title: Pros / Cons to Different Binding Approaches using MVVM and RIA Services
body: <p>I have been building an application, which uses the LoadOperation's Entities to return an IEnumerable which becomes the source of a CollectionViewSource in my View Model.  I am now discovering the potential pitfall to this approach, when adding Entities in my Silverlight client, I cannot see these entities, unless I either submit the New Entity, then reload, or Maintain a separate collection of items, which I am binding to.</p>
  
  <p>What I really see as my options are:</p>
  
  <ol>
  <li>Add an ObservableCollection to use as the Source of the CollectionViewSource property in my ViewModel - this way I can add to both the DomainContext and the ObservableCollection at the same time to keep the collections in sync.</li>
  <li>Change the Binding to the EntitySet directly, and add a filtering event handler to provide the filtering on the CollectionViewSource.</li>
  </ol>
  
  <p>If anyone has tips or thoughts about pros/cons of each, I would greatly appreciate it.  In particular, I am wondering, if there are performance and/or programming benefits in favor of one or the other?</p>