module ActiveRecord #:nodoc:
  module CreateUpdateBy

    def self.included(base)#:nodoc:
      super
      base.class_eval do
        # alias (new name, old name)
        alias_method :old_save, :save
        alias_method :save, :save_with_user
        
        alias_method :old_update_attributes, :update_attributes
        alias_method :update_attributes, :update_attributes_with_user
      end
    end

    # modified update_attributes to accept a user id as a parameter
    # This parameter will be mapped to the 'updated_at' column in the
    # database if it exists.
    def update_attributes_with_user(attributes, user=nil)
        self.attributes = attributes
        save(user) # should actually call save_with_user via alias method
    end

    # Save takes an optional 'user id' parameter and will attempt
    # to record the value of that user id in the columns
    # 'created_by' and 'updated_by' if the model contains those attributes.
    def save_with_user(user = nil)
      raise ActiveRecord::ReadOnlyRecord if readonly?
      unless user == nil
        write_attribute(:created_by, user) if respond_to?(:created_by) and self.created_by.nil?
        write_attribute(:updated_by, user) if respond_to?(:updated_by)
      end
      old_save
    end





  end
end