I did look at using the AsyncSerialTask to do this and came up with something which works, but is a bit ugly.  Pending entity resolution is not currently handled the same way as other asynchronous actions within DevForce, but we will look at making this easier.  The sample below takes advantage of how the AsyncSerialTask passes arguments and results from step to step. 

 

      AsyncSerialTask.Create<Customer>("DeleteCustomer")
        .AddAsyncAction<AsyncEventArgs>(SetupDeletion)
        .AddAction(args => DoDelete((Customer)args.UserState))
        .Execute(aCustomerToBeDeleted);

 

    // "callback" is called when entities are available

    //  the Customer is passed as the userState to the AsyncEventArgs

    private void SetupDeletion(Customer cust, AsyncCompletedCallback<AsyncEventArgs> callback) {
      var list = cust.OrderSummaries;
      bool isPending = list.IsPendingEntityList;
      if (isPending) {
        list.PendingEntityListResolved += (o, args) => {
          callback(new AsyncEventArgs(cust));
        };
      } else {
        callback(new AsyncEventArgs(cust));
      }
    }

 

    // Called by AsyncSerialTask when the prior step completes.

    private void DoDelete(Customer cust) {
      cust.EntityAspect.Delete();
      foreach (var order in cust.OrderSummaries.ToList()) {
        order.EntityAspect.Delete();
      }
    }

The above solution appears to work properly, when the Orders are in the cache.  However when not in the cache, I've got to do the pending list solution:

 

 

 

 

 

 

Setting the handler in the entity constructor is not a good idea for two reasons - 1) the event is fired for the EntityGroup and creating a handler for each entity instance means there will be many more handlers than needed, and 2) more importantly, and for obscure reasons, the EntityGroup used in entity construction turns out not to be the EntityGroup used to cache the entities.  What you should do instead is ask the EntityManager for the EntityGroup and set the handler once:

 

     _entityManager.GetEntityGroup(typeof(Customer)).EntityChanging += EntityGroup_EntityChanging;

 

The handler can get the Entity involved via the EntityChangingEventArgs.

 

We'll take a look at how we can better document the EntityGroup and its events, or change the API, so this isn't so cryptic.

We're having a problem while deleting an entity that has related entities.  In DevForce Classic, you used to be able to override Delete() and handle any additional cleanup there, but that seems to have been removed from EF.  The Reference Help document indicates that to get around this:

 

 

For another bad example... Customer has Orders, we want to remove the Orders associated with a Customer via code (meaning, we're not looking for a database solution here).  Following the above guidelines, we have the following: