php - How to know if this request triggered by a redirection in Silex? -

i have php web app silex. in url need know if page redirected, , if so, redirected url. tried $request->headers->get('referer')) has value, when request triggered click on page. tried use "url interface" fro redirection this:

$app->get('/redirect/{url}', function (\silex\application $app, $url) {     $url=str_replace("!","/",$url);     return $app->redirect($url,302); }); 

and instance changed redirect /sell/insert redirection /redirect/!sell!insert. time $request->headers->get('referer')) returns first url, not /redirct.

so how can know if request triggered redirection, , if so, redirected url?

having example in mind, can send url parameter, , check request it, instead of checking referer. way store url in session before doing redirect, , check session in route/s expecting it.

depending on trying achieve, may interesed in forwarding instead of redirecting.