Ruby Module Example

ruby-module-example.rb

module Person
  attr_accessor :name
  def self.included(base) # included is invoked whenever a module is included; base is implicit
    base.extend ClassMethods  # extend will add the methods defined in ClassMethods as class methods
  end
  module ClassMethods
    def can_speak
      include InstanceMethods # This includes all the instance methods
    end
  end
  module InstanceMethods
    def speak
      puts "I can talk, my name is #{@name}!"
    end
  end
  def initialize(name)
    @name = name
  end
end
class Guy
  include Person
  can_speak
end
class ShyGuy
  include Person
end
john = Guy.new('John')
bob = ShyGuy.new('Bob')
john.methods.include?(:speak)   # true
bob.methods.include?(:speak)    # false