Rails Against The Machine

#example of adding a method to a class
class NoiseMachine; end

def add_gun_to obj
 obj.class.class_eval do
   def pull_trigger
     puts "BANG!"
   end
 end
end

a=NoiseMachine.new
add_gun_to a
a.pull_trigger 

#example of adding a method to an object 
#this is a so called 'eigenclass' method
b=NoiseMachine.new

def add_button_to o
  def o.push_button
    puts "beep"
  end
end

add_button_to b
b.push_button

#example of dynamicaly defining a methods
class NoticeBoard
 def self.notices(*args)
   args.each do |arg|
     define_method "i_want_to_"+arg do
        puts "You can " + arg.gsub( /_/, ' ') +" in this village"
     end
   end
 end

 notices "buy_a_dog", "take_spanish_lessons", "do_baby_yoga"
end

post_office=NoticeBoard.new
post_office.i_want_to_buy_a_dog
post_office.i_want_to_take_spanish_lessons
post_office.i_want_to_do_baby_yoga

posted by ~J  # 09:16