Using acts_as_list storing the information in a session


I have an order model that i am storing in a session, that is not
currently in the database. I am updating the page using ajax, and I do
not want to store the order in the database untill it is completely
filled out.

I have order_items that I am adding to the order, and I have used the
acts_as_list within the order_item model.

My problem comes when i try and rearrange the order_items using the
following code:

def move_item_up
@order = find_order
session[:order] = @order
render:partial => ‘order_contents’

It gives me the following error:

ActiveRecord::RecordNotFound (Couldn’t find Order without an ID):
find_from_ids' /usr/local/lib/ruby/gems/1.8/gems/activerecord-1.14.2/lib/active_record/base.rb:382:infind’

This is happening with the reload function, which i am assuming tries to
refresh the order_items in the order, by gathering them from the

Is there another way to do this, where I can still hold these within the
session, without having to store them in the database?