Ionic 4 JWT Authentication Tutorial: Using Angular HttpClient with Node & Express.js Server

Ionic 4 JWT Authentication Tutorial: Using Angular HttpClient with Node & Express.js Server

Ionic 4 is the latest version of Ionic which is as of this writing in RC. In this tutorial, we'll be learning how to use Ionic 4 and Angular 7 to build a login & registration module for authenticating users.

Originally published  at techiediaries.com on 22 Jan 2019

We'll learn about using Angular modules, services, forms (via FormsModule) and HTTP (via HttpClient) among other features.

We'll learn how to use HttpClient to send POST requests to a back-end authentication server created with Node and Express.js and the BehaviorSubject type of RxJS Observable to track the authentication state.

We'll learn how to use the Ionic Storage module for persisting JWT information returned from our Express.js server such as the access token and the expiration date.

Before your proceed, you need to make sure you have Node.js and NPM installed on your development machine. You should be able to install them by downloading the binaries for your system from the official website.

Now, let's get started!

Setting up Ionic CLI 4

Our first step is installing the Ionic CLI 4. Open your terminal and run this command:

$ npm install -g ionic

This will install the ionic package globally on your system. If you get any permission errors simply use sudobefore your command. If you are in Windows, use a CMD prompt with administrator access.

Creating an Ionic 4 Project

Let's now proceed by creating an Ionic 4 project. Head back to your terminal and run the following command:

$ ionic start ionic-auth-demo blank --type=angular   

We use the --type to specify the type of the framework we want to use with Ionic. Starting with v4, Ionic is only a mobile UI library that can be used on top of Angular, Vue and React or simply plain JavaScript to build hybrid mobile apps or progressive web apps.

We use the blank template for generating a project which comes with one page called home.

A couple of questions will be asked by the CLI such as if you want to install Cordova and if you want to Install the free Ionic Appflow SDK and connect your app?. Answer those questions as you prefer because this won't affect our next steps in this tutorial.

Wait for the dependencies to be installed then navigate in your project's root folder and serve your application using these commands:

$ cd ionic-auth-demo 
$ ionic serve

You can access your mobile application using your web browser from the localhost:8100 address.

Creating an Angular Module

Modules are used to organize your application code. For the authentication feature in our application we'll create a module that encapsulates the service and pages that handle user authentication. In your terminal, run:

$ ionic generate module auth

The src/app/auth/auth.module.ts file will be created with the basic code for a module:

import { NgModule } from '@angular/core';
import { CommonModule } from '@angular/common';

@NgModule({
declarations: [],
imports: [
CommonModule
]
})
export class AuthModule { }

Our auth module only imports the CommonModule which is a built in Angular module that exports all the basic Angular directives and pipes, such as [NgIf](https://angular.io/api/common/NgIf)[NgForOf](https://angular.io/api/common/NgForOf)[DecimalPipe](https://angular.io/api/common/DecimalPipe), and so on.

You need to import the auth module in the root application module of our Ionic 4 application. Open the src/app/app.module.ts file and import AuthModule then add it to the imports array:

import { AuthModule } from  './auth/auth.module';

@NgModule({
declarations: [AppComponent],
entryComponents: [],
imports: [BrowserModule, IonicModule.forRoot(), AppRoutingModule,
AuthModule
],
providers: [
StatusBar,
SplashScreen,
{ provide: RouteReuseStrategy, useClass: IonicRouteStrategy }
],
bootstrap: [AppComponent]
})
export class AppModule {}

Let's import other modules that are necessary for our application such as HttpClient for sending HTTP requests, FormsModule for working with forms and Ionic Storage module for working with local storage in Ionic apps.

Importing HttpClient

HttpClient is the official http client of Angular so we need to import it in our Ionic/Angular project. Open the src/app/auth/auth.module.ts file and import HttpClientModule:

import { NgModule } from '@angular/core';
import { CommonModule } from '@angular/common';
import { HttpClientModule } from '@angular/common/http';

@NgModule({
declarations: [],
imports: [
CommonModule,
HttpClientModule
]
})
export class AuthModule { }

That's all we need to import HttpClient in our authentication module.

