title: Using Angular2, how to redirect to previous url before login redirect
body: <p>Using Angular2 to create a single page app, I'm intercepting unauthenticated user access to non-public routes in a custom <code>RouterOutlet</code> and redirecting them to a login view.  After a successful login, I want to redirect the user to their originally requested view, rather than the default view.</p>
  
  <p>I've noticed that <code>Router</code> has a <code>renavigate()</code> function that navigates to the last successful route BUT the last successful route was <code>/auth/login</code> and not the originally requested url.</p>
  
  <p><em>Basically : How can I access, or determine the previously requested url?</em></p>
  
  <p>I don't really want to resort to passing query string parameters around, unless I really have to.  Ideally it would be nice to have access to <code>history</code> collection as part of the <code>Router</code> component, similar to <code>backbone.history</code>!</p>