If you want to use the IDoc object type's methods InputForeground and InputBackground, you need to use your IDoc object type (IDOCXAMPLE) as a reference for IDOC_PACKET.

Doing this means that you must ensure that only one IDoc at a time is passed to ALE, i.e. packets of size 1. The reason is simple: the methods InputForeground and InputBackground deal with a single IDoc object, so you need to define the binding so that it can deal with the object contained in IDOC_PACKET. The methods do not use the variable Unprocessed_IDOCs, and hence are unaware of any other IDocs in the packet.