title: How to track entity changes with WCF Ria Services?
body: <p>I need to log changes made to an entity that occur on the client to a database table.  However, when I make changes and inspect the ChangeTracker property, it claims that no changes have occurred.</p>
  
  <p><strong>[Service]</strong></p>
  
  <pre><code>    private static readonly ISomeDao someDao = DataAccess.SomeDao;
      [Query]
      public List&lt;SomeEntity&gt; GetSomeEntites(int someId)
      {
          var entities = someDao.GetSomeEntites(someId);
          entities.ForEach(e =&gt; e.StartTracking());
          return entities;
      }
  
      [Update]
      public void UpdateSomeEntity(SomeEntity entity)
      {
          // inspect entity.ChangeTracker.OriginalValues.... nothing
          entity.StopTracking();
          // inspect entity.ChangeTracker.OriginalValues.... nothing
          ...
          // Update log table 
      }
  </code></pre>
  
  <p><strong>[Client]</strong></p>
  
  <pre><code>    public EntitySet&lt;SomeEntity&gt; SomeEntities
      {
          get { return _someEntity; }
          set
          {
              if (_someEntity!= value)
              {
                  _someEntity= value;
                  OnPropertyChanged("SomeEntities");
              }
          }
      }
  </code></pre>
  
  <p>So, if, self-tracking entities and WCF Ria Services can't live together (which is what I'm suspecting), how does one track changes?</p>