eca-1.0.x-dev/modules/base/src/Plugin/Action/WarningMessage.php

<?php

namespace Drupal\eca_base\Plugin\Action;

use Drupal\Core\Action\Attribute\Action;
use Drupal\Core\Action\Plugin\Action\MessageAction;
use Drupal\Core\StringTranslation\TranslatableMarkup;
use Drupal\eca\Attribute\EcaAction;

/**
 * Sends a warning message to the current user's screen.
 */
#[Action(
  id: 'eca_warning_message',
  label: new TranslatableMarkup('Display a warning message to the user'),
  type: 'system',
)]
#[EcaAction(
  version_introduced: '1.1.0',
)]
class WarningMessage extends MessageAction {

  /**
   * {@inheritdoc}
   *
   * Mainly copied from parent execute method, except for a different messenger
   * instruction.
   */
  public function execute(mixed $entity = NULL): void {
    if (empty($this->configuration['node'])) {
      $this->configuration['node'] = $entity;
    }
    $message = $this->token->replace($this->configuration['message'], $this->configuration);
    $build = [
      '#markup' => $message,
    ];

    // @todo Fix in https://www.drupal.org/node/2577827
    $this->messenger->addWarning($this->renderer->renderInIsolation($build));
  }

}