How to Create Search Engine-friendly Internationalized Web Apps with Angular Universal and ngx-translate

<em>Originally published on the&nbsp;</em><a href="https://www.twilio.com/blog/create-search-engine-friendly-internationalized-web-apps-angular-universal-ngx-translate" target="_blank"><em>Twilio Blog</em></a>

Originally published on the Twilio Blog

Search Engine Optimization (SEO) is important for many Angular single-page applications (SPAs). You can build SEO-friendly Angular websites with Angular Universal, but how do you make your app SEO-friendly in every language your website supports? Google, Yandex, and Baidu, might request your pages in English, Spanish, Russian, or Chinese: how do you make your server-side rendering return the correct language?

The answer is ngx-translate, the internationalization (i18n) and localization library for Angular. This module makes it easy to use translation files that provide the correct language for both client-side and server-side rendering. This post will show you how to use it.

In this post we will:

  • Create an Angular application with one component, the home page
  • Add server-side rendering for SEO purposes with Angular Universal
  • Set up internationalization in four languages with ngx-translate

To accomplish the tasks in this post you will need to install the following:

Set up the Angular project and run Hello World!

Every Angular project begins with installation and initialization of the packages. Type the following at the command prompt:

ng new angular-universal-i18n --style css --routing false

When the project is initialized, navigate to its directory:

cd angular-universal-i18n

And run the application by typing:

ng serve -o

You should see following output in the console:

** Angular Live Development Server is listening on localhost:4200, open your browser on http://localhost:4200/ ** 
Date: 2018-10-29T08:58:37.685Z
Hash: cb54e4608cfb1115882b
Time: 7682mschunk {main} main.js, main.js.map (main) 10.7 kB [initial] [rendered]
chunk {polyfills} polyfills.js, polyfills.js.map (polyfills) 227 kB [initial] [rendered]
chunk {runtime} runtime.js, runtime.js.map (runtime) 5.22 kB [entry] [rendered]
chunk {styles} styles.js, styles.js.map (styles) 15.9 kB [initial] [rendered]
chunk {vendor} vendor.js, vendor.js.map (vendor) 3.29 MB [initial] [rendered]

The -o flag will open the application in your default browser. (In Chrome version 63 or higher you must set flags to open HTTP links and sites without a valid security certificate, such as localhost). You can navigate manually to the URL provided in the command output.

You should see the following screen in your browser:

Implement server-side rendering with Angular Universal

Now we are ready to add server-side rendering to our application with Angular Universal, a technology that renders web pages on the server so your site’s pages can be quickly and easily read by a search engine crawler. To install it, execute this command:

ng add @ng-toolkit/universal
Verify server-side rendering is working

Check to see if Angular Universal is working correctly by running the app and performing a curl request on it:

npm run build:prod;npm run server

curl http://localhost:8080

If you don’t want to use curl you can open the URL in a browser and inspect the page source. The results, as follows, should be the same:

<!DOCTYPE html><html lang="en"><head>
<meta charset="utf-8">
<title>angular-universal-i18n</title>
<base href="/">

<meta name="viewport" content="width=device-width, initial-scale=1">
<link rel="icon" type="image/x-icon" href="favicon.ico">
<link rel="stylesheet" href="styles.3bb2a9d4949b7dc120a9.css">
<style ng-transition="app-root">
/*# sourceMappingURL=data:application/json;
base64,eyJ2ZXJzaW9uIjozLCJzb3VyY2VzIjpbXSwibmFtZXMiOltdLCJtYXBwaW5ncyI6IiIsImZpbGUiOiJzcmMvYXBwL2FwcC5jb21wb25lbnQuY3NzIn0= */
</style></head>
<body>
<app-root _nghost-sc0="" ng-version="7.0.4"><div _ngcontent-sc0="" style="text-align:center"><h1 _ngcontent-sc0=""> Welcome to angular-universal-i18n! </h1>
...
</div>
<h2 _ngcontent-sc0="">Here are some links to help you start: </h2>
<ul _ngcontent-sc0="">
<li _ngcontent-sc0="">
<h2 _ngcontent-sc0=""><a _ngcontent-sc0="" href="https://on.morioh.net/b0a3f595aa?r=https://angular.io/tutorial" rel="nofollow noopener" target="_blank" rel="noopener" target="_blank">Tour of Heroes</a></h2>
</li>
<li _ngcontent-sc0="">
<h2 _ngcontent-sc0=""><a _ngcontent-sc0="" href="https://on.morioh.net/b0a3f595aa?r=https://github.com/angular/angular-cli/wiki" rel="nofollow noopener" target="_blank" rel="noopener" target="_blank">CLI Documentation</a></h2>
</li><li _ngcontent-sc0="">
<h2 _ngcontent-sc0=""><a _ngcontent-sc0="" href="https://on.morioh.net/b0a3f595aa?r=https://blog.angular.io/" rel="nofollow noopener" target="_blank" rel="noopener" target="_blank">Angular blog</a></h2>
</li></ul></app-root>

<script type="text/javascript" src="runtime.ec2944dd8b20ec099bf3.js"></script><script type="text/javascript" src="polyfills.c6871e56cb80756a5498.js"></script>
<script type="text/javascript" src="main.f27bf40180c4a8476e2e.js"></script>

<script id="app-root-state" type="application/json">{}</script>
</body></html>

If you want to catch up to this step:

git clone https://github.com/maciejtreder/angular-universal-i18n.git
cd angular-universal-i18n
git checkout step1
npm install
ng serve -o
Add internationalization to the app with ngx-translate

Let’s make our application more friendly for users around the world. To achieve that, we are going to add internationalization (i18n) to it with the ngx-translate library. We will provide our website visitors with clickable links they can use to switch between different translations. Those translations will be loaded from .json files for each language by ngx-translate. For each translate key in our app.component.html template a translated value will be injected.

