app.component.ts

import { Component } from '@angular/core';
import { SplashScreen } from '@ionic-native/splash-screen/ngx';
import { StatusBar } from '@ionic-native/status-bar/ngx';
import { Events, NavController, Platform } from '@ionic/angular';
import { AmplifyService } from 'aws-amplify-angular';


@Component({
  selector: 'app-root',
  templateUrl: 'app.component.html',
  styleUrls: ['app.component.scss']
})
export class AppComponent {

  constructor(
    private platform: Platform,
    private splashScreen: SplashScreen,
    private statusBar: StatusBar,
    private amplifyService: AmplifyService,
    private navCtrl: NavController,
    private events: Events,
  ) {
    this.initializeApp();
    this.amplifyService.authStateChange$.subscribe(authState => {
      switch (authState.state) {
        case 'signedOut':
          this.navCtrl.navigateRoot('unauthorised')
          this.events.publish('loggedIn', false)
          break;
        case 'signedIn':
          this.events.publish('loggedIn', true)
          this.navCtrl.navigateRoot('authourised')
          breaks
      }
    })
  }

  initializeApp() {
    this.platform.ready().then(() => {
      this.statusBar.styleDefault();
      this.splashScreen.hide(); //Or wait until authState has been determined to hide the splashscreen
    });
  }
}