batch_process

batch_process($redirect = NULL, Url $url = NULL, $redirect_callback = NULL)

function batch_process($redirect = NULL, Url $url = NULL, $redirect_callback = NULL) {
  $batch = &batch_get();

  if (isset($batch)) {
    // Add process information
    $process_info = array(
      'current_set' => 0,
      'progressive' => TRUE,
      'url' => isset($url) ? $url : Url::fromRoute('system.batch_page.html'),
      'source_url' => Url::fromRouteMatch(\Drupal::routeMatch()),
      'batch_redirect' => $redirect,
      'theme' => \Drupal::theme()->getActiveTheme()->getName(),
      'redirect_callback' => $redirect_callback,
    );
    $batch += $process_info;

    // The batch is now completely built. Allow other modules to make changes
    // to the batch so that it is easier to reuse batch processes in other
    // environments.
    \Drupal::moduleHandler()->alter('batch', $batch);

    // Assign an arbitrary id: don't rely on a serial column in the 'batch'
    // table, since non-progressive batches skip database storage completely.
    $batch['id'] = db_next_id();

    // Move operations to a job queue. Non-progressive batches will use a
    // memory-based queue.
    foreach ($batch['sets'] as $key => $batch_set) {
      _batch_populate_queue($batch, $key);
    }

    // Initiate processing.
    if ($batch['progressive']) {
      // Now that we have a batch id, we can generate the redirection link in
      // the generic error message.
      /** @var \Drupal\Core\Url $batch_url */
      $batch_url = $batch['url'];
      /** @var \Drupal\Core\Url $error_url */
      $error_url = clone $batch_url;
      $query_options = $error_url->getOption('query');
      $query_options['id'] = $batch['id'];
      $query_options['op'] = 'finished';
      $error_url->setOption('query', $query_options);

      $batch['error_message'] = t('Please continue to <a href=":error_url">the error page</a>', array(':error_url' => $error_url->toString(TRUE)->getGeneratedUrl()));

      // Clear the way for the redirection to the batch processing page, by
      // saving and unsetting the 'destination', if there is any.
      $request = \Drupal::request();
      if ($request->query->has('destination')) {
        $batch['destination'] = $request->query->get('destination');
        $request->query->remove('destination');
      }

      // Store the batch.
      \Drupal::service('batch.storage')->create($batch);

      // Set the batch number in the session to guarantee that it will stay alive.
      $_SESSION['batches'][$batch['id']] = TRUE;

      // Redirect for processing.
      $query_options = $error_url->getOption('query');
      $query_options['op'] = 'start';
      $query_options['id'] = $batch['id'];
      $batch_url->setOption('query', $query_options);
      if (($function = $batch['redirect_callback']) && function_exists($function)) {
        $function($batch_url->toString(), ['query' => $query_options]);
      }
      else {
        return new RedirectResponse($batch_url->setAbsolute()->toString(TRUE)->getGeneratedUrl());
      }
    }
    else {
      // Non-progressive execution: bypass the whole progressbar workflow
      // and execute the batch in one pass.
      require_once __DIR__ . '/batch.inc';
      _batch_process();
    }
  }
}