webpack
Version:
Packs CommonJs/AMD modules for the browser. Allows to split your codebase into multiple bundles, which can be loaded on demand. Support loaders to preprocess files, i.e. json, jade, coffee, css, less, ... and your custom stuff.
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Markdown
This example demonstrate how to build a library with webpack that has dependencies to other libraries which should not be included in the compiled version.
We use the `libraryTarget: "umd"` option to build a UMD module that is consumable in CommonJs, AMD and with script tags. We don't specify the `library` option so the library is exported to the root namespace.
We use the `externals` option to define dependencies that should be resolved in the target environment.
In the simple case we just need to specify a string (`"add"`). Than it's resolved as `"add"` module in CommonJs and AMD, and as global `add` when used with script tag.
In the complex case we specify different values for each environment:
| environment | config value | resolved as |
|--------------------|--------------------------|------------------------------|
| CommonJs (strict) | `["./math", "subtract"]` | `require("./math").subtract` |
| CommonJs (node.js) | `"./subtract"` | `require("./subtract")` |
| AMD | `"subtract"` | `define(["subtract"], ...)` |
| script tag | `"subtract"` | `this.subtract` |
# example.js
``` javascript
var add = require("add");
var subtract = require("subtract");
exports.exampleValue = subtract(add(42, 2), 2);
```
# webpack.config.js
``` javascript
module.exports = {
output: {
libraryTarget: "umd"
},
externals: [
"add",
{
"subtract": {
root: "subtract",
commonjs2: "./subtract",
commonjs: ["./math", "subtract"],
amd: "subtract"
}
}
]
}
```
# js/output.js
``` javascript
(function webpackUniversalModuleDefinition(root, factory) {
if(typeof exports === 'object' && typeof module === 'object')
module.exports = factory(require("add"), require("./subtract"));
else if(typeof define === 'function' && define.amd)
define(["add", "subtract"], factory);
else {
var a = typeof exports === 'object' ? factory(require("add"), require("./math")["subtract"]) : factory(root["add"], root["subtract"]);
for(var i in a) (typeof exports === 'object' ? exports : root)[i] = a[i];
}
})(this, function(__WEBPACK_EXTERNAL_MODULE_1__, __WEBPACK_EXTERNAL_MODULE_2__) {
return /******/ (function(modules) { // webpackBootstrap
/******/ // The module cache
/******/ var installedModules = {};
/******/
/******/ // The require function
/******/ function __webpack_require__(moduleId) {
/******/
/******/ // Check if module is in cache
/******/ if(installedModules[moduleId])
/******/ return installedModules[moduleId].exports;
/******/
/******/ // Create a new module (and put it into the cache)
/******/ var module = installedModules[moduleId] = {
/******/ exports: {},
/******/ id: moduleId,
/******/ loaded: false
/******/ };
/******/
/******/ // Execute the module function
/******/ modules[moduleId].call(module.exports, module, module.exports, __webpack_require__);
/******/
/******/ // Flag the module as loaded
/******/ module.loaded = true;
/******/
/******/ // Return the exports of the module
/******/ return module.exports;
/******/ }
/******/
/******/
/******/ // expose the modules object (__webpack_modules__)
/******/ __webpack_require__.m = modules;
/******/
/******/ // expose the module cache
/******/ __webpack_require__.c = installedModules;
/******/
/******/ // __webpack_public_path__
/******/ __webpack_require__.p = "js/";
/******/
/******/ // Load entry module and return exports
/******/ return __webpack_require__(0);
/******/ })
/************************************************************************/
/******/ ([
/* 0 */
/*!********************!*\
!*** ./example.js ***!
\********************/
/***/ function(module, exports, __webpack_require__) {
var add = __webpack_require__(/*! add */ 1);
var subtract = __webpack_require__(/*! subtract */ 2);
exports.exampleValue = subtract(add(42, 2), 2);
/***/ },
/* 1 */
/*!**********************!*\
!*** external "add" ***!
\**********************/
/***/ function(module, exports, __webpack_require__) {
module.exports = __WEBPACK_EXTERNAL_MODULE_1__;
/***/ },
/* 2 */
/*!***************************************************************************************************************!*\
!*** external {"root":"subtract","commonjs2":"./subtract","commonjs":["./math","subtract"],"amd":"subtract"} ***!
\***************************************************************************************************************/
/***/ function(module, exports, __webpack_require__) {
module.exports = __WEBPACK_EXTERNAL_MODULE_2__;
/***/ }
/******/ ])
})
```
# Info
## Uncompressed
```
Hash: b71fd8ed4ddc8b851798
Version: webpack 1.3.2-beta7
Time: 33ms
Asset Size Chunks Chunk Names
output.js 3008 0 [emitted] main
chunk {0} output.js (main) 197 [rendered]
> main [0] ./example.js
[0] ./example.js 113 {0} [built]
```
## Minimized (uglify-js, no zip)
```
Hash: 67a052a42079fa51aad1
Version: webpack 1.3.2-beta7
Time: 80ms
Asset Size Chunks Chunk Names
output.js 706 0 [emitted] main
chunk {0} output.js (main) 197 [rendered]
> main [0] ./example.js
[0] ./example.js 113 {0} [built]
```