How to load non module scripts into global scope in Webpack?

2个答案

In Webpack, you may occasionally need to load non-module scripts (i.e., scripts that do not adhere to CommonJS or ES6 module specifications) into the global scope or the window object. This can be achieved through several methods; here are some examples:

Using `expose-loader`

Webpack's expose-loader allows you to expose modules to the global object. For example, if you want to expose a global variable named someLibrary to the global scope, you can configure it in module.rules as follows:

javascript
// webpack.config.js

module.exports = {
  // ... other configurations ...
  module: {
    rules: [
      {
        test: require.resolve('path-to-non-module-script'),
        use: [{
          loader: 'expose-loader',
          options: {
            exposes: ['someLibrary'],
          },
        }],
      },
    ],
  },
  // ... other configurations ...
};

The above configuration will expose the script pointed to by path-to-non-module-script as the global someLibrary object.

Using `script-loader`

script-loader executes the script in the global context, similar to using a <script> tag. This means the script can affect the global scope. Adding script-loader to your Webpack configuration rules is shown as follows:

javascript
// webpack.config.js

module.exports = {
  // ... other configurations ...
  module: {
    rules: [
      {
        test: require.resolve('path-to-non-module-script'),
        use: [{
          loader: 'script-loader'
        }],
      },
    ],
  },
  // ... other configurations ...
};

Using `imports-loader`

Using imports-loader can set the this context inside the module to the window object, which can be helpful in certain cases, especially when the script expects its context to be the global context.

javascript
// webpack.config.js

module.exports = {
  // ... other configurations ...
  module: {
    rules: [
      {
        test: require.resolve('path-to-non-module-script'),
        use: [{
          loader: 'imports-loader',
          options: {
            wrapper: 'window',
          },
        }],
      },
    ],
  },
  // ... other configurations ...
};

Manually Mounting to `window`

If you don't want to use loaders, you can manually mount libraries or features to the window object within the module system. For example:

javascript
// In your entry script or anywhere suitable
import * as myNonModuleLibrary from 'path-to-non-module-script';

// Mount the library to the window object
window.myNonModuleLibrary = myNonModuleLibrary;

This approach requires you to explicitly know the object or library you want to mount and manually perform the mounting.

Summary

Loading non-module scripts into the global scope is a common requirement in the Webpack environment. Depending on your specific situation, you can choose to use expose-loader, script-loader, imports-loader, or manually mount the scripts to the window object. Each method has its applicable scenarios, and you should choose the most suitable approach based on project requirements and script characteristics.

2024年6月29日 12:07 回复

Loading non-module scripts into the global scope in Webpack can typically be achieved through several methods. Non-module scripts refer to scripts that do not adhere to the CommonJS, AMD, or ES6 module systems. Here are several common approaches:

1. `expose-loader`

expose-loader exposes a module to the global object (such as window). If you need to expose global variables from a non-module script, this loader is suitable.

For example, to introduce jQuery globally (even though jQuery is a module, this method works for non-module scripts as well), configure it as follows:

javascript
module: {
  rules: [
    {
      test: require.resolve('jquery'),
      use: [{
        loader: 'expose-loader',
        options: {
          exposes: ['$', 'jQuery'],
        },
      }],
    },
  ],
}

In this configuration, expose-loader exposes $ and jQuery in the global scope, allowing them to be accessed globally.

2. Using `script-loader`

script-loader executes scripts outside the module system, adding them directly to the global scope.

For instance, if you have a legacy.js file containing global variables or functions, configure it as follows:

javascript
module: {
  rules: [
    {
      test: /legacy\.js$/, 
      use: [{
        loader: 'script-loader',
      }],
    },
  ],
}

The code in legacy.js executes directly, with its internal declarations exposed as global variables.

3. Using `imports-loader`

imports-loader injects dependencies into non-module scripts, which is useful when passing global variables to such scripts.

For example, configure it as follows:

javascript
module: {
  rules: [
    {
      test: /some-library\.js$/, 
      use: [{
        loader: 'imports-loader',
        options: {
          type: 'commonjs',
          imports: 'single window=>global',
        },
      }],
    },
  ],
}

This injects the global window object into some-library.js as global.

4. Directly include via `<script>` tag in HTML files

Even in Webpack projects, you can use the traditional approach of including non-module scripts directly in HTML files via the <script> tag, which executes them in the global scope.

For example:

html
<script src="path/to/your/non-module-script.js"></script>

This method requires no Webpack configuration but necessitates manual management of script loading order and dependencies.

When using any of these methods to load non-module scripts, ensure you apply best practices for code splitting and lazy loading to avoid unnecessarily increasing the main bundle size. Additionally, exercise caution with global variables to prevent potential conflicts and maintainability issues.

2024年6月29日 12:07 回复

How to load non module scripts into global scope in Webpack?

2个答案

Using expose-loader

Using script-loader

Using imports-loader

Manually Mounting to window

Summary

1. expose-loader

2. Using script-loader

3. Using imports-loader

4. Directly include via <script> tag in HTML files

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