python ruby-programming-language Smalltalk Vue.js Knockoutjs TypeScript JavaScript, OOPs JavaScript Angular 8,7,6,5,4 and 2 Interview Questions and Answers Angular 8,7,6,5,4 and 2 Interview Questions and Answers Angular 4 Angular 2 AngularJs 1.x NodeJs Perl Programming R Programming RequireJs Rust Programming Backbonejs closure programming language go-programming-language kotlin-programming-language
Angular 4 vs. Angular 5

Angular 5 Auth Guard and Route Guards

How to Implementing Auth Guard with Component less Route in Angular 5?
In this article, we take a look with few of the different types of guards and how to implement them for specific use-
1.      Maybe the user must authenticate and then login in the app.
2.      If user has logged in but is not authorized to navigate to the target component.
3.      We might ask the user if its OK to discard pending changes rather than save them.

There are four different types of Guards -
1.      CanActivate – It use to checks to see if a user can visit a route.
2.      CanActivateChild - It use to checks to see if a user can visit a routes child.
3.      CanDeactivate - It use to checks to see if a user can exit a route.
4.      Resolve - It use to perform route data retrieval before route activation.

5.      CanLoad - It use to checks  to see if a user can route to a module that lazy loaded

Let’s start how to Generate Guard, I am using Angular CLI command for generating Auth Guard on Angular 5 applications.

The Auth Guard implementation is quite simple and Auth Guard CLI command is –
ng generate guard auth



Why Use Auth Guard in Angular 5?
The Auth Guard is used to redirect the user to the page they landed on before being forced to login.

Now, go to your project directory and execute the guard command i.e.
D:\Angular\AngularMaterial>ng generate guard auth
  create src/app/auth.guard.spec.ts (346 bytes)
  create src/app/auth.guard.ts (401 bytes)


auth.guard.ts
import { Injectable } from '@angular/core';
import { CanActivate, ActivatedRouteSnapshot, RouterStateSnapshot } from '@angular/router';
import { Observable } from 'rxjs/Observable';

@Injectable()
export class AuthGuard implements CanActivate {
  canActivate(
    next: ActivatedRouteSnapshot,
    state: RouterStateSnapshot): Observable<boolean> | Promise<boolean> | boolean {
    return true;
  }
}
And

auth.guard.spec.ts
import { TestBed, async, inject } from '@angular/core/testing';

import { AuthGuard } from './auth.guard';

describe('AuthGuard', () => {
  beforeEach(() => {
    TestBed.configureTestingModule({
      providers: [AuthGuard]
    });
  });

  it('should ...', inject([AuthGuard], (guard: AuthGuard) => {
    expect(guard).toBeTruthy();
  }));
});

Now, we generate the login component for using angular gourd –
D:\Angular\AngularMaterial>ng g component login
  create src/app/login/login.component.html (24 bytes)
  create src/app/login/login.component.spec.ts (621 bytes)
  create src/app/login/login.component.ts (265 bytes)
  create src/app/login/login.component.css (0 bytes)
  update src/app/app.module.ts (394 bytes)


And the app.module.ts looks like –
import { BrowserModule } from '@angular/platform-browser';
import { NgModule } from '@angular/core';
import {FormsModule, FormGroup} from '@angular/forms';
import {RouterModule} from '@angular/router';

//MY COMPONENTS
import { AppComponent } from './app.component';
import { LoginComponent } from './login/login.component';
import { RegisterComponent } from './register/register.component';
@NgModule({
  declarations: [
    AppComponent,
    LoginComponent,
    RegisterComponent
  ],
  imports: [
    BrowserModule,
    FormsModule,
    RouterModule.forRoot([
      { path: '', component: AppComponent, pathMatch: 'full' },
      { path: 'register', component: RegisterComponent },
      { path: 'login', component: LoginComponent}])
  ],
  providers: [],
  bootstrap: [AppComponent]
})
export class AppModule { }


Now, Create Auth Service-
D:\Angular\AngularMaterial>ng g service AuthService
  create src/app/auth-service.service.spec.ts (405 bytes)
  create src/app/auth-service.service.ts (117 bytes)


