Basic Auth manager for Ember

authManager.coffee

App.authManager = Ember.StateManager.create
   # The "stack" contains the currently logged-in user
   stack: []
   
   # Callbacks to be ran once the user is authenticated
   callbacks: {}
 
 
   # Grabs the current auth object and returns it
   # If callback argument is given, will run the callback function with current auth object as first argument
   # If there is no authenticated user:
   #   callback provided: ask for authentication, then run callback
   #   callback not provided: return undefined
   current: (callback) ->
      # if callback is given, use callback, invoking login window if needed
      if callback
         if(current = @current())
            callback current
         else
            @force_login callback
		
      # else, find current authenticated user
      # if no user, return undefined 
      else
         # simple case: stack already exists
         if @stack.length > 0
            _.last(@stack)
         # else, stack doesn't have any auths, search in store and rerun function
         else
            # SEE IF AUTH EXISTS in sessionStorage
            # (WILL NEED to modify this to fit your code)
            records = App.sessionStore.findAll(App.Auth)
            _.each records.get("content"), (element, index) =>
               @stack.push records.objectAtContent index
            
            if @stack.length > 0
               return _.last(@stack)
            else
               return undefined
 
   force_login: (callback) ->
      @add_callback "after_authenticate", callback
      @transitionTo "authenticating"	
 
   authenticate: (user) ->
      # check if the user is valid, probably by sending credentials via AJAX request
 
# CALLBACKS
   add_callback: (type, callback) ->
      @callbacks[type] = [] unless typeof @callbacks[type] is "object"
      @callbacks[type].push callback
 
   do_callbacks: (type, args) ->
      _.each @callbacks[type], (_callback) ->
         _callback args
      @clear_callbacks type
 
   clear_callbacks: (type) ->
      @callbacks[type] = []
 
# STATES
   authenticating: Em.State.create
      enter: (manager) ->
         App.get("router").get('applicationController').connectOutlet
            controller: App.get("router").get('authController')
            outletName: 'modal'
            viewClass: App.NewAuthView
            context: App.Auth.createRecord()
 
      exit: (manager) ->
         App.get("router").get("applicationController").get("modal").close ->
            App.get("router").get('applicationController').disconnectOutlet("modal")
 
   authenticated: Em.State.create
      enter: (manager) ->
         App.authManager.do_callbacks "after_authenticate", _.last(App.authManager.stack)

exampleFunction.coffee

App.authManager.current (auth) =>
   # This function is only ran once auth is available (the user logs in)
   # So you are safe to do functions that requires a logged in user

   # In my implementation, this method is part of my ember-data restful-api adapter, and simply 
   # overrides the default ajax method, wrapping it inside this calback...