extracting url component in rails 3

I am trying to build a facebook based application, I am not using any pre-existing facebook gems etc, therefore have to build it afresh.

After authentic开发者_如何转开发ation, I receive the access_token back from facebook as part of the callback url. It comes along as https://server/path#access_token=<token from facebook>

I need to extract access_token for authenticating my further requests. I am not able to get the # onwards parts of the url in the reqeust object...

I have already tried the request object and params hash... nothing provides me the "complete" url...

help...