Next.js and React are frameworks often utilized in front-end development. React has established itself as the most popular library or framework among developers, making it the recommended primary framework for new developers in the JavaScript ecosystem.

But come to think of it, Next.js is developed using the same React library. So, what makes Next.JS a better alternative than React? In this article, we dive deeper into the benefits and features of Next.JS and why you should prefer it over other frameworks.

What is Next.js?

Next.js is a React framework that helps build blocks to create fast web applications. In addition, Next.js has server-side rendering capability and speedy and easy Search Engine Optimization (SEO).Next.js claims to be the Web's Software Development Kit with all the tools needed to make the web faster.

So far, the claim remains undisputed. It provides structure to React functionalities and adds a few of its own. Next.js framework is built on top of React and mainly focuses on creating production-ready applications with the essentials of configuration and code.

Why Next.js over React.js?

Next.js offers server-side rendering (SSR), whereas React offers client-side rendering. In addition, Next.js has several tools and functions for project management. On the other hand, React is the best for developing user interfaces for single-page applications.

React has a framework called Create React App (CRA), whereas Next.js has a different approach from CRA; it moves the rendering aspect to the server, which improves the performance and SEO because the server pre-renders the pages and then sends the final HTML to the client, resulting in minimal JS, which directly impacts the performance and speed because there is less code to load.

Sitecore JavaScript Rendering SDK (JSS) for Next.js

The Sitecore JavaScript Rendering SDK represents a set of JavaScript packages and sample applications that helps add first-class support for JavaScript frameworks and enables the development of applications that consume Sitecore Data.

JSS for Next.js uses many features of Next.js, which helps to simplify and enhance the development workflow. Next.js extends the React Framework, mainly there are two differences in Sitecore JSS projects.

• Server-side rendering: The main difference is that server-side rendering is handled by Next.js instead of using a configurable boilerplate in React. In terms of fetching data Next.js has multiple ways of being configured.
• Code splitting: In a traditional JSS and React build, code splitting can be achieved, whereas, with Next.js, that is done with the framework "dynamic" module. However, nothing is set up out of the box; the module allows for components to be imported dynamically and reduces the overall size of JavaScript files loaded over the network.

Advantages of using JSS for Next.js compared to other Frameworks

• Development and production runtime parity, including server-side rendering during development.
• Fewer application modes and deployment requirements.
• SSR in production or integrating Sitecore tracking does not require the headless SSR proxy.
• More straightforward integration with advanced Sitecore content and layout editors without the need to deploy your application bundle to the Content Management instance.

Features supported by JSS for Next.js

• Next.js static HTML export, incremental static site generation, server-side rendering and hybrid rendering.
• Dynamic author-defined URLs through the Next.js file-based router and the Sitecore Layout Service.
• Dynamic component rendering based on author-defined page layouts.
• Helper components for rendering various Sitecore field types.
• Integration with advanced Sitecore content and layout editors through Next.js preview mode.
• Sitecore route querying for static site generation.
• Next.js client-side routing support for Sitecore link and rich text fields.
• Internationalization support through Sitecore language versions and Next.js internationalized routing.
• Component-level data fetching for Sitecore-driven components.
• Sitecore analytics and personalization support, this feature requires you to SSR the Next.js app and use the Sitecore Layout Service REST API.
• Support for JSS code-first workflow and mock Sitecore services.
• A TypeScript-enabled app sample demonstrating everyday use cases.
• Containerized template for windows-based developers.
• Other built-in Next.js features like component-level CSS, code splitting, fast refresh and more.
• Apps are compatible with Vercel deployment.

Pages and Routes

Next.js uses a file system-based router, i.e., whenever we add any page to the Pages directory, it is automatically available via URL.

1. Index Routes: An index.js file in the folder maps to the directory's root.
Example: pages/employee/index.js maps to '/employee'

2. Nested Routes: Any nested folder structure in the pages directory because routes URL automatically.
Example: pages/employee/data.js maps to '/employee/data'

3. Dynamic Routes: We can also use named parameters to match URLs. Use brackets for the same.
Example: pages/employee/[id].s maps to '/employee/:id' where we can use a URL like '/employee/1'

Next.js allows linking pages on the client-side using Link react component.