The first step is installation of dependencies:

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

Create the following file structure for the translations:

src/assets/i18n/en.json
src/assets/i18n/es.json
src/assets/i18n/ru.json
src/assets/i18n/zh.json

Place the following key-value pairs in each file. For src/assets/i18n/en.json:

{
"Welcome to": "Welcome to",
"Here are some links to help you start": "Here are some links to help you start"
}

src/assets/i18n/es.json:

{
"Welcome to": "Bienvenido a",
"Here are some links to help you start": "Aquí hay algunos enlaces para ayudarte a comenzar"
}

src/assets/i18n/ru.json:

{
"Welcome to": "Добро пожаловать в",
"Here are some links to help you start": "Вот несколько ссылок, которые помогут вам начать"
}

src/assets/i18n/zh.json:

{
"Welcome to": "欢迎来到",
"Here are some links to help you start": "以下是一些可帮助您入门的链接"
}

We have provided translations in four languages. Now we’ll implement the translation mechanism in our application. Import the ngx-translate module and translations loader by replacing the contents of src/app/app.browser.module.ts with the following code:

import { AppComponent } from './app.component';
import { AppModule } from './app.module';
import { NgModule } from '@angular/core';
import { BrowserModule } from '@angular/platform-browser';
import { HttpClient, HttpClientModule } from '@angular/common/http';
import { TranslateLoader, TranslateModule } from '@ngx-translate/core';
import { TranslateHttpLoader } from '@ngx-translate/http-loader';

export function HttpLoaderFactory(http: HttpClient) {
return new TranslateHttpLoader(http);
}

@NgModule({
bootstrap: [AppComponent],
imports: [
BrowserModule.withServerTransition({appId: 'app-root'}),
AppModule,
HttpClientModule,
TranslateModule.forRoot({
loader: {provide: TranslateLoader, useFactory: HttpLoaderFactory, deps: [HttpClient]}
})
]
})
export class AppBrowserModule {}

What we did here is import HttpClientModule from the @angular/common/http library. We need it to provide an HttpClient, which is injected into the factory method and used for loading translation files using HTTP requests:

export function HttpLoaderFactory(http: HttpClient) {
return new TranslateHttpLoader(http);
}

Finally, we import the TranslateModule and provide our loader into it:

TranslateModule.forRoot({
loader: {provide: TranslateLoader, useFactory: HttpLoaderFactory, deps: [HttpClient]}
})

We also need to import TranslateModule into the src/app/app.module.ts file:

import { NgtUniversalModule } from '@ng-toolkit/universal';
import { CommonModule } from '@angular/common';
import { NgModule } from '@angular/core';

import { AppComponent } from './app.component';
import { TranslateModule } from '@ngx-translate/core';

@NgModule({
declarations: [
AppComponent
],
imports: [
CommonModule,
NgtUniversalModule,
TranslateModule.forChild(),
]
})
export class AppModule { }

Replace the code in the src/app/app.component.html template with the following to provide translation keys and links for switching between languages:

<div style="text-align:center">
<h1>
{{'Welcome to' | translate}} {{ title }}!
</h1>
<div>
<span (click)="switchLanguage('en')">English</span>&nbsp;
<span (click)="switchLanguage('es')">Español</span>&nbsp;
<span (click)="switchLanguage('ru')">Pусский язык</span>&nbsp;
<span (click)="switchLanguage('zh')">中文</span>
</div>

</div>
<h2>{{'Here are some links to help you start' | translate}}: </h2>
<ul>
<li>
<h2><a target="_blank" rel="noopener" href="https://on.morioh.net/b0a3f595aa?r=https://angular.io/tutorial" rel="nofollow noopener" target="_blank">Tour of Heroes</a></h2>
</li>
<li>
<h2><a target="_blank" rel="noopener" href="https://on.morioh.net/b0a3f595aa?r=https://github.com/angular/angular-cli/wiki" rel="nofollow noopener" target="_blank">CLI Documentation</a></h2>
</li>
<li>
<h2><a target="_blank" rel="noopener" href="https://on.morioh.net/b0a3f595aa?r=https://blog.angular.io/" rel="nofollow noopener" target="_blank">Angular blog</a></h2>
</li>
</ul>

The final step in providing internationalization in the browser-side code is to implement the switchLanguage method in our component and provide default translations for the active region. Make following changes in the src/app/app.component.ts:

import { Component, OnInit, Inject, PLATFORM_ID, Optional } from '@angular/core';
import { TranslateService } from '@ngx-translate/core';

@Component({
selector: 'app-root',
templateUrl: './app.component.html',
styleUrls: ['./app.component.css']
})
export class AppComponent implements OnInit {
title = 'angular-universal-i18n';

constructor(private translate: TranslateService) {}

public ngOnInit(): void {
this.setDefaultTranslation();
}

private setDefaultTranslation(): void {
if (['en', 'es', 'zh', 'ru'].indexOf(this.translate.getBrowserLang()) > -1) {
this.translate.setDefaultLang(this.translate.getBrowserLang());
} else {
this.translate.setDefaultLang('en');
}
}

public switchLanguage(lang: string): void {
this.translate.setDefaultLang(lang);
}
}

We got it! Internationalization on the browser side is implemented! Let’s check it out:

ng serve -o

After navigating to http://localhost:4200 and changing the selected language to Español we can see:

