>Hi everybody,
>
>I have a custom class (defined in a program) that has an object property defined like this
>
>oSomeObject = null
>
>In the Init I instantiate this object using
>
>this.oSomeObject = newobject('MyClass','myClasslib.vcx')
>
>Now, from that class I want to invoke methods of 'its parent'. However, oSomeObject doesn't know that it's a property of another class and therefore returns U when I check for its parent.
>
>What can I do to make it aware of the 'parent' class? Do I need to add Parent property and populate it? And if yes, how can I avoid dangling references?
>

The way I handle this kind of thing is to pass the instantiating class as a parameter and store it in a property of the newly instantiated class:

* Init
LPARAMETERS oCallingClass

IF VARTYPE(m.oCallingClass) = "O"
   This.oCaller = m.oCallingClass
ENDIF

As you note, you do have to clean stuff like this up. One easy way is that Destroy from the calling class calls a custom method of MyClass:

* Calling class.Destroy
This.oSomeObject.CleanUpReferences()

*MyClass.CleanUpReferences
This.oCaller = .null.

For hierarchies involving collections, I actually have some in my base collection class to ensure that every member of the collection handles this clean up.

Tamar