gistfile1.txt

back-end request for retrieving users
##########
  def filter
    @users = User.where facebook_id: params[:facebook_ids]
    respond_with @users
  end

front-end request in Coffeescript/Backbone for retrieving the list of FB friends 
##########
  getListOfFacebookFriends: ->
    ids = null
    FB.api('/me/friends', (response) =>
      ids = _.pluck(response.data, 'id')
      if ids.length == 0
        hide_certain_elements()
      else
        @fetchFacebookFriendsOnGOOD(response.data)
    )

  fetchGOODFacebookFriends: (FBFriends) ->
    ids = _.pluck(FBFriends, 'id')
    friends = new good.citizen.collections.FacebookFriends
    friends.fetch
      data: {facebook_ids: ids},
      type: 'POST',
      success: (GOODFriends) =>
        @showFriendsOnGOODToFollow(GOODFriends)
        @showFriendsNotOnGOODToInvite(FBFriends, GOODFriends)