dschulten commented on issue #3648:
URL: 
https://github.com/apache/incubator-kie-tools/issues/3648#issuecomment-4983153596

   In DMN, it seems an input that is not present should always exist, but it 
should have a value of null. Only then you can handle it as null. The DMN 
Engine does it that way. 
   DMN has no concept of `undefined` like Javascript, where you could omit an 
input altogether. Also, DMN has no concept of empty strings for a value that 
has not been entered. To me it seems that omitting an attribute of unknown 
value or setting it to the empty string is a natural thing in Javascript, but 
totally unexpected in DMN. I would say, almost every html form on the interwebs 
does not allow you to enter an empty string. You can only enter nothing, and 
applications treat that as a missing field, if it's mandatory.
   
   ### Strings:
   * User wants to send null: enter no value in the Sandbox form
   * User wants to send "null": enter "null"
   * User wants to send "" - why would they want to do that in the Sandbox?
   * User does not want to send any value - enter no value. Omitting the 
attribute is the current behaviour and it breaks the DMN engine in 
extended-services
   
   ### Numbers
   * User wants to send null: enter no value
   * User does not want to send any value: enter no value. Not sending the 
attribute breaks the DMN engine in extended-services.
   
   It boils down to this: The DMN model can und must handle `null` as missing 
input. Giving the user the choice that sending nothing can mean three thrings 
(not there, empty string, null) complicates the life of modelers enormously, 
and if you ask me, it gains nothing.


-- 
This is an automated message from the Apache Git Service.
To respond to the message, please log on to GitHub and use the
URL above to go to the specific comment.

To unsubscribe, e-mail: [email protected]

For queries about this service, please contact Infrastructure at:
[email protected]


---------------------------------------------------------------------
To unsubscribe, e-mail: [email protected]
For additional commands, e-mail: [email protected]

Reply via email to