Hi,

I opened myself a good can of worms yesterday.

The long and short of it is the following behave differently (with regard to the DRL generated):-

XLS Decision Tables
Templates
KIE-WB Guided Decision Tables
KIE-WB Guided Decision Table Template fragments

There is a further complication: https://bugzilla.redhat.com/show_bug.cgi?id=996964

All of the listed rule types currently discount a constraint if it#s value is empty, or value.trim() is empty. The requirement really only affects String field types. The difficulty is how to differentiate between a null-value (empty cell) and empty-string that works consistently with XLS and the KIE-WB editors.

So, my question is what behaviour should we standardize on?

I propose the following:

For a Pattern, with no constraints we exclude the pattern (this is current XLS behaviour).

e.g. Person( name == $name, age == $age ). If we don't provide values for $name and $age we don't include the Person pattern. If a user wants to include the Pattern they'd need to add a constraint "this != null".

If we include the pattern when there are no constraints then it is more difficult to provide a work-around to exclude the pattern if this is what some users need (and since it's the existing behaviour; less likely to be an issue for the majority of XLS users).

Support escaping String literals with quotes; so a user would enter "" or " ". This make it obvious that the cell contains a non-null value. The surrounding quotation marks would be stripped before being used in the DRL.

WDYT? Should I put this out to the community for opinions too?

With kind regards,

Mike