Auth Service looks like- auth-service.service.ts
import { Injectable } from '@angular/core';
import { Router } from '@angular/router';

@Injectable()
export class AuthServiceService {

   constructor(private router: Router) { }

   //Set User Secure Token
  setSecureToken(secure_token: string) {
    localStorage.setItem("LoggedIn", secure_token)
  }

  //Set User Secure Token
  getSecureToken() {
    return localStorage.getItem("LoggedIn")
  }

  //Check User is LoggedIn or not!
  isLoggednIn() {
    return this.getSecureToken() !== null;
  }

  //Logout method
  logout() {
    localStorage.removeItem("LoggedIn");
    this.router.navigate(["login"]);
  }
}

Now, calling the login service methods to validate user on login components and it looks like – login.component.ts
import { Component, OnInit } from '@angular/core';
import { FormBuilder, Validators } from '@angular/forms';
import { Router } from '@angular/router';
import { AuthServiceService } from '../auth-service.service';

@Component({
  selector: 'app-login',
  templateUrl: './login.component.html',
  styleUrls: ['./login.component.css']
})
export class LoginComponent implements OnInit {
  //variable initialization
  form;

  //constructor initialization
  constructor(private fbuilder: FormBuilder,
    private route: Router,
    private authService: AuthServiceService) {
      this.form = fbuilder.group({
        email: ['', [Validators.required, Validators.email]],
        password: ['', Validators.required, Validators.minLength]
      });
  }

  //ngOnInit method
  ngOnInit() {
  }

  //This method use for Login
  login() {
    if (this.form.valid) {
      this.authService.setSecureToken(this.form.value.email)
      this.route.navigate(["dashboard"]);
    }
  }
}

 Now, coming to your Auth Gourd and use your Auth service to validate the users and returns your status –
import { Injectable } from '@angular/core';
import { CanActivate, ActivatedRouteSnapshot, RouterStateSnapshot } from '@angular/router';
import { Observable } from 'rxjs/Observable';
import {Router} from '@angular/router';
import { AuthServiceService } from './auth-service.service';

@Injectable()
export class AuthGuard implements CanActivate {

  //constructor initialization
  constructor(private authService: AuthServiceService,   private route: Router){  }

  canActivate(
    next: ActivatedRouteSnapshot,
    state: RouterStateSnapshot): Observable<boolean> | Promise<boolean> | boolean {
      if(this.authService.isLoggednIn()){
        return true;
      }else{
        this.route.navigate(["login"]);
        return false;
      }
  }
}

You must add your Auth Service and Auth Guard in you app.module.ts and its looks like –

import { BrowserModule } from '@angular/platform-browser';
import { NgModule } from '@angular/core';
import {FormsModule, FormGroup} from '@angular/forms';
import {RouterModule} from '@angular/router';

//MY COMPONENTS
import { AppComponent } from './app.component';
import { LoginComponent } from './login/login.component';
import { RegisterComponent } from './register/register.component';

import { AuthServiceService } from './auth-service.service';
import { AuthGuard } from './auth.guard';

@NgModule({
  declarations: [
    AppComponent,
    LoginComponent,
    RegisterComponent
  ],
  imports: [
    BrowserModule,
    FormsModule,
    RouterModule.forRoot([
      { path: '', component: AppComponent, pathMatch: 'full', canActivate: [AuthGuard] },
      { path: 'register', component: RegisterComponent },
      { path: 'login', component: LoginComponent}])
  ],
  providers: [],
  bootstrap: [AppComponent]
})
export class AppModule { }


I hope you are enjoying with this post! Please share with you friends. Thank you so much!
ANIL SINGH

Hey! I'm Anil Singh. I author this blog. I'm Active Blogger, Programmer. I love learning new technologies, programming, blogging and participating the forum discussions more...
My Blogs - http://code-sample.com and http://code-sample.xyz
My Books - Interview Questions and Answers Books- Get Your Book in 15+ Digital Stores Worldwide..

You Might Also Like
www.code-sample.com/. Powered by Blogger.
ASK Questions