PendingEntityList

Originally posted by tj62 My third question regarding this: If the pending list has a one2one relation to another Entity. Is it somehow possible to force the load of the related entity when the PendingEntityListResolved event is triggered for the list. Just to explain better: If I would like to do this in LINQ, I would use the .Include("One2OneRelatedEntity") to load it.   Doing a special load for each of the entities in the pending list is quite expensive....so I would like to force inclusion in the PengingEntityListResolved event.

You can always issue your own query for the child entities instead of using the navigation property. On that you can use Include().

Alternatively, it's always faster to preload in bulk; so if you can write a query that will preload the needed related entities before you start iterating through the parents, do that.

My third question regarding this: If the pending list has a one2one relation to another Entity. Is it somehow possible to force the load of the related entity when the PendingEntityListResolved event is triggered for the list.

Silverlight requires all data retrieval to be performed asynchronously.

When you reference a navigation property that returns a collection, e.g., aCustomer.Orders, you are launching a query -- which is necessarily asynchronous.

Therefore DevForce needs a callback method to exercise when the asynchronous retrieval operation is completed. You supply this when you set up a PendingEntityListResolved handler for the aCustomer.Orders property.  That handler then receives the collection of returned child entities via the ResolvedEntities property of its PendingEntityListResolvedEventArgs parameter. Then you take whatever action you wanted to take once those entities were available.

For navigation properties that return a scalar result (single entity, e.g., anOrder.Customer), there is a corresponding event, PendingEntityResolved, which is used in a similar fashion.

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Related info: On the EntityManager, there is a property UseAsyncNavigation which determines whether asynchronous data retrieval is used when satisfying references to navigation properties. This property is set to true by default in Silverlight applications; false in other types of applications. If you wanted to write an application with both WPF and Silverlight front ends, you could set this property to true and then write all of your controller logic to perform data operations asynchronously.



Edited by GregD - 02-Oct-2009 at 11:24am