ds-8.x-3.9/src/Plugin/DsFieldTemplate/Reset.php

<?php

namespace Drupal\ds\Plugin\DsFieldTemplate;

use Drupal\Core\StringTranslation\TranslatableMarkup;
use Drupal\ds\Attribute\DsFieldTemplate;

/**
 * Plugin for the reset field template.
 */
#[DsFieldTemplate(
  id: 'reset',
  title: new TranslatableMarkup('Full reset'),
  theme: 'ds_field_reset'
)]
class Reset extends DsFieldTemplateBase {

  /**
   * {@inheritdoc}
   */
  public function alterForm(&$form) {
    $config = $this->getConfiguration();

    $form['lb'] = [
      '#type' => 'textfield',
      '#title' => $this->t('Label'),
      '#size' => '10',
      '#default_value' => $config['lb'],
    ];
  }

  /**
   * {@inheritdoc}
   */
  public function defaultConfiguration() {
    $config = [];
    $config['lb'] = '';

    return $config;
  }

  /**
   * {@inheritdoc}
   */
  public function massageRenderValues(&$field_settings, $values) {
    if (!empty($values['lb'])) {
      $field_settings['lb'] = $values['lb'];
    }
  }

}