improvements-2.x-dev/modules/improvements_contact/src/Plugin/Derivative/ContactFormMessagesLocalTaskDeriver.php

<?php

namespace Drupal\improvements_contact\Plugin\Derivative;

use Drupal\Component\Plugin\Derivative\DeriverBase;
use Drupal\Core\StringTranslation\StringTranslationTrait;
use Drupal\improvements_contact\Plugin\Menu\LocalTask\ContactFormMessagesLocalTask;

class ContactFormMessagesLocalTaskDeriver extends DeriverBase {

  use StringTranslationTrait;

  /**
   * {@inheritDoc}
   */
  public function getDerivativeDefinitions($base_plugin_definition): array {
    if (\Drupal::moduleHandler()->moduleExists('contact_storage')) {
      $this->derivatives[$base_plugin_definition['id']] = [
        'title' => $this->t('Messages'),
        'route_name' => 'view.contact_messages.page_1',
        'base_route' => 'entity.contact_form.edit_form',
        'weight' => -99,
        'class' => ContactFormMessagesLocalTask::class,
      ];
    }

    return $this->derivatives;
  }

}