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

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');
     }
   });
   

now in order to get the user info, you have to subscribe for getting the auth information. Ex

  constructor(public af: AngularFire) {
    this.af.auth.subscribe(auth => console.log(auth));// user info is inside auth object
  }

auth object will be null if auth state does not exist