Question

If I have classes like this,

class A < ActiveRecord::Base
  include ExampleModule
end

class B < ActiveRecord::Base
  include ExampleModule
end

module ExampleModule
  module ClassMethods
    ...
  end      

  def included(base)
    ...
  end
end

how do I get the a reference to class A or B inside of ExampleModule upon referencing including this module into either one of those classes? I’m asking this question because I wanted to do something like adding has_one :association or after_create :do_something to class A or B via including ExampleModule such as below.

class A < ActiveRecord::Base
  include ExampleModule
end

class B < ActiveRecord::Base
  include ExampleModule
end

module ExampleModule
  has_one :association
  after_create :do_something      

  module ClassMethods
    ...
  end      

  def included(base)
    ...
  end
end

Is there a better way to do this as well? Thanks!

Answer 1

If you extend ActiveSupport::Concern, you should be able to do it when the module is included:

module ExampleModule

  extend ActiveSupport::Concern

  def do_something
    # ...
  end

  included do
    has_one :association
    after_create :do_something      
  end
end