder($entityTypeId)
            ->view($_entity_revision, $view_mode);
        $page['#entity_type'] = $entityTypeId;
        $page['#' . $entityTypeId] = $_entity_revision;
        return $page;
    }
    
    /**
     * Provides a title callback for a revision of an entity.
     *
     * @param \Drupal\Core\Entity\RevisionableInterface $_entity_revision
     *   The revisionable entity, passed in directly from request attributes.
     *
     * @return \Drupal\Core\StringTranslation\TranslatableMarkup
     *   The title for the entity revision view page.
     */
    public function title(RevisionableInterface $_entity_revision) : TranslatableMarkup {
        $revision = $this->entityRepository
            ->getTranslationFromContext($_entity_revision);
        $titleArgs = [
            '%title' => $revision->label(),
        ];
        if (!$revision instanceof RevisionLogInterface) {
            return $this->t('Revision of %title', $titleArgs);
        }
        $titleArgs['%date'] = $this->dateFormatter
            ->format($revision->getRevisionCreationTime());
        return $this->t('Revision of %title from %date', $titleArgs);
    }

}