A comprehensive step by step tutorial on how to build app authentication using Ionic 2 and REST API. We already create a tutorial for email and password authentication using Ionic 2 and Firebase, right now we will implementing authentication using our own REST API server. In other words, this tutorial is Ionic REST API login and register.

Create New Ionic 2 App

As usual, we always start the tutorial from scratch. It means starting with a new and fresh app. Open terminal or cmd then go to your projects folder. Type this command for creating new Ionic 2 app or project.

ionic start Ionic2RestAuth --v2

That command will create a new project with the name 'Ionic2RestAuth' with Ionic version 2 and default Tabs view. Go to the newly created project folder then run the app to make sure everything still on the path.

cd Ionic2RestAuth
ionic serve --lab

It should automatically open and run in the browser. If you see the app view like below that means we ready to move on.

Ionic 2 Rest API Authentication - Ionic 2 Home Page

Create Ionic Provider or Service

Now, create a provider or service for accessing REST API. Type this command to create the new provider. Before doing that, stop the app by pressing Command+C on OS X or ctrl+c in Windows.

ionic g provider AuthService

Next, we will add function for calling login, register and log out REST API. For that, Open and edit file src/providers/auth-service.ts. Replace all codes with these codes.

import { Injectable } from '@angular/core';
import { Http, Headers } from '@angular/http';
import 'rxjs/add/operator/map';

let apiUrl = 'http://localhost:8080/api/';

@Injectable()
export class AuthService {

  constructor(public http: Http) {}

  login(credentials) {
    return new Promise((resolve, reject) => {
        let headers = new Headers();
        headers.append('Content-Type', 'application/json');

        this.http.post(apiUrl+'login', JSON.stringify(credentials), {headers: headers})
          .subscribe(res => {
            resolve(res.json());
          }, (err) => {
            reject(err);
          });
    });
  }

  register(data) {
    return new Promise((resolve, reject) => {
        let headers = new Headers();
        headers.append('Content-Type', 'application/json');

        this.http.post(apiUrl+'guest/signup', JSON.stringify(data), {headers: headers})
          .subscribe(res => {
            resolve(res.json());
          }, (err) => {
            reject(err);
          });
    });
  }

  logout(){
    return new Promise((resolve, reject) => {
        let headers = new Headers();
        headers.append('X-Auth-Token', localStorage.getItem('token'));

        this.http.post(apiUrl+'logout', {}, {headers: headers})
          .subscribe(res => {
            localStorage.clear();
          }, (err) => {
            reject(err);
          });
    });
  }

}

You can change 'apiUrl' constant with your REST API URL.

Now, add this provider or service to src/app/app.module.ts in import and @NgModule providers.

import { AuthService } from '../providers/auth-service';

providers: [{provide: ErrorHandler, useClass: IonicErrorHandler}, AuthService]

Now, we will be creating a login page which contains view, controller, and stylesheet. Type this command to create the new page.

ionic g page Login
ionic g page Register

import { LoginPage } from '../pages/login/login';
import { RegisterPage } from '../pages/register/register';

Declare LoginPage in @NgModule declaration and components.

@NgModule({
  declarations: [
    MyApp,
    AboutPage,
    ContactPage,
    HomePage,
    TabsPage,
    LoginPage,
    RegisterPage
  ],
  imports: [
    IonicModule.forRoot(MyApp)
  ],
  bootstrap: [IonicApp],
  entryComponents: [
    MyApp,
    AboutPage,
    ContactPage,
    HomePage,
    TabsPage,
    LoginPage,
    RegisterPage
  ],
  providers: [{provide: ErrorHandler, useClass: IonicErrorHandler}, AuthService]
})

Open and edit src/pages/login/login.ts then replace all codes with this.

import { Component } from '@angular/core';
import { NavController, LoadingController, ToastController } from 'ionic-angular';
import { AuthService } from '../../providers/auth-service';
import { TabsPage } from '../tabs/tabs';
import { RegisterPage } from '../register/register';

@Component({
  selector: 'page-login',
  templateUrl: 'login.html'
})
export class LoginPage {

  loading: any;
  loginData = { username:'', password:'' };
  data: any;

  constructor(public navCtrl: NavController, public authService: AuthService, public loadingCtrl: LoadingController, private toastCtrl: ToastController) {}

  doLogin() {
    this.showLoader();
    this.authService.login(this.loginData).then((result) => {
      this.loading.dismiss();
      this.data = result;
      localStorage.setItem('token', this.data.access_token);
      this.navCtrl.setRoot(TabsPage);
    }, (err) => {
      this.loading.dismiss();
      this.presentToast(err);
    });
  }

  register() {
    this.navCtrl.push(RegisterPage);
  }

  showLoader(){
    this.loading = this.loadingCtrl.create({
        content: 'Authenticating...'
    });

    this.loading.present();
  }

  presentToast(msg) {
    let toast = this.toastCtrl.create({
      message: msg,
      duration: 3000,
      position: 'bottom',
      dismissOnPageChange: true
    });

    toast.onDidDismiss(() => {
      console.log('Dismissed toast');
    });

    toast.present();
  }

}

That code adds built-in Ionic 2 module they are LoadingController and ToastController. There is an initial model for hold username and password in the login form. Login function calls AuthService then after successful response token saved in local storage.

Next, add HTML tags to the login view. Open and edit pages/login/login.html then replace all tags with this.

