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Async Navigation in SL causes modified entities

Printed From: IdeaBlade
Category: DevForce
Forum Name: DevForce 2010
Forum Discription: For .NET 4.0
URL: http://www.ideablade.com/forum/forum_posts.asp?TID=2223
Printed Date: 02-Feb-2026 at 5:52pm


Topic: Async Navigation in SL causes modified entities
Posted By: pompomJuice
Subject: Async Navigation in SL causes modified entities
Date Posted: 12-Oct-2010 at 8:54am
Hi.

Whenever I access Navigational properties of entities in Silverlight asynchronously, my entities get marked as "Modified" by devforce. This is causing severe confusion in my UI.

Any idea when this might be fixed?

W


Replies:
Posted By: sbelini
Date Posted: 12-Oct-2010 at 1:15pm

Hi,

 
How are you acesssing the navigation properties?
I wrote a small test (below) and the nav properties are Unchanged.
 
Can you provide a test case (preferably against NorthwindIB) reproducing the issue?
 
 
var employeesQuery = mgr.Employees.Include("Orders");
mgr.ExecuteQueryAsync(
  employeesQuery,
    args => {
      if (args.HasError) {
        throw args.Error;
      }
      var orders = args.Results.First().Orders;
      var numberOfOrders = orders.Count();
      Random randNum = new Random();
      var index = randNum.Next(numberOfOrders - 1);
      var anOrder = orders[index];
      if (anOrder.EntityAspect.EntityState == EntityState.Unchanged) {
        MessageBox.Show("EntityState is Unchanged as expected");
      } else {
        MessageBox.Show("Something is wrong. EntityState is " + anOrder.EntityAspect.EntityState.ToString());
      }
    },
    null);

Posted By: pompomJuice
Date Posted: 13-Oct-2010 at 12:51am
That is not going to produce the error. You are not accessing anything asynchronously in that test.

The kind of navigation I am talking about is the same as what would happen between the Product.SupplierID relationship.

Try something like this:

                mgr.ExecuteQueryAsync(mgr.Products).Completed+=(s,e)=>
                {
                    e.Results.ToList().ForEach( p =>
                        {
                            p.Supplier.EntityAspect.PendingEntityResolved+=(sender,args)=>
                                {
                                    if (p.EntityAspect.EntityState == EntityState.Unchanged)
                                    {
                                        MessageBox.Show("EntityState is Unchanged as expected");
                                    }
                                    else
                                    {
                                        MessageBox.Show("Something is wrong. EntityState is " + p.EntityAspect.EntityState.ToString());
                                    }
                                };
                        });
                };

The call to r.Supplier triggers devforce to fetch the supplier asynchronously, while handing a fake one to you. So far so good. Once the async  fetch is complete however, the fake value is supposed to get a PropertyChangedEvent. Instead no event seems to occur and r.Supplier is marked as modified. Disaster!

Posted By: kimj
Date Posted: 13-Oct-2010 at 6:56am
pompomJuice - we've fixed this bug in the 6.0.6 release.   This release is due out within a week, and an EAP build is available now upon request.

Posted By: pompomJuice
Date Posted: 13-Oct-2010 at 7:08am
That is good news. Thanks!

Posted By: pompomJuice
Date Posted: 20-Oct-2010 at 2:06am
Confirmed this issue is fixed in 6.06.


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