class BreakLockLink

class BreakLockLink extends RenderElementBase implements ContainerFactoryPluginInterface {
  
  /**
   * The date formatter.
   *
   * @var \Drupal\Core\Datetime\DateFormatterInterface
   */
  protected $dateFormatter;
  
  /**
   * The entity type manager.
   *
   * @var \Drupal\Core\Entity\EntityTypeManagerInterface
   */
  protected $entityTypeManager;
  
  /**
   * The renderer.
   *
   * @var \Drupal\Core\Render\RendererInterface
   */
  protected $renderer;
  
  /**
   * Constructs a new BreakLockLink.
   *
   * @param array $configuration
   *   A configuration array containing information about the plugin instance.
   * @param string $plugin_id
   *   The plugin ID for the plugin instance.
   * @param mixed $plugin_definition
   *   The plugin implementation definition.
   * @param \Drupal\Core\Datetime\DateFormatterInterface $date_formatter
   *   The date formatter.
   * @param \Drupal\Core\Entity\EntityTypeManagerInterface $entity_type_manager
   *   The entity type manager.
   * @param \Drupal\Core\Render\RendererInterface $renderer
   *   The renderer.
   */
  public function __construct(array $configuration, $plugin_id, $plugin_definition, DateFormatterInterface $date_formatter, EntityTypeManagerInterface $entity_type_manager, RendererInterface $renderer) {
    parent::__construct($configuration, $plugin_id, $plugin_definition);
    $this->dateFormatter = $date_formatter;
    $this->entityTypeManager = $entity_type_manager;
    $this->renderer = $renderer;
  }
  
  /**
   * {@inheritdoc}
   */
  public static function create(ContainerInterface $container, array $configuration, $plugin_id, $plugin_definition) {
    return new static($configuration, $plugin_id, $plugin_definition, $container->get('date.formatter'), $container->get('entity_type.manager'), $container->get('renderer'));
  }
  
  /**
   * {@inheritdoc}
   */
  public function getInfo() {
    return [
      '#pre_render' => [
        [
          $this,
          'preRenderLock',
        ],
      ],
    ];
  }
  
  /**
   * Pre-render callback: Renders a lock into #markup.
   *
   * @param array $element
   *   A structured array with the following keys:
   *   - #label: The label of the object that is locked.
   *   - #lock: The lock object.
   *   - #url: The URL object with the destination to the break lock form.
   *
   * @return array
   *   The passed-in element containing a rendered lock in '#markup'.
   */
  public function preRenderLock($element) {
    if (isset($element['#lock']) && isset($element['#label']) && isset($element['#url'])) {
      /** @var \Drupal\Core\TempStore\Lock $lock */
      $lock = $element['#lock'];
      $age = $this->dateFormatter
        ->formatTimeDiffSince($lock->getUpdated());
      $owner = $this->entityTypeManager
        ->getStorage('user')
        ->load($lock->getOwnerId());
      $username = [
        '#theme' => 'username',
        '#account' => $owner,
      ];
      $element['#markup'] = $this->t('This @label is being edited by user @user, and is therefore locked from editing by others. This lock is @age old. Click here to <a href=":url">break this lock</a>.', [
        '@label' => $element['#label'],
        '@user' => $this->renderer
          ->render($username),
        '@age' => $age,
        ':url' => $element['#url']->toString(),
      ]);
    }
    return $element;
  }

}