custom_field-1.0.x-dev/src/Plugin/Field/FieldWidget/CustomStackedWidget.php

<?php

namespace Drupal\custom_field\Plugin\Field\FieldWidget;

use Drupal\Core\Field\Attribute\FieldWidget;
use Drupal\Core\Field\FieldItemListInterface;
use Drupal\Core\Form\FormStateInterface;
use Drupal\Core\StringTranslation\TranslatableMarkup;

/**
 * Plugin implementation of the 'custom_stacked' widget.
 */
#[FieldWidget(
  id: 'custom_stacked',
  label: new TranslatableMarkup('Stacked'),
  field_types: [
    'custom',
  ],
  weight: 2,
)]
class CustomStackedWidget extends CustomWidgetBase {

  /**
   * {@inheritdoc}
   *
   * @throws \Drupal\Component\Plugin\Exception\PluginException
   */
  public function formElement(FieldItemListInterface $items, $delta, array $element, array &$form, FormStateInterface $form_state): array {
    $element = parent::formElement($items, $delta, $element, $form, $form_state);
    $fields = $this->getSetting('fields') ?? [];

    // Account for unsaved fields in field config default values form.
    if (!empty($form_state->get('current_settings'))) {
      $current_settings = $form_state->get('current_settings');
      $custom_items = $this->customFieldTypeManager->getCustomFieldItems($current_settings);
    }
    else {
      $custom_items = $this->sortFields($fields);
    }

    foreach ($custom_items as $name => $custom_item) {
      $settings = $fields[$name] ?? [];
      $type = $settings['type'] ?? $custom_item->getDefaultWidget();
      if (!in_array($type, $this->customFieldWidgetManager->getWidgetsForField($custom_item->getPluginId()))) {
        $type = $custom_item->getDefaultWidget();
      }
      /** @var \Drupal\custom_field\Plugin\CustomFieldWidgetInterface $widget_plugin */
      $widget_plugin = $this->customFieldWidgetManager->createInstance((string) $type, ['settings' => $settings]);
      $element[$name] = $widget_plugin->widget($items, $delta, $element, $form, $form_state, $custom_item);
    }

    return $element;
  }

}