Drools: Variables can not be used inside bindings

Question

I get the error

Variables can not be used inside bindings

on the following Drools-Rule Code

rule "minGapsBetweenAppointments"
when
    $leftAssignment : AppointmentRequest(feasibleAppointment != null)
    $totalValue : Number( ) from accumulate(
            AppointmentRequest(feasibleAppointment != null,
                    $leftAssignment.requestId != requestId,
                    $quality : this.getOccupiedSurroundingsValue($leftAssignment)),
            sum( $quality )
            ) // ERROR LINE
then
    scoreHolder.addSoftConstraintMatch(kcontext, $totalValue.intValue());
end

Although i found this post from another question, it's not helping me much, as I need to call function getOccupiedSurroundingsValue for all other AppointmentRequests, as they're related.

Any help appreciated.

Answer 1

That code should work. There's nothing wrong with it as far as I can see. Double check if you it's exactly the same as the code you're executing it. I use similar code in my examples and those work.

If it's OK, then it might be a bug in Drools Expert. There are 2 ways to proceed:

• The easy way: repost this question on the drools mailing list, maybe Edson or Wolfgang sees something I don't. Post a jira if no one sees a user-mistake.

• The fastest way to solve your problem: create a new test in MiscTest that proves your case and submit it as pull request. Either you find out what you're doing wrong or you prove without a shadow of a doubt there's a bug we need to fix asap :)