This is a minimal example project that demonstrates how to integrate the Foxit PDF SDK for Web into a Next.js application. The project was created using create-next-app and is designed to serve as a starting point for developers who want to add PDF viewing and annotation capabilities to their Next.js applications.

You have two options to get started with this example:

1. Use this project as a boilerplate: If you want to use this project as a boilerplate, you can clone this repository and start building on top of it. This approach allows you to add features like App Router or make any other modifications you need.

2. Start from scratch: If you prefer to start from scratch, you can create a new Next.js project using create-next-app and integrate the Foxit PDF SDK for Web into your new project.

Before you begin, make sure you have the following installed:

• Node.js (version specified in the project's .nvmrc)
• npm (usually comes bundled with Node.js)

1. Clone the repository:

   git clone [email protected]:foxitsoftware/FoxitPDFSDKForWeb-NextJS-Example.git nextjs-websdk

2. Install dependencies:

   cd nextjs-websdk
   npm install

3. Obtain license key:

   To use the Foxit PDF SDK for Web, you need to obtain licence key from our sales. Once you have the license key, update the licenseSN and licenseKey values defined in src/pages/index.js.

4. Start the development server:

   npm run dev

   This will start the Next.js development server, and you can access the application at http://localhost:3000.

The official Next.js documentation suggests creating a new project via create-next-app. To create a project, run:

npx [email protected]

On installation, you'll see the following prompts:

What is your project named? nextjs-websdk
Would you like to use TypeScript? No / Yes              ——>N
Would you like to use ESLint? No / Yes                  ——>N
Would you like to use Tailwind CSS? No / Yes            ——>N
Would you like to use `src/` directory? No / Yes        ——>Y
Would you like to use App Router? (recommended) No / Yes        ——>Y
Would you like to customize the default import alias (@/*)? No / Yes    ——>N
What import alias would you like configured? @/*

After the prompts, create-next-app will create a folder with your project name and install required dependencies.

From here, you can refer to the later section Integrating into your own project to integrate Foxit PDF SDK for Web into your project.

For more details on how to create a Next.js project, we recommend that you refer to the Next js official documentation:

https://www.npmjs.com/package/create-next-app https://nextjs.org/docs/getting-started/installation

Install the Foxit PDF SDK for Web into your project using following command:

npm install @foxitsoftware/foxit-pdf-sdk-for-web-library

And then, install copy-webpack-plugin as develop dependency:

npm install -D copy-webpack-plugin

This will be used to configure webpack to copy the static resources of Foxit PDF SDK for Web into public directory.

Due to the Foxit PDF SDK for Web requiring additional static resources during runtime, you need to configure Next.js webpack settings. In your next.config.mjs file, add the following webpack configuration:

import CopyWebpackPlugin from 'copy-webpack-plugin';
import path from 'path';
const libraryModulePath = path.resolve('node_modules/@foxitsoftware/foxit-pdf-sdk-for-web-library');

/** @type {import('next').NextConfig} */
const nextConfig = {
  reactStrictMode: false,
  webpack: (config, options) => {
    config.plugins.push(
      new CopyWebpackPlugin({
        patterns: [
          {
            from: path.resolve(libraryModulePath, 'lib'),
            to: path.resolve('./public/FoxitPDFSDKForWeb/lib'),
            force: true,
            info: {minimized: true},
          }
        ]
      }),
    );
    return config;
  }
}

export default nextConfig;

This configuration uses copy-webpack-plugin to copy static resources from node_modules/@foxitsoftware/foxit-pdf-sdk-for-web-library/lib to the public/FoxitPDFSDKForWeb/lib directory.

Note:

Prior to [email protected], the configuration file was named next.config.js (Refer to this PR: vercel/next.js#60494), and should be written in CommonJS style.

In your Next.js components or pages where you want to use the PDF SDK, import the necessary modules and initialize the SDK as needed.

