Description: Runs after one or more items have been added to the selected side of an IDList.
Execution: The visible lists have already been changed, but the new value has not yet been written to EntryData. The regular OnChange chain follows this event.
Arguments: Argument_SelectedIDList is a Variant array containing the complete selected ID list after the change, not only the newly added IDs. It is Null when the resulting list is empty. The declared common event arguments are not populated by this executor.
Result: Any value assigned to Result is ignored.
Availability: Desktop only. Web add operations update the value but do not execute OnAddItems.
Example: Convert the complete post-change selection to text for logging or display.
SelectedIDText := VarArrayToCommaText(Argument_SelectedIDList, "[]");