BatchController.php

<?php

namespace Drupal\system\Controller;

use Drupal\Core\Batch\BatchStorageInterface;
use Drupal\Core\DependencyInjection\ContainerInjectionInterface;
use Drupal\Core\StringTranslation\StringTranslationTrait;
use Symfony\Component\DependencyInjection\ContainerInterface;
use Symfony\Component\HttpFoundation\Request;
use Symfony\Component\HttpFoundation\Response;
use Symfony\Component\HttpKernel\Exception\AccessDeniedHttpException;

/**
 * Controller routines for batch routes.
 */
class BatchController implements ContainerInjectionInterface {
  use StringTranslationTrait;
  
  /**
   * Constructs a new BatchController.
   */
  public function __construct(protected string $root, protected BatchStorageInterface $batchStorage) {
    require_once $this->root . '/core/includes/batch.inc';
  }
  
  /**
   * {@inheritdoc}
   */
  public static function create(ContainerInterface $container) {
    return new static($container->getParameter('app.root'), $container->get('batch.storage'));
  }
  
  /**
   * Returns a system batch page.
   *
   * @param \Symfony\Component\HttpFoundation\Request $request
   *   The current request object.
   *
   * @return \Symfony\Component\HttpFoundation\Response|array
   *   A \Symfony\Component\HttpFoundation\Response object or render array.
   *
   * @throws \Symfony\Component\HttpKernel\Exception\AccessDeniedHttpException
   */
  public function batchPage(Request $request) {
    $output = _batch_page($request);
    if ($output === FALSE) {
      throw new AccessDeniedHttpException();
    }
    elseif ($output instanceof Response) {
      return $output;
    }
    elseif (isset($output)) {
      $title = $output['#title'] ?? NULL;
      $page = [
        '#type' => 'page',
        '#title' => $title,
        '#show_messages' => FALSE,
        'content' => $output,
      ];
      // Also inject title as a page header (if available).
      if ($title) {
        $page['header'] = [
          '#type' => 'page_title',
          '#title' => $title,
        ];
      }
      return $page;
    }
  }
  
  /**
   * The _title_callback for the system.batch_page.html route.
   *
   * @return string
   *   The page title.
   */
  public function batchPageTitle(Request $request) {
    $batch =& batch_get();
    if (!($request_id = $request->query
      ->get('id'))) {
      return '';
    }
    // Retrieve the current state of the batch.
    if (!$batch) {
      $batch = $this->batchStorage
        ->load($request_id);
    }
    if (!$batch) {
      return '';
    }
    $current_set = _batch_current_set();
    return !empty($current_set['title']) ? $current_set['title'] : '';
  }

}