title: Getting the username inside a model class
body: <p>I'm trying to implement basic auditing with some of my models (like CreatedAt, UpdatedAt, CreatedBy and UpdatedBy).</p>
  
  <p>The date/time part is done. I'm throwing events on my models when a property is changed (implementing <code>INotifyPropertyChanging, INotifyPropertyChanged</code>) and can update the correspondent fields just fine.</p>
  
  <p>I just need to know how to get the current user name without having to pass it through the controller every time I instantiate or get an existing instance of a model.</p>