Zoneless change detection in Angular 18

Introduction

Angular change detection is a critical process that identifies the specific parts of an Angular app that need to be refreshed when a change occurs. This process is managed by change detectors present in every component, forming a change detector tree that mirrors the component structure. Change detection starts at the bottom of the component tree.

Zone.js and Change Detection

Zone.js is a library that helps manage asynchronous operations in Angular by creating wrappers around functions. However, the current change detection mechanism based on Zone.js faces challenges as the application grows, including difficulties in debugging, performance issues, and the overhead of Zone.js.

Issues with Zone.js

The use of Zone.js in change detection can lead to difficulties in debugging, performance bottlenecks in large applications, and overhead costs that may slow down the application launch.

Zoneless Change Detection

The experimental feature of "zoneless change detection" in Angular 18 aims to address the issues associated with Zone.js. In zoneless change detection, components themselves inform Angular's change detection mechanism when their data or state changes. This approach results in faster load times and reduced bandwidth consumption.

Experiment with Zoneless Change Detection

To experiment with zoneless change detection, developers can enable the feature in a new Angular app by adding a provider function and removing the Zone.js reference in the code.

Detecting Timer Events with Zoneless

In zoneless change detection, timer events like setTimeout are not automatically detected. Developers need to use Angular signals or interact with elements in the template to trigger a re-render.

Zone.js and Zoneless

While Angular continues to support Zone.js for existing applications, the experimental zoneless change detection feature offers a new approach to improve performance and reduce overhead costs.

Future of Zoneless in Angular

Zoneless change detection in Angular is currently an optional experimental feature, and its adoption may bring significant changes to APIs and behavior. It is not yet ready for production use.

I hope you find this post informative and helpful.