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ActsAsPolymorphic
=================

TODO: Add documentation.

This is important because the introduction of a polymorphic association means that more than one model is going to have a 'has_many :as'.  Now, while this may not seem too repetitive to add to a few different classes, it easily can be.  This is especially true if you start caring about the :dependent relationship.  Or, if you add new methods based on the association.


Example
=======

TODO: This example isn't great because it illustrates something that is common with a many-to-many

class Tag < ActiveRecord::Base
  belongs_to :taggable, :polymorphic => true
end

class Movie < ActiveRecord::Base
  acts_as_taggable
end

class Photo < ActiveRecord::Base
	acts_as_taggable
end

class Song < ActiveRecord::Base
  acts_as_taggable
end

All you need to do is run this:
script/generate acts_as_polyorphic taggable tags
or
script/generate acts_as_polyorphic taggable tags tag destroy

which generates (in the former case)

module ActiveRecord
  module Acts
    module Taggable
      def self.included(base)
        base.extend(ClassMethods)
      end

      module ClassMethods
        def acts_as_taggable
          class_eval do
            include ActiveRecord::Acts::Taggable::InstanceMethods

            has_many :tags, :class_name => "Tag",
                            :as         => :taggable,
                            :dependent  => :nullify
          end
        end
      end

      module InstanceMethods
        # Add instance methods here for the taggables
      end 
    end
  end
end

ActiveRecord::Base.class_eval { include ActiveRecord::Acts::Taggable }


Copyright (c) 2010 Chris Morris, released under the MIT license