Chris@0: <?php
Chris@0: 
Chris@0: namespace Drupal\node\Controller;
Chris@0: 
Chris@0: use Drupal\Core\Entity\EntityInterface;
Chris@0: use Drupal\Core\Entity\Controller\EntityViewController;
Chris@0: use Drupal\Core\Entity\EntityManagerInterface;
Chris@0: use Drupal\Core\Render\RendererInterface;
Chris@0: use Drupal\Core\Session\AccountInterface;
Chris@0: use Symfony\Component\DependencyInjection\ContainerInterface;
Chris@0: 
Chris@0: /**
Chris@0:  * Defines a controller to render a single node.
Chris@0:  */
Chris@0: class NodeViewController extends EntityViewController {
Chris@0: 
Chris@0:   /**
Chris@0:    * The current user.
Chris@0:    *
Chris@0:    * @var \Drupal\Core\Session\AccountInterface
Chris@0:    */
Chris@0:   protected $currentUser;
Chris@0: 
Chris@0:   /**
Chris@0:    * Creates an NodeViewController object.
Chris@0:    *
Chris@0:    * @param \Drupal\Core\Entity\EntityManagerInterface $entity_manager
Chris@0:    *   The entity manager.
Chris@0:    * @param \Drupal\Core\Render\RendererInterface $renderer
Chris@0:    *   The renderer service.
Chris@0:    * @param \Drupal\Core\Session\AccountInterface $current_user
Chris@0:    *   The current user. For backwards compatibility this is optional, however
Chris@0:    *   this will be removed before Drupal 9.0.0.
Chris@0:    */
Chris@0:   public function __construct(EntityManagerInterface $entity_manager, RendererInterface $renderer, AccountInterface $current_user = NULL) {
Chris@0:     parent::__construct($entity_manager, $renderer);
Chris@0:     $this->currentUser = $current_user ?: \Drupal::currentUser();
Chris@0:   }
Chris@0: 
Chris@0:   /**
Chris@0:    * {@inheritdoc}
Chris@0:    */
Chris@0:   public static function create(ContainerInterface $container) {
Chris@0:     return new static(
Chris@0:       $container->get('entity.manager'),
Chris@0:       $container->get('renderer'),
Chris@0:       $container->get('current_user')
Chris@0:     );
Chris@0:   }
Chris@0: 
Chris@0:   /**
Chris@0:    * {@inheritdoc}
Chris@0:    */
Chris@0:   public function view(EntityInterface $node, $view_mode = 'full', $langcode = NULL) {
Chris@0:     $build = parent::view($node, $view_mode, $langcode);
Chris@0: 
Chris@0:     foreach ($node->uriRelationships() as $rel) {
Chris@0:       $url = $node->toUrl($rel);
Chris@0:       // Add link relationships if the user is authenticated or if the anonymous
Chris@0:       // user has access. Access checking must be done for anonymous users to
Chris@0:       // avoid traffic to inaccessible pages from web crawlers. For
Chris@0:       // authenticated users, showing the links in HTML head does not impact
Chris@0:       // user experience or security, since the routes are access checked when
Chris@0:       // visited and only visible via view source. This prevents doing
Chris@0:       // potentially expensive and hard to cache access checks on every request.
Chris@0:       // This means that the page will vary by user.permissions. We also rely on
Chris@0:       // the access checking fallback to ensure the correct cacheability
Chris@0:       // metadata if we have to check access.
Chris@0:       if ($this->currentUser->isAuthenticated() || $url->access($this->currentUser)) {
Chris@0:         // Set the node path as the canonical URL to prevent duplicate content.
Chris@0:         $build['#attached']['html_head_link'][] = [
Chris@0:           [
Chris@0:             'rel' => $rel,
Chris@0:             'href' => $url->toString(),
Chris@0:           ],
Chris@0:           TRUE,
Chris@0:         ];
Chris@0:       }
Chris@0: 
Chris@0:       if ($rel == 'canonical') {
Chris@0:         // Set the non-aliased canonical path as a default shortlink.
Chris@0:         $build['#attached']['html_head_link'][] = [
Chris@0:           [
Chris@0:             'rel' => 'shortlink',
Chris@0:             'href' => $url->setOption('alias', TRUE)->toString(),
Chris@0:           ],
Chris@0:           TRUE,
Chris@0:         ];
Chris@0:       }
Chris@0:     }
Chris@0: 
Chris@0:     // Given this varies by $this->currentUser->isAuthenticated(), add a cache
Chris@0:     // context based on the anonymous role.
Chris@0:     $build['#cache']['contexts'][] = 'user.roles:anonymous';
Chris@0: 
Chris@0:     return $build;
Chris@0:   }
Chris@0: 
Chris@0:   /**
Chris@0:    * The _title_callback for the page that renders a single node.
Chris@0:    *
Chris@0:    * @param \Drupal\Core\Entity\EntityInterface $node
Chris@0:    *   The current node.
Chris@0:    *
Chris@0:    * @return string
Chris@0:    *   The page title.
Chris@0:    */
Chris@0:   public function title(EntityInterface $node) {
Chris@0:     return $this->entityManager->getTranslationFromContext($node)->label();
Chris@0:   }
Chris@0: 
Chris@0: }