WCF Data services SaveChanges not firing WritingEntity event

Question

I am using WCF data services (5.6 now) and since Enums are not supported (and for other reasons), I have some additional properties added to the client side classes that I intend to remove during SaveChanges using the WritingEntity event following the example in http://blogs.msdn.com/b/phaniraj/archive/2008/12/11/customizing-serialization-of-entities-in-the-ado-net-data-services-client-library.aspx

My constructor attaches the event but I find that sometimes the event fires and other times (more often) it doesn't.

public MyDataContext(System.Uri serviceRoot, bool ignoreProperties)
    : this(serviceRoot)
{
    if (ignoreProperties)
        this.WritingEntity += EdiContext_WritingEntity;
    this.SendingRequest2+=OnSendingRequest;
}

To Save changes

db.AttachTo("Maps", map, "*");
db.UpdateObject(map);
ProcessMapCoordinates(db, map);
ProcessModifiers(map, db);
db.SaveChanges();

The SendingRequest2 event does fire, I use it to attach some header information to the request in order to support multiple data

private void OnSendingRequest(object sender, SendingRequest2EventArgs e)
{
    e.RequestMessage.SetHeader("profile", ClientSettings.Instance.Profile);
}

Does anyone know under what circumstances the WritingEntity event will not fire?

Is there another way to prevent extended properties from the partial class from being serialized?

Thanks

Answer 1

It appears this was caused by the use of public Enums on the client side partial class. Once I changed the access modifier of the enum to internal the problem went away.

In the process I learned an even better way of controlling what properties are serialized, by hooking into the RequestPipeline events:

if (ignoreProperties)
{
    this.Configurations.RequestPipeline.OnEntryStarting((a =>
    {
        entityType = Type.GetType(a.Entry.TypeName);
        if (entityType != null)
        {
            var props =
                entityType.GetProperties()
                    .Where(
                        property =>
                            property.GetCustomAttributes(typeof (DoNotSerializeAttribute), false).Length > 0)
                    .Select(p => p.Name)
                    .ToArray();
            a.Entry.RemoveProperties(props);
        }
    }));
}