How to check if %ZEN.proxyObject has a property in Caché Object Script?

Question

How to properly check that some %ZEN.proxyObject's object has a specific property?

In my case I have %ZEN.proxyObject instance. My guess is set p = $PROPERTY(object, "propertyName"). $PROPERTY returns an empty string if property does not exists, but what if the property value is an empty string?

Answer 1

Use %data property of %ZEN.proxyObject:

Set obj = ##class(%ZEN.proxyObject).%New()
Set obj.a = 2
Write $Data(obj.%data("a"))
>1
Write $Data(obj.%data("b"))
>0