protected function AjaxResponse::ajaxRender

Prepares the AJAX commands for sending back to the client.

Parameters

Request $request: The request object that the AJAX is responding to.

Return value

array An array of commands ready to be returned as JSON.

File

drupal/core/lib/Drupal/Core/Ajax/AjaxResponse.php, line 71

Definition of Drupal\Core\Ajax\AjaxResponse.

Class

AjaxResponse

JSON response object for AJAX requests.

Namespace

Code

protected function ajaxRender(Request $request) {

  // Ajax responses aren't rendered with html.tpl.php, so we have to call
  // drupal_get_css() and drupal_get_js() here, in order to have new files
  // added during this request to be loaded by the page. We only want to send
  // back files that the page hasn't already loaded, so we implement simple
  // diffing logic using array_diff_key().
  $ajax_page_state = $request->request
    ->get('ajax_page_state');
  foreach (array(
    'css',
    'js',
  ) as $type) {

    // It is highly suspicious if $_POST['ajax_page_state'][$type] is empty,
    // since the base page ought to have at least one JS file and one CSS file
    // loaded. It probably indicates an error, and rather than making the page
    // reload all of the files, instead we return no new files.
    if (empty($ajax_page_state[$type])) {
      $items[$type] = array();
    }
    else {
      $function = 'drupal_add_' . $type;
      $items[$type] = $function();
      drupal_alter($type, $items[$type]);

      // @todo Inline CSS and JS items are indexed numerically. These can't be
      //   reliably diffed with array_diff_key(), since the number can change
      //   due to factors unrelated to the inline content, so for now, we
      //   strip the inline items from Ajax responses, and can add support for
      //   them when drupal_add_css() and drupal_add_js() are changed to use
      //   a hash of the inline content as the array key.
      foreach ($items[$type] as $key => $item) {
        if (is_numeric($key)) {
          unset($items[$type][$key]);
        }
      }

      // Ensure that the page doesn't reload what it already has.
      $items[$type] = array_diff_key($items[$type], $ajax_page_state[$type]);
    }
  }

  // Render the HTML to load these files, and add AJAX commands to insert this
  // HTML in the page. We pass TRUE as the $skip_alter argument to prevent the
  // data from being altered again, as we already altered it above. Settings
  // are handled separately, afterwards.
  if (isset($items['js']['settings'])) {
    unset($items['js']['settings']);
  }
  $styles = drupal_get_css($items['css'], TRUE);
  $scripts_footer = drupal_get_js('footer', $items['js'], TRUE);
  $scripts_header = drupal_get_js('header', $items['js'], TRUE);

  // Prepend commands to add the resources, preserving their relative order.
  $resource_commands = array();
  if (!empty($styles)) {
    $resource_commands[] = new AddCssCommand($styles);
  }
  if (!empty($scripts_header)) {
    $resource_commands[] = new PrependCommand('head', $scripts_header);
  }
  if (!empty($scripts_footer)) {
    $resource_commands[] = new AppendCommand('body', $scripts_footer);
  }
  foreach (array_reverse($resource_commands) as $resource_command) {
    $this
      ->addCommand($resource_command, TRUE);
  }

  // Prepend a command to merge changes and additions to Drupal.settings.
  $scripts = drupal_add_js();
  if (!empty($scripts['settings'])) {
    $settings = drupal_merge_js_settings($scripts['settings']['data']);
    $this
      ->addCommand(new SettingsCommand($settings, TRUE), TRUE);
  }
  $commands = $this->commands;
  drupal_alter('ajax_render', $commands);
  return $commands;
}