If you want to catch up to this step:

git clone https://github.com/maciejtreder/angular-universal-i18n.git
cd angular-universal-i18n
git checkout step2
npm install
ng serve -o
Add server-side internationalization

Check to see if our client-side implementation broke anything on the server side. Start the app in server mode by running the following commands:

npm run build:prod
npm run server

After navigating to http://localhost:8080 we can see that our app is no longer working:

More error information can be seen in the console:

ERROR { Error: StaticInjectorError(AppServerModule)[TranslateService -> TranslateStore]:
StaticInjectorError(Platform: core)[TranslateService -> TranslateStore]:
NullInjectorError: No provider for TranslateStore!
at NullInjector.module.exports.NullInjector.get (/Users/mtreder/angular-universal-i18n/dist/server.js:1361:19)
at resolveToken (/Users/mtreder/angular-universal-i18n/dist/server.js:1598:24)
at tryResolveToken (/Users/mtreder/angular-universal-i18n/dist/server.js:1542:16)
at StaticInjector.module.exports.StaticInjector.get (/Users/mtreder/angular-universal-i18n/dist/server.js:1439:20)
at resolveToken (/Users/mtreder/angular-universal-i18n/dist/server.js:1598:24)
at tryResolveToken (/Users/mtreder/angular-universal-i18n/dist/server.js:1542:16)
at StaticInjector.module.exports.StaticInjector.get (/Users/mtreder/angular-universal-i18n/dist/server.js:1439:20)
at resolveNgModuleDep (/Users/mtreder/angular-universal-i18n/dist/server.js:18300:29)
at _createClass (/Users/mtreder/angular-universal-i18n/dist/server.js:18353:32)
at _createProviderInstance (/Users/mtreder/angular-universal-i18n/dist/server.js:18317:26)
ngTempTokenPath: null,
ngTokenPath: [ 'TranslateService', [Function: TranslateStore] ] }

To fix this issue we need to provide TranslateModule in the server module as well. Make following changes in the src/app/app.server.module.ts:

import { AppComponent } from './app.component';
import { AppModule } from './app.module';
import { NgModule } from '@angular/core';
import { ServerModule, ServerTransferStateModule } from '@angular/platform-server';
import { ModuleMapLoaderModule } from '@nguniversal/module-map-ngfactory-loader';
import { BrowserModule } from '@angular/platform-browser';
import { NoopAnimationsModule } from '@angular/platform-browser/animations';
import { TranslateLoader, TranslateModule } from '@ngx-translate/core';
import { Observable, Observer } from 'rxjs';
import { readFileSync } from 'fs';

export function universalLoader(): TranslateLoader {
return {
getTranslation: (lang: string) => {
return Observable.create((observer: Observer<any>) => {
observer.next(JSON.parse(readFileSync(./dist/browser/assets/i18n/${lang}.json, 'utf8')));
observer.complete();
});
}
} as TranslateLoader;
}

@NgModule({
bootstrap: [AppComponent],
imports: [
BrowserModule.withServerTransition({appId: 'app-root'}),
AppModule,
ServerModule,
NoopAnimationsModule,
ModuleMapLoaderModule,
ServerTransferStateModule,
TranslateModule.forRoot({
loader: {provide: TranslateLoader, useFactory: universalLoader}
})
]
})
export class AppServerModule {}

We also need to make changes in src/app/app.component.ts to implement i18n on the server side. Replace the contents with the following code:

import { Component, OnInit, Inject, PLATFORM_ID, Optional } from '@angular/core';
import { TranslateService } from '@ngx-translate/core';
import { REQUEST } from '@nguniversal/express-engine/tokens';
import { isPlatformBrowser } from '@angular/common';

@Component({
selector: 'app-root',
templateUrl: './app.component.html',
styleUrls: ['./app.component.css']
})
export class AppComponent implements OnInit {
title = 'angular-universal-i18n';

constructor(
private translate: TranslateService,
@Optional()
@Inject(REQUEST) private request: Request,
@Inject(PLATFORM_ID) private platformId: any
) {}

public ngOnInit(): void {
const language = this.getLang();
if (['en', 'es', 'zh', 'ru'].indexOf(language) > -1) {
this.translate.setDefaultLang(language);
} else {
this.translate.setDefaultLang('en');
}
}

public getLang(): string {
let lang: string;
if (isPlatformBrowser(this.platformId)) {
lang = this.translate.getBrowserLang();
} else {
lang = (this.request.headers['accept-language'] || '').substring(0, 2);
}
return lang;
}

public switchLanguage(lang: string): void {
this.translate.setDefaultLang(lang);
}
}

The additional code determines the current language for the user agent by reading the HTTP accept-language header sent by user agent (browser or web crawler) when requesting the page at the URI specified by the user agent. To retrieve this header we need to inject a @REQUEST provided in @nguniversal/express-engine/tokens.

After that we determine if we are executing code on the browser side or server side by using the isPlatformBrowser method together with the @PLATFORM_ID token. If we are on the browser side we set the language in the same way as previously, by retrieving it from the translate service. If we are on the server side we read it from the header with:

lang = (this.request.headers['accept-language'] || '').substring(0, 2);

We also need to make small change in the typescript configuration file, src/tsconfig.app.json:

{
"extends": "../tsconfig.json",
"compilerOptions": {
"outDir": "../out-tsc/app",
"types": ["node"]
},
"exclude": [
"test.ts",
"**/*.spec.ts"
]
}

We added the node value to the types section. We need that because we are using fs to load translation files directly from the file-system when we are performing server-side rendering.

