I’ve got a fact which contains a collection (a set of strings to be precise). I want to write a rule which fires if there are any invalid values (where the valid values are defined as a list).

 

What I’m trying to do is express this within a decision table.

Expressed as a drl rule the following works:

 

rule "ValidateList"

      when

            Fact(col : collection != null)

            String(this not in ($param)) from col

      Then

      #generate error

End

 

Where $param = ‘“1”, “3”, “valid”’

 

The decision tables seem to assume that the fact type is the last element in the line and then appends “( conditions... )” this means there is no way to then insert a “from ...” after it.

 

Does anybody know either a different way to structure the rule so that I don’t need a from or a way to get the decision table to use it? (unfortunately adding the collection directly as a fact isn’t an option).

 

Thanks,

 

Thomas