Question

I’m using Facebook OAuth interface but can’t get immediate mode parameter working. Do you have any idea how that works with FB or any other url to use instead?!

(I don’t/can’t use FB JS libraries.)

Answer 1

I have extracted following url from FB php-sdk (which Quentin reminds me):

https://www.facebook.com/extern/login_status.php
  ?api_key=<your app-id or api-key>
  &no_user=<callback url>
  &no_session=<callback url>
  &ok_session=<callback url>
  &session_version=3

When you redirects user to above url (or open it as an iframe or popup) Facebook silently/immediately redirects backs user/browser to:

• no_user when user has NOT signed in.
• no_session when user has signed in but has NOT authorized your app yet.
• ok_session when user has signed in and already authorized your app. Additional parameters (user identification and required token) will be appended to this url by FB which you need to validate.

For example:

https://www.facebook.com/extern/login_status.php
  ?api_key=123456789012345
  &no_user=http://example.com/signin/fb/no_user
  &no_session=http://example.com/signin/fb/no_session
  &ok_session=http://example.com/signin/fb/ok_session
  &session_version=3

Put them in one line whit no spaces and don’t forget to encode urls if needed.

See OpenID Immediate mode to find out why this is useful.