If user already logged in then re-direct navigate on Home page

import { AuthProvider } from '../providers/auth/auth';
import { AngularFireAuth } from 'angularfire2/auth';

@Component({
  templateUrl: 'app.html'
})
export class MyApp {
  rootPage:any = ' ' ;

  constructor(public afAuth : AngularFireAuth, public auth : AuthProvider, public platform: Platform, public statusBar: StatusBar, splashScreen: SplashScreen) {
    platform.ready().then(() => {
     this.statusBar.backgroundColorByHexString('#024e44');
      splashScreen.hide();
    });
    this.afAuth.authState
    .subscribe(
      user => {
        if (user) {
          this.rootPage = TabsPage;
        } else {
          this.rootPage = LoginPage;
        }
      },
      () => {
        this.rootPage = LoginPage;
      }
    );
  }
}