Up till last month, React 18 was in the beta phase of testing and development. However, on March 08, 2022, the team at Facebook has released the release candidate for the framework for industry enthusiasts to try and give their feedback for further improvement.

First announced back in June 2021, the latest version of the cross-platform app development framework is sure to pack a punch. The team has promised to offer some exciting new features that will be powered by a new concurrent renderer with a gradual adoption strategy.

Can’t wait to upgrade to React 18? Must be wondering when it’ll get released. Right? Let’s find out:

React 18 Release Date?

There has not been an official date confirmed by the React team for the general availability of the framework for everyone to try on. However, they have mentioned the official build will be launched at least several weeks after the RC candidate launch. So, from this, we can expect the React 18 to arrive maybe in April end or May start.

But until the general availability of React 18, let’s discuss what punch this new version is going to pack for the app developers.

React 18: What Can We Expect?

If you don’t know, React or ReactJS is an open-source JavaScript UI toolkit from Facebook for the frontend development of web-based apps. Thanks to the new concurrent rendering mechanism, the framework can create multiple versions of the UI at the same time. Let’s explore more such improvements and performance enhancements:

1. New Root API Introduced

Before we understand why the new root API was introduced, it is crucial to understand what issues the old root API (ReactDOM.render) had. The root is a pointer to the top-level data structure that helps React to track tree render.

The legacy root API was not so transparent with users as it was usually attached to the DOM. Also, it was only accessible through the DOM node that too without exposing it to the users. However, there was no need to store the root to the DOM node.

Furthermore, the legacy root API had issues with running updates. Issues like passing the container into render continuously even when it never changed were removed with the introduction of the new Root API. Also, it allows us to eliminate the hydrate method and replace it with the root option.

2. Automate Batching

Batching is a process where React forces to update multiple upgrades simultaneously into a single render state to achieve better computational performance. This creates several bugs at times as it prevents the rendering of components that were in the ‘Half Finished’ state where only one component variable gets updated. React does not batch every update rather it would perform two independent batches.

React 18 will have the capability to automatically batch updates, irrespective of the origin. In previous versions, updates were not batched by default for many cases. Automatic batching in React 18 resolves this issue. By addressing this issue, it makes the batching process more efficient and consistent.

3. StartTransition for Concurrent Rendering and Responsive App

startTrasition is one of the most significant updates coming up with the React 18 version. It helps keep the app responsive throughout the large screens by using concurrent rendering. During heavy updates operations, your screen may freeze or the app may become unresponsive, which causes disruptions in workflow. In such cases, the startTransition API comes in handy to tackle such situations.

The inclusion of this API enhances the user interaction by making specific movements as transitions. This enables React to know which updates are important and which are not. Also, the UI will be able to ignore the secondary update that might be slower or make the app update unresponsive.

4. New Suspense SSR and Architectural Improvements

The latest version of React will add an architectural improvement to the Server-Side Rendering offered in React. SSR is a method of rendering components and generating HTML directly from the server and sharing it with users.

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This enables users to see the preview of the page even before the JavaScript bundle loads and presents itself. But many times, the JavaScript takes longer to get processed. This time is known as the Hydration time.

The new updates introduce the Suspense, which decides which part of the app might take longer to load and what shall get rendered directly. This will enable the framework to stream HTML directly on the server and send the pieces of components as and when they render. The components wrapped with Suspense will not block hydration time by using this selective hydration method.

5. Gradually Adoption Strategy for Easy Update

React 18 will have opt-in for concurrency, meaning there won’t be significant out-of-the-box breaking changes to component behavior. Upgrading to the React 18 is simple and easy with minimal to no changes in the code. This can be comparable to the typical major React release.

The React team mentions that upgrading to the React 18 may only take around one afternoon and most React components out of the tens of thousands shipped concurrent features work without additional changes.

6. Dropping Support for Internet Explorer

In this new upgrade, React team has announced the support of Internet Explorer has been dropped. The Internet Explorer is going out of support by Microsoft from June 15, 2022. Also, the new features in React are and will be built using modern browsers features, for instance, microtasks that do not fit in the IE.

Conclusion

As the Release Candidate of the React 18 has been released, users can install and upgrade to try it out for their apps. The latest version of this frontend user interface development framework packs some promising features as we mentioned above.