CommentViewBuilder::buildComponents

public CommentViewBuilder::buildComponents(array &$build, array $entities, array $displays, $view_mode)

public function buildComponents(array &$build, array $entities, array $displays, $view_mode) {
  /** @var \Drupal\comment\CommentInterface[] $entities */
  if (empty($entities)) {
    return;
  }

  // Pre-load associated users into cache to leverage multiple loading.
  $uids = array();
  foreach ($entities as $entity) {
    $uids[] = $entity->getOwnerId();
  }
  $this->entityManager->getStorage('user')->loadMultiple(array_unique($uids));

  parent::buildComponents($build, $entities, $displays, $view_mode);

  // A counter to track the indentation level.
  $current_indent = 0;

  foreach ($entities as $id => $entity) {
    if ($build[$id]['#comment_threaded']) {
      $comment_indent = count(explode('.', $entity->getThread())) - 1;
      if ($comment_indent > $current_indent) {
        // Set 1 to indent this comment from the previous one (its parent).
        // Set only one extra level of indenting even if the difference in
        // depth is higher.
        $build[$id]['#comment_indent'] = 1;
        $current_indent++;
      }
      else {
        // Set zero if this comment is on the same level as the previous one
        // or negative value to point an amount indents to close.
        $build[$id]['#comment_indent'] = $comment_indent - $current_indent;
        $current_indent = $comment_indent;
      }
    }

    // Commented entities already loaded after self::getBuildDefaults().
    $commented_entity = $entity->getCommentedEntity();

    $build[$id]['#entity'] = $entity;
    $build[$id]['#theme'] = 'comment__' . $entity->getFieldName() . '__' . $commented_entity->bundle();

    $display = $displays[$entity->bundle()];
    if ($display->getComponent('links')) {
      $build[$id]['links'] = array(
        '#lazy_builder' => ['comment.lazy_builders:renderLinks', [
          $entity->id(),
          $view_mode,
          $entity->language()->getId(),
          !empty($entity->in_preview),
        ]],
        '#create_placeholder' => TRUE,
      );
    }

    if (!isset($build[$id]['#attached'])) {
      $build[$id]['#attached'] = array();
    }
    $build[$id]['#attached']['library'][] = 'comment/drupal.comment-by-viewer';
    if ($this->moduleHandler->moduleExists('history') && $this->currentUser->isAuthenticated()) {
      $build[$id]['#attached']['library'][] = 'comment/drupal.comment-new-indicator';

      // Embed the metadata for the comment "new" indicators on this node.
      $build[$id]['history'] = [
        '#lazy_builder' => ['history_attach_timestamp', [$commented_entity->id()]],
        '#create_placeholder' => TRUE,
      ];
    }
  }
  if ($build[$id]['#comment_threaded']) {
    // The final comment must close up some hanging divs.
    $build[$id]['#comment_indent_final'] = $current_indent;
  }
}