This example show how to use Code Splitting with the ES6 module syntax.
The standard import is sync.
System.import(module: string) -> Promise can be used to load modules on demand. This acts as split point for webpack and creates a chunk.
Providing dynamic expressions to System.import is possible. The same limits as with dynamic expressions in require calls apply here. Each possible module creates an additional chunk. In this example System.import("c/" + name) creates two additional chunks (one for each file in node_modules/c/). This is called "async context".
import a from "a";
System.import("b").then(function(b) {
console.log("b loaded", b);
})
function loadC(name) {
return System.import("c/" + name)
}
Promise.all([loadC("1"), loadC("2")]).then(function(arr) {
console.log("c/1 and c/2 loaded", arr);
});/******/ (function(modules) { // webpackBootstrap
/******/ // install a JSONP callback for chunk loading
/******/ var parentJsonpFunction = window["webpackJsonp"];
/******/ window["webpackJsonp"] = function webpackJsonpCallback(chunkIds, moreModules, executeModule) {
/******/ // add "moreModules" to the modules object,
/******/ // then flag all "chunkIds" as loaded and fire callback
/******/ var moduleId, chunkId, i = 0, resolves = [];
/******/ for(;i < chunkIds.length; i++) {
/******/ chunkId = chunkIds[i];
/******/ if(installedChunks[chunkId])
/******/ resolves.push(installedChunks[chunkId][0]);
/******/ installedChunks[chunkId] = 0;
/******/ }
/******/ for(moduleId in moreModules) {
/******/ modules[moduleId] = moreModules[moduleId];
/******/ }
/******/ if(parentJsonpFunction) parentJsonpFunction(chunkIds, moreModules);
/******/ while(resolves.length)
/******/ resolves.shift()();
/******/ };
/******/ // The module cache
/******/ var installedModules = {};
/******/ // objects to store loaded and loading chunks
/******/ var installedChunks = {
/******/ 2: 0
/******/ };
/******/ // 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;
/******/ }
/******/ // This file contains only the entry chunk.
/******/ // The chunk loading function for additional chunks
/******/ __webpack_require__.e = function requireEnsure(chunkId) {
/******/ if(installedChunks[chunkId] === 0)
/******/ return Promise.resolve()
/******/ // an Promise means "currently loading".
/******/ if(installedChunks[chunkId]) {
/******/ return installedChunks[chunkId][2];
/******/ }
/******/ // start chunk loading
/******/ var head = document.getElementsByTagName('head')[0];
/******/ var script = document.createElement('script');
/******/ script.type = 'text/javascript';
/******/ script.charset = 'utf-8';
/******/ script.async = true;
/******/ script.timeout = 120000;
/******/ script.src = __webpack_require__.p + "" + chunkId + ".js";
/******/ var timeout = setTimeout(onScriptComplete, 120000);
/******/ script.onerror = script.onload = onScriptComplete;
/******/ function onScriptComplete() {
/******/ // avoid mem leaks in IE.
/******/ script.onerror = script.onload = null;
/******/ clearTimeout(timeout);
/******/ var chunk = installedChunks[chunkId];
/******/ if(chunk !== 0) {
/******/ if(chunk) chunk[1](new Error('Loading chunk ' + chunkId + ' failed.'));
/******/ installedChunks[chunkId] = undefined;
/******/ }
/******/ };
/******/ head.appendChild(script);
/******/ var promise = new Promise(function(resolve, reject) {
/******/ installedChunks[chunkId] = [resolve, reject];
/******/ });
/******/ return installedChunks[chunkId][2] = promise;
/******/ };
/******/ // 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/";
/******/ // on error function for async loading
/******/ __webpack_require__.oe = function(err) { throw err; };
/******/ // Load entry module and return exports
/******/ return __webpack_require__(__webpack_require__.s = 4);
/******/ })
/************************************************************************/
/******/ ([
/* 0 */
/*!****************!*\
!*** ./~/a.js ***!
\****************/
/***/ function(module, exports) {
// module a
/***/ },
/* 1 */
/*!****************************!*\
!*** ./~/c async ^\.\/.*$ ***!
