class DialogRenderer

class DialogRenderer implements MainContentRendererInterface {
  
  /**
   * The title resolver.
   *
   * @var \Drupal\Core\Controller\TitleResolverInterface
   */
  protected $titleResolver;
  
  /**
   * The renderer.
   *
   * @var \Drupal\Core\Render\RendererInterface
   */
  protected $renderer;
  
  /**
   * Constructs a new DialogRenderer.
   *
   * @param \Drupal\Core\Controller\TitleResolverInterface $title_resolver
   *   The title resolver.
   * @param \Drupal\Core\Render\RendererInterface $renderer
   *   The renderer.
   */
  public function __construct(TitleResolverInterface $title_resolver, RendererInterface $renderer) {
    $this->titleResolver = $title_resolver;
    $this->renderer = $renderer;
  }
  
  /**
   * {@inheritdoc}
   */
  public function renderResponse(array $main_content, Request $request, RouteMatchInterface $route_match) {
    $response = new AjaxResponse();
    // First render the main content, because it might provide a title.
    $content = $this->renderer
      ->renderRoot($main_content);
    // Attach the library necessary for using the OpenDialogCommand and set the
    // attachments for this Ajax response.
    $main_content['#attached']['library'][] = 'core/drupal.dialog.ajax';
    $response->setAttachments($main_content['#attached']);
    // Determine the title.
    $title = $this->getTitleAsStringable($main_content, $request, $route_match);
    // Determine the dialog options and the target for the OpenDialogCommand.
    $options = $this->getDialogOptions($request);
    $target = $this->determineTargetSelector($options, $route_match);
    $response->addCommand(new OpenDialogCommand($target, $title, $content, $options));
    return $response;
  }
  
  /**
   * Determine the target selector for the OpenDialogCommand.
   *
   * @param array &$options
   *   The 'target' option, if set, is used, and then removed from $options.
   * @param \Drupal\Core\Routing\RouteMatchInterface $route_match
   *   When no 'target' option is set in $options, $route_match is used instead
   *   to determine the target.
   *
   * @return string
   *   The target selector.
   */
  protected function determineTargetSelector(array &$options, RouteMatchInterface $route_match) {
    // Generate the target wrapper for the dialog.
    if (isset($options['target'])) {
      // If the target was nominated in the incoming options, use that.
      $target = $options['target'];
      // Ensure the target includes the #.
      if (!str_starts_with($target, '#')) {
        $target = '#' . $target;
      }
      // This shouldn't be passed on to jQuery.ui.dialog.
      unset($options['target']);
    }
    else {
      // Generate a target based on the route id.
      $route_name = $route_match->getRouteName();
      $target = '#' . Html::getUniqueId("drupal-dialog-{$route_name}");
    }
    return $target;
  }
  
  /**
   * Returns the dialog options from request.
   *
   * @param \Symfony\Component\HttpFoundation\Request $request
   *   The HTTP request.
   *
   * @return array
   *   The dialog options used for OpenDialogCommand.
   */
  protected function getDialogOptions(Request $request) : array {
    if ($request->getMethod() === 'GET') {
      return $request->query
        ->all('dialogOptions');
    }
    return $request->request
      ->all('dialogOptions');
  }
  
  /**
   * Gets the title as a string or stringable object.
   *
   * Uses the title provided by the main content if any, otherwise gets it from
   * the routing information.
   *
   * @param array $main_content
   *   The main content array.
   * @param \Symfony\Component\HttpFoundation\Request $request
   *   The request.
   * @param \Drupal\Core\Routing\RouteMatchInterface $route_match
   *   The route match.
   *
   * @return \Stringable|string|null
   *   The title as a string or stringable object.
   */
  protected function getTitleAsStringable(array $main_content, Request $request, RouteMatchInterface $route_match) : \Stringable|string|null {
    $title = $main_content['#title'] ?? $this->titleResolver
      ->getTitle($request, $route_match->getRouteObject());
    if (is_array($title)) {
      $title = $this->renderer
        ->renderInIsolation($title);
    }
    return $title;
  }

}