At the moment i use the PHP serverside OAuth-Authentification by creating a "Login by facebook" button. As the App also is in the sidebar, i want to use the authentificated referrals for users to directly access that App. The problem is that, even though the access may be granted, i need to get this login-query-string to my website to save all access tokens, informations etc.
So - how exactly can i set the url to redirect the user to after the app is given permission?
When the user is sent to your app facebook will also send the auth data along with the request.
In the Authenticated Referrals section of the Auth Dialog documentation it says:
If your app is a canvas app you'll simply get all the needed data with the "signed_request", otherwise it will be part of the querystring.
For more user data you then simply make api requests.