How do you define routes in Angular

Defining routes in Angular involves setting up the routing configuration for your application, specifying the mapping between URL paths and corresponding components to be displayed. Here’s a step-by-step guide on how to define routes in Angular:

Step-by-Step Guide to Define Routes in Angular

1. Create a Routing Module (if not already created): Angular typically uses a separate module to handle routing configuration. If you haven't created a routing module yet, create one using Angular CLI or manually.

ng generate module app-routing --flat --module=app

This command generates a app-routing.module.ts file and includes it in the AppModule.

2. Import Required Modules: Open app-routing.module.ts and import RouterModule and Routes from @angular/router.

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

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

3. Define Routes: Define an array of Routes that specifies the route configuration for your application. Each route is an object with a path (URL segment) and a component (the component to display when the path matches).

const routes: Routes = [

  { path: '', redirectTo: '/home', pathMatch: 'full' }, // Default route

  { path: 'home', component: HomeComponent },

  { path: 'about', component: AboutComponent },

  { path: 'contact', component: ContactComponent },

  { path: '**', component: PageNotFoundComponent } // Wildcard route for 404

];

Default Route: redirectTo and pathMatch are used to define the default route when the application starts ('' redirects to '/home').

Wildcard Route: ** is a wildcard route that matches any URL path that doesn't match any defined routes. It's typically used for displaying a "Page Not Found" component or handling unknown routes.

4 . Configure RouterModule: In the @NgModule metadata, configure RouterModule with the routes defined in the previous step using RouterModule.forRoot().

@NgModule({

  imports: [RouterModule.forRoot(routes)],

  exports: [RouterModule]

})

export class AppRoutingModule { }




forRoot() vs forChild(): Use forRoot() in the root routing module (usually AppRoutingModule) and forChild() in feature modules to avoid re-importing the router configuration.

5. Use <router-outlet> in the App Component: In your app.component.html, use the <router-outlet> directive where Angular will dynamically render the component corresponding to the current route.

<div>

  <router-outlet></router-outlet>

</div>

6. Add Router Links: In your navigation menus or anywhere you want to navigate within the application, use Angular's router links to navigate between routes without causing a full page reload.

<ul>

  <li><a routerLink="/home">Home</a></li>

  <li><a routerLink="/about">About</a></li>

  <li><a routerLink="/contact">Contact</a></li>

</ul>

Summary

Defining routes in Angular involves setting up routes using the Routes array, configuring the RouterModule with these routes, using <router-outlet> in the main application component, and using router links (<a routerLink="...">) for navigation. Angular Router provides powerful features like lazy loading, route parameters, guards, and more to manage navigation and state within single-page applications effectively.