Next.js: Using Dynamic Import with a Named Export

Introduction

Dynamic import in Next.js harnesses the power of code splitting, enabling you to load components on demand to optimize your app’s performance. This tutorial guides you through the process of using named exports with this feature.

Getting Started with Dynamic Import

Dynamic imports in Next.js are powered by Webpack’s code splitting feature. It allows you to split your JavaScript bundles into smaller chunks which can be loaded on demand. A classic use case is for components that are only required under certain conditions, like modal dialogs or complex forms.

import dynamic from 'next/dynamic';

const DynamicComponent = dynamic(() => import('./MyComponent'));

function HomePage() {
  return (
     "Welcome to My App"
  );
}

The above code will load MyComponent only when HomePage is rendered.

Dynamic Import of Named Exports

What if your file exports multiple components, and you only want to import one of them dynamically? That’s where named exports come into play.

const DynamicFeature = dynamic(() =>
  import('./Features').then((mod) => mod.Feature)
);

function HomePage() {
  return (/* ...*/);
}

In this example, we’re importing the named export Feature from the Features.js file dynamically.

Loading Components with Props

Sometimes your dynamically imported component requires props. Here’s how you can handle that:

const DynamicGreeting = dynamic(() => import('./Greeting'));

function Welcome({ name }) {
  return (/*...*/);
}

This will load the Greeting component dynamically and pass the name prop to it.

Custom Loading Components

While your component is being loaded, you may want to display a loader. Next.js makes it easy to implement this pattern.

const DynamicProfile = dynamic(() => import('./Profile'), {
  loading: () => "Loading..."
});

function UserPage() {
  return (
    
  );
}

The loading option allows you to specify what should be rendered while waiting for the component to load.

Server-side Rendering and Dynamic Imports

By default, dynamically imported components are not rendered on the server. If you need server-side rendering for a dynamically imported component, you can use the ssr flag.

const DynamicArticle = dynamic(() => import('./Article'), {
  ssr: true
});

function BlogPage() {
  return (/*...*/);
}

With ssr: true, Next.js will render the component on the server before sending the HTML to the client.

Using with TypeScript

Integrating dynamic imports with TypeScript involves ensuring type safety for dynamically loaded components.

import dynamic from 'next/dynamic';

const DynamicTypedComponent = dynamic<{ customProp: string }>(() =>
  import('./TypedComponent').then((mod) => mod.TypedComponent)
);

function HomePage() {
  return (/*...*/);
}

Here we’re ensuring that TypedComponent receives a customProp of type string.

Advanced Usage: Custom Babel Configuration

For advanced cases, you might need a custom Babel configuration to better handle dynamic imports.

// .babelrc
{
  "plugins": [
    "syntax-dynamic-import"
  ]
}

This custom configuration can help streamline the dynamic import process, especially if you’re managing your own Webpack setup.

Conclusion

This tutorial covered the essentials of leveraging dynamic imports with named exports in Next.js. We walked through various scenarios showcasing the benefits of code splitting and the impact on performance and user experience. As you continue to build out your Next.js applications, experimenting with these techniques will be integral to optimizing load times and ensuring a smooth interaction for your users.