Routing Best Practices in Angular

Routing is a cornerstone of building Single Page Applications (SPAs) in Angular. It allows developers to manage navigation between different components, handle dynamic URLs, and create a seamless user experience. While Angular provides a powerful Router module, building an effective, maintainable, and scalable routing system requires following certain best practices.

In this post, we will cover the most important routing best practices in Angular, including defining default routes, implementing lazy loading, handling unknown routes, managing nested routes, using route guards, and optimizing navigation for performance and maintainability.

What Are Angular Routing Best Practices?

Routing best practices are guidelines and strategies to structure your Angular application routes effectively. They ensure that your application is:

Organized: Clear structure makes it easier to maintain and scale.
User-friendly: Users can navigate the app intuitively.
Secure: Sensitive routes are protected using guards.
Performant: Efficient loading of modules and components.
Flexible: Easy to modify and extend as the application grows.

Always Define a Default Route

A default route is the route that Angular navigates to when the application is loaded without any path specified. It ensures that users are directed to a valid starting point of your application, typically the home page or a landing page.

Example: Default Route

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

import { AppComponent } from './app.component';
import { HomeComponent } from './home/home.component';
import { AboutComponent } from './about/about.component';

const routes: Routes = [
  { path: '', component: HomeComponent },  // Default route
  { path: 'about', component: AboutComponent }
];

@NgModule({
  declarations: [
AppComponent,
HomeComponent,
AboutComponent  ],
  imports: [
BrowserModule,
RouterModule.forRoot(routes)  ],
  providers: [],
  bootstrap: [AppComponent]
})
export class AppModule { }

The path '' ensures that when users visit the root URL of your application, they are redirected to the HomeComponent.
Without a default route, the application could render a blank page or an unintended component.

Best Practices for Default Routes

Always use the home page or landing page as the default route.
If your application requires authentication, consider redirecting to a login page or dashboard.
Use redirectTo in complex routing scenarios to guide users appropriately.

{ path: '', redirectTo: 'home', pathMatch: 'full' }

pathMatch: 'full' ensures the redirect only occurs when the full URL matches the empty path.

Use Lazy Loading for Large Modules

As applications grow, loading all components and modules upfront can slow down the initial load time. Lazy loading is a technique that loads modules only when they are needed, improving performance and user experience.

Setting Up Lazy Loading

Suppose you have an AdminModule that is not needed immediately on application startup. You can lazy load it as follows:

const routes: Routes = [
  { path: '', component: HomeComponent },
  { path: 'about', component: AboutComponent },
  {
path: 'admin',
loadChildren: () =&gt; import('./admin/admin.module').then(m =&gt; m.AdminModule)  }
];

loadChildren dynamically imports the module when the user navigates to /admin.
Lazy loading reduces the size of the main bundle and speeds up the initial page load.

Admin Module Example

import { NgModule } from '@angular/core';
import { CommonModule } from '@angular/common';
import { RouterModule, Routes } from '@angular/router';
import { AdminDashboardComponent } from './admin-dashboard/admin-dashboard.component';

const routes: Routes = [
  { path: '', component: AdminDashboardComponent }
];

@NgModule({
  declarations: [AdminDashboardComponent],
  imports: [CommonModule, RouterModule.forChild(routes)]
})
export class AdminModule { }

Best Practices for Lazy Loading

Only lazy load modules that are not needed immediately.
Keep lazy-loaded modules self-contained with their own routing.
Avoid lazy loading very small modules as it may add unnecessary overhead.
Use preloading strategies for modules that are likely to be visited soon after the app loads.

Handle Unknown Routes with a Wildcard

Users may sometimes navigate to a URL that does not exist in your application. Handling unknown routes ensures they see a proper 404 page instead of a broken page or blank screen.

Wildcard Route Example

import { PageNotFoundComponent } from './page-not-found/page-not-found.component';

const routes: Routes = [
  { path: '', component: HomeComponent },
  { path: 'about', component: AboutComponent },
  { path: '**', component: PageNotFoundComponent }  // Wildcard route
];

The ** path acts as a catch-all for undefined routes.
It should always be placed at the end of the routes array.

PageNotFoundComponent

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

@Component({
  selector: 'app-page-not-found',
  template: &lt;h1&gt;404 - Page Not Found&lt;/h1&gt;&lt;p&gt;The page you are looking for does not exist.&lt;/p&gt;
})
export class PageNotFoundComponent { }

Best Practices for Wildcard Routes

Always provide a user-friendly message.
Offer navigation options back to the home page or main sections.
Use wildcard routes to redirect users if needed:

{ path: '**', redirectTo: '', pathMatch: 'full' }

Organize Routes Using Feature Modules

For large applications, it’s important to structure routes by feature modules rather than having a monolithic routing configuration. Each feature module should have its own routing module.

Example: Product Feature Module

import { NgModule } from '@angular/core';
import { RouterModule, Routes } from '@angular/router';
import { ProductListComponent } from './product-list/product-list.component';
import { ProductDetailComponent } from './product-detail/product-detail.component';

const routes: Routes = [
  { path: '', component: ProductListComponent },
  { path: ':id', component: ProductDetailComponent }
];

@NgModule({
  imports: [RouterModule.forChild(routes)],
  exports: [RouterModule]
})
export class ProductRoutingModule { }

Best Practices for Feature Modules

Keep routes related to the feature inside the module.
Use forChild instead of forRoot.
Avoid deeply nested routes unless necessary.

Use Route Guards for Security

Route guards help protect sensitive routes by controlling access based on authentication, roles, or other conditions. Angular provides several types of guards:

CanActivate: Prevent access to routes.
CanActivateChild: Protect child routes.
CanDeactivate: Prevent leaving a route with unsaved changes.
Resolve: Preload data before activating a route.

Example: AuthGuard

import { Injectable } from '@angular/core';
import { CanActivate, Router } from '@angular/router';

@Injectable({
  providedIn: 'root'
})
export class AuthGuard implements CanActivate {
  constructor(private router: Router) {}

  canActivate(): boolean {
const isLoggedIn = false;  // Replace with real authentication check
if (!isLoggedIn) {
  this.router.navigate(&#91;'/login']);
  return false;
}
return true;  }
}

Applying the Guard to a Route

{ path: 'dashboard', component: DashboardComponent, canActivate: [AuthGuard] }

Use Descriptive and Consistent Route Names

Clear and consistent route paths improve the maintainability of your application and the usability of your URLs.

Example

const routes: Routes = [
  { path: '', component: HomeComponent },
  { path: 'about-us', component: AboutComponent },
  { path: 'products', component: ProductListComponent },
  { path: 'products/:id', component: ProductDetailComponent }
];

Use kebab-case for URLs (about-us instead of AboutUs).
Avoid unnecessary abbreviations or cryptic names.
Maintain consistency across the entire application.

Optimize Navigation for Performance

Preload Modules: Angular supports preloading strategies to load lazy modules after the initial app load.

RouterModule.forRoot(routes, { preloadingStrategy: PreloadAllModules })

Avoid Redundant Navigation: Check if the user is already on the target route before navigating programmatically.

if (this.router.url !== '/dashboard') {
  this.router.navigate(['/dashboard']);
}

Limit Nested Routes: Deeply nested routes can lead to complex URL structures and slow performance.

Summary of Routing Best Practices

Default Route: Always define a route for the root path (path: '') to guide users to a starting point.
Lazy Loading: Load feature modules only when required to improve initial load performance.
Wildcard Routes: Handle unknown routes using path: '**' to display a 404 page or redirect.
Feature Modules: Organize routes within modules using RouterModule.forChild.
Route Guards: Protect sensitive routes using guards like CanActivate and CanDeactivate.
Descriptive Routes: Use clear, consistent, and SEO-friendly route paths.
Performance Optimizations: Preload modules, limit nested routes, and prevent redundant navigation.

Complete Example

const routes: Routes = [
  { path: '', component: HomeComponent },
  { path: 'about-us', component: AboutComponent },
  { path: 'products', component: ProductListComponent },
  { path: 'products/:id', component: ProductDetailComponent },
  {
path: 'admin',
loadChildren: () =&gt; import('./admin/admin.module').then(m =&gt; m.AdminModule),
canActivate: &#91;AuthGuard]  },
  { path: '**', component: PageNotFoundComponent }
];