Test server-side internationalization rendering

We are done with translations on the server side. Check it out by running the application and performing a curl request with a customized header. Build and run the app as follows:

npm run build:prod
npm run server

Then make the curl request specifying Russian (ru_RU) as the current user agent language:

curl http://localhost:8080 --header "accept-language: ru_RU"

Alternately, you can inspect the page source in your browser’s developer toolsafter clicking Pусский язык on the home page. Note, however, that using “View page source” will reload the page and show you the English (or your default) language version.

The results should look like this:

<!DOCTYPE html><html lang="en"><head>
<meta charset="utf-8">
<title>angular-universal-i18n</title>
<base href="/">

<meta name="viewport" content="width=device-width, initial-scale=1">
<link rel="icon" type="image/x-icon" href="favicon.ico">
<link rel="stylesheet" href="styles.3bb2a9d4949b7dc120a9.css"><style ng-transition="app-root">
/*# sourceMappingURL=data:application/json;
base64,eyJ2ZXJzaW9uIjozLCJzb3VyY2VzIjpbXSwibmFtZXMiOltdLCJtYXBwaW5ncyI6IiIsImZpbGUiOiJzcmMvYXBwL2FwcC5jb21wb25lbnQuY3NzIn0= */
</style></head>
<body>
<app-root _nghost-sc0="" ng-version="7.0.4"><div _ngcontent-sc0="" style="text-align:center"><h1 _ngcontent-sc0=""> Добро пожаловать в angular-universal-i18n! </h1><div _ngcontent-sc0=""><span _ngcontent-sc0="">English</span>&nbsp; <span _ngcontent-sc0="">Español</span>&nbsp; <span _ngcontent-sc0="">Pусский язык</span>&nbsp; <span _ngcontent-sc0="">中文</span></div></div><h2 _ngcontent-sc0="">Вот несколько ссылок, которые помогут вам начать: </h2><ul _ngcontent-sc0=""><li _ngcontent-sc0=""><h2 _ngcontent-sc0=""><a _ngcontent-sc0="" href="https://angular.io/tutorial" rel="noopener" target="_blank">Tour of Heroes</a></h2></li><li _ngcontent-sc0=""><h2 _ngcontent-sc0=""><a _ngcontent-sc0="" href="https://github.com/angular/angular-cli/wiki" rel="noopener" target="_blank">CLI Documentation</a></h2></li><li _ngcontent-sc0=""><h2 _ngcontent-sc0=""><a _ngcontent-sc0="" href="https://on.morioh.net/b0a3f595aa?r=https://blog.angular.io/" rel="nofollow noopener" target="_blank" rel="noopener" target="_blank">Angular blog</a></h2></li></ul></app-root>
<script type="text/javascript" src="runtime.ec2944dd8b20ec099bf3.js"></script><script type="text/javascript" src="polyfills.c6871e56cb80756a5498.js"></script><script type="text/javascript" src="main.3d5a73b9ae1f4de7b2c1.js"></script>

<script id="app-root-state" type="application/json">{}</script></body></html>

Yay! As we expect, our website is rendered on the server side, and the Russian translations have been applied!

If you want to catch up to this step:

git clone https://github.com/maciejtreder/angular-universal-i18n.git
cd angular-universal-i18n
git checkout step3
npm install
npm run build:prod
npm run server
Summary

Today we covered an important challenge for all mature applications: internationalization. As you can see; you can bring internationalization to server-side rendering, making your application search engine optimized in every language that you support.

If you want to learn more about Angular Universal techniques, check out my post on the Twilio blog: Getting Started with Serverless Angular Universal on AWS Lambda.

The GitHub repository, for the code used in this post can be found here: https://github.com/maciejtreder/angular-universal-i18n

You can also contact me via [email protected]https://www.maciejtreder.com or @maciejtreder (GitHubTwitterLinkedIn).

How to Use Cookies in Angular for Storing user’s Credentials

How to Use Cookies in Angular for Storing user’s Credentials

In this post, I will be explaining about using Cookies in Angular for Storing user’s Credentials

By using cookies we are going to store the user's login data, if the user's credentials are valid, then it will be directed to the Dashboard page.

In this post, I will be explaining about Angular cookies. So what is a cookie? Cookies are like a small package of information that is stored by the user’s browser. Cookies persist across multiple requests and browser sessions that should be set so that they can be a great method for authentication in web applications. Sometimes we will have some queries about which is to be used -- either local storage or cookies? Before that, I like to say that the cookies and local storage serve different purposes.

The local storage can be read on the client-side, whereas the cookies are being read on the server-side. The biggest difference is the data size is about to store, the local storage will give more space to store, whereas the cookie is limited by the size of to store.

As I said above the cookies are used on the server-side whereas the local storage is used on the client-side. The local storage is a way of storing the data in the client’s PC, by saving the key/ value pair in a web browser with no expiration date. We will discuss about using local storage in the next article, so coming to the point, as I said the cookies are a kind of small file that are stored on the user’s browser.

The cookie is a small table which will contain key and data values so, by using this it will be very useful to carry information from one session to another session. Once we are about to store data on the server without using cookies then it will be difficult to retrieve a particular user’s information without a login on each visit to that website.

So far we have seen about the overview of a cookie and the usage of it. Now in this article, I will explain about storing the username and password of a static user in the cookie table. So, I have created two components, namely the login component and dashboard component, and I have set a static username and password in authservice.ts file.

So, when a user logs in to the login form by providing his user’s credentials the authservice checks the input and redirects the user to the dashboard if the user’s credentials are valid. If the user’s credentials are not valid it will alert by throwing enter valid email or password. And if the dashboard page is being accessed by unauthorized usage the page will be redirected to the login page automatically.

