webpack/examples/loader/README.md

example.js

// use our loader
console.dir(require("./loader!./file"));

// use buildin json loader
console.dir(require("./test.json")); // default by extension
console.dir(require("!json!./test.json")); // manual

file.js

exports.foo = "bar";

loader.js

module.exports = function(content) {
	return "exports.answer = 42;\n" + content;
}

test.json

{
	"foobar": 1234
}

js/output.js

(function(modules) { // webpackBootstrap
// The module cache
var installedModules = {};

// The require function
function 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(null, module, module.exports, require);
	
	// Flag the module as loaded
	module.loaded = true;
	
	// Return the exports of the module
	return module.exports;
}

require.e = function requireEnsure(_, callback) {
	callback.call(null, require);
};
require.modules = modules;
require.cache = installedModules;


// Load entry module and return exports
return require(0);
})
/************************************************************************/
({
// __webpack_public_path__

c: "",
/***/ 0:
/*!********************!*\
  !*** ./example.js ***!
  \********************/
/***/ function(module, exports, require) {

// use our loader
console.dir(require(/*! ./loader!./file */ 2));

// use buildin json loader
console.dir(require(/*! ./test.json */ 1)); // default by extension
console.dir(require(/*! json!./test.json */ 1)); // manual

/***/ },

/***/ 1:
/*!************************************************************************************!*\
  !*** (webpack)/~/json-loader!./test.json ***!
  \************************************************************************************/
/***/ function(module, exports, require) {

module.exports = {
	"foobar": 1234
}

/***/ },

/***/ 2:
/*!*****************************!*\
  !*** ./loader.js!./file.js ***!
  \*****************************/
/***/ function(module, exports, require) {

exports.answer = 42;
exports.foo = "bar";

/***/ }
})

Console output

Prints in node.js (enhanced-require example.js) and in browser:

{ answer: 42, foo: 'bar' }
{ foobar: 1234 }
{ foobar: 1234 }

Info

Uncompressed

Hash: 5caaa03683d41f386ba25cd5e2812588
Version: webpack 0.10.0-beta1
Time: 57ms
    Asset  Size  Chunks  Chunk Names
output.js  1889       0  main       
chunk    {0} output.js (main) 282
    [0] ./example.js 205 [built] {0}
    [1] (webpack)/~/json-loader!./test.json 36 [built] {0}
        cjs require ./test.json [0] ./example.js 5:12-34
        cjs require !json!./test.json [0] ./example.js 6:12-40
    [2] ./loader.js!./file.js 41 [not cacheable] [built] {0}
        cjs require ./loader!./file [0] ./example.js 2:12-38