Href: Name of the page in the pages directory. For example,/employee/data refers to data.js present in the pages/employee directory.

If you want dynamic pages in the same folder but with different slugs, Next.js allows you to render the same page component by wrapping the filename in brackets. Next.js conveniently exposes a useRouter React hook to access information about the app location or history easily.

SEO in Next.js

Pages in web applications need not only data within the HTML body but meta tags as well. So, for example, a Create React Application would require installing an external dependency called React Helmet.

But in Next.js, we can use the Head component from next/head to conveniently add metadata to our web pages to be shown in search results and embeds. The Head component should be included on any page, usually within the opening tag.

API Routes

API routes are a way to create rest API using Next.js. Next.js maps any file in /pages/api folder and will be treated as the API endpoint.

• req is an instance of http.IncomingMessage used to get data from the request.
• res is an instance of http.ServerResponse used to send data as a response.

API routes in Next.js have built-in middleware, which helps in parsing incoming requests.

• req.cookies contain the cookies sent by the request. The default value is {}.
• req.query includes the query string. The default value is {}.
• req.body has the request body parsed using 'content-type'. The default value is null.

Response helper methods are as follows:

• res.status(code): This method sets the response's status. Code passed must be a valid HTTP status.
• req.json(JSON): This method returns a JSON response. json passed must be a helpful JSON object.
• req.send(body): This method sends an HTTP response. The response can be a string, object or buffer.

Request Data Client-side

The traditional approach to request data from our API routes and use the data in our client pages can be made using useEffect and useState.

This approach works but requires a lot of boilerplate code. An improved/ better way to fetch and catch data upon future visits is to use the library SWR.

SWR gives us a convenient hook useSWR to more easily fetch data and handle loading and errors state.

The hook is named after this "cache invalidation" strategy: "stale-while-revalidate".

Example:

import useSWR from "swr";

const fetcher = (...args) => fetch(...args).then((res) => res.json())

export default function About() {

  const { data, error } = useSWR("/api/about", fetcher)

  if (error) return <div>Error fetching data</div>

  if (!data) return <div>Loading...</div>

  return (

    <div>

      <h1>{data.name}</h1>

    </div>

  )

}

Request Data Server-side

Mainly there are two functions you can include directly within the page files that allow you to fetch data from the server.

• GetServerSideProps: It runs for every page visit. As a result, it is beneficial on pages with dynamic data or needs requests to be informed every time, like getting authenticated user data.
• GetStaticProps: This function is more appropriate for more static pages that change less frequently. This function executes our server code and makes a GET request on the server. GetStaticProps only makes requests on every page visit during development.

Environmental variables

Next.js has support for publishing environmental variables in nodes which we can use in connecting to the server. For this, we need to create an env. local file in the root directory. We can also create env.production.

• Create .env.local: Create .env.local in the root directory with the following content.
  DB_HOST=localhost
  DB_USER=sainath
  DB_PASS=admin@1

• Create env.js: Create a page named env.js with the following contents in the page/employee directory, where we will use the environment variables using process.env.
  
  

import Head from 'next/head' 
import Container from '../../components/container' 

export default function FirstPost(props) { 
   return ( 
      <> 
         <Container> 
            <Head> 
               <title>Environment Variables</title> 
            </Head> 
            <h1>Database Credentials</h1> 
               <p>Host: {props.host}</p> 
               <p>Username: {props.username}</p> 
               <p>Password: {props.password}</p> 
         </Container> 
      </>    
   ) 
} 


export async function getStaticProps() { 
   // Connect to Database using DB properties 
   return { 
      props: {  
         host: process.env.DB_HOST, 
         username: process.env.DB_USER, 
         password: process.env.DB_PASS 
      } 
   } 
} 

Conclusion

Now you know that Next.js is an excellent choice for developers looking to build fast and SEO-friendly web applications. Its server-side rendering capabilities and built-in tools for project management make it a perfect framework for creating production-ready applications.

With Next.js, developers can enjoy faster page loads, better SEO, and a more structured approach to building their projects.

Moreover, Next.js has excellent community support, and developers can easily find several tutorials and helpful resources online. Ultimately, if you are looking for a framework that provides all the essentials for creating development-ready web applications, Next.js should be your choice. Contact us for more queries or concerns and our team will get back to you.