How to handle case where user is still authenticated they can skip login

Ionic Framework ionic-v3
2

I don’t really like complex interactions with the navigation system, so I avoid all of that with an AuthService that exposes an authNotifier property that is a ReplaySubject<boolean> with stack depth 1. In its constructor, you could do this:

constructor(storage: Storage) {
  storage.ready().then(() => storage.get('jwt'))
  .then((jwt) => {
    this.authNotifier.next(isValid(jwt));
  });
}

In the app component, you can do this:

constructor(auth: AuthService) {
  auth.authNotifier.subscribe((authed) => {
    if (authed) {
      this.rootPage = DashboardPage;
    } else {
      this.rootPage = LoginPage;
    }
  });
}

An additional benefit of this approach is that it makes logout dead easy: inject AuthService from anywhere and call next(false) on its authNotifier. No navigation interaction needed. Wherever you are checking and noticing that the token has expired can do this as well.

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