Trying to figure out how to disaggregate a model so that its important bits can be open-sourced

automobile_options.rb

# This is what we have in our app now:

class Automobile < ActiveRecord::Base
  include Leap # provides #decide classmethod

  decide :emission do
    # important stuff described in DSL
  end
  
  # lots of other boring stuff
end

# But we want the "important stuff" to be open-source
# while keeping the "boring stuff" private.
# Here are two options. Perhaps there are better ones.

# -----------------
# OPTION ONE (only works if model is loaded before gem)

# app/models/automobile.rb
class Automobile < ActiveRecord::Base
  # lots of other boring stuff
end

# in the gem
class Automobile
  include Leap # provides #decide classmethod

  decide :emission do
    # important stuff described in DSL
  end
end

# ----------------
# OPTION TWO (safer, but more verbose)

# app/models/automobile.rb
class Automobile < ActiveRecord::Base
  include BrighterPlanet::Automobile
  # lots of other boring stuff
end

# in the gem
module BrighterPlanet
  module Automobile
    def self.included(base)
      base.extend ::Leap::Subject # provides #decide classmethod
      base.decide :emission do
        # important stuff described in DSL
      end
    end
  end
end