I have a parent entity Activity which has a 1-1 relation on ActivityBM. When I do the following:

 activity.ActivityBMEntity = new ActivityBMEntity();

the PropertyChanged notification is fired.

Now, when I do this:

 activity.ActivityBMEntity = null;

no PropertyChanged notification is fired.

I have attempted to use OnRelatedEntityUnset, like so:

protected override void OnRelatedEntityUnset(IEntity2 relatedEntity, string fieldName)
        {
            base.OnRelatedEntityUnset(relatedEntity, fieldName);
            this.OnPropertyChanged(fieldName);
        }

but the related object isn't null at this point, so the call doesn't help.

How can I get PropertyChanged notification when a 1-1 related entity is set to null?

Thanks, Josh

-- using the latest templates/drivers/runtime libs (just downloaded) for 2.6

Are these entities in an inheritance hierarchy? If Yes are they of Tye TargetPerHierarchy?

The Activity entity is a super-type (Target Per Entity), though ActivityBM is not part of a hierarchy.

tomahawk wrote:

I have a parent entity Activity which has a 1-1 relation on ActivityBM. When I do the following:

 activity.ActivityBMEntity = new ActivityBMEntity();

the PropertyChanged notification is fired.

It can be there are several notifications being raised: the ActivityBMEntity property but also the FK fields in 'activity', as these have been changed (if activity had a reference to another activityBMEntity. )

Now, when I do this:

 activity.ActivityBMEntity = null;

no PropertyChanged notification is fired.

The problem is that the code sees this as a 'dereference' only, and dereferences aren't notified as you'd get twice the notifications when you set a property to a different value. This is indeed a problem. It's in the template, the setter of the property: there it tests for null and if so, it calls the desetupsync method, but that one doesn't notify anything.

I have attempted to use OnRelatedEntityUnset, like so:

protected override void OnRelatedEntityUnset(IEntity2 relatedEntity, string fieldName)
        {
            base.OnRelatedEntityUnset(relatedEntity, fieldName);
            this.OnPropertyChanged(fieldName);
        }

but the related object isn't null at this point, so the call doesn't help.

That's by design, as it passes in the entity which is about to be unset, so not the 'null' value but the entity which is being dereferenced because the reference is set to null.

I'll adjust the template so the propertychanged event is raised properly.

Please use the attached template (entityIncludeAdapter.template), which (after generating the code) will fix your problem.

Keep in mind that PropertyChanged isn't some event you should use for BL, it's meant for UI controls which act according to changes of properties.

Excellent, that solves it. And yes, this property is bound directly to a WPF UI via a ValueConverter.