User exit ZXPADU02 - evaluating SY-UCOMM

Question

Hello everyone,
I am trying to display an error message whenever someone tries to create a new work schedule rule (P0007-SCHKZ) in infotype 7. However, the error message should just come up when the user is trying to save his data.
I am using user exit ZXPADU02 for this purpose. My problem is that SY-UCOMM does not seem to hold reliable data in this user exit, and SSCRFIELDS does not seem to be supported at all.
My code looks like this (only the relevant code snippet in ZXPADU02):
CASE INNNN-INFTY.
        WHEN '0007'.
      CALL METHOD CL_HR_PNNNN_TYPE_CAST=>PRELP_TO_PNNNN
        EXPORTING PRELP = INNNN
        IMPORTING PNNNN = P0007.
      CALL METHOD CL_HR_PNNNN_TYPE_CAST=>PRELP_TO_PNNNN
        EXPORTING PRELP = PSAVE
        IMPORTING PNNNN = P0007_ALT.
      IF P0007_ALT-SCHKZ <> P0007-SCHKZ
      AND IPSYST-MASSN IS INITIAL " do not warn within an info group of a personnel action
      AND SY-UCOMM = 'UPD'. " only warn when saving the data -> problem here <-
        MESSAGE 'Do not change IT7 directly or else.' TYPE 'I' DISPLAY LIKE 'E'.
        SHOW_DATA_AGAIN = 'X'.
      ENDIF.
At first glance, the above works nicely.  But this is what happens when I test more thoroughly:
I create a new period in IT 7, enter a P0007-SCHKZ other than the one that was previously valid, press F11. Some warnings appear (for different reasons), which I dismiss using the Enter key. Afterwards, the above code fires, the error message is being displayed, and I am thrown back into the data screen. So far, so good.
Now I simply alter the value in the field "Weekly hours" (P0007-WOSTD) and press Enter (!). Again a series of warnings appear, including one that a dataset is going to be deleted (seeing that an IT 7-period with just the same date range already exists). I confirm that with Enter, and the data is being saved. The above code does not fire because I have only pressed Enter - but the data is being saved anyway!
Looks like a pretty erroneous behavior on the side of the SAP system. The question is whether I have a chance to do something about it in the code.

Answer 1

Mihir Nagar wrote:
Dear Petersen,
Your IF condition seems ok. I doubt on the message statement. Can you replace your message statement with type E.
MESSAGE 'Do not change IT7 directly or else.' TYPE 'E'.
      ENDIF.
Hope this works.
Regards,
Mihir.
I did not expect this to work, because normally you use type 'E'-messages only in certain PAI-environments, but it does the job, thank you!
make use of  field IOPER of the structure  PSYST to check on the infotype actions INS, MOD, COP, DEL...
In this particular case I did not care, so I did not check that. IT 7 should only be maintained through personnel actions in our case.
Next you can check with sy-ucomm field the different between "enter" and "save". With "save" sy-ucomm will be 'UPD'.
That is what I did, but as I described, there was a situation when SY-UCOMM is SPACE, but the system saved anyway due to a prior save attempt.