Adding the internationalization (i18n) component to an Angular application

Adding the internationalization (i18n) component to an Angular application

Application example built with Angular 15 and adding the internationalization (i18n) component using the @ngx-translate/core library.

Introduction

Angular is a development platform for building WEB, mobile and desktop applications using HTML, CSS and TypeScript (JavaScript). Currently, Angular is at version 15 and Google is the main maintainer of the project.

@ngx-translate is an internationalization (i18n) component library with many configuration options.

Prerequisites

Before you start, you need to install and configure the tools:

Getting started

Create the Angular application

1. Let's create the application with the Angular base structure using the @angular/cli with the route file and the SCSS style format.

ng new angular-internationalization
? Would you like to add Angular routing? Yes
? Which stylesheet format would you like to use? SCSS   [ https://sass-lang.com/documentation/syntax#scss                ]
CREATE angular-internationalization/README.md (1073 bytes)
CREATE angular-internationalization/.editorconfig (274 bytes)
CREATE angular-internationalization/.gitignore (604 bytes)
CREATE angular-internationalization/angular.json (3339 bytes)
CREATE angular-internationalization/package.json (1090 bytes)
CREATE angular-internationalization/tsconfig.json (783 bytes)
CREATE angular-internationalization/.browserslistrc (703 bytes)
CREATE angular-internationalization/karma.conf.js (1445 bytes)
CREATE angular-internationalization/tsconfig.app.json (287 bytes)
CREATE angular-internationalization/tsconfig.spec.json (333 bytes)
CREATE angular-internationalization/src/favicon.ico (948 bytes)
CREATE angular-internationalization/src/index.html (313 bytes)
CREATE angular-internationalization/src/main.ts (372 bytes)
CREATE angular-internationalization/src/polyfills.ts (2820 bytes)
CREATE angular-internationalization/src/styles.scss (80 bytes)
CREATE angular-internationalization/src/test.ts (788 bytes)
CREATE angular-internationalization/src/assets/.gitkeep (0 bytes)
CREATE angular-internationalization/src/environments/environment.prod.ts (51 bytes)
CREATE angular-internationalization/src/environments/environment.ts (658 bytes)
CREATE angular-internationalization/src/app/app-routing.module.ts (245 bytes)
CREATE angular-internationalization/src/app/app.module.ts (393 bytes)
CREATE angular-internationalization/src/app/app.component.scss (0 bytes)
CREATE angular-internationalization/src/app/app.component.html (24617 bytes)
CREATE angular-internationalization/src/app/app.component.spec.ts (1139 bytes)
CREATE angular-internationalization/src/app/app.component.ts (233 bytes)
✔ Packages installed successfully.

2. Install and configure the Bootstrap CSS framework. Do steps 2 and 3 of the post Adding the Bootstrap CSS framework to an Angular application.

3. Install the @ngx-translate/core and @ngx-translate/http-loader libraries.

npm install @ngx-translate/core @ngx-translate/http-loader

4. Import the HttpClient, HttpClientModule, TranslateModule, TranslateLoader and TranslateHttpLoader modules. Change the app.module.ts file and add the lines as below.

import { HttpClient, HttpClientModule } from '@angular/common/http';
import { TranslateModule, TranslateLoader } from '@ngx-translate/core';
import { TranslateHttpLoader } from '@ngx-translate/http-loader';

export function createTranslateLoader(http: HttpClient) {
  return new TranslateHttpLoader(http, './assets/i18n/', '.json');
}

imports: [
  BrowserModule,
  HttpClientModule,
  TranslateModule.forRoot({
    loader: {
      provide: TranslateLoader,
      useFactory: (createTranslateLoader),
      deps: [HttpClient],
    },
    defaultLanguage: 'en-US',
  }),
  AppRoutingModule,
],

5. Create the de-DE.json, en-US.json, es-ES.json, fr-FR.json and pt-BR.json files in the src/assets/i18n folder.

6. Add the content below in the de-DE.json file.

{
  "hello": "Hallo, {{name}}!"
}

7. Add the content below in the en-US.json file.

{
  "hello": "Hello, {{name}}!"
}

8. Add the content below in the es-ES.json file.

{
  "hello": "Hola, {{name}}!"
}

9. Add the content below in the fr-FR.json file.

{
  "hello": "Bonjour, {{name}}!"
}

10. Add the content below in the pt-BR.json file.

{
  "hello": "Olá, {{name}}!"
}

11. Remove the contents of the AppComponent class from the src/app/app.component.ts file. Import the TranslateService service and create the changeLanguage method as below.

import { Component } from '@angular/core';
import { TranslateService } from '@ngx-translate/core';

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

  constructor(public translateService: TranslateService) {
  }

  public changeLanguage(language: string): void {
    this.translateService.use(language);
  }

}

12. Remove the contents of the src/app/app.component.html file. Add the buttons as below.

<div class="container-fluid py-3">
  <h1>Angular Internationalization (i18n)</h1>

  <div class="btn-group btn-group-sm py-5">
    <button type="button" class="btn btn-sm btn-outline-secondary" (click)="changeLanguage('en-US')" [class.active]="translateService.currentLang !== 'pt-BR'">English</button>
    <button type="button" class="btn btn-sm btn-outline-secondary" (click)="changeLanguage('pt-BR')" [class.active]="translateService.currentLang === 'pt-BR'">Português</button>
  </div>

  <h3>{{ "hello" | translate: { name: "Angular" } }}</h3>
</div>

13. Run the application with the command below.

npm start

> angular-internationalization@1.0.0 start
> ng serve

✔ Browser application bundle generation complete.

Initial Chunk Files | Names         |      Size
vendor.js           | vendor        |   2.57 MB
styles.css          | styles        | 266.58 kB
polyfills.js        | polyfills     | 128.54 kB
scripts.js          | scripts       |  76.67 kB
main.js             | main          |  13.03 kB
runtime.js          | runtime       |   6.66 kB

                    | Initial Total |   3.05 MB

Build at: 2021-08-15T20:12:53.818Z - Hash: 9462fdcfd1de35681ab4 - Time: 11933ms

** Angular Live Development Server is listening on localhost:4200, open your browser on http://localhost:4200/ **


✔ Compiled successfully.

14. Ready! Access the URL http://localhost:4200/ and check if the application is working. See the application working on GitHub Pages and Stackblitz.

Angular Internationalization

The application repository is available at https://github.com/rodrigokamada/angular-internationalization.

This tutorial was posted on my blog in portuguese.