FormatterBase::view

public FormatterBase::view(FieldItemListInterface $items, $langcode = NULL)

public function view(FieldItemListInterface $items, $langcode = NULL) {
  // Default the language to the current content language.
  if (empty($langcode)) {
    $langcode = \Drupal::languageManager()->getCurrentLanguage(LanguageInterface::TYPE_CONTENT)->getId();
  }
  $elements = $this->viewElements($items, $langcode);

  // If there are actual renderable children, use #theme => field, otherwise,
  // let access cacheability metadata pass through for correct bubbling.
  if (Element::children($elements)) {
    $entity = $items->getEntity();
    $entity_type = $entity->getEntityTypeId();
    $field_name = $this->fieldDefinition->getName();
    $info = array(
      '#theme' => 'field',
      '#title' => $this->fieldDefinition->getLabel(),
      '#label_display' => $this->label,
      '#view_mode' => $this->viewMode,
      '#language' => $items->getLangcode(),
      '#field_name' => $field_name,
      '#field_type' => $this->fieldDefinition->getType(),
      '#field_translatable' => $this->fieldDefinition->isTranslatable(),
      '#entity_type' => $entity_type,
      '#bundle' => $entity->bundle(),
      '#object' => $entity,
      '#items' => $items,
      '#formatter' => $this->getPluginId(),
      '#is_multiple' => $this->fieldDefinition->getFieldStorageDefinition()->isMultiple(),
    );

    $elements = array_merge($info, $elements);
  }

  return $elements;
}