gaearon / expose-loader

expose loader module for webpack

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.

This line works to expose React to the web browser to enable the Chrome React devtools:

require("expose-loader?React!react");

Thus, window.React is then available to the Chrome React devtools extension.

Alternately, you can set this in your config file:

webpack v1 usage

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

webpack v2 usage

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

Also 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 -- check the node.js docs instead). 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.

Documentation: Using loaders

Maintainers

Juho Vepsäläinen

Joshua Wiens

Kees Kluskens

Sean Larkin