Let's say you have a route that you want to restrict to logged-in users; maybe you have a /profile page that lets your users fill in some information about themselves, but it wouldn't work if they weren't logged in. Open /client/app/profile/profile.js, and add authenticate: true to the options passed to $routeProvider.when like so:
$routeProvider
.when('/profile', {
templateUrl: 'app/profile/profile.html',
controller: 'ProfileCtrl',
authenticate: true // restrict to authenticated users
});This way, if the user isn't authenticated when they try to access the /profile page, they'll be redirected to your login screen to authenticate before continuing to their profile page.