How would one define a class property that is readable from outside the class but is restricted to read-only?

I have made the property public and just applied a cProperty_Assign method with…
ERROR 1743, This.Name + ".cProperty"

This does allow one to read the property from outside the class and disallows changes, but it prevents changes from within the class as well. I am also wondering if there is a way to define the property so that:

SYS(1269, oObjectName, "cProperty", 1)

would return .T.

Any suggestions?