Rails ActiveRecord - inheriting from a base class with no table

Question

What i'm looking to do is have a base class for some of my models that has some default activerecord behavior:

class Option < ActiveRecord::Base
  has_many :products

  def some_method
    #stuff
  end

  #etc..etc..
end

class ColorOption < Option
  #stuff...
end


class FabricOption < Option
  #stuff...
end

However, I want ColorOption and FabricOption to each be in their own tables. I do NOT want to use STI or have a table for the base class "Option". The only way I've gotten this to work is with some non-inheritance metaprogramming magic. But I wondered if there was a way to tell AR that the base class does not need a table. Its just there for extra behavior, and to put the other subclasses in their own table as usual.

Thanks, Craig

Answer 1

Hi you may check this post but you'll need to redefi ne self.columns in your child classes

Answer 2

Looks like a case for a module that you include.

module Option
  def self.included(base)
    base.has_many :products
  end

  # other instance methods
end

class ColorOption < ActiveRecord::Base
  include Option
  set_table_name '???' # unless ColorOption / FabricOption have same table -> move to Option module

  #stuff...

end


class FabricOption < Option
  include Option
  set_table_name '???' # unless ColorOption / FabricOption have same table -> move to Option module

  #stuff...
end

http://mediumexposure.com/multiple-table-inheritance-active-record/

Stephan

Answer 3

What you want is an abstract class:

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

class ColorOption < Option
  set_table_name "color_options"
end

class FabricOption < Option
  set_table_name "fabric_options"
end

I have some extra information about STI and #abstract_class on my blog.