Monkey patch for the Rails plugin "acts_as_taggable_on" to handle dirty tracking

patch_acts_as_taggable_on.rb

# Monkey patch for the Rails plugin "acts_as_taggable_on" to handle dirty tracking
# http://github.com/mbleigh/acts-as-taggable-on/issues#issue/1

module ActsAsTaggableOn::Taggable
  module Core
    module InstanceMethods
      def set_tag_list_on_with_dirty_tracking(context,new_list)
        value = new_list.to_s
        attr = "#{context.to_s.singularize}_list"
        
        if changed_attributes.include?(attr)
          # The attribute already has an unsaved change.
          old = changed_attributes[attr]
          changed_attributes.delete(attr) if (old == value)
        else
          old = tag_list_on(context).to_s
          changed_attributes[attr] = old if (old != value)
        end
        
        set_tag_list_on_without_dirty_tracking(context,new_list)
      end
      alias_method_chain :set_tag_list_on, :dirty_tracking
    end
  end
end

There is a typo:

value = new_list.is_a?(Array) ? new_list.join(', ') : value

But correct is:

value = new_list.is_a?(Array) ? new_list.join(', ') : new_list

Thanks for sharing it!

Thanks @dsmalko, I have updated the gist and made it a little bit more simple