Dynamically adding/editing list items in a “new” form of another list?

Question

I'm new to Sharepoint, so I'm looking for some advice on how to tackle a problem I'm having when developing a solution for a client. This is a simplified example:

I have two lists: one containing Orders, and a second one containing Items related to Orders.

My client wants to be able to add everything on the fly from one screen. He wants to hit the "New" button on the Orders list, fill in a Name, Date, etc. of the Order and then add Items to the Order right away.

Basically, a dynamic list containing records from the Items list, within the New-form of the Order list.

I was thinking of using a custom Webpart for the new/edit forms for the Order list with regular form fields, and a gridview for the Items related to that Order. However, I cannot contemplate how this could ever work. When I'm creating a new Order, there's no way to filter or create Items related to that Order as there's no OrderID yet, right?

How do I tackle this? I can't seem to wrap my head around this.

Answer 1

if you are using custom code, why do you actually need to save the list items before the order is created? Cant you just store them locally in the code until the submission is completed?

If you cannot, have your webpart generates its own GUID that it can use to store all of the order items in a temporary list before they are ready to be added to the Order/Item list.

Please let me know if this is sufficient to get you started!