Setting up Forms

Angular provides powerful APIs for working with forms either through the template-based forms or reactive forms. In this tutorial, we'll use template-based forms so we need to import FormsModule in our main application module. In the same src/app/auth/auth.module.ts file:

import { NgModule } from '@angular/core';
import { CommonModule } from '@angular/common';
import { HttpClientModule } from '@angular/common/http';
import { FormsModule } from '@angular/forms';

@NgModule({
declarations: [],
imports: [
CommonModule,
HttpClientModule,
FormsModule
]
})
export class AuthModule { }

Setting up Ionic Storage Module

The Ionic team provides the Ionic Storage module that can be used to work with the browser's local storage in mobile devices but before we can use it in our application, we need to install it from npm and import it in our authentication module. Head back to your terminal and run the following command:

$ npm install --save @ionic/storage

As of this writing, ionic/storage v2.2.0 will be installed on your project.

Next, include IonicStorageModule.forRoot() in the imports array:

import { NgModule } from '@angular/core';
import { CommonModule } from '@angular/common';
import { HttpClientModule } from '@angular/common/http';
import { FormsModule } from '@angular/forms';

import { IonicStorageModule } from '@ionic/storage';

@NgModule({
declarations: [],
imports: [
CommonModule,
HttpClientModule,
FormsModule,
IonicStorageModule.forRoot()
]
})
export class AuthModule { }

Creating the Angular Authentication Service

After setting up the necessary modules for our project, let's now create an authentication service that encapsulates communication with the Express server via HttpClient. In your terminal, run:

$ ionic generate interface auth/user

This will generate a user interface in the src/app/auth/user.ts file. Open the file and update it accordingly:

export interface User {
id: number;
name: string;
email: string;
password: string;
}
Note: We prefixed the interface name by auth/ to tell the CLI to generate it inside the auth module.

Also, you need to generate an interface for the server response:

$ ionic generate interface auth/auth-response

Open the src/app/auth/auth-response.ts file and update it accordingly:

export interface AuthResponse {
user: {
id: number,
name: string,
email: string,
access_token: string,
expires_in: number
}
}

This corresponds to the response that will be returned from the authentication server that we'll be creating in the next section with Node and Express.js.

Next, generate the service using:

$ ionic generate service auth/auth

Two src/app/auth/auth.service.ts and src/app/auth/auth.service.spec.ts (tests) files will be generated.

Note: We prefixed the service name by auth/ to tell the CLI to generate it inside the auth module.

Open the src/app/auth/auth.service.ts file and update it by following these steps. First add the necessary imports:

import { Injectable } from  '@angular/core';
import { HttpClient } from '@angular/common/http';
import { tap } from 'rxjs/operators';
import { Observable, BehaviorSubject } from 'rxjs';

import { Storage } from '@ionic/storage';
import { User } from './user';
import { AuthResponse } from './auth-response';

We import:

  • HttpClient for sending POST request to the Express server that handles authentication,
  • The tap() operator for performing side effects when subscribing to the observables returned by the HttpClient methods,
  • The Storage module for persisting the access token and expiration date in the local storage,
  • The ObservableBehaviorSubject APIs for working with asynchronous operations,
  • The User and AuthResponse interfaces.

This is the definition of BehaviorSubject:

One of the variants of Subjects is the BehaviorSubject, which has a notion of "the current value". It stores the latest value emitted to its consumers, and whenever a new Observer subscribes, it will immediately receive the "current value" from the BehaviorSubject.

Next, declare these variables in the service class:

AUTH_SERVER_ADDRESS:  string  =  'http://localhost:3000';
authSubject = new BehaviorSubject(false);

The AUTH_SERVER_ADDRESS holds the address of the Express authentication server and authSubject is a type of Observable that will be used to subscribe to the authentication state.

