GetParentchain not working

Hi!

I am currently working on a software that uses NativeActivities to describe a sequence consisting of different objects, but the GetParentchain class does not seem to work.

Supposing I have the Native Activities : Globe, Continent, Country, City., which are used asModelItems

Globe has a collection of coninents, countries, and cities

Continent cas a collection of countries and cities

and countries has a collection of cities.

I want to Validate the the above rules using a the CheckParent Function example on the msdn Declarative constraints webpage.

After writing the constraint exactly as described above and callling it throuth the following snippet , the constraint does not seem to work

        public static ValidationResults Validate_ModelItem(ModelItem item)
        {
            ValidationResults results = null;
            results = ActivityValidationServices.Validate((NativeActivity)item.GetCurrentValue());
            return results;
        }

Using the same method to get the childrem of each Activity, I get the desired results.

While looking into the variables on real time I notice that the Parent is always null and the actual parent of my object is under the Parent/Parent tag

Any suggestions/ideas?