ContextErrorException: Notice: Undefined property: stdClass::$duration in    
/var/www/symfony/src/123/DepBundle/Controller/DefaultController.php line 217
	
public function getDepartmentAction()
{
    $doctrine = $this->getDoctrine();
    $em = $doctrine->getManager();

    $response = $request = Request::createFromGlobals();
    $locationid = $response->request->get( 'locationid' );
    $userselection = $response->request->get( 'userselection' );

    $niederlassungsrepo = $em->getRepository( 'MbsNiederlassungBundle:Niederlassung' );
    $niederlassung = $niederlassungsrepo->findOneById( $locationid );

        $bezeichnung = $niederlassung->getBezeichnung();
        $strasse = $niederlassung->getStrasse();
        $plz = $niederlassung->getPlz();
        $ort = $niederlassung->getOrt();
        $telefonbuero = $niederlassung->getTelefonbuero();

        $link = $this->generateUrl('_niederlassung', array('filiale' => $bezeichnung));

    $distance = $this->getDistance( $userselection, $plz );   <====== here i wanna call it

    $result = array("bezeichnung" => $bezeichnung,
                    "strasse" => $strasse,
                    "plz" => $plz,
                    "ort" => $ort,
                    "telefonbuero" => $telefonbuero,
                    "link" => $link,
                    "entfernung" => $distance['distance']);


    $encoder = [new JsonEncoder()];
    $normalizer = [new GetSetMethodNormalizer()];
    $serializer = new Serializer($normalizer, $encoder);

    $newData = $serializer->serialize($result, 'json');

    return new Response($newData);
}
	
private function getDistance($start,$end)
{
    $from = urlencode($start);
    $to = urlencode($end);

    $data = file_get_contents("http://maps.googleapis.com/maps/api/distancematrix/json?origins=$from&destinations=$to&language=de-de&sensor=false");
    $data = json_decode($data);

    $time = 0;
    $distance = 0;

    foreach($data->rows[0]->elements as $road) {
        $time += $road->duration->value;            <=======   Line 217
        $distance += $road->distance->value;
    }

    $result['time'] = $time / 60;
    $result['distance'] = $distance / 1000;

    return $result;
}