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