Add extra parameters to return from facebook auth dialog

How can I have the facebook auth dialog to return me an extra parameter upon success from the auth dialog?

To be more specific, I want to add a "returnUrl" that is the page that a user tried to access before being authenticated.

I tried adding as a querystring parameter to the url set in redirect_uri but it d开发者_运维技巧oesn't work when I try to get the token later from oauth/access_token.

thanks!

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Adding a query string parameter to the redirect_uri should work; I have done it in the past. Just make sure you pass the exact same URL (including the query string parameter) to oauth/access_token.