Applicable when condition with BO.BO_Reference

JonP

Before I give in and add a stupid change-marker attribute (which shouldn't be necessary), I thought I'd run this by you guys.

I have a UseCase BO and a UseCaseStep BO with relationship attributes between them. I have a button on the UseCase form called "Create First Step" that I want to be shown only when there are no use case steps for a use case.

In "Applicable when" I tried...

UseCase.pm_UseCaseSteps IS UNDEFINED

as well as

LIST_SIZE(UseCase.pm_UseCaseSteps)=0

Is there no way to use a multiple reference-attribute in an operation condition? If not, can that please be added to 8.1 (and make the operation condition expandable - some of mine are fairly long)?

rocketman

Think I read somewhere that you can't interrogate reference attributes in an "applicable when" condition.

You might try putting a count attribute in your UseCase B.O, then COUNT the referenced items in a B.O rule triggered during form initialisation, then your "Applicable When" could just be UseCaseBo.StepsCount > 0

Whether this will actually work will depend on whether the form gets rendered before or after any B.O initialisation rules.

JonP

Yeah, that's what I figured. Thanks!

aware_support

You can also try the aggregate expression with COUNT directly in the applicability condition without introducing a new attribute. Cannot guarantee that it will work, but it might

JonP

I tried...

COUNT UseCaseStep WHERE (UseCaseStep IN UseCase.pm_UseCaseSteps)=0

as well as

COUNT UseCaseStep WHERE (UseCaseStep.UseCase=UseCase)=0

But I got the same message: "Aggregate operations are not allowed as presentation conditions".

Is that what you meant?

aware_support

Yes, so back to the new attribute solution, then

JonP

Oh well, adding NumberOfSteps to UseCase is not the end of the world.