Setting up

In order to use cookies in Angular, we need to install the Angular cookie library by using the following npm package manager.

npm install ngx-cookie-service –save

After installing the package manager, we need to import the cookie service in the inside of our modules.

I have used the ng zorro library UI for form design, and you can find more information about ng zorro from the following link. The next step is to design a login form. So, open login.component.html file and replace the following code.

<form fxFill #Login="ngForm" (ngSubmit)="onsubmit()">  
    <div nz-row>  
        <div nz-col nzMd="12" nzXs="24">  
            <hr />  
            <nz-form-item>  
                <nz-input-group>  
                    <div nz-col nzMd="11" nzXs="8">  
                        <nz-input-group nzPrefixIcon="user">  
                            <input type="text" nz-input name="Login_name" placeholder="User Name" id="userName"  
 
#userName="ngModel" [(ngModel)]="Obj.username">  
                            </nz-input-group>  
                            <div *ngIf="Login.submitted && userName.errors" style="color: red">  
                                <div *ngIf="userName.hasError('required')">  
  
Login ID is required  
  
</div>  
                            </div>  
                        </div>  
                    </nz-input-group>  
                </nz-form-item>  
                <nz-form-item>  
                    <div nz-col nzMd="11" nzXs="8">  
                        <nz-input-group nzPrefixIcon="lock">  
                            <input type="password" nz-input name="user_password" placeholder="Password"  
  
id="password" #password="ngModel" [(ngModel)]="Obj.password">  
                            </nz-input-group>  
                            <div *ngIf="Login.submitted && password.errors" style="color: red">  
                                <div *ngIf="password.hasError('required')">  
  
Password is required  
  
</div>  
                            </div>  
                        </div>  
                    </nz-form-item>  
                    <div class="button">  
                        <button nz-button nzType="primary">  
  
submit  
  
</button>  
                    </div>  
                </div>  
            </div>  
        </form>  

Now open login.component.ts file and replace the following code in it.

import {  
    Component,  
    OnInit  
} from '@angular/core';  
import {  
    FormGroup  
} from '@angular/forms';  
import {  
    AuthService,  
    User  
} from '../services/authservice.service';  
import {  
    Router,  
    ActivatedRoute  
} from '@angular/router';  
import {  
    CookieService  
} from 'ngx-cookie-service';  
@Component({  
    selector: 'nz-demo-card-simple',  
    templateUrl: './login.component.html'  
})  
export class LoginComponent implements OnInit {  
    Obj: User;  
    constructor(private srvLogin: AuthService, private router: Router, public activatedRoute: ActivatedRoute, private cookieService: CookieService) {  
        this.Obj = new User();  
    }  
    ngOnInit(): void {}  
    onsubmit(): void {  
        this.cookieService.set('username', this.Obj.username);  
        this.cookieService.set('password', this.Obj.password);  
        console.log(this.cookieService.get('username'));  
        console.log(this.cookieService.get('password'));  
        const a = this.Obj;  
        if (this.srvLogin.checkLogValues(this.Obj)) {  
            this.srvLogin.isloggedin = true;  
            console.log(this.srvLogin.isloggedin);  
            this.router.navigate(['/dashboard']);  
        }  
    }  
}  

The next point is to create an authentication service, we can create a service file by using the syntax.

ng generate service AuthService

The service name which I have given is Authservice and the service will be created and I have provided a default static username and password in service file so that the validation will be executed and redirected to another page (dashboard page) if the user’s credentials are being valid. Open Authservice service.ts file and replace the following code and import it in both service and as well in app-module.ts file.

import {  
    Injectable  
} from '@angular/core';  
import {  
    HttpClient  
} from '@angular/common/http';  
import {  
    CookieService  
} from 'ngx-cookie-service';  
@Injectable({  
    providedIn: 'root'  
})  
export class AuthService {  
    private username = 'vidya';  
    private password = '123456';  
    isloggedin = false;  
    constructor(private http: HttpClient) {}  
    checkLogValues(value: User): boolean {  
        if (this.username === value.username && this.password === value.password) {  
            console.log(this.username);  
            console.log(this.password);  
            // alert('Login valid');  
            return true;  
        } else {  
            alert('please enter valid data');  
            return false;  
        }  
    }  
}  
export class User {  
    username: string;  
    password: string;  
}  

After that create a component named as dashboard and open dashboard.component.html file and replace the following code.

<h3>Hello {{userDisplayName}} you are in Dashboard </h3>  
<div style="text-align:right">  
   <button nz-button nzType="danger" (click)="logout()">Logout</button>  
</div>  

The next step is to open dashboard.component.ts file and replace the following code inside it.

import {  
    Component,  
    OnInit  
} from '@angular/core';  
import {  
    AuthService,  
    User  
} from '../services/authservice.service';  
import {  
    Router,  
    ActivatedRoute  
} from '@angular/router';  
import {  
    CookieService  
} from 'ngx-cookie-service';  
@Component({  
    selector: 'dashboard',  
    templateUrl: './dashboard.component.html'  
})  
export class DashboardComponent implements OnInit {  
    Obj: User;  
    [x: string]: any;  
    userDisplayName = '';  
    password = '';  
    constructor(private srvLogin: AuthService, private router: Router, public activatedRoute: ActivatedRoute, private cookieService: CookieService) {  
        this.Obj = new User();  
        this.userDisplayName = this.cookieService.get('username');  
        this.password = this.cookieService.get('password');  
        this.Obj.username = this.userDisplayName;  
        this.Obj.password = this.password;  
        if (!srvLogin.checkLogValues(this.Obj)) {  
            router.navigate(['/login']);  
        }  
    }  
    ngOnInit(): void {}  
    logout(): void {  
        this.router.navigate(['/login']);  
        this.cookieService.deleteAll();  
    }  
}  

The following next step is to log in to the dashboard by providing the user’s credentials and after the valid login, we can see the user’s name in dashboard as a welcome note by using the user’s login name. So, after entering into the dashboard page open the developer’s tool in the browser and navigate -> Application and select cookies from storage. So, on that, we can see the user name and password have been stored in the cookie table.

