title: How to handle Firebase auth in single page app
body: <p>I am using firebase simple login auth with angularjs and I want to create a single page app.
  Before this, I have tried using <code>service</code>, <code>main controller</code> to handle it but I don't think it is good enough because I have to call FirebaseAuthClient() every time there is a route.
  I also try to put FirebaseAuthClient() in angularjs .run() which initialize when app is start.
  But it won't work when there is a route, I think it is because not a full page load.</p>
  
  <p>Ok,
  And here is what I want, </p>
  
  <ul>
  <li>except login page, every route (pages) are required login.</li>
  <li>A global FirebaseAuthClient() checking on every route so I don't need to call it again.</li>
  <li>A global <code>user</code> which return from FirebaseAuthClient()</li>
  </ul>