class Mapping < ActiveRecord::Base belongs_to :topic, :class_name => "Topic", :foreign_key => "topic_id" belongs_to :synapse, :class_name => "Synapse", :foreign_key => "synapse_id" belongs_to :map, :class_name => "Map", :foreign_key => "map_id" belongs_to :user def user_name self.user.name end def user_image self.user.image.url end def as_json(options={}) super(:methods =>[:user_name, :user_image]) end end