<ion-content padding>
  <h2>Please, Login</h2>
  <form (submit)="doLogin()">
    <ion-item>
      <ion-label stacked>Username</ion-label>
      <ion-input [(ngModel)]="loginData.username" name="username" type="text" placeholder="Username" ></ion-input>
    </ion-item>
    <ion-item>
      <ion-label stacked>Password</ion-label>
      <ion-input [(ngModel)]="loginData.password" name="password" type="password" placeholder="Password"></ion-input>
    </ion-item>
    <button ion-button block type="submit">
      Login
    </button>
  </form>

  <button ion-button block clear (click)="register()">
    No have an account? Register Now
  </button>
</ion-content>

Next, we have to add the register function. Open and edit pages/register/register.ts then replace all with this codes.

import { Component } from '@angular/core';
import { NavController, NavParams, LoadingController, ToastController } from 'ionic-angular';
import { AuthService } from '../../providers/auth-service';

@Component({
  selector: 'page-register',
  templateUrl: 'register.html'
})
export class RegisterPage {

  loading: any;
  regData = { username:'', password:'' };

  constructor(public navCtrl: NavController, public navParams: NavParams, public authService: AuthService, public loadingCtrl: LoadingController, private toastCtrl: ToastController) {}

  doSignup() {
    this.showLoader();
    this.authService.register(this.regData).then((result) => {
      this.loading.dismiss();
      this.navCtrl.pop();
    }, (err) => {
      this.loading.dismiss();
      this.presentToast(err);
    });
  }

  showLoader(){
    this.loading = this.loadingCtrl.create({
        content: 'Authenticating...'
    });

    this.loading.present();
  }

  presentToast(msg) {
    let toast = this.toastCtrl.create({
      message: msg,
      duration: 3000,
      position: 'bottom',
      dismissOnPageChange: true
    });

    toast.onDidDismiss(() => {
      console.log('Dismissed toast');
    });

    toast.present();
  }

}

Now, open and edit pages/register/register.html then replace all HTML tags with these tags.

<ion-content padding>
  <h2>Register Here</h2>
  <form (submit)="doSignup()">
    <ion-item>
      <ion-label stacked>Username</ion-label>
      <ion-input [(ngModel)]="regData.username" name="username" type="text" placeholder="Your username" ></ion-input>
    </ion-item>
    <ion-item>
      <ion-label stacked>Password</ion-label>
      <ion-input [(ngModel)]="regData.password" name="password" type="password" placeholder="Your password"></ion-input>
    </ion-item>
    <button ion-button block type="submit">
      SignUp
    </button>
  </form>
</ion-content>

Add Ionic Logout and Token Checker

The last thing to complete this tutorial is adding logout function that will put in Home Page and also create a token checker to check if there is no token, the app will redirect to Login Page. Open and edit pages/tabs/tabs.ts then replace all with this codes.

import { Component } from '@angular/core';
import { NavController } from 'ionic-angular';
import { HomePage } from '../home/home';
import { AboutPage } from '../about/about';
import { ContactPage } from '../contact/contact';
import { LoginPage } from '../login/login';

@Component({
  templateUrl: 'tabs.html'
})
export class TabsPage {
  // this tells the tabs component which Pages
  // should be each tab's root Page
  tab1Root: any = HomePage;
  tab2Root: any = AboutPage;
  tab3Root: any = ContactPage;

  constructor(public navCtrl: NavController) {
    if(!localStorage.getItem("token")) {
      navCtrl.setRoot(LoginPage);
    }
  }
}

Next, open and edit pages/home/home.ts and replace all codes with this.

import { Component } from '@angular/core';
import { AuthService } from '../../providers/auth-service';
import { NavController, App, LoadingController, ToastController } from 'ionic-angular';
import { LoginPage } from '../login/login';

@Component({
  selector: 'page-home',
  templateUrl: 'home.html'
})
export class HomePage {

  loading: any;
  isLoggedIn: boolean = false;

  constructor(public app: App, public navCtrl: NavController, public authService: AuthService, public loadingCtrl: LoadingController, private toastCtrl: ToastController) {
    if(localStorage.getItem("token")) {
      this.isLoggedIn = true;
    }
  }

  logout() {
    this.authService.logout().then((result) => {
      this.loading.dismiss();
      let nav = this.app.getRootNav();
      nav.setRoot(LoginPage);
    }, (err) => {
      this.loading.dismiss();
      this.presentToast(err);
    });
  }

  showLoader(){
    this.loading = this.loadingCtrl.create({
        content: 'Authenticating...'
    });

    this.loading.present();
  }

  presentToast(msg) {
    let toast = this.toastCtrl.create({
      message: msg,
      duration: 3000,
      position: 'bottom',
      dismissOnPageChange: true
    });

    toast.onDidDismiss(() => {
      console.log('Dismissed toast');
    });

    toast.present();
  }

}

The last, add the log out button to Home Page by adding these tags in nav section.

<ion-header>
  <ion-navbar>
    <button ion-button clear (click)="logout()">
      <ion-icon name="log-out"></ion-icon>
    </button>
    <ion-title>Home</ion-title>
  </ion-navbar>
</ion-header>

Finally, run your app.

ionic serve --lab

It will automatically open the browser. Now, you can test all the functionality of the app that we have been created.

Ionic 2 Rest Api Authentication - Page Views

If you found any problem with this tutorial. Please, feel free to fill the comment below.

Full source code can find on our GitHub.

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Thanks.

Endpoint	Request	Response
/login	{ username: '',password: '' }	auth_token
/logout	add a token to headers
/register	{ username: '', password: '' }

Step by step tutorial building Ionic 2 REST API Authentication

Step by step tutorial about how to build app authentication using Ionic 2 and REST API.

Table of Contents:

Create New Ionic 2 App

Create Ionic Provider or Service

Add Ionic Logout and Token Checker

Step by step tutorial building Ionic 2 REST API Authentication

Step by step tutorial about how to build app authentication using Ionic 2 and REST API.

Table of Contents:

Create New Ionic 2 App

Create Ionic Provider or Service

Create Login and Register Page

Add Ionic Logout and Token Checker

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