public static void AddOrAttachLink(this DataServiceContext context, object source, string propertyName, object target)
{
var descriptor = context.GetLinkDescriptor(source, propertyName, target);
if (descriptor == null)
{
context.AddLink(source, propertyName, target);
}
else if (descriptor.State == EntityStates.Deleted)
{
context.DetachLink(source, propertyName, target);
context.AttachLink(source, propertyName, target);
}
}
