Cross-Type Verifiers

   Hi Guys

I have been trying to implement cross type verifiers, followng the 
examples from 
http://drc.ideablade.com/xwiki/bin/view/Documentation/validation%2Dcreate%2Dcustom%2Dverifier. 
 My first try worked fine, but i am now having some issues with a second
 object structure i am trying to implement it on.

I have 2 object types in my graph, these are Person and PersonPosition. 
The person position is a collection of positions the person held while 
employed by a company, each of these has a start and end date.

i,e,

Person

      PersonPositions (enumerable list of person position)

           StartDate (propery of person position)

           EndDate (propery of person position)

The business rule i am trying to implement is that none of the person 
positions' dates can overlap with other positions. I can do this in the 
person position object and it works reasonably well (shows that the 
position i just edited has an error), however when one of the dates is 
chaged, i want all the person positions to run validation to check 
against the other positions. This is so i can show the user all 
positions that have overlapping dates.

I tried to implement this at the person object level using the code 
below. it compiles and runs fine, but cant seem to get the triggers to 
fire. I am hoping its something small i am doing wrong.

///<summary>Get the PersonPosition Verifier.</summary>

            private static Verifier GetPersonPositionVerifier()

            {

                string description =

                  "Position dates must not overlap";

                DelegateVerifier<Person> v = new 
DelegateVerifier<Person>(description, 
PersonPositionValidCondition);

                v.VerifierOptions.ExecutionModes =VerifierExecutionModes.InstanceAndOnAfterSetTriggers;

                TriggerItem startDateTriggerItem = new 
TriggerItem(typeof(PersonPosition), PersonPosition.PathFor(e => 
e.StartDate));

                TriggerLink startDateTriggerLink = new 
TriggerLink(startDateTriggerItem, GetPositionsAssociatedWithPerson, 
true);

                v.AddTrigger(startDateTriggerLink);

                TriggerItem endDateTriggerItem = new 
TriggerItem(typeof(PersonPosition), PersonPosition.PathFor(e => 
e.EndDate));

                TriggerLink endDateTriggerLink = new TriggerLink(endDateTriggerItem, GetPositionsAssociatedWithPerson, true);

                v.AddTrigger(endDateTriggerLink);

                return v;

            }

            public static IEnumerable<PersonPosition> GetPositionsAssociatedWithPerson(Object person)

            {

                var aPerson = (Person)person;

                return aPerson.PersonPositions;

            }

private static VerifierResult PersonPositionValidCondition(

              Person pTarget, TriggerContext pTriggerContext,

              VerifierContext pVerifierContext)

            {

               //Do validation stuff here

            }

Any help would be greatly appriciated

regards

Jason