Next, inject HttpClient and Storage services via the service's constructor:

constructor(private  httpClient:  HttpClient, private  storage:  Storage) { }

Sending a POST Request with HttpClient for Registering Users

Next, add the register() method that will be used for registering users in the Express server:

  register(user: User): Observable<AuthResponse> {
return this.httpClient.post<AuthResponse>(${this.AUTH_SERVER_ADDRESS}/register, user).pipe(
tap(async (res: AuthResponse ) => {

    if (res.user) {
      await this.storage.set("ACCESS_TOKEN", res.user.access_token);
      await this.storage.set("EXPIRES_IN", res.user.expires_in);
      this.authSubject.next(true);
    }
  })

);

}

We simply use the post() method to send a POST request to the /register endpoint exposed by our authentication server that will be running from the localhost:3000/ address. We'll be creating the server with Node and Express.js in the next section.

We use the pipe() function to chain multiple operators. In our case we want to perform a side effect for storing JWT information (the access token and expiration date) in the local storage so we use the tap()operator that's available from RxJS.

In the tap() operator we check if the response has a user object and we set persist the access token and expiration date with the ACCESS_TOKEN and EXPIRES_IN keys. Next, we emit a true value to our authSubject using the next() method.

Sending a POST Request with HttpClient for Authenticating Users

Next, add the login() method that will be used for authenticating users:

  login(user: User): Observable<AuthResponse> {
return this.httpClient.post(${this.AUTH_SERVER_ADDRESS}/login, user).pipe(
tap(async (res: AuthResponse) => {

    if (res.user) {
      await this.storage.set("ACCESS_TOKEN", res.user.access_token);
      await this.storage.set("EXPIRES_IN", res.user.expires_in);
      this.authSubject.next(true);
    }
  })
);

}

We send a POST request with HttpClient to the /login endpoint of our Express.js server that handles JWT authentication. Next, we perform a side effect using the pipe() method and tap() operator available from RxJS for persist the JWT access token and expiration date returned from the server.

Logging out Users

Next, add the logout() method that will be used for removing JWT authentication information from the local storage:

  async logout() {
await this.storage.remove("ACCESS_TOKEN");
await this.storage.remove("EXPIRES_IN");
this.authSubject.next(false);
}

We also emit a false value in the BehaviorSubject representing the authentication state.

Getting the Authentication State

Finally add the isLoggedIn() method that will be used for checking id the user is logged in or not:

  isLoggedIn() {
return this.authSubject.asObservable();
}

We simply return authSubject variable casted to an Observable using the asObservable() method. You can check if the user is logged in by subscribing to call of this method.

Creating Ionic Pages

Now that we've created the service for authenticating users. Let's create the user interface with Ionic 4 UI components.

Check out this second tutorial: Ionic 4 Tutorial: Build a Login & Register UI.

Creating and Running an Express.js Authentication Server

Let's create a authentication server that exposes two /register and /login endpoints using Node.js and Express.js and a bunch of other modules.

First, create a folder for the server code:

$ mkdir express-auth-demo

Navigate in the folder and create a package.json file:

$ npm init -y

Next, install the following dependencies:

$ npm install --save express body-parser sqlite3 bcryptjs jsonwebtoken cors

Next, create an index.js file and add the following code:

"use strict";
const express = require('express');
const bodyParser = require('body-parser');
const cors = require('cors')
const sqlite3 = require('sqlite3').verbose();
const jwt = require('jsonwebtoken');
const bcrypt = require('bcryptjs');

const SECRET_KEY = "secretkey23456";

const app = express();
const router = express.Router();
app.use(cors())

router.use(bodyParser.urlencoded({ extended: false }));
router.use(bodyParser.json());
const database = new sqlite3.Database("./my.db");

const createUsersTable = () => {
const sqlQuery = CREATE TABLE IF NOT EXISTS users ( id integer PRIMARY KEY, name text, email text UNIQUE, password text);

return  database.run(sqlQuery);

