Everything You Need to Know about React 19

Hey Folks! hope you all are doing extremely well, so you might have been aware of the news that our very favourite Javascript frontend library React just got an update, the major upgrade succeeding React 18 i.e., React 19.

React 19 will include some major changes and improvements, and thus comes with a variety of new features designed to streamline web development and enhance performance.

So, let us see what React 19 has to provide!

Now, Time for the Take Off, Are You Ready? 3...2...1 and here we go🚀

Key Features Of React 19🚀

👉React Compiler

So, the first and major change is that React will now use a compiler and you may notice that a lot of the big Frameworks seem to copy each other and so React also did the same. They've created a new compiler that will compile your React code into regular JavaScript potentially doubling its performance.

It'll do automatic memoization which is the process of optimizing components to to prevent unnecessary rerenders which has been a pain point with React for a lot of years now, right? For this optimal rerendering, we used to employ useMemo() and useCallback() hooks, but from now on this optimal rerendering is automated.

So, I'm very glad that we are not going to use these hooks anymore!

While presently discretionary, employing the compiler is poised to evolve into the default approach for React in the imminent future.

👉use() Hook

There is a new hook that came up in React 19, which is just called as use and this allows us to read and asynchronously load the value of a resource such as a promise or even context in fact use like this use and then passing in context is going to completely replace the the useContext hook which I know can be annoying because you may have just learned about Context API.

And after knowing this, you no longer need it anymore and have to learn something else for the same kinds of stuff... Hmmm, I can feel the pain but this is what Tech is all about, every single day things are getting changed so rather than holding grudges and complaining, try embracing it and you are all set!

👉Server Components

if you've used Next.js you would have used React Server Components. The wait is over now, Server Components got introduced here as well.

it has the major benefit you might be knowing i.e., these components carry out their functions on the server before presenting the final page to the user. This leads to quicker website loading, enhanced search engine efficiency (better SEO), and more seamless data management.

👉Document Metadata

Effortlessly handle titles and meta tags using the <DocumentHead> component. This newly introduced feature streamlines the process of adding titles and meta tags to your web pages, contributing to enhanced SEO and consistent brand representation across your site. Say goodbye to the hassle of duplicating code in multiple locations.

You no longer have to use Third Party Packages for SEO and Metadata as React19 have the built in support for metadata like title, description and the keywords.

👉Actions API

<form action={formAction} >

Actions can now be used for both client and server components.. This feature was there in Nextjs i.e., Actions can now be used for both client and server components.

This is gonna make working with the forms much easier and more intuitive.

News hooks also got introduced for form handling such as useFormStatus() and useFormState(), which will work very well with actions

👉Asset Loading

With the latest React 19 feature, the acceleration of image and file preparation is made possible. This feature initiates the background loading of these elements while users explore the current page, reducing the waiting time when moving to a new page.

👉Web Components

React 19 has enhanced its compatibility with Web Components, facilitating a smooth integration of various sections on your website. This improvement paves the way for new opportunities to incorporate React into areas that posed challenges for implementation in the past.

👉No More React.lazy

The React team now recommends using the React Suspense Compiler (RSC) along with promise-as-child syntax for lazy loading components instead of React.lazy.

To use RSC for lazy loading, you will need to create a separate module for each component that you want to lazy load. This module should export a promise that resolves to the component.

For example, here is a module for a lazy-loaded component called MyComponent:

// MyComponent.js
export default new Promise((resolve) => {
  setTimeout(() => {
    resolve(() => <MyComponent />);
  }, 1000);
});

You can then use this module in your app like this:

// App.js
import MyComponent from './MyComponent';

const App = () => {
  return (
    <Suspense fallback={<div>Loading...</div>}>
      <MyComponent />
    </Suspense>
  );
};

export default App

When the app is first rendered, the MyComponent component will not be loaded. Instead, the fallback UI will be displayed. After 1000 milliseconds, the MyComponent component will be loaded and the fallback UI will be removed.

RSC is a more efficient way to lazy load components than React.lazy because it does not require a separate bundle for each lazy-loaded component. This can improve the performance of your app, especially on mobile devices.

👉<Context.Provider> replaced with <Context>

The <Context> provider has a few advantages over the older provider:

• It is more concise and easier to read.

• It is more performant.

• It is more flexible.

👉ref passed as a regular prop

That means No More forwardRef. This simplifies the usage of refs, as they are treated like any other prop, eliminating the need for forwardRef wrappers.

Conclusion

React 19 has made its debut, streamlining the development of websites and applications. With the introduction of new tools such as the React Compiler, Actions API, and improved Hooks, coding becomes more efficient, and data management is simplified.

This update not only enhances coding capabilities but also optimizes app performance, resulting in smoother user experiences and faster loading times. These improvements benefit both users and search engines alike. Additionally, React 19's compatibility with web components adds versatility, enabling a broader range of applications for React.

In essence, React 19 empowers developers to build high-performing apps, fostering innovation and interactivity in websites and applications. As its adoption continues to grow, we can anticipate an exciting evolution in the digital landscape.

With That Set, let us End Up Here!, I hope that I was able to add some knowledge and value to your learnings through this blog!
Still Doubtful ?🤔🤷‍♂️ Comments are always open. I will be Glad to help!

👉Do Consider Subscribing to The Newsletter, so that you never miss an update from us!

#LearningInPublic #Reactjs #React19 #javascript

#HappyLearningFolks!