title: Angular 1.5, component router detect unsaved changes and alert
body: <p>When I use angular 1.3, I am used this (<a href="https://stackoverflow.com/questions/14852802/detect-unsaved-changes-and-alert-user-using-angularjs">Detect Unsaved changes and alert user using angularjs</a>) to detect unsaved change and alert to user, everything work fine. But when use angular 1.5 (component router) the value of <code>$ctrl.form.$dirty</code> was destroyed after <code>$locationChangeStart</code> so I can't get this value( before <code>$locationChangeStart</code>, this value show correctly when I debug by show it on the html code)</p>
  
  <p>Anyone have suggestion
  Thank so much!</p>