ember.js facebook: Accessing object defined in mixin

ember.js facebook: Accessing object defined in mixin

I am very new to ember and trying to implement authentication via facebook
I am using ember-facebook.js library to connect with facebook. This
library creates a App.FBUser object in mixin which is populated from the
facebook response. How can I access this object in my Route.beforeModel()
hook.
What I want to transition to index route if this object is already
present(user is already login)
Any help is greatly appreciated. Thanks