Here's a basic example of how you might integrate the PDF SDK into a Next.js component, with the key steps demonstrated in the following simplified code:

function Home() {
    const elementRef = useRef();
    const pdfuiRef = useRef();
    useEffect(() => {
        // Determine if the element instance is available
        if(!elementRef.current) {
            return;
        }
        // Avoid PDFUI instances from being initialized multiple times in the same page
        if(!!pdfuiRef.current) {
            return;
        }
        const pdfui = new UIExtension.PDFUI({
            // ...
        });
        // Save PDFUI instance to pdfuiRef
        pdfuiRef.current = pdfui;
    }, [elementRef])
    
    return (<>
        { /* ... */ }
        <div ref={elementRef}></div>
        { /* ... */ }
    </>
    )
}

For completed implementation, please refer to the code in src/pages/index.js.

In this example, for the convenience of demonstration, we directly save the PDFUI instance on Ref. In actual development, we recommend saving the PDFUI instance on Context, which makes it easier to share PDFUI instances among different components.

For more information about the usage of Foxit PDF SDK for Web, please refer to the official documentation.

Developer Guide: https://webviewer-demo.foxit.com/docs/developer-guide

API Reference: https://webviewer-demo.foxit.com/docs/api_reference/html/index.html

The Foxit PDF SDK for Web offers various external services, including the snapshot service and the signature service (available in Linux and Windows versions). These services are located in the server directory. Below, we take the snapshot service as an example to explain how to configure and use these services in Next.js.

First, based on the configuration mentioned above, we add the copy-webpack-plugin configuration to copy the server directory into the deployment directory:

const nextConfig = {
  // ...
  webpack: (config, options) => {
    config.plugins.push(
      new CopyWebpackPlugin({
        patterns: [
          // ...
          {
            from: path.resolve(libraryModulePath, 'server'),
            to: path.resolve('./public/FoxitPDFSDKForWeb/server'),
            force: true,
            info: {minimized: true},
          }
        ]
      }),
    );
    return config;
  }
}

Next, we configure the proxy to prevent cross-origin requests between the frontend and the server:

const nextConfig = {
    async rewrites() {
    return [
      {
        source: '/snapshot/:path*',
        destination: 'http://localhost:3002/snapshot/:path*',
      },
    ]
  },
  // ...
}

For the complete configuration, please refer to next.config.mjs.

After modifying the above configurations, we run npm run dev to start the development server, and open http://localhost:3000 in the browser. Next.js will automatically start webpack, and the node_modules/@foxitsoftware/foxit-pdf-sdk-for-web-library/server directory will be automatically copied to public/FoxitPDFSDKForWeb/server, while requests from http://localhost:3000/snapshot/:path will be proxied to http://localhost:3002/snapshot/:path.

Navigate to public/FoxitPDFSDKForWeb/server/snapshot, and execute the following command:

npm install
npm run start

After completing these operations, we can use the snapshot functionality.

Starting from FoxitPDFSDK for Web version 10.0.0, since service worker is used, it is necessary to add this field in the HTTP response header of the Service Worker script. Its value is the maximum allowed scope path:

Service-Worker-Allowed /;

If you are using Nginx as your server, you can add the Service-Worker-Allowed response header by modifying the Nginx configuration file. Below is an example configuration：

server {
    location /sw.js {
        add_header Service-Worker-Allowed /;
    }
}

If you use Node Dev Server for local development, you can add Service-Worker-Allowed response headers by configuring devServer. The following is a configuration example：

// next.config.mjs
module.exports = {
    // 其他配置
    async headers() {
    return [
      {
        // Apply these headers to all routes in your application.
        source: '/:path*',
        headers: [
          { key: 'Service-Worker-Allowed', value: '/' },
        ],
      },
    ];
  }
};

Next.js 12's built-in style processing is incompatible with certain styled-jsx usage patterns. If you encounter the following error:

Failed to compile
    -/pages/index.js
    Error: failed to process index out of bounds: the len is 0 but the index is 0

Solution: Move the global styles :global { ... }{} from index.js to styles/globals.css.