active_resource.rb

class ActiveResource::Base

  attr_accessor :dirty_attributes

  def update_attribute(name, value)
    dirty_attributes ||= []
    dirty_attributes << name.to_sym
    super(*args)
  end

  def update
    run_callbacks :update do
      patch_data = {}
      dirty_attributes.each do |dirty_attr|
        patch_data[dirty_attr] = self.attributes[dirty_attr.to_s]
      end

      encoded_patch_data = patch_data.send("to_#{self.class.format.extension}")

      connection.patch(element_path(prefix_options), encoded_patch_data, self.class.headers).tap do |response|
        dirty_attributes = nil
        load_attributes_from_response(response)
      end
    end
  end
end