How to get currently logged in auth state/user from angularfire2

Question

I have an ionic2 app and am using Firebase and angularFire2. I'd like to get the current authentication state and current auth object/user from firebase using angularFire2.

Here's what's working so far - I can authenticate the user and subscribe to the FirebaseAuthState to get the facebook user object.

  constructor(platform: Platform, private auth: FirebaseAuth) {

    auth.subscribe((user: FirebaseAuthState) => {
      if (user) {
        // I could store user in localstorage, but I'd like to see an All Firebase solution
        this.rootPage = TabsPage;
      } else {
        this.rootPage = LoginPage;
      }
    });

Now I can just set localstorage here and cache my user object to remember auth state. However, I am curious to see how I can use Firebase only without me implementing my own custom local storage key. I see that Firebase stores a localStorage key of it's own so knows that its logged in.

How can I get the auth object from code? Additionally, I tried the listed example in the AngularFire2 documentation to render the auth state in the template - but that gives me an error.

import {FirebaseAuth} from 'angularfire2';
@Component({
  selector: 'auth-status',
  template: `
    <div *ng-if="auth | async">You are logged in</div>
    <div *ng-if="!(auth | async)">Please log in</div>
  `
})
class App {
  constructor (@Inject(FirebaseAuth) public auth: FirebaseAuth) {}
}

Answer 1

1. Import: import { AngularFireAuth } from 'angularfire2/auth';
2. Inject: constructor(public afAuth: AngularFireAuth) { }

3. Check:

   this.afAuth.authState.subscribe(res => {
     if (res && res.uid) {
       console.log('user is logged in');
     } else {
       console.log('user not logged in');
     }
   });