expose-loader's Introduction

Expose Loader

The expose loader adds modules to the global object. This is useful for debugging, or supporting libraries that depend on libraries in globals.

Install

npm i expose-loader --save

Usage

Note: Modules must be require()'d within in your bundle, or they will not be exposed.

require("expose-loader?libraryName!./file.js");
// Exposes the exports for file.js to the global context on property "libraryName".
// In web browsers, window.libraryName is then available.

For example, let's say you want to expose jQuery as a global called $:

require("expose-loader?$!jquery");

Thus, window.$ is then available in the browser console.

Alternately, you can set this in your config file:

webpack v1 usage

module: {
  loaders: [
    { test: require.resolve("jquery"), loader: "expose-loader?$" }
  ]
}

webpack v2 usage

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

Let's say you also want to expose it as window.jQuery in addition to window.$. For multiple expose you can use ! in loader string:

webpack v1 usage

module: {
  loaders: [
    { test: require.resolve("jquery"), loader: "expose-loader?$!expose-loader?jQuery" },
  ]
}

webpack v2 usage

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

The require.resolve is a Node.js call (unrelated to require.resolve in webpack processing). require.resolve gives you the absolute path to the module ("/.../app/node_modules/react/react.js"). So the expose only applies to the react module. And it's only exposed when used in the bundle.