title: Angular UI Bootstrap - Clear model value when a Typeahead dropdown value is not selected?
body: <p>I'm trying to figure out how to have a UI.Bootstrap Typeahead (<a href="http://angular-ui.github.io/bootstrap/" rel="nofollow">http://angular-ui.github.io/bootstrap/</a>) only set the model value if a selection is made from the dropdown, and clear the field if no selection was made. </p>
  
  <p>If there's a different control out there that does this that would work too.</p>
  
  <p>The Typeahead is selecting an object and if the user just types a few characters and then leaves the field, the model value is set to the string value of the  field. I can obviously test for this case but modifying the scope model value doesn't refresh the form validity. So if I have a required field I also have to set the field's validity to false. </p>
  
  <p>This all seems like a lot of work that someone must have already figured out. Any suggestions?</p>
  
  <p><strong>Edit</strong></p>
  
  <p>Another thought I had was, is it best practice to separate the Typeahead from the scope values that are being submitted back to the server?</p>