HOSN-app/app/src/app/app.component.ts

import { Component, ViewChild } from '@angular/core';
import { Nav, Platform } from 'ionic-angular';
import { StatusBar } from '@ionic-native/status-bar';
import { SplashScreen } from '@ionic-native/splash-screen';

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

import { HomePage } from '../pages/home/home';
import { SearchPage } from '../pages/search/search';
import { SettingsPage } from '../pages/settings/settings';
import { LoginPage } from '../pages/login/login';

@Component({
  templateUrl: 'app.html'
})
export class MyApp {
  @ViewChild(Nav) nav: Nav;

  rootPage: any;

  pages: Array<{ title: string, icon: string, component: any }>;

  constructor(
    platform: Platform,
    statusBar: StatusBar,
    splashScreen: SplashScreen,
    private authProvider: AuthProvider
  ) {
    platform.ready().then(() => {
      // Okay, so the platform is ready and our plugins are available.
      // Here you can do any higher level native things you might need.
      //this.setHomepage();

      statusBar.styleDefault();
      splashScreen.hide();
      authProvider.isLoggedIn().then(isLoggedIn => {
        this.rootPage = isLoggedIn ? HomePage : LoginPage;
      })
    });

    this.pages = [
      { title: 'Home', icon: 'home', component: HomePage },
      { title: 'Search', icon: 'search', component: SearchPage },
      { title: 'Settings', icon: 'settings', component: SettingsPage }
    ];
  }

  openPage(page) {
    // Reset the content nav to have just this page
    // we wouldn't want the back button to show in this scenario
    this.nav.setRoot(page.component);
  }

  logout() {
    this.authProvider.logout();
  }
}