What does "self.included(base)" mean in a module?

Question

I see this pattern a lot:

module Article::Score

    def self.included(base)
        base.send :extend, ClassMethods
        base.send :include, InstanceMethods
    end

    module ClassMethods
    ...
    end

    module InstanceMethods
    ...
    end
end

Then in the article model, I see this

class Article
   include Article::Score
   ...
end

so my guess is that "base" probably refers to the article class and we're just including the instance methods and extending the class methods. But can someone explain the snippet "self.included(base)" and give an overview of what's going on there?

Answer 1

The self.included function is called when the module is included. It allows methods to be executed in the context of the base (where the module is included).