For each instance of an XML-enabled class I want to control whether a property is projected as an empty element or not projected at all. With string properties, I can set the value as $c(0) for an empty element, or an empty string for no projection. But it looks like this isn't consistent for properties with type %Boolean or %Integer. With booleans $c(0) gets projected as "false". With integers $c(0) stays as a zero-width space in the XML output (which gives me a SAX parser error if I try to read it).
Is there a way to do this that works for all datatype properties?