BO 'Rules when Object is Deleted' Question

bwalk

Good Day All,
I'm having a problem getting any rule to execute when deleting a BO.
In a property management BS I have a Property BO (parent) and a Building BO (child). The Property BO has an attribute NumberBuildings which gets updated every time a new Building is created for a given property. This is working fine.
Now of course when a Building is deleted I need to update this count accordingly. Seems simple enough but I'm struggling with it. Whatever I do to update this attribute has no effect.
In the BO 'Rules (When Object is Deleted)' section I have tried a multitude of formulas.
Here are just a few examples of trying to get any value into the Property.NumberBuildings attribute I have tried many others.
Building.ob_Property.NumberBuildings=500
ThisBuilding.ob_Property.NumberBuildings=500
Building.ob_Property.NumberBuildings=Building.ob_Property.NumberBuildings -1
etc., etc.
Nothing changes the current value of the parents attribute. I must be missing something very basic that I hope someone out there can point out the error of my ways.
Thanks for taking the time to read the post.

idpSteve

What I'd do is:

Under UPDATE RULES of Property I'd add:

IF Building WAS ADDED TO Property.om_Buildings THEN INCREASE Property.NumberBuildings BY 1

and a second rule:

IF Building WAS REMOVED FROM Property.om_Buildings THEN INCREASE Property.NumberBuildings BY -1

You'd need to refresh the form of Property to see the number change I think..

bwalk

Works like a charm !!
Thank you very much idpSteve.
I have been struggling with this for way too long.