angular - AngularFire2 4.0 Display user email in Header -

im trying display user email in header component following angularfire 2 version 4.0 upgrade documentation: https://github.com/angular/angularfire2/blob/master/docs/version-4-upgrade.md

header.component

import { component, oninit } '@angular/core'; import { authservice } './auth.service'; import * firebase 'firebase/app'; import { observable } 'rxjs/observable'; import { router } '@angular/router'; import { angularfireauth } 'angularfire2/auth'; import { angularfiredatabase, firebaselistobservable,firebaseobjectobservable } 'angularfire2/database';  @component({   selector: 'app-header',   templateurl: './header.component.html',   styleurls: ['./header.component.css'] }) export class headercomponent implements oninit {   user: observable<firebase.user>;   constructor(afauth: angularfireauth) {     this.user = afauth.authstate;   } 

header.html

<div> {{ (user | async)? | json }} </div> 

if object object in html. if remove question mark outside parenthesis, html displays json lot of info, including email. want display email in html, this:

<div> {{ user?.email }} </div> 

my second question have user email in firebase database also. should use firebase auth or firebase database display info? if should use firebase database, how can that?

as always, help!

i stumbled upon problem well. happening user @ moment of evaluation still observable rather result of login. once resolves (|async) email becomes available. in div need put:

{{(user | async)?.email}} 

that's it.

hope helps.