PolymorphicAsTable

I wrote this out of the need to deal with a legacy database that had the correct schema for utlizing ActiveRecord[http://ar.rubyonrails.org/]‘s polymorphic associations, but required that the “type” columns contain the value of the tablename they pointed to as opposed to the class name they resolved to.

There are probably bugs and cases where it will break that I haven’t found. Please open bug reports to let me know about them, preferably with code demonstrating the behaviour if possible, on the bugtracker on github.

In addition, I’m not exactly a Ruby or ActiveRecord guru. If I’m doing something wrong, feel free to send a pull request. If you lend an explanation, I’ll love you forever.

Usage

class MyPolymorphicModel < ActiveRecord::Base
  is_polymorphic_as_table
  belongs_to :entity, :polymorphic => true
end

class MyOtherModel < ActiveRecord::Base
  has_polymorphic_as_table
  has_many :my_polymorphic_models, :as => :entity
end

If you’re testing with rspec-rails, you’ll need to put the following at the top of config/environments/test.rb :

require 'active_record'
require 'active_record/associations'
require 'active_record/associations/through_association_scope'

This is due to ActiveRecord’s use of autoload, and the way rspec-rails initializes itself, I think. :/