Hi,

>Is the AddProperty() method allowed in COM implementation?

It's allowed - but since the property is added at runtime it will not be available via the COM interface (which is defined at compile time). For example with the following DLL:

DEFINE CLASS Viv AS SESSION OLEPUBLIC
  PROCEDURE ADDP(NAME,CLASS)
    o = CREATEOBJECT(NAME)
    THIS.ADDPROPERTY(NAME,o)
  ENDPROC
  PROCEDURE ReturnValue(x)
    RETURN EVALUATE(x)
  ENDPROC
ENDDEFINE

DEFINE CLASS VivTest AS CURSOR
  ss = "Hello, world"
ENDDEFINE

then

lO = CreateObject("whatever.whatever")
lO.AddP("VivTest")
? lO.ReturnValue("this.VivText.ss")

works showing that the object was created OK but only visible through Properties/Methods exposed in the COM interface...

HTH,
Viv