}

const findUserByEmail = (email, cb) => {
return database.get(SELECT * FROM users WHERE email = ?,[email], (err, row) => {
cb(err, row)
});
}

const createUser = (user, cb) => {
return database.run('INSERT INTO users (name, email, password) VALUES (?,?,?)',user, (err) => {
cb(err)
});
}

createUsersTable();

router.get('/', (req, res) => {
res.status(200).send('This is an authentication server');
});

router.post('/register', (req, res) => {

const  name  =  req.body.name;
const  email  =  req.body.email;
console.log(req.body);
const  password  =  bcrypt.hashSync(req.body.password);

createUser([name, email, password], (err)=&gt;{
    if(err) return  res.status(500).send("Server error!");
    findUserByEmail(email, (err, user)=&gt;{
        if (err) return  res.status(500).send('Server error!');  
        const  expiresIn  =  24  *  60  *  60;
        const  accessToken  =  jwt.sign({ id:  user.id }, SECRET_KEY, {
            expiresIn:  expiresIn
        });
        res.status(200).send({ "user":  user, "access_token":  accessToken, "expires_in":  expiresIn          
        });
    });
});

});

router.post('/login', (req, res) => {
const email = req.body.email;
const password = req.body.password;
findUserByEmail(email, (err, user)=>{
if (err) return res.status(500).send('Server error!');
if (!user) return res.status(404).send('User not found!');
const result = bcrypt.compareSync(password, user.password);
if(!result) return res.status(401).send('Password not valid!');

    const  expiresIn  =  24  *  60  *  60;
    const  accessToken  =  jwt.sign({ id:  user.id }, SECRET_KEY, {
        expiresIn:  expiresIn
    });
    res.status(200).send({ "user":  user, "access_token":  accessToken, "expires_in":  expiresIn});
});

});

app.use(router);
const port = process.env.PORT || 3000;
const server = app.listen(port, () => {
console.log('Server listening at http://localhost:' + port);
});

For more details about this code, check out Node Express JWT Authentication — jsonwebtoken and bcryptjs.

Next, add a start script in package.json:

"scripts": {
"start": "node index.js"
},

You can now, run your authentication server using:

$ npm start

Your server will be running from http://localhost:3000.

You can use cURL to send POST requests to the authentication endpoints before creating the Ionic 4 UI. First run this command in a new terminal to register a user:

 curl -H "Content-Type: application/json" -d '{"email":"[email protected]","name":"test", "password":"test"}' http://localhost:3000/register

Next, run this command to login the user:

 curl -H "Content-Type: application/json" -d '{"email":"[email protected]", "password":"test"}' http://localhost:3000/login
Conclusion

In this tutorial, we've learned how to implement JWT authentication with Ionic 4, Angular 7 on the front-end and Node and Express.js in the back-end. We've seen how to send POST requests using HttpClient and how to persist values on the local storage using the Ionic Storage module.

Originally published  at techiediaries.com on 22 Jan 2019

==========================================

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☞ Ionic 4 & Angular Tutorial For Beginners - Crash Course

How to Build Mobile Apps with Angular, Ionic 4, and Spring Boot

How to Build Mobile Apps with Angular, Ionic 4, and Spring Boot

Run Your Ionic App on Android. Make sure you're using Java 8. Run ionic cordova prepare android. Open platforms/android in Android Studio, upgrade Gradle if prompted. Set launchMode to singleTask in AndroidManifest.xml. Start your app using Android Studio...

In this brief tutorial, I’ll show you to use Ionic for JHipster v4 with Spring Boot and JHipster 6.

To complete this tutorial, you’ll need to have Java 8+, Node.js 10+, and Docker installed. You’ll also need to create an Okta developer account.

Create a Spring Boot + Angular App with JHipster

You can install JHipster via Homebrew (brew install jhipster) or with npm.

npm i -g [email protected]

Once you have JHipster installed, you have two choices. There’s the quick way to generate an app (which I recommend), and there’s the tedious way of picking all your options. I don’t care which one you use, but you must select OAuth 2.0 / OIDCauthentication to complete this tutorial successfully.

