loopback protected routes/ensure login - express

Question

How do I ensure that a user is logged in before I render a view using loopback?
I can loggin in the front end using my angular app. But I wanted to block anonymous users from viewing the page.
I thought it would be a header, something like headers.authorization_token, but it does not seem to be there.
I am looking for something like connect-ensurelogin for passport, without having to use passport.

Answer 1

This is the $interceptor that solves your problem.
This code detects 401 responses (user not logged in or the access token is expired) from Loopback REST server and redirect the user to the login page:
// Inside app config block
$httpProvider.interceptors.push(function($q, $location) {
return {
responseError: function(rejection) {
if (rejection.status == 401) {
$location.nextAfterLogin = $location.path();
$location.path('/login');
}
return $q.reject(rejection);
}
};
});
And this code will redirect to the requested page once the user is logged in
// In the Login controller
User.login($scope.credentials, function() {
var next = $location.nextAfterLogin || '/';
$location.nextAfterLogin = null;
$location.path(next);
});

Answer 2

Here is one possible approach that has worked for me (details may vary):
Design each of the Pages in your Single Page Angular App to make at one of your REST API calls when the Angular Route is resolved.
Secure all of your REST API Routes using the AccessToken/User/Role/ACL scheme that LoopBack provides.
When no valid Access Token is detected on the REST Server side, pass back a 401 Unauthorized Error.
On the Client Side Data Access, when you detect a 401 on your REST Call, redirect to your Logic Route.
For the smoothest User Experience, whenever you redirect to Login, store the Route the User wanted to access globally
(localStore, $RootScope, etc.) and redirect back there when the User
Logs in and gets a valid Access Token.
Here is the LoopBack Access Control sample: https://github.com/strongloop/loopback-example-access-control