app/models/approval_exinfo.rb
class ApprovalExinfo < ActiveRecord::Base
attr_accessible :approval_id, :name, :value, :position
acts_as_list :scope => [:approval_id, :name]
default_scope order: "position"
belongs_to :approval
has_paper_trail
belongs_to :keycode, class_name: "Keycode", foreign_key: :value
end