Here’s the easy way:

mkdir app && cd app

echo "application { config { baseName oauth2, authenticationType oauth2, \
  buildTool gradle, testFrameworks [protractor] }}" >> app.jh

jhipster import-jdl app.jh

The hard way is you run jhipster and answer a number of questions. There are so many choices when you run this option that you might question your sanity. At last count, I remember reading that JHipster allows 26K+ combinations!

The project generation process will take a couple of minutes to complete if you’re on fast internet and have a bad-ass laptop. When it’s finished, you should see output like the following.

OIDC with Keycloak and Spring Security

JHipster has several authentication options: JWT, OAuth 2.0 / OIDC, and UAA. With JWT (the default), you store the access token on the client (in local storage). This works but isn’t the most secure. UAA involves using your own OAuth 2.0 authorization server (powered by Spring Security), and OAuth 2.0 / OIDC allows you to use Keycloak or Okta.

Spring Security makes Keycloak and Okta integration so incredibly easy it’s silly. Keycloak and Okta are called "identity providers" and if you have a similar solution that is OIDC-compliant, I’m confident it’ll work with Spring Security and JHipster.

Having Keycloak set by default is nice because you can use it without having an internet connection.

To log into the JHipster app you just created, you’ll need to have Keycloak up and running. When you create a JHipster project with OIDC for authentication, it creates a Docker container definition that has the default users and roles. Start Keycloak using the following command.

docker-compose -f src/main/docker/keycloak.yml up -d

Start your application with ./gradlew (or ./mvnw if you chose Maven) and you should be able to log in using "admin/admin" for your credentials.

Open another terminal and prove all the end-to-end tests pass:

npm run e2e

If your environment is setup correctly, you’ll see output like the following:

> [email protected] e2e /Users/mraible/app
> protractor src/test/javascript/protractor.conf.js

[16:02:18] W/configParser - pattern ./e2e/entities/**/*.spec.ts did not match any files.
[16:02:18] I/launcher - Running 1 instances of WebDriver
[16:02:18] I/direct - Using ChromeDriver directly...


  account
    ✓ should fail to login with bad password
    ✓ should login successfully with admin account (1754ms)

  administration
    ✓ should load metrics
    ✓ should load health
    ✓ should load configuration
    ✓ should load audits
    ✓ should load logs


  7 passing (15s)

[16:02:36] I/launcher - 0 instance(s) of WebDriver still running
[16:02:36] I/launcher - chrome #01 passed
Execution time: 19 s.

OIDC with Okta and Spring Security

To switch to Okta, you’ll first need to create an OIDC app. If you don’t have an Okta Developer account, now is the time!

Log in to your Okta Developer account.

  • In the top menu, click on Applications
  • Click on Add Application
  • Select Web and click Next
  • Enter JHipster FTW! for the Name (this value doesn’t matter, so feel free to change it)
  • Change the Login redirect URI to be <a href="http://localhost:8080/login/oauth2/code/oidc" target="_blank">http://localhost:8080/login/oauth2/code/oidc</a>
  • Click Done, then Edit and add <a href="http://localhost:8080" target="_blank">http://localhost:8080</a> as a Logout redirect URI
  • Click Save

These are the steps you’ll need to complete for JHipster. Start your JHipster app using a command like the following:

SPRING_SECURITY_OAUTH2_CLIENT_PROVIDER_OIDC_ISSUER_URI=https://{yourOktaDomain}/oauth2/default \
  SPRING_SECURITY_OAUTH2_CLIENT_REGISTRATION_OIDC_CLIENT_ID=$clientId \
  SPRING_SECURITY_OAUTH2_CLIENT_REGISTRATION_OIDC_CLIENT_SECRET=$clientSecret ./gradlew

Create a Native App for Ionic

You’ll also need to create a Native app for Ionic. The reason for this is because Ionic for JHipster is configured to use PKCE(Proof Key for Code Exchange). The current Spring Security OIDC support in JHipster still requires a client secret. PKCE does not.

