class UserPreference < ActiveRecord::Base self.primary_keys = "user_id", "k" belongs_to :user validates :user, :presence => true, :associated => true validates :k, :v, :length => 1..255 # Turn this Node in to an XML Node without the wrapper. def to_xml_node el1 = XML::Node.new "preference" el1["k"] = k el1["v"] = v el1 end end