Angular, the popular JavaScript framework, has been continuously evolving to meet the demands of modern web development. With each major release, Angular brings new features, enhancements, and optimizations.
Angular v16 is no exception, and it introduces several groundbreaking changes that make it an ultimate game changer for developers. In this article, we will explore the top new inclusions and exclusions in Angular v16 and discuss how they revolutionize the development experience.
So, let’s get started!
What’s New in Angular v16? — Top New Inclusions and Exclusions
Binding router Information to Component Inputs
First and foremost, Angular v16 allows you to bind router information to component inputs to eliminate boilerplate code during development. You can access the router data including resolved router data, params, and queryParams without using ActivatedRoute.
That’s because this new feature gets the router data available as input in the component itself. So, you can use those inputs to fetch the values instead of messing up with ActivatedRoute. Here’s an example:
// Current approach, which would still work
@Component({
...
})
class SomeComponent {
route = inject(ActivatedRoute);
data = this.route.snapshot.data['dataKey'];
params = this.route.snapshot.params['paramKey']
}
//New approach
@Component({
...
})
class SomeComponent {
@Input() dataKey: string;
@Input() paramKey: string;
//or
@Input() set dataKey(value: string){
//react to the value
};
@Input() set paramKey(value: string){
//react to the value
};
}
Angular Signals
Angular Signals is a new feature in Angular v16 that enables the communication between components using a publish-subscribe pattern. It allows components to emit signals and subscribe to signals emitted by other components.
This feature promotes loose coupling and makes it easier to build modular and reusable components.
import { Component, Signal } from '@angular/core';
@component ({
selector:'app-parent',
template: '
<button (click)="sendieszage()*>Send Mezzage</button>'
})
export class Parentcoponent {
@Signa1() messagesignal: Eventemstter<string>;
sendMessage() {
this.messageSignal.emit('Hello from parent!');
}
}
@Component({
semprater: 'app-child',
template: '
<div>{{ message }} </div>'
})
export class ChildComponent {
constructon(@signal() messageSignal: EventEmitter<string>){
messageSignal.subscribe((message) => {
this: message = message;
});
}
message: string;
}
In this example, the `ParentComponent` emits a signal when the button is clicked, and the `ChildComponent` subscribes to that signal and displays the message.
RxJS Interoperability
Angular v16 brings improved interoperability with RxJS, making it easier to work with observables and leverage the power of reactive programming. The new `@rxjs` package provides decorators and utilities for integrating RxJS into Angular components seamlessly.
For instance, you can use the `@rxjs/debounceTime` decorator to debounce user input in an Angular component:
import { Component } from '@angular/core';
import { debounce } from '@rxjs/debounceTime';
@component ({
selector:'app-example',
template: '
<input (input)="handleInput($event.target.value)"/>'
})
export class ExampleComponent {
@debounceTime(300)
handleInput(value: string){
// Perform operations with debounced value
}
}The `@rxjs/debounceTime` decorator automatically applies the `debounceTime` operator to the `handleInput` method, simplifying the usage of RxJS operators within Angular components.
DestroyRef
Managing subscriptions and resources in Angular components can be a challenge. Angular v16 introduces the `DestroyRef` interface, which simplifies the cleanup process when a component is destroyed.
By implementing the `DestroyRef` interface, you can automatically unsubscribe from subscriptions and perform cleanup tasks when the component is destroyed:
import { Component, OnInit, OnDestroy } from '@angular/core';
import { Subscription } from '@rxjs';
import { DestroyReg } from '@angular/destroy-ref';
@Component ({
selector:'app-example',
template: '
<p>Example Component</p>'
})
export class ExampleComponent implements OnInit, OnDestroy, DestroyReg {
private subscription: Subscription;
ngOnInit(){
this.subscription = /* ... */; // Initialize subscription
}
ngOnDestroy(){
this.ngOnDestroy();
}
}The `DestroyRef` interface ensures that the `onDestroy` method is called automatically when the component is destroyed, reducing the risk of memory leaks and resource wastage.
Non-Destruction Hydration
Angular v16 introduces non-destruction hydration, a feature that improves the performance of hydration during server-side rendering (SSR). In previous versions, Angular would destroy and recreate components during hydration, which could be costly in terms of performance.
With non-destruction hydration, Angular now preserves the existing component instances during hydration, enhancing SSR performance. This change significantly reduces the overhead of rendering on the server and improves the overall user experience
import { Component, NgModule } from '@angular/core';
import { BrowserModule, TransferState } from '@angular/platform-browser';
@Component ({
selector:'app-root',
template: '
<h1>{{ title }}</h1>
<p>{{ content }}</p>'
})
export class AppComponent {
title: string;
content: string;
constructor(private transferDtate: TransferState) {
// Retrieve data from server-side Iendering
const data = this.transferState.get<any>('pageData', {});
this.title = data.title;
this.content = data.content;
}
}
@NgModule({
declarations: [AppComponent],
imports: [BrowserModule.widthServerTransition({ appId: 'my-app'})],
providers: [TransferState],
bootstrap: [AppComponent]
})
export class AppModule {}In this example, we have an AppComponent that displays a title and content. During server-side rendering, the data is transferred using TransferState and stored in the state.
When the Angular application is initialized on the client side, the AppComponent constructor retrieves the data from TransferState and assigns it to the component properties. This way, the component is hydrated without destroying and recreating it, improving the performance of server-side rendering.
CSP Support for inline-styles
Content Security Policy (CSP) is an important security mechanism to protect web applications against cross-site scripting (XSS) attacks. In Angular v16, inline styles are now compatible with CSP restrictions. This means that you can safely use inline styles within your Angular templates while adhering to CSP rules.
The Angular compiler in v16 generates the necessary hashes for inline styles, ensuring they are safely executed within the CSP policy. This change provides more flexibility for developers to style their components without compromising security.
Exclusion of ngcc
In previous versions of Angular, the ngcc (Angular Compatibility Compiler) was used to compile and transform third-party libraries to be compatible with the Angular Ivy compiler. However, Angular v16 removes the need for ngcc altogether.
With the advancements in Ivy and the ecosystem’s migration to Ivy-compatible libraries, ngcc is no longer required. This simplifies the build process and improves the overall build performance, making Angular projects faster to compile and deploy.
Esbuild dev server
Angular v16 introduces a new dev server powered by Esbuild, a fast JavaScript bundler. The Esbuild dev server significantly reduces the startup time of Angular applications during development. It achieves this by leveraging the speed of Esbuild’s bundling and incremental compilation capabilities.
The new dev server provides a smoother development experience with near-instantaneous rebuilds, allowing developers to iterate and test their code more efficiently.
Conclusion
Angular v16 brings a plethora of exciting features and enhancements that revolutionize the development experience. The binding router information to component inputs simplifies route parameter access, while Angular Signals facilitate component communication.
Improved RxJS interoperability, DestroyRef, and non-destruction hydration streamline the management of observables, resource cleanup, and server-side rendering. Additionally, CSP support for inline styles enhances security, the exclusion of ngcc improves build performance, and the esbuild dev server boosts development speed.
With these advancements, Angular v16 empowers developers to build robust, performant, and secure web applications more efficiently than ever before. Stay tuned for the release of Angular v16 and unlock the full potential of this ultimate game-changer.
