WeekDays Metaprogrammed example

week.rb

class Week

  WEEKDAYS = %w( :segunda_feira, :terca_feira, :quarta_feira, :quinta_feira, :sexta_feira )

  def custom_attr_accessor(attr)
    self.class_eval("def #{attr};@#{attr};end")
    self.class_eval("def #{attr}=(val);@#{attr}=val;end")
  end

  WEEKDAYS.each do |day|
    custom_attr_accessor day
  end

  def initialize(args)
    args.each do |key, value|
      self.send(key, value)
    end
  end

  def dias_true
    "[" + WEEKDAYS.select { |day| self.send(day) == true }.join(",") + "]"
  end
end