How to encode the redirect_uri for facebook login

Question

I'm trying to build a login link for facebook and I'm I'm getting errors only in some cases. I'm trying to specify aa querystring parameter in redirect_uri token so that I can redirect them back to a specific area of my site after logging in. Here's what works and what doesn't work.

&redirect_uri=http://mydomain.com/login?returnUrl=returnUrl - works &redirect_uri=http://mydomain.com/login?returnurl=/return/url -doesn't work &redirect_uri=http%3a%2f%2fmyagentcheckin.com%2flogin%3freturnUrl%3d%2freturn%2furl -doesn't work

It seems that the / in the querystring are causing it to fail. Facebook returns an error when I try it. Anyone know of a way around this?

Answer 1

Instead of including the returnUrl parameter as part of your redirect_uri value, use the state parameter to store this data.

For instance,

https://graph.facebook.com/oauth/authorize?type=web_server&client_id= {appid}&redirect_uri=http://www.yoursite.com/oauth/handshake&state=/requested/page

Answer 2

I have experienced something similar, especially with multiple redirects as above.

My solution is to put the returnUrl into the user's session (or perhaps a cookie), so I don't have to wrestle with double-encoding. For the redirect_url, just omit the querystring.

Answer 3

Try using this API that put together. It will remove the hassle of this for you.

No url encoding necessary.

Sample Authentication

Imports Branches.FBAPI
...
Dim SI As New SessionInfo("[application_id]","applicaiton_secret")
SI.AuthenticateUser("http://[my url]", New SessionInfo.PermissionsEnum(){SessionInfo.PermissionsEnum.email, SessionInfo.PermissionsEnum.read_stream}))

Read the response from the URL you provided above from that page.

Dim FSR = FS.ReadFacebooAuthResponse

Answer 4

When I tried what you do, I got a redirect callback something like this. http://mydomain.com/login?returnurl=%2Freturn%2Furl&code= ...

And I decode the "returnurl" value. Then it worked fine for me.