So  far we have seen about storing the user’s details in the cookie table and now we can take an overview on clearing the cookies in the cookie table; for that use deleteall() method for clearing the cookies table if  the user is about to click-> logout button.

Conclusion

In this post, we have seen about using cookies in Angular for storing user’s credentials. I hope this article will be useful for you.

Angular Tutorial - Learn Angular from Scratch

Angular Tutorial - Learn Angular from Scratch

Angular Tutorial - Learn Angular from Scratch: This course is for beginners who are curious on how to get started with Angular. In this course you will learn how to download, install and play around with Angular. We teach you the main components of Angular, so that you can get up and running with it asap. You will learn now to start building applications with Angular.

This course is for beginners who are curious on how to get started with Angular. In this course you will learn how to download, install and play around with Angular. We teach you the main components of Angular, so that you can get up and running with it asap. You will learn now to start building applications with Angular.

Learning Angular can be a daunting experience that's why this course was created; to give you an easier learning experience with it.

What am I going to get from this course?

  • You will learn the mayor fundamentals of Angular
  • You will learn how to get up and running with Angular
  • You will learn to create Applications using Angular 5 and beyond

What you'll learn

  • You will learn the mayor fundamentals of Angular
  • You will learn how to get up and running with Angular
  • You will learn to create Applications using Angular 5 and beyond

An Angular Roadmap — The Past, Present, and Future of Angular

An Angular Roadmap — The Past, Present, and Future of Angular

✅Interested in being an Angular developer in 2019? ... blog post it's most likely that you've written some code in javaScript in the past.

Paleolithic JavaScript — SproutCore

In the beginning, there was SproutCore. It was the first comprehensive JavaScript framework aimed at making it easy to build desktop-quality single-page web apps. It’s not that this wasn’t possible before. When Google released Gmail, it showed the world that web apps really could replace complex desktop applications. Google even open-sourced the Closure toolkit — a set of libraries and an optimizing compiler that it used to build Gmail.

The problem was that Google’s Closure tools weren’t very developer-friendly. They relied heavily on Java, which alienated web developers who were used to working with JavaScript, PHP, Ruby, and Python. Gmail was a great demonstration of what was possible, but developing similar applications still felt out of reach for many.

Some courageous developers managed to string together amazing single page apps using a combination of jQuery, duct tape, and hope. While these apps looked amazing to end-users, for the developers working on them, the apps quickly turned into hulking piles of technical debt that made the dev team dread heading to work in the morning.

As a result, a few enterprising developers began to work on frameworks that would bring Gmail-like apps within easy reach of web developers everywhere. SproutCore was the first of these frameworks to take off. It came with a complete set of widgets that made it possible to build complex web applications without even touching HTML or CSS.

This ended up being great for former desktop developers who had been dragged kicking and screaming onto the web. Several more frameworks popped up with similar goals; GWT and Cappuccino were the most prominent. These frameworks even avoided JavaScript by transpiling other languages into JS. Again, this was great for desktop developers. But it left passionate web developers out in the cold and made them feel as though their hard-won HTML, CSS, and JavaScript skills weren’t valuable.

This left an opening for a framework that truly embraced the web, instead of trying to plaster over it and pretend it was something else. A couple of early frameworks (Backbone and Knockout) appeared, and achieved a moderate amount of success. Ember also showed up around this time. It took SproutCore, stripped it down to its bones, and tried to rebuild it into something truly web-friendly. Ember wanted to be the Six Million Dollar Man of the JavaScript world: rebuilt better, stronger, and faster.

None of these frameworks rocketed to popularity. The world was waiting for something better. In 2010, that something better appeared — it was named Angular.

The Golden Age of Angular

Even before Angular version 1.0 had been released, Angular took the front-end development world by storm. Finally, we had an easy-to-use JavaScript framework that treated HTML as a first-class citizen. Developers and designers could now work together to build amazing single-page applications. This came as a relief to designers, who had been annoyed and offended because older frameworks had treated HTML and CSS as tools for barbarians, tools that no civilized developer should have to touch.

The first thing that seemed magical to developers trying Angular for the first time was two-way data binding. Prior to this, most developers had only seen this kind of data binding in desktop frameworks like WPF and Windows Forms. It was great to be able to bind forms and other UI elements to JavaScript model objects. While two-way data binding could cause performance problems when overused, teams that used it judiciously found that Angular enabled them to create complex front-end applications much more quickly than ever before.

Angular proved to be popular for more than just easy binding of data to HTML elements. Angular directives provided an easy way to create reusable HTML + CSS components. Although other JavaScript frameworks provided this before Angular, Angular was the first one that became extremely popular. Reusable components had long been in-use in server-side frameworks. ASP.NET user controls and partial templates in Rails and Django are but a few examples.

