/**
 * Wrapper for request to widget controller
 * 
 * @param   string  $uri           Request uri(widget name)
 * @param   array   $data          Send data
 * @param   string  $method        Request method
 * @param   boolean $auto_render   Execute request and return body?
 * @return  mixed(string|Request)
 * @uses    Request::factory
 * @uses    HTML::chars
 * @throws  Request_Exception
 */
public static function widget($uri, array $data = NULL, $method = Request::GET, $auto_render = TRUE)
{
   // Create request
   if ( ! $widget = Request::factory('widget'.DIRECTORY_SEPARATOR.$uri))
   {
      throw new Request_Exception('Request to widget :uri failed', array(':uri' => $uri));
   }
   // Set data
   switch ($method)
   {
      case Request::GET:
         $widget->query($data);
         break;
      case Request::POST:
         $widget->post($data);
         break;
      default:
         throw new Request_Exception('Unknown method :method of widget :uri', array(':method' => $method, ':uri' => $uri));
   }
   // Set data sending method
   $widget->method($method);
   // Return result as string or Request object
   return ($auto_render ? $widget->execute()->body() : $widget);
}

class Controller_Summ extends Controller_Template {

public function before(){
parent::before;
}

public function action_index(){
$summ = new Model_Uses();
if($summ->get_summ($_POST['a'], $_POST['b'])):

$data['summ'] = $summ->result;
$data['sum_ok'] = '';
else:
$data['summ'] = '';
$data['summ_error'] = '';
endif;

$this->template->summ = View::factory('summ', $data);
}
}

class Model_Uses {
   public function get_summ($a, $b){

      $this->result = $a + $b;
      
      return TRUE;
   }