class MenuLinkContentAccessControlHandler

class MenuLinkContentAccessControlHandler extends EntityAccessControlHandler implements EntityHandlerInterface {
    
    /**
     * The access manager to check routes by name.
     *
     * @var \Drupal\Core\Access\AccessManagerInterface
     */
    protected $accessManager;
    
    /**
     * Creates a new MenuLinkContentAccessControlHandler.
     *
     * @param \Drupal\Core\Entity\EntityTypeInterface $entity_type
     *   The entity type definition.
     * @param \Drupal\Core\Access\AccessManagerInterface $access_manager
     *   The access manager to check routes by name.
     */
    public function __construct(EntityTypeInterface $entity_type, AccessManagerInterface $access_manager) {
        parent::__construct($entity_type);
        $this->accessManager = $access_manager;
    }
    
    /**
     * {@inheritdoc}
     */
    public static function createInstance(ContainerInterface $container, EntityTypeInterface $entity_type) {
        return new static($entity_type, $container->get('access_manager'));
    }
    
    /**
     * {@inheritdoc}
     */
    protected function checkAccess(EntityInterface $entity, $operation, AccountInterface $account) {
        switch ($operation) {
            case 'view':
                // There is no direct viewing of a menu link, but still for purposes of
                // content_translation we need a generic way to check access.
                return AccessResult::allowedIfHasPermission($account, 'administer menu');
            case 'update':
                if (!$account->hasPermission('administer menu')) {
                    return AccessResult::neutral("The 'administer menu' permission is required.")->cachePerPermissions();
                }
                else {
                    // Assume that access is allowed.
                    $access = AccessResult::allowed()->cachePerPermissions()
                        ->addCacheableDependency($entity);
                    
                    /** @var \Drupal\menu_link_content\MenuLinkContentInterface $entity */
                    // If the link is routed determine whether the user has access unless
                    // they have the 'link to any page' permission.
                    if (!$account->hasPermission('link to any page') && ($url_object = $entity->getUrlObject()) && $url_object->isRouted()) {
                        $link_access = $this->accessManager
                            ->checkNamedRoute($url_object->getRouteName(), $url_object->getRouteParameters(), $account, TRUE);
                        $access = $access->andIf($link_access);
                    }
                    return $access;
                }
            case 'delete':
                return AccessResult::allowedIfHasPermission($account, 'administer menu')->andIf(AccessResult::allowedIf(!$entity->isNew())
                    ->addCacheableDependency($entity));
            default:
                return parent::checkAccess($entity, $operation, $account);
        }
    }

}