Go back to the Okta developer console and follow the steps below:

  • In the top menu, click on Applications
  • Click on Add Application
  • Select Native and click Next
  • Enter Ionic FTW! for the Name
  • Add Login redirect URIs: <a href="http://localhost:8100/implicit/callback" target="_blank">http://localhost:8100/implicit/callback</a> and dev.localhost.ionic:/callback
  • Click Done, then Edit and add Logout redirect URIs: <a href="http://localhost:8100/implicit/logout" target="_blank">http://localhost:8100/implicit/logout</a> and dev.localhost.ionic:/logout
  • Click Save

You’ll need the client ID from your Native app, so keep your browser tab open or copy/paste it somewhere.

Create Groups and Add Them as Claims to the ID Token

In order to login to your JHipster app, you’ll need to adjust your Okta authorization server to include a groups claim.

On Okta, navigate to Users > Groups. Create ROLE_ADMIN and ROLE_USER groups and add your account to them.

Navigate to API > Authorization Servers, click the Authorization Servers tab and edit the default one. Click the Claims tab and Add Claim. Name it "groups" or "roles" and include it in the ID Token. Set the value type to "Groups" and set the filter to be a Regex of .*. Click Create.

Navigate to <a href="http://localhost:8080" target="_blank">http://localhost:8080</a>, click sign in and you’ll be redirected to Okta to log in.

Enter the credentials you used to signup for your account, and you should be redirected back to your JHipster app.

Generate Entities for a Photo Gallery

Let’s enhance this example a bit and create a photo gallery that you can upload pictures to. Kinda like Flickr, but waaayyyy more primitive.

JHipster has a JDL (JHipster Domain Language) feature that allows you to model the data in your app, and generate entities from it. You can use its JDL Studio feature to do this online and save it locally once you’ve finished.

I created a data model for this app that has an Album, Photo, and Tag entities and set up relationships between them. Below is a screenshot of what it looks like in JDL Studio.

Copy the JDL below and save it in a photos.jdl file in the root directory of your project.

entity Album {
  title String required,
  description TextBlob,
  created Instant
}

entity Photo {
  title String required,
  description TextBlob,
  image ImageBlob required,
  taken Instant
}

entity Tag {
  name String required minlength(2)
}

relationship ManyToOne {
  Album{user(login)} to User,
  Photo{album(title)} to Album
}

relationship ManyToMany {
  Photo{tag(name)} to Tag{photo}
}

paginate Album with pagination
paginate Photo, Tag with infinite-scroll

You can generate entities and CRUD code (Java for Spring Boot; TypeScript and HTML for Angular) using the following command:

jhipster import-jdl photos.jdl

When prompted, type a to update existing files.

This process will create Liquibase changelog files (to create your database tables), entities, repositories, Spring MVC controllers, and all the Angular code that’s necessary to create, read, update, and delete your data objects. It’ll even generate Jest unit tests and Protractor end-to-end tests!

When the process completes, restart your app, and confirm that all your entities exist (and work) under the Entities menu.

You might notice that the entity list screen is pre-loaded with data. This is done by faker.js. To turn it off, edit src/main/resources/config/application-dev.yml, search for liquibase and set its contexts value to dev. I made this change in this example’s code and ran ./gradlew clean to clear the database.

liquibase:
  # Add 'faker' if you want the sample data to be loaded automatically
  contexts: dev

Develop a Mobile App with Ionic and Angular

Getting started with Ionic for JHipster is similar to JHipster. You simply have to install the Ionic CLI, Yeoman, the module itself, and run a command to create the app.

npm i -g [email protected] [email protected] yo
yo jhipster-ionic

If you have your app application at ~/app, you should run this command from your home directory (~). Ionic for JHipster will prompt you for the location of your backend application. Use mobile for your app’s name and app for the JHipster app’s location.

Type a when prompted to overwrite mobile/src/app/app.component.ts.

Open mobile/src/app/auth/auth.service.ts in an editor, search for data.clientId and replace it with the client ID from your Native app on Okta.

