on facebook connect login uri, can I add an extra get param on url, and have that passed to my script once user logs in?

Question

Hi there, to connect to an app on facebook, the user types in

www.facebook.com/login.php?api=12312312323123123

how can I add an extra get var to this url and pass it to my script on successful login?

Answer 1

Do you add a redirect_url as part of the login call?

If so you can add the GET parameter to that. For instance let us say you are asking Facebook to redirect to http://tld/fbhandler after user logs in. You can change that to http://tld/fbhandler?extra=value.

This URL is specified at the time of making the (OAuth) login call to Facebook and therefore you can change the value as you see fit.

Answer 2

You cannot do this. Facebook will strip custom query values from the url. I have found that there are two ways to do this. The first is that they will let you have a single query value at the end of the url if you encode the ? to %3F. For example:

redirect_url=http://www.example.com%3FmyextraParameter

You could use this approach to do something like base64url encode your values and add them at the end.

The other thing that I have done is to change the parameters to be path variables

redirect_url=http://www.example.com/realUrl/parameter1/parameter2

Neither are great solutions, but I have yet to find a way to send querystring values without them being stripped off.