Sign-in with twitter using angular

Question

I am trying to implement singin functioanlity using angular2 , Read from official documentation also from here , But didn\'t get how the flow is going on. my questions are

Answer 1

If you use AngularFire2, then you can get it done by just one line and that is

logintwitter(){
    this.afAuth.auth.signInWithPopup(new firebase.auth.TwitterAuthProvider());
  }