// try to get the oauth settings from the server
this.requestor.xhr({method: 'GET', url: AUTH_CONFIG_URI}).then(async (data: any) => {
  this.authConfig = {
    identity_client: '{yourClientId}',
    identity_server: data.issuer,
    redirect_url: redirectUri,
    end_session_redirect_url: logoutRedirectUri,
    scopes,
    usePkce: true
  };
  ...
}

When using Keycloak, this change is not necessary.### Add Claims to Access Token

In order to authentication successfully with your Ionic app, you have to do a bit more configuration in Okta. Since the Ionic client will only send an access token to JHipster, you need to 1) add a groups claim to the access token and 2) add a couple more claims so the user’s name will be available in JHipster.

Navigate to API > Authorization Servers, click the Authorization Servers tab and edit the default one. Click the Claims tab and Add Claim. Name it "groups" and include it in the Access Token. Set the value type to "Groups" and set the filter to be a Regex of .*. Click Create.

Add another claim, name it given_name, include it in the access token, use Expression in the value type, and set the value to user.firstName. Optionally, include it in the profile scope. Perform the same actions to create a family_name claim and use expression user.lastName.

When you are finished, your claims should look as follows.

Run the following commands to start your Ionic app.

cd mobile
ionic serve

You’ll see a screen with a sign-in button. Click on it, and you’ll be redirected to Okta to authenticate.

Now that you having log in working, you can use the entity generator to generate Ionic pages for your data model. Run the following commands (in your ~/mobile directory) to generate screens for your entities.

yo jhipster-ionic:entity album

When prompted to generate this entity from an existing one, type Y. Enter ../app as the path to your existing application. When prompted to regenerate entities and overwrite files, type Y. Enter a when asked about conflicting files.

Go back to your browser where your Ionic app is running (or restart it if you stopped it). Click on Entities on the bottom, then Albums. Click the blue + icon in the bottom corner, and add a new album.

Click the ✔️ in the top right corner to save your album. You’ll see a success message and it listed on the next screen.

Refresh your JHipster app’s album list and you’ll see it there too!

Generate code for the other entities using the following commands and the same answers as above.

yo jhipster-ionic:entity photo
yo jhipster-ionic:entity tag

Run Your Ionic App on iOS

To generate an iOS project for your Ionic application, run the following command:

ionic cordova prepare ios

When prompted to install the ios platform, type Y. When the process completes, open your project in Xcode:

open platforms/ios/MyApp.xcworkspace

You’ll need to configure code signing in the General tab, then you should be able to run your app in Simulator.

Log in to your Ionic app, tap Entities and view the list of photos.

Add a photo in the JHipster app at <a href="http://localhost:8080" target="_blank">http://localhost:8080</a>.

To see this new album in your Ionic app, pull down with your mouse to simulate the pull-to-refresh gesture on a phone. Looky there - it works!

There are some gestures you should know about on this screen. Clicking on the row will take you to a view screen where you can see the photo’s details. You can also swipe left to expose edit and delete buttons.

Run Your Ionic App on Android

Deploying your app on Android is very similar to iOS. In short:

  1. Make sure you’re using Java 8
  2. Run ionic cordova prepare android
  3. Open platforms/android in Android Studio, upgrade Gradle if prompted
  4. Set launchMode to singleTask in AndroidManifest.xml
  5. Start your app using Android Studio
  6. While your app is starting, run adb reverse tcp:8080 tcp:8080 so the emulator can talk to JHipster
Learn More About Ionic 4 and JHipster 6

Ionic is a nice way to leverage your web development skills to build mobile apps. You can do most of your development in the browser, and deploy to your device when you’re ready to test it. You can also just deploy your app as a PWA and not both to deploy it to an app store.

JHipster supports PWAs too, but I think Ionic apps look like native apps, which is a nice effect. There’s a lot more I could cover about JHipster and Ionic, but this should be enough to get you started.

You can find the source code for the application developed in this post on GitHub at @oktadeveloper/okta-ionic4-jhipster-example.

