sealink/activerecord_null_object

require 'active_support/concern'

module ActiveRecordNullObject
  module NullObject
    extend ActiveSupport::Concern

    included do
      validate :unsavable
    end

    def id
      nil
    end

    def nil?
      true
    end

    def empty?
      true
    end

    def blank?
      true
    end

    def present?
      false
    end

    def unsavable
      errors.add(:base, "is a null object and can't be saved")
    end

  end
end