Tuesday, January 28, 2020

DSPRCD refresh trick and a few extra tips.

Today I was asked to fix a DSPRCD screen that wasn’t refreshing after an up-screen EDIT function (Command Key) had changed some values. Upon returning to the DSPRCD it still showed the original values.

DISCLAIMER: This is correct behaviour for a 2E function but a little bewildering for the user as they are hesitant as to whether they actually made the change in the update screen.

For a DSPFIL we would use the *reload subfile to force a reload of the screen.
For a PMTRCD we can set the function option ‘Repeat Prompt’ to get the same behaviour.
For DSPRCD etc it is a little trickier…….

Typically, I have seen people utilise a driver program and execute the screen in a loop and simply recall the screen or exit.  This is doable……    There is however, (as always)…. An alternative, a trick and as it is much simpler I will show you.

The answer is to force the transaction to continue.  You maybe be aware of the PGM.*Continue Transaction field in 2E.   It is typically used (in action diagrams) for the DSPTRN and EDTTRN function types.  The same field is used in many AD’s including the DSPRCD.



In this instance it is simply there to initiate a loop.  Typically this field only has one condition (*NO) for using the EDTTRN and DSPTRN.  See these notes in the 2E manual….



The trick is that the DSPRCD generates code that says if W0TRN (*Continue Transaction) = ‘R’ then keep re-showing screen. 


Our issue (default model)  is that we have no way (default way) of setting it…… We do now. 

I have simply added a new condition to the field *Continue Transaction (I’ve done it at many sites).  The condition is called ‘*Reload Trick’ and we just need to set in after we’ve called our screen.



Please note you may need to follow this with a *QUIT depending on your circumstances.

Voila…. It works 😊

Additionally, did you know.....?

  1. USER:Process Command Keys has got nothing to do with command keys. Command key processing should normally be added to USER:Validate Detail Screen. 

or for DSPRCDx
  1. The correct screen context DTL/2ND/3RD must be used for error message parameters to ensure that field is highlighted. Normally in any action diagram coding the screen context is not significant.
  2. The validation cycle processes data from all pages together, therefore, the relation settings apply to the function as a whole, and not to individual screens.
  3. It is not possible to control, which page the user sees. If there is an error the function always displays the first page, which has an error outstanding, but this may not correspond to the actual error message displayed on the message subfile line. The messages are displayed according to the sequence they were sent. Therefore, you may have to review the validation sequence.
Tip: Validate a page at a time and only start validating a subsequent page if *PGMERR is not set.


Thanks for reading. 
Lee.

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