Angular 17 Introduces Deferrable Views as a New Feature

Angular 17 has introduced a new feature called Deferrable Views, which allows developers to defer the rendering of certain components until they are actually needed. This can improve the performance of your application by reducing the initial load time and only rendering components when they are actually needed.

In this tutorial, we will explore how to use Deferrable Views in Angular 17 and how it can benefit your application.

1. Setting up your Angular project

First, make sure you have Node.js and Angular CLI installed on your machine. You can install them by running the following commands in your terminal:

npm install -g @angular/cli

Next, create a new Angular project by running the following command:

ng new my-deferrable-views-app

Navigate into your project directory by running:

cd my-deferrable-views-app

1. Creating a deferrable view

To create a deferrable view in Angular, you need to use the deferred attribute in the component’s template. This attribute tells Angular to defer the rendering of the component until it is actually needed.

For example, let’s create a simple component with a deferrable view. First, generate a new component by running:

ng generate component lazy-loaded

Next, open the lazy-loaded.component.html file in the app/lazy-loaded directory, and add the deferred attribute to the root element of the template:

<div deferred>
  <p>This is a deferrable view!</p>
</div>

1. Lazy loading the deferrable view

To actually defer the rendering of the component, we need to lazy load it in our application. We can use Angular’s routing system to achieve this.

Open the app-routing.module.ts file in the src/app directory, and modify it to lazy load the LazyLoadedComponent when a certain route is accessed:

const routes: Routes = [
  { path: 'lazy-loaded', loadChildren: () => import('./lazy-loaded/lazy-loaded.module').then((m) => m.LazyLoadedModule) },
];

Next, create a new module for the LazyLoadedComponent by running:

ng generate module lazy-loaded/lazy-loaded --route lazy-loaded --module app.module

This will generate a new module and route for the LazyLoadedComponent, and configure it for lazy loading.

1. Testing the deferrable view

Now that we have created a deferrable view and lazy loaded it in our application, let’s test it out.

Start your Angular development server by running:

ng serve

Navigate to http://localhost:4200/lazy-loaded in your browser, and you should see the deferrable view rendered on the page. If you inspect the DOM, you will notice that the component was only rendered when the route was accessed, demonstrating the power of deferrable views in Angular 17.

Conclusion

Deferrable Views are a powerful new feature in Angular 17 that allows you to defer the rendering of certain components until they are actually needed. This can significantly improve the performance of your application by reducing the initial load time and only rendering components when they are required.

In this tutorial, we covered how to create a deferrable view in Angular, lazy load it in the application, and test it out. I hope you found this tutorial helpful and that you can leverage deferrable views to optimize your Angular application.