Using JSP, how to add new items to Fuego Business Object "Group" ?

Question

Given the classic Fuego Business Object (FBO) example of an Order, which has a few attributes (orderNumber, customerName, Order Date) and a GROUP attribute called OrderItems (ItemName, ItemPrice, etc.), I want to use a JSP to allow user to submit order. My JSP has a form and uses the Fuego Tag Library. There are FORM INPUT elements for Order.orderNumber, Order.customerName, Order.OrderDate, and a table using dynamic HTML to add rows and INPUT elements for new items to add to the GROUP attribute OrderItems - ItemName, ItemPrice, etc.)
But when the user wants to add "OrderItems" to the order, I don't know how to get Fuego to create OrderItem Objects to add to the array (aka GROUP).
Thx in advance.

Answer 1

###### below is the response I response I received from a BEA Engineer. From looking at the html source of fuego presentations that implement desired functionality, it appears as though they handle it using the first suggested workaround below ######
Hi,
The short answer to your question is that there is no out of the box feature to support directly what you are asking for.
The problem is that JSPs receives a Fuego Object that is accessed at rendering time (JSP compilation/ HTML rendering). And then all the updated values are sent back to the engine in a new request when you hit the submit button of a FOR tag that has the postResult tag in the action attribute. At this point all these values are automatically taken from the request and the Fuego Object instance variable in the screenflow is updated.
After saying this you will notice that it doesn’t make sense to update the Fuego Object instance on the JSP. Because you only could do this ate rendering time and because this instance is not going back to the engine (just the values).
Fuego Object tag Library was designed basically to be able to show Fuego Object data and invoke runs-on-server FO methods.
I see 3 different approaches to solve the problem you have:
1)Use JavaScript to call a runs-on-server method that recive the required arguments to extend the group and set the values. You should use the new tag called invokeUrl that allows you to use AjaX, in this way you could update the page with partial rendering.
2)Use JavaScritp to submit the form when the user click the add row button. And have a loop in the Screenflow with an automatic activity that will extend the group and the go back to the component activity that now will show the page again but with one more row. The drawback is that each time the user wants to add a row, it will require the entire page to be refresh.
3)Handle the table and values using JavaScritp and DHTML, and put all the new values in the request (input element), then in the Screenflow use an automatic activity to set this values to the Fuego Object.
Look at the Samples of using Fuego Tag Lib and AJaX
albpm5.7\studio\samples\Integration\Portlets\PFoodDelivery.fpr
albpm5.7\studio\samples\Integration\ThirdParty\AJaX.fpr