Unlock Blazing Fast UX: Mastering Nex.js Streaming for Enhanced Performance

Next.js is a top web framework. It offers smart features. But many developers don't use its full power. This is because some advanced ideas are tough to grasp. This article explains Next.js streaming. It's a React feature. Used with Next.js, it makes apps way faster. You'll learn how to build super-speedy apps. Your users will love the smooth experience.

Traditional server-side rendering (SSR) often makes users wait. Pages appear blank. Interactions are slow. Users click a button. They expect a fast response. Instead, they see a spinner. Or the page doesn't work at all. This makes users unsure. Did the click even happen? This bad experience hurts app speed. Understanding why delays happen is key. Then we can build a better way.

This article looks at what causes these delays. We'll see how streaming helps. We'll show you how to do both automatic and custom streaming. You'll learn how to give users a smooth, fast experience.

The Problem with Traditional SSR in Nex.js

Understanding the Load Delay

Imagine clicking a button. The page takes a long time to load. This is a bad user experience. It’s unclear if the click even worked. What causes this wait? It's because parts of the page load slowly. These parts are fetched as data comes in.

The Root Cause: Asynchronous Operations

Server components fetch data. This fetching happens slowly. It's an asynchronous process. Everything on the page waits. It waits for all data to arrive. This is done on the server. The whole page is built before it's sent.

The Code Breakdown: Simulating Delays

Let's look at the code. A page uses a component called ToolsCard. This card fetches tool data. It uses a function called getTools. This function simulates a delay. It uses setTimeout for 3 seconds. It makes an array of promises. Each promise is for one tool. Then, Promise.all waits for all promises. It gets the data back. Then, it shows the cards. Each card shows a tool's name and icon.

Identifying the UX Pitfalls

There are two main issues. First, the page takes too long to load. Users wait too much. Second, there's a "false interaction." You might click a button. A heart appears. Then the page reloads. The heart is gone. This is confusing. It happens because the page rehydrates. The old click is lost. This is a downside of SSR.

How SSR Works: Rendering and Hydration Explained

When a user visits your page, a request goes to the server. This starts Phase A. The server does its work. It fetches data. Then, it makes the HTML. This is Phase B. The HTML and CSS go to the browser. That's Phase C. Finally, the JavaScript loads. The browser makes things interactive. This last step is hydration.

The Request Lifecycle: Server to Browser

The process is step-by-step. First, the server gets the request. Then, it does async tasks. After that, it makes HTML. The browser gets the HTML. Then, the browser runs JavaScript. This makes the page work.

The Crucial Role of Hydration

Hydration connects JavaScript to the HTML. It makes components interactive. Without hydration, client components don't work. A click won't do anything. If these terms are fuzzy, watch my video on Nex.js rendering. It clears everything up.

The Bottleneck: Sequential Processing

SSR has a bottleneck. Tasks happen one after another. Data must fetch first. Then HTML is made. Then it goes to the browser. Then hydration happens. If one part is slow, everything waits. Imagine nine cards. Card one waits for data. Then card two waits. All cards load together. This causes delays.

Introducing Streaming: A Solution for Smoother UX

What if we could show parts of the page faster? What if component A is ready? We could send it right away. Component B could still be loading. This is called streaming. It's like YouTube. You start watching a video. It doesn't wait to download fully. It plays. The rest loads in chunks. This is buffering. You don't feel lag. Streaming does this for web pages.

The Core Concept: Sending Components as They're Ready

Streaming lets you send parts of your page. They go to the browser as they finish. It's not all or nothing. Parts of the UI can load alone. This is much better than old SSR. Users see content sooner. They feel like the app is faster.

Streaming vs. Traditional SSR

Traditional SSR waits for everything. Streaming shows content as it's ready. If one part is slow, it doesn't stop others. This makes the user experience better. You see content piece by piece.

The Enabler: React Suspense

React has a tool called Suspense. This makes streaming happen. Streaming works with server components. Suspense tells React when data is ready. It shows a fallback while waiting.

Implementing Automatic Streaming in Nex.js

Nex.js makes streaming easy. You can use automatic streaming. This needs just one file.

The loading.js Convention

Create a file named loading.js. Put it in your route folder. Nex.js sees this file. It adds a Suspense boundary. It uses your loading.js file as the fallback. This wraps your page component.

Building Skeleton Loaders

Your loading.js file shows a loading state. Make it look like your real content. This is a skeleton UI. Use placeholder elements. They match the card's shape. We'll use the card-skeleton component. It uses ShadCN UI's skeleton. We map it nine times. This creates nine skeleton cards.

The Result: Improved Loading Experience

Now, when you load the page, you see skeletons. The page looks better. You can't click on things that aren't ready. This stops false interactions. The loading experience is much smoother. But the whole page segment still loads at once. We can make it even better.

Mastering Custom Streaming with Suspense Boundaries

For more control, use custom streaming. You can stream individual components.

Moving Beyond Page-Level Streaming

You can stream parts of your page. This needs manual setup. Delete the loading.js file. Now, Nex.js won't stream automatically.

Refactoring Components for Suspense

Go to the tools-card.js file. Remove Promise.all. We'll loop through promises directly. Wrap each IconCard in Suspense. This component needs a fallback. Use the CardSkeleton for the fallback.

Creating the ToolCard Component

We need a ToolCard component. It takes a promise. It uses the use hook. This hook resolves the promise. The resolved data goes to IconCard. So, ToolCard uses use and returns IconCard. This shows the data when ready.

The Power of Individual Streaming

Now, cards stream in one by one. Whichever finishes first appears. Your interactions stay put. False interactions are gone. This gives a great experience.

Dynamic Rendering and Production Considerations

How does Nex.js decide to render? It depends on your code.

Static Site Generation (SSG) vs. SSR

Your demo page might look static. Nex.js might make it SSG. SSG means the page is built ahead of time. SSR means it's built when requested. Streaming makes more sense with SSR. If it's static, there's no server fetching on request.

Forcing Dynamic Rendering

To ensure SSR, add export const dynamic = 'force-dynamic';. This tells Nex.js to always render on the server. This makes streaming truly useful. It works on every request.

Streaming in Production

With force-dynamic, streaming works in production. The experience is the same. The page renders on demand. Streaming delivers content as it's ready.

Conclusion: Streamlining Your Nex.js Applications

Streaming in Nex.js is powerful. It fixes SSR's slow loading. It stops confusing false interactions. You can use automatic streaming. Just add loading.js. For component streaming, use Suspense manually. Remember force-dynamic. This makes sure your page is always dynamic.

Key Takeaways for Seamless UX

Start with automatic streaming. It's the easiest. Then try custom streaming. Wrap components in Suspense. This gives fine-grained control. Use force-dynamic for true SSR streaming.

Actionable Tips for Implementation

Apply these ideas to your projects. Make your apps feel fast. Users will appreciate the speed. They won't get frustrated.

The Future of Fast Web Experiences

Streaming is a great technique. It improves user experience a lot. Try it in your next app. You'll see a big difference. Thanks for reading! Don't forget to like and share. It helps the channel. See you next time.

Courtesy of  logicBase Labs