Finally, Angular made dependency injection popular in the front-end development world. Dependency injection had long been popular in enterprise applications, which is perhaps why it hadn’t caught on in the JavaScript world. Front-end developers have long been averse to what they see as needlessly complex enterprise software design patterns. This concern isn’t without merit. Have you ever, in the course of writing an application, said to yourself “What I really need here is a “SimpleBeanFactoryAwareAspectInstanceFactory?”

Dependency injection, though, has proven its worth. And Angular made dependency injection easy to use for an audience that hadn’t used it much in the past. Need an HTTP client? Or perhaps you’d like to do some animation? No problem. Angular had built-in services for those. Just ask for them, and Angular would inject them into your components. No need to instantiate anything yourself.

Or perhaps you wanted to use the browser’s window or location objects without making it impossible to unit test your components outside of a browser? Angular had you covered there too, with its built-in $window and $location services. At runtime, you’d get the browser objects you were expecting. And when running unit tests server-side in Node.js, you could pass mock services into your components to ensure they behaved as expected in various scenarios.

If all of this wasn’t enough, Angular also made it simple to register and inject your own services. For developers who were used to binding all their data to the DOM and hoping for the best, this was awesome. If you were writing a new front-end app that called for APIs that would cost your company a lot of money if overused, you’d probably prefer to be able to write tests ahead of time to ensure that your application doesn’t try to do something like calling the Twilio API 800 million times.

So you’d create a Twilio service that gets injected at runtime. At testing time, you’d create a mock service that records the cost of every API call your application is trying to make. You’d write tests that cover common usage scenarios and ensure that these scenarios don’t result in your company receiving a 7-figure bill. Overall, most developers found that Angular directives combined with dependency injection made it possible to write modular, testable front-end applications using tried-and-true software engineering techniques. Many development teams decided that this resulted in a happy state of affairs, and decided to go all-in on Angular.

The Angular Decline? The Rise of React

While things were mostly great in the world of Angular, it wasn’t all sunshine and lollipops. Developers were starting to run into severe performance problems when they tried to bind too many model objects to too many DOM elements. Some applications slowed to a crawl. Direct calls to $digest and other black-magic sorcery started becoming necessary to achieve acceptable performance. Around the same time, a new challenger appeared: React. At first, React didn’t seem to pose too large a danger to Angular. After all, these React weirdos had gone to the trouble of inventing JSX, which looked a lot like a way to mix markup into your code. Hadn’t we gone to a lot of trouble to invent templating languages for the explicit reason of avoiding mixing markup and code?

As it turned out, React’s approach was pretty popular in the front-end development community. It didn’t rocket to popularity, however. Angular was still dominant, and it looked like it would remain that way. Until that is, Angular’s popularity was given a good kick in the teeth from an unexpected source: the Angular team itself.

The Introduction of Angular 2

Angular 2 was first announced at the ng-europe conference in 2014. The Angular team’s plans came as a shock to the Angular community, to say the least. Reaction from Angular developers was swift and negative… and not without reason. Angular 2 would be getting rid of many familiar concepts from Angular 1, introducing a new, incompatible templating language (and oh, by the way) would also be programmed using an entirely new language.

AngularJS

Although both Angular 1 and Angular 2 were called ‘Angular,’ in reality, they were very different frameworks with a few things in common. To help prevent confusion, the Angular team started referring to the old version of Angular as ‘AngularJS’, and the new version as simply ‘Angular.’ This makes intuitive sense since AngularJS was written in JavaScript, and Angular was not. To keep the distinction between the frameworks clear, I’ll be referring to Angular 1 as AngularJS from this point forward.

As a result of all of this, AngularJS developers lost faith in the framework’s future. They threatened to move to a new framework on future projects, and that is precisely what many of them did. React was the biggest beneficiary of the mass exodus from AngularJS.

Although React didn’t do as much as AngularJS, in a way that was positive. If you’re using a view library that doesn’t try to include everything plus the kitchen sink, it’s a lot more difficult for the developers of that library to pull the rug out from under you in the future. In the beginning, using React was a bit of a pain compared to AngularJS. You had to cobble together a patchwork of libraries just to cover the functionality the AngularJS provided out of the box.

Many teams saw this as a good way to reduce risk, because it was unlikely that the developers of all of those libraries would decide to make backward incompatible breaking changes at the same time, which is essentially what Angular had done.

The Emergence of Vue

To compound AngularJS’ woes, another framework named Vue showed up at about the same time the drama over Angular 2 was occurring. Vue was inspired by AngularJS but aimed to simplify it and get rid of what Vue’s creator saw as unnecessary complexity (so Vue felt very familiar to existing AngularJS developers). Vue provided a safe haven for many AngularJS developers who didn’t want to move over to React.

This doesn’t mean that AngularJS developers were not waiting patiently for Angular 2 to appear. But it’s clear that there was a mass exodus from AngularJS to React and Vue due to the uncertainty caused by the plans for Angular 2.

Rising From the Ashes with Angular 2

Eventually, Angular 2 was released. As expected, it did away with many familiar concepts from AngularJS but kept a few of the best pieces like services and dependency injection. Fortunately for the sanity of developers, Angular uses plain TypeScript and not a fork as originally planned.

To make things more confusing, the Angular team maintained a fork of the new framework that used the Dart programming language instead of TypeScript. Initially, the TypeScript and Dart versions were developed in sync, generated from a single code base. Eventually, the TS and Dart versions of Angular decided to go their separate ways, and Angular Dart now exists on its own.

Even with this confusion, Angular’s popularity began to increase again after the Angular 2 release. It happened slowly. As often occurs in software development, trends shifted. Developers realized that a big, batteries-included framework might actually be useful. After all, when your application grows large enough, you end up actually needing all of those batteries.

