The Irish Penguin

Ho ho, this one can catch you out more than once so it’s high time to write a blog post to cover this off. Turns out it’s a commonly used pattern to the rescue. Thanks to eoin on #ruby.ie for pointing to the solution on RailsTips.org.

Here’s quite a tasty diagram too for easy reference.

module Swingable

    def self.included(base)
        base.extend(ClassMethods)
    end

    def instance_swing
        puts 'Did an instance swing!'
    end

    module ClassMethods
        def static_swing
            puts 'Did a static swing!'
        end
    end
end

class BaseballBat
   include Swingable
end

BaseballBat.static_swing
BaseballBat.new.instance_swing