Thank you for reading!

Angular with ionic 4 required

Please provide me angular and ionic 4 tutorials with some examples.

Please provide me angular and ionic 4 tutorials with some examples.


Thank you.

Ionic 4/Angular Modals - Tutorial

Ionic 4/Angular Modals - Tutorial

In this tutorial, we are going to see how to use modals in Ionic 4/Angular apps by creating a simple demo app so let's get started!

First of all, We need to mention that we are using the Ionic CLI 4 so if you didn't yet upgrade to this release make sure to use the equivalent commands for Ionic CLI prior versions.

Generating a New Ionic 4/Angular Project

Before implementing our modal example, let's first generate a brand new Ionic 4 project based on Angular.

Go ahead and open your terminal window then type the following command:

ionic start ionic-modals blank --type=angular

Next, navigate inside your project directory and serve your app using the following command:

cd ionic-modals
ionic serve 

You should be able to visit your app by going to the http://localhost:8100 address.

Importing and using ModalController

Open src/pages/home/home.ts then import ModalController from ionic-angular:

import { ModalController } from 'ionic-angular';

Next we need to inject via component constructor:

@Component({
selector: 'page-home',
templateUrl: 'home.html'
})
export class HomePage {
constructor(public navCtrl: NavController,public modalCtrl : ModalController) {

}

}

Opening a Modal Page

The next step is to add the openModal() method to the HomePage component and bind it to a button on the home.html file:

public openModal(){

}

<button ion-button (click)="openModal()">Open Modal</button>

Before adding an implementation for the openModal() method, let's first add a new page to be used by our modal.

Head to your terminal inside your project folder and run the following command:

ionic g page ModalPage

Then in the home.ts file, use the create() method of ModalController to create a modal and then show it:

public openModal(){ var modalPage = this.modalCtrl.create('ModalPage'); modalPage.present(); }

Now if you click on open modal button you should be able to see a modal page popups.

Closing the Modal Page

We have added a method for opening a modal, now let's add a method to close the modal page once it is opened.

Open the src/pages/modal/modal.tsthen add thecloseModal()method to theModalPage` component:

public closeModal(){

}

Then open the src/pages/modal/modal.html file and add a button to close the modal:

<ion-header>

<ion-navbar>
<ion-title>ModalPage</ion-title>
<ion-buttons end>
<button ion-button (click)="closeModal()">Close</button>
</ion-buttons>
</ion-navbar>

</ion-header>

<ion-content padding>

</ion-content>

Now let's implement the closeModal() method.

First we need to import ViewController from the ionic-angular package:

import { ViewController } from 'ionic-angular';

Inject ViewController via component constructor:

export class ModalPage {

constructor(public viewCtrl : ViewController ) {
}

Next, use the dismiss() method to close the modal:

export class ModalPage {

constructor(public navCtrl: NavController, public viewCtrl : ViewController ,public navParams: NavParams) {
}
public closeModal(){
this.viewCtrl.dismiss();
}

}

Passing Data to Modal Page Component

You can also pass some data to a modal page component using the second parameter of the create() method. Passed data can be of any type: string , number or object.

Go ahead, change the openModal() method to pass some data object:

public openModal(){
var data = { message : 'hello world' };
var modalPage = this.modalCtrl.create('ModalPage',data);
modalPage.present();
}

Now let's get the passed parameters using NavParams:

@IonicPage()
@Component({
selector: 'page-modal',
templateUrl: 'modal.html',
})
export class ModalPage {

constructor(public navCtrl: NavController, public viewCtrl : ViewController ,public navParams: NavParams) {
}
public closeModal(){
this.viewCtrl.dismiss();
}
ionViewDidLoad() {
console.log('ionViewDidLoad ModalPage');
console.log(this.navParams.get('message'));
}

}

Conclusion

This is the end of this tutorial. We have seen how to use modals in Ionic 4/Angular.

Originally published  at  techiediaries.com on 01 Aug 2019

==========================================

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