[Bug ?] Iterate on empty list : IndexOutOfBoundsException : "Index: 0, Size: 0"


I have a process where I multi-instanciate a task for each value of a list. Yesterday I note that when the list is empty, the process crash with this error :

Group that can be duplicated, dynamically

My client requirement is that, after selecting an item on a Select list, he can upload files and descriptions according to that selected item. The idea is to dynamically populate a group that can be duplicated, with the requested data. But as I've seen on Bonita, it doesn't seem possible to dynamically change the amount of group items. How can I achieve this? And, is there any way to consume a REST service from Bonita? Thanks.

Also, I can't find anything useful about Iterate (a practical example) on the documentation, is there any example of this?