Enterprise developers, in particular, began moving back to Angular. This makes sense. Usually, when you start an enterprise web app, you know it is going to be complex. There’s no point in starting with a tiny MVP when you know from the beginning all 87 things your application is going to be expected to do.

Where’s Angular 3?

Although Angular 2 wasn’t perfect, many developers of complex web applications began to realize that the new-and-improved Angular was a good fit for their needs. Fortunately for them, Angular had some exciting improvements in store. More importantly, the Angular team demonstrated that it could consistently publish new versions of the framework with few breaking changes between versions

In a move that seemed odd at the time, the Angular team decided to skip version 3 entirely and move to version 4. This was done for good reason: the team working on Angular’s router package had already pushed ahead and released version 3, while the remainder of Angular was still at version 2.3. They decided to keep all Angular package versions in sync moving forward, and bumping everything up to version 4 for the next release was the easiest way to achieve this.

Angular 4

Angular 4 had some significant changes, including added ahead of time compilation, which resulted in small production JavaScript bundles and shorter application load time. Support for server-side rendering was added, which was a boost for teams that wanted to render their app ahead of time to improve initial load performance. Many other improvements were added throughout the framework, but upgrading apps from Angular 2 to 4 was quick and painless in most cases.

Angular 4.3 and Angular 5

Angular 4.3 added a new HTTP client that was easier to use than the old HTTP service. In Angular 5, the old HTTP service was deprecated and would be dropped in the next release. In spite of this inconvenience, there was relatively little grumbling because the upgrade in most cases was straightforward. Angular 5 also added better internationalization support and further build optimizations.

Angular 6 and 7

Angular 6 and 7 were disappointing to some developers. There were no large changes, but there were many small quality of life improvements, especially to the Angular CLI tooling. The decreasing number of visible changes isn’t an indication that the Angular team has stopped innovating. Instead, it shows that the framework is mature, so the development team is now free to do more work behind the scenes, fixing bugs and improving performance.

The stability of the framework since the release of Angular 2 has drawn some old-school AngularJS developers back into the Angular world. It has also attracted the attention of enterprise development teams. When you’re building enterprise apps that may live for decades it’s ideal to use a framework that gets new releases on a predictable schedule but doesn’t change too rapidly. A developer who had only used Angular 2 could be up and running and contributing to an Angular 7 app within minutes.

The Future of Angular

Angular 8 and Angular Ivy

And that brings us to today. As we’ve seen, Angular has come a long way. It has gone from loved by web developers to being reviled to being admired, although it isn’t yet loved again like it was in its early days.

On the horizon, we have Angular 8. A ton of work has been done in Angular 8 to make it easy to use with the Bazel build system, which is absolutely amazing news for all 3 developers who are using it outside of Google. More excitingly, though, the Angular team is hard at work on a new rendered called Angular Ivy. It’s intended to be a drop-in replacement for the current rendered. For the most part, current apps won’t need to make any changes to use Angular Ivy.

If Angular Ivy is a drop-in replacement, why should developers care? Two important reasons: speed, and bundle size — two very important concerns. For a few years, it seemed like web developers had gone a bit crazy. Teams were shipping JavaScript bundles that were 5MB, 10MB, or even larger, and thinking that there was no problem with this. After all, the applications worked perfectly on the developers’ i7-powered MacBook Pros so they should work fine for everyone, right?

Unfortunately, in the real world, not everyone is running the latest and greatest hardware. Hundreds of millions of people access the internet solely on older Android phones with slightly more processing power than a potato, through internet connections only a little faster than dial-up. For these users, a huge JavaScript bundle takes forever to load, and even longer for their device to parse and run. Even in less extreme cases, there are countless users around the world who aren’t using the latest and greatest hardware. For them, massive JavaScript apps are usable (but painful).

Angular Ivy Expectations

The Angular Ivy renderer will help in several ways:

  1. It is being written with an eye on efficiency, so it will accomplish the same tasks while executing far fewer CPU instructions. This will improve both the battery life and the sanity of users with less-than-powerful devices.
  2. The renderer will be written in a much more modular fashion that the current renderer. This will make it much more amenable to tree-shaking and dead code elimination. As a result, your production JavaScript bundle will include only the code that is needed to run your application, instead of bundling together everything plus the kitchen sink as often happens with the current rendered.
  3. In addition to the bundle-size reduction and improved rendering speed, Angular Ivy has another few quality-of-life enhancements for Angular developers. Rebuild times are significantly faster. So if you’re running your app in development mode and waiting for your changes to appear, you’re now going to be spending a lot less time waiting.
  4. Template-type checking is improved, which means you’ll catch more errors at compile time instead of at runtime. Runtime template bugs are annoying, because they either bite you during testing, or they bite your users when they’re trying to use your app.
  5. The Angular Ivy template compiler will generate code that is human readable, which the current View Engine compiler doesn’t do. This will come in handy when trying to track down tough template bugs.

The net result: smaller apps, faster apps, happier developers, and happier users.

Angular’s Past, Present, and Future

If you’ve been using Angular from its early days all the way until now, then congratulations! While there have been plenty of rough patches, we’ve ended up with a fast, modern framework that is fun to use.

If you were an AngularJS developer but moved on to React, Vue, or something else, I encourage you to give Angular another look. It’s worth your time, even if you decide to stick with what you’re using now.

And if you’ve never used Angular at all, why not give it a shot?

We’ve just been on a whirlwind tour through Angular’s past, present, and future. Without a doubt, it has been quite a ride. Regardless of your Angular background, I hope you’ve enjoyed the tour!

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