Kohana Validation sample

public function action_handleUpload()
    {
    Session::instance()->delete('errors');
        $validation = Validation::factory(array_merge($_POST, $_FILES))
                ->rule('rules', 'not_empty')
                ->rule('rules', 'equals', array(':value', '1'))
                ->rule('photo', 'Upload::valid')
                ->rule('photo', 'Upload::not_empty')
                ->rule('photo', 'Upload::type', array(':value', array('jpg', 'jpeg', 'png', 'gif')))
                ->rule('photo', 'Upload::size', array(':value', '5M'));
        if ($validation->check())
        {
            //save file
            Model_Photos::handleFileUpload($_FILES['photo']['tmp_name'], $filename);
            $this->request->redirect('upload/success');
        } else
        {
            //params invalid
            Session::instance()->set('errors', $validation->errors());
            $this->request->redirect('upload/form');
        }
    }