gist:5291554

## gistfile1.php
namespace Acme\DemoBundle\Controller;

use Symfony\Bundle\FrameworkBundle\Controller\Controller;
use Sensio\Bundle\FrameworkExtraBundle\Configuration\Route;
use Sensio\Bundle\FrameworkExtraBundle\Configuration\Template;
use Symfony\Component\HttpFoundation\Request;

use Acme\DemoBundle\Form\Type\SettingsFormType;


class SettingsController extends Controller
{

    /**
     * The action to manipulate application wide settings
     *
     * @Route("/settings", name="manage_settings")
     * @Template()
     *
     * @param \Symfony\Component\HttpFoundation\Request $request
     */
    public function settingsAction(Request $request)
    {
        $form = $this->createForm(new SettingsFormType($this->get('settings')));

        if ($request->isMethod('POST')) {
            $form->bind($request);
            if ($form->isValid()) {
                $this->get('settings')->setReadOnly(false);
                foreach ($form->getViewData() as $key => $data) {
                    $settingKey = str_replace('_', '.', $key);
                    $this->get('settings')->set($settingKey, $data);
                }
                $this->get('settings')->saveToFile();
                $this->get('settings')->setReadOnly(true);
                $this->get('session')->getFlashBag()->add('success', 'The settings have been saved');
            }
        }
        return array(
            'form' => $form->createView()
        );
    }
}