Tracing a DATA-GEN operation

If you want to know the sequence of the calls from DATA-GEN to the generator and the calls from the generator back to DATA-GEN using the callback procedures, use the QIBM_RPG_DATA_GEN_TRACE environment variable to enable tracing. See the DATA-GEN section of the IBM® Rational® Development Studio for i: ILE RPG Reference.

Here is an example of a trace:

The generator has written its own trace message. The nested parameter was '0', so the trace message was printed started in column 1.
The generator has called the QrnDgAddText callback procedure.
The generator has written its own trace message. The nested parameter was '1', so the trace message was printed at the current indent level.


Start DATA-GEN
 Event 3 (Start)
  Event 5 (StartStruct) for ds
Terminate event enabled                 1 
   Event 11 (ScalarValue) for item
    AddText: 'Book'                     2 
   Event 11 (ScalarValue) for price
    AddText: '25.99'                    2 
   Event 11 (ScalarValue) for discount
    Looking up the discount             3 
    AddText: 'sub=-12.50'               2 
  Event 6 (EndStruct) for ds
 Event 4 (End)
 Event 12 (Terminate)
End DATA-GEN

Note: The trace output may not show up immediately, or it may flash by too quickly to see. For information on how to handle this situation, see Tracing a DATA-INTO parser.