Steps to create a nextJS application

What is Server Side Rendering?

Server-side rendering (SSR) is a technique used to deliver HTML content to a client’s browser by pre-rendering it on the server. This approach helps reduce the load on the client’s browser and improves page loading times, resulting in faster access to web pages. A quick way to verify if an application is using SSR is to disable JavaScript in the client’s browser. If the requested page still loads with content, it indicates that server-side rendering is being employed....

What is Client Side Rendering?

Client-side rendering (CSR) is a method in which all webpage files, such as HTML, CSS, and JavaScript, are delivered to the client’s browser. The browser then processes these files locally to render the content on the webpage, requesting resources from the server as needed. This approach shifts the computational load to the client’s browser, potentially resulting in slower initial page loading times but allowing for more dynamic and interactive user experiences....

Detecting server vs client-side rendering

Detecting whether Next.js applications are running on the server side or the client side is indeed an essential task to avoid unnecessary hydration errors in our application. Hydration errors occur when there is a mismatch between the server-rendered content and the content rendered on the client side. Knowing whether the application is running on the client or server side is crucial for preventing such errors....

Steps to create a nextJS application

Step 1: Create a nextJS app...

Approach 1: Using typeof window

Since window object is only available on the client side, you can use typeof window to check if it’s defined. If it’s undefined, the code is running on the server side....

Approach 2: Using process.browser

Next.js provides a built-in variable process.browser which is true on the client side and false on the server side....

Approach 3: Using a custom flag

You can set a custom flag during the server-side render and check for its presence on the client side....

Approach 4: Using req object in getServerSideProps

In server-side rendering methods like getServerSideProps, you have access to the req object. If req is defined, it signifies that the code is executing on the server side. Since getServerSideProps exclusively operates on the server, any code within it will not be executed on the client side. Therefore, the else part meant for client-side execution will not be triggered....

Approach 5: Using window object inside useEffect

If you’re using React hooks, you can utilize the useEffect hook and check for the window object. This method is particularly suitable for functional components. Since the useEffect hook is part of React, it executes on the client side after the component mounts. Therefore, if you simply need to determine if the code is running on the client side, this approach works well. For instance, it’s useful for generating a random number without encountering server-side errors....

Conclusion

In summary, detecting server vs client-side rendering in Next.js is essential for managing hydration errors and optimizing performance. Methods like checking typeof window, process.browser, custom flags, req object in getServerSideProps, and useEffect with the window object offer versatile approaches. By selecting the appropriate method based on specific requirements, developers can ensure seamless execution and enhance the user experience in Next.js applications....