gistfile1.rb

module Settings
  def self.included(source)
    source.class_eval do
      def self.setting(*args)
        args.each do |setting|
          attr_accessor setting

          define_method "#{setting}_on" do
            self.send("#{setting}=", true)
          end

          define_method "#{setting}_off" do
            self.send("#{setting}=", false)
          end

          define_method "#{setting}_on?" do
            !!self.send(setting)
          end

          define_method "#{setting}_off?" do
            !self.send(setting)
          end
        end
      end    
    end
  end
  
end

class MattConfig
  include Settings
  setting :power
end