Rails extending ActiveRecord::Base

Question

I\'ve done some reading about how to extend ActiveRecord:Base class so my models would have some special methods. What is the easy way to extend it (step by step tutorial)?<

Answer 1

You can just extend the class and simply use inheritance.

class AbstractModel < ActiveRecord::Base  
  self.abstract_class = true
end

class Foo < AbstractModel
end

class Bar < AbstractModel
end

Answer 2

I have

ActiveRecord::Base.extend Foo::Bar

in an initializer

For a module like below

module Foo
  module Bar
  end
end

Answer 3

You can also use ActiveSupport::Concern and be more Rails core idiomatic like:

module MyExtension
  extend ActiveSupport::Concern

  def foo
  end

  module ClassMethods
    def bar
    end
  end
end

ActiveRecord::Base.send(:include, MyExtension)

[Edit] following the comment from @daniel

Then all your models will have the method foo included as an instance method and the methods in ClassMethods included as class methods. E.g. on a FooBar < ActiveRecord::Base you will have: FooBar.bar and FooBar#foo

http://api.rubyonrails.org/classes/ActiveSupport/Concern.html