Routing

Basic Setup

import { Routes } from '@angular/router';

export const routes: Routes = [
  { path: '', component: HomeComponent },
  { path: 'about', component: AboutComponent },
  { path: 'users/:id', component: UserDetailComponent },
  { path: '**', component: NotFoundComponent } // Wildcard
];

// main.ts
import { provideRouter } from '@angular/router';
import { routes } from './app.routes';

bootstrapApplication(AppComponent, {
  providers: [provideRouter(routes)]
});

Router Outlet

@Component({
  selector: 'app-root',
  standalone: true,
  imports: [RouterOutlet, RouterLink],
  template: `
    <nav>
      <a routerLink="/">Home</a>
      <a routerLink="/about">About</a>
      <a [routerLink]="['/users', userId]">User</a>
    </nav>
    <router-outlet></router-outlet>
  `
})
export class AppComponent {}

Route Parameters

import { Component } from '@angular/core';
import { ActivatedRoute } from '@angular/router';

@Component({
  template: `<p>User ID: {{ userId }}</p>`
})
export class UserDetailComponent {
  route = inject(ActivatedRoute);
  userId: string | null = null;

  ngOnInit() {
    // Snapshot (one-time)
    this.userId = this.route.snapshot.paramMap.get('id');

    // Observable (reactive)
    this.route.paramMap.subscribe(params => {
      this.userId = params.get('id');
    });
  }
}

Query Parameters

// Navigate with query params
router.navigate(['/search'], { queryParams: { q: 'angular', page: 1 } });
// URL: /search?q=angular&page=1

// Read query params
this.route.queryParamMap.subscribe(params => {
  const query = params.get('q');
  const page = params.get('page');
});

Programmatic Navigation

import { Router } from '@angular/router';

export class AppComponent {
  router = inject(Router);

  goToUser(id: number) {
    this.router.navigate(['/users', id]);
  }

  goToSearch() {
    this.router.navigate(['/search'], {
      queryParams: { q: 'angular' },
      fragment: 'section1' // URL: /search?q=angular#section1
    });
  }

  goBack() {
    this.router.navigate(['..'], { relativeTo: this.route });
  }
}

Child Routes

export const routes: Routes = [
  {
    path: 'products',
    component: ProductsComponent,
    children: [
      { path: '', component: ProductListComponent },
      { path: ':id', component: ProductDetailComponent },
      { path: ':id/edit', component: ProductEditComponent }
    ]
  }
];

// ProductsComponent template
@Component({
  template: `
    <h1>Products</h1>
    <router-outlet></router-outlet> <!-- Child routes render here -->
  `
})

Router Link Active

<a routerLink="/home"
   routerLinkActive="active"
   [routerLinkActiveOptions]="{ exact: true }">
  Home
</a>

<style>
  .active { font-weight: bold; color: blue; }
</style>

Route Data & Resolvers

// Static data
{
  path: 'admin',
  component: AdminComponent,
  data: { title: 'Admin Panel', role: 'admin' }
}

// Read data
this.route.data.subscribe(data => {
  console.log(data['title']); // 'Admin Panel'
});

Named Outlets

{
  path: 'dashboard',
  component: DashboardComponent,
  children: [
    { path: '', component: MainContentComponent },
    { path: 'sidebar', component: SidebarComponent, outlet: 'sidebar' }
  ]
}

// Template
<router-outlet></router-outlet>
<router-outlet name="sidebar"></router-outlet>

// Navigate
router.navigate(['/dashboard', { outlets: { sidebar: ['sidebar'] } }]);

Best Practices

• Use lazy loading for large modules
• Always handle 404 with wildcard route
• Use guards for authentication/authorization
• Prefer relative navigation in child routes
• Use resolvers to pre-fetch data