symfony backend routing link to frontend

http://www.symfony-project.org/cookbook/1_2/en/cross-application-links

// apps/backend/config/backendConfiguration.class.php
class backendConfiguration extends sfApplicationConfiguration
{
  protected $frontendRouting = null;
 
  public function generateFrontendUrl($name, $parameters = array())
  {
    return 'http://frontend.example.com'.$this->getFrontendRouting()->generate($name, $parameters);
  }
 
  public function getFrontendRouting()
  {
    if (!$this->frontendRouting)
    {
      $this->frontendRouting = new sfPatternRouting(new sfEventDispatcher());
 
      $config = new sfRoutingConfigHandler();
      $routes = $config->evaluate(array(sfConfig::get('sf_apps_dir').'/frontend/config/routing.yml'));
 
      $this->frontendRouting->setRoutes($routes);
    }
 
    return $this->frontendRouting;
  }
 
  // ...
}

// in backend action

$this->redirect($this->getContext()->getConfiguration()->generateFrontendUrl('hello', array('name' => 'Bar')));