Key Highlights of Angular 17: What You Need to Know
Last updated 67 Days ago | 7 Min Read | 178 views
Angular, Google's popular open-source web application framework, has been a cornerstone of modern web development since its inception. With each new version, Angular brings enhancements, optimizations, and cutting-edge features to the table, empowering developers to build robust and scalable applications.
Now, with the release of Angular 17, developers have even more tools at their disposal to create exceptional web experiences. Angular 17 builds upon the foundation laid by its predecessors, introducing several significant updates aimed at improving developer productivity, application performance, and user experience.
What’s New in Angular 17: Features and Updates
Angular 17 brings a host of new features and updates aimed at addressing common pain points in web development and improving overall developer productivity. Let's delve into some of the most noteworthy additions:
- Declarative Control Flow
Declarative control flow introduces a new built-in syntax in Angular 17, merging the functionality of NgIf, NgFor, and NgSwitch directly into the framework. This means that developers can utilize straightforward expressions like @if, @else, @for, and @switch to manage the rendering of templates without relying on external directives. This enhancement streamlines template coding, making it more concise, readable, and uniform across projects.
What does this code flow look like?
As demonstrated in the code, there's no need to import ngIf and ngFor directives anymore. This built-in code flow within Angular simplifies component integration, particularly when working with Angular signals.
Structural directives like NgIf and NgFor are not deprecated in Angular 17, and there are no immediate plans for deprecation. However, in the future, only the ngIf, ngFor, and ngSwitch directives are likely to face deprecation.
- Automatic Migration to Build-in Control Flow
If you're looking to automatically transition your code to the new built-in control flow syntax, Angular 17 provides a convenient schematic in the @angular/core package:
Running this schematic will automatically migrate your existing code to leverage the updated control flow syntax, ensuring compatibility with the latest features and enhancements in Angular 17.
- Build Performance with ESBuild
Angular CLI, the popular tool used for generating bundles using Webpack, now faces competition from more recent and faster alternatives. Angular 17 introduces a stable version of Angular CLI by default for new projects, integrated with the Application Builder.
To leverage the improved build performance offered by ESBuild, you can update your existing projects by modifying the angular.json file:
Simply add "-esbuild" at the end of the builder configuration. With this update, commands like "ng serve" and "ng build" should function as usual, but with significantly improved speed. The CLI team has also implemented several additional performance enhancements, ensuring a smoother development experience.
- The Most Awaited Feature: Defer
Angular 17 brings a highly anticipated feature called "defer," which revolutionizes lazy loading of components in web development. While previous methods such as EsModules and the *ngComponentOutlet directive allowed for lazy loading, they often resulted in complexities and limitations, leaving much to be desired in terms of developer experience.
With the introduction of defer in Angular 17, lazy loading becomes a breeze, offering a seamless solution that addresses the entire loading process. Let's take a look at how defer can be utilized:
As shown in the example, defer allows for specifying different stages of lazy loading, including a placeholder shown until the chunk file begins loading, a loading indicator displayed during the loading process, and an error message in case of loading errors.
However, it's crucial to apply defer thoughtfully, considering factors such as network conditions and component size. By doing so, developers can optimize user experience and effectively tackle Core Web Vitals' Largest Contentful Paint (LCP) and Cumulative Layout Shift (CLS) metrics.
Exploring Signals in Angular 17
Signal was initially introduced as a developer preview in Angular 16, but with the release of Angular 17, Signal is now stable and ready for use. When you pair Signals with the 'ChangeDetection.OnPush' option, you can ensure that only the specific component affected by a signal change gets updated, making your app more efficient.
However, note that the ‘mutate’ method on signals is no longer accessible in Angular 17. Also, effects are still in the testing phase, meaning they're being worked on to make them better before the final release.
Conclusion
Angular 17 brings several new features without any breaking changes, making the migration from Angular 16 seamless. It represents a significant evolution of the Angular web development framework, offering enhanced flexibility, performance, and productivity for developers. In essence, Angular 17 marks a rebirth of the framework, introducing a new era of web development possibilities.
