Router Improvements and Lazy Loading in Angular 17: A Detailed Tutorial

Introduction

Angular 17 introduces significant improvements to the Router, including lazy loading, standalone components, and enhanced routing parameters. These features simplify routing configuration, improve performance, and provide more flexibility in building complex applications.

What’s new in Angular 17 Router?

• Lazy loading with standalone components
• Improved routing parameters (e.g., params, data, and resolve)
• Enhanced support for nested routing
• Protective routing (e.g., guards and resolvers)
• Simplified routing configuration

Lazy Loading with Standalone Components

Lazy loading allows you to load components only when needed, reducing initial bundle size and improving performance. Standalone components simplify the process by eliminating the need for NgModules.

Example 1: Lazy Loading with Standalone Components

import { Component, RouterModule } from '@angular/core';

@Component({
  selector: 'app-home',
  template: '<p>Home Component</p>',
  standalone: true
})
export class HomeComponent {}const routes = [
  {
    path: '',
    component: HomeComponent,
    loadChildren: () => import('./home/home.component').then(m => m.HomeComponent)
  }
];

Nested Routing

Nested routing allows you to create complex routing hierarchies. Angular 17 improves support for nested routing, making it easier to manage.

Example 2: Nested Routing

import { Component, RouterModule } from '@angular/core';

@Component({
  selector: 'app-dashboard',
  template: '<p>Dashboard Component</p>',
  standalone: true
})
export class DashboardComponent {}const routes = [
  {
    path: '',
    component: HomeComponent,
    children: [
      {
        path: 'dashboard',
        component: DashboardComponent
      }
    ]
  }
];

Router Parameters

Angular 17 introduces improved routing parameters, including:

• params: Access route parameters in components
• data: Pass data to components through routes
• resolve: Resolve data before component instantiation

Example 3: Router Parameters

import { Component, RouterModule } from '@angular/core';

@Component({
  selector: 'app-user',
  template: '<p>User Component {{ userId }}</p>',
  standalone: true
})
export class UserComponent {
  userId: string;
  constructor(private route: ActivatedRoute) {
    this.userId = this.route.snapshot.paramMap.get('id');
  }
}const routes = [
  {
    path: 'user/:id',
    component: UserComponent,
    data: { title: 'User Profile' }
  }
];

Protective Routing

Protective routing features include:

• Guards: Control access to routes
• Resolvers: Resolve data before component instantiation

Example 4: Protective Routing

import { Component, RouterModule } from '@angular/core';

@Component({
  selector: 'app-admin',
  template: '<p>Admin Component</p>',
  standalone: true
})
export class AdminComponent {}const routes = [
  {
    path: 'admin',
    component: AdminComponent,
    canActivate: [AuthGuard]
  }
];@Injectable()
export class AuthGuard implements CanActivate {
  canActivate(route: ActivatedRouteSnapshot, state: RouterStateSnapshot) {
    return true; // or false, depending on authentication logic
  }
}

Conclusion

Angular 17’s Router improvements and lazy loading features simplify routing configuration, improve performance, and provide more flexibility in building complex applications. Standalone components, nested routing, router parameters, and protective routing features make it easier to manage and secure your application’s routing. By leveraging these features, you can build faster, more scalable, and more maintainable applications.