Dynamic Import Magic

On today's episode of my Coding Chronicle, I want to share with you how I solved the dreaded 'document is not defined' error during a deployment.

If you're working with Next.js or any other server-side rendered framework, you may have encountered this issue when trying to use browser-specific features (like document) in a way that isn’t compatible with server-side rendering (SSR). The error typically occurs when you're trying to use client-side only libraries in a server-rendered environment.

The Problem When deploying a Next.js app, I ran into an issue where the following error kept popping up

Error: document is not defined

This issue happens because Next.js does server-side rendering by default, and any code that references document, which is a browser-specific API, will fail during the SSR phase because document doesn't exist on the server.

The Solution: Dynamic Imports One way to resolve this is by using dynamic imports to load client-side only code, ensuring that it only gets executed in the browser. The next/dynamic function allows us to dynamically import a component, and you can even specify that it should only be rendered client-side by using the ssr: false option.

Here’s how I fixed the issue:

// Import dynamic from Next.js
import dynamic from 'next/dynamic'
 
// Dynamically import the Hello component
const DynamicComponent = dynamic(() =>
  import('../components/hello').then((mod) => mod.Hello),
  { ssr: false }  // Ensure it is not rendered server-side
)
 
export function Page() {
  return (
    <div>
      <h1>Welcome to My Page</h1>
      <DynamicComponent />  {/* This will only render on the client-side */}
    </div>
  )
}

Dynamic(): This Next.js utility allows you to load components asynchronously. By using it with ssr: false , we ensure that the Hello component is only rendered on the client-side, preventing the document is not defined error. Server-Side Rendering (SSR): With ssr: false, the component will not attempt to render on the server, avoiding the browser-specific API call during SSR.

Using dynamic imports in Next.js is a powerful solution for handling client-side only libraries or components. It prevents server-side rendering issues like the "document is not defined" error and ensures that your app works seamlessly on both the server and client. So, the next time you run into this issue, try leveraging dynamic imports, and you’ll be back on track in no time.

I knew you’d learn something new! Feel free to share your insights and help others who might be facing the same challenges. Thanks for reading, and happy coding! 🚀