\****************************/
/***/ function(module, exports, __webpack_require__) {
var map = {
"./1": [
2,
1
],
"./1.js": [
2,
1
],
"./2": [
3,
0
],
"./2.js": [
3,
0
]
};
function webpackAsyncContext(req) {
var ids = map[req]; if(!ids)
return Promise.reject(new Error("Cannot find module '" + req + "'."));
return __webpack_require__.e(ids[1]).then(function() {
return __webpack_require__(ids[0]);
});
};
webpackAsyncContext.keys = function webpackAsyncContextKeys() {
return Object.keys(map);
};
module.exports = webpackAsyncContext;
webpackAsyncContext.id = 1;
/***/ },
/* 2 */,
/* 3 */,
/* 4 */
/*!********************!*\
!*** ./example.js ***!
\********************/
/***/ function(module, exports, __webpack_require__) {
/* harmony import */ var __WEBPACK_IMPORTED_MODULE_0_a__ = __webpack_require__(/*! a */ 0);
/* harmony import */ var __WEBPACK_IMPORTED_MODULE_0_a___default = __WEBPACK_IMPORTED_MODULE_0_a__ && __WEBPACK_IMPORTED_MODULE_0_a__.__esModule ? function() { return __WEBPACK_IMPORTED_MODULE_0_a__['default'] } : function() { return __WEBPACK_IMPORTED_MODULE_0_a__; }
/* harmony import */ Object.defineProperty(__WEBPACK_IMPORTED_MODULE_0_a___default, 'a', { get: __WEBPACK_IMPORTED_MODULE_0_a___default });
__webpack_require__.e/* System.import */(3).then(__webpack_require__.bind(null, /*! b */ 5)).then(function(b) {
console.log("b loaded", b);
})
function loadC(name) {
return __webpack_require__(/*! c */ 1)("./" + name)
}
Promise.all([loadC("1"), loadC("2")]).then(function(arr) {
console.log("c/1 and c/2 loaded", arr);
});
/***/ }
/******/ ]);Hash: cefcab66a83c5000d38e
Version: webpack 2.0.6-beta
Time: 141ms
Asset Size Chunks Chunk Names
0.js 163 bytes 0 [emitted]
1.js 163 bytes 1 [emitted]
output.js 5.95 kB 2 [emitted] main
3.js 155 bytes 3 [emitted]
chunk {0} 0.js 13 bytes {2} [rendered]
[3] ./~/c/2.js 13 bytes {0} [optional] [built]
context element ./2 [1] ./~/c async ^\.\/.*$
context element ./2.js [1] ./~/c async ^\.\/.*$
chunk {1} 1.js 13 bytes {2} [rendered]
[2] ./~/c/1.js 13 bytes {1} [optional] [built]
context element ./1 [1] ./~/c async ^\.\/.*$
context element ./1.js [1] ./~/c async ^\.\/.*$
chunk {2} output.js (main) 440 bytes [rendered]
> main [4] ./example.js
[0] ./~/a.js 11 bytes {2} [built]
harmony import a [4] ./example.js 1:0-18
[1] ./~/c async ^\.\/.*$ 160 bytes {2} [built]
System.import context c [4] ./example.js 8:8-34
[4] ./example.js 269 bytes {2} [built]
chunk {3} 3.js 11 bytes {2} [rendered]
> [4] ./example.js 3:0-18
[5] ./~/b.js 11 bytes {3} [built]
System.import b [4] ./example.js 3:0-18
Hash: cefcab66a83c5000d38e
Version: webpack 2.0.6-beta
Time: 239ms
Asset Size Chunks Chunk Names
0.js 38 bytes 0 [emitted]
1.js 38 bytes 1 [emitted]
output.js 1.56 kB 2 [emitted] main
3.js 38 bytes 3 [emitted]
chunk {0} 0.js 13 bytes {2} [rendered]
[3] ./~/c/2.js 13 bytes {0} [optional] [built]
context element ./2 [1] ./~/c async ^\.\/.*$
context element ./2.js [1] ./~/c async ^\.\/.*$
chunk {1} 1.js 13 bytes {2} [rendered]
[2] ./~/c/1.js 13 bytes {1} [optional] [built]
context element ./1 [1] ./~/c async ^\.\/.*$
context element ./1.js [1] ./~/c async ^\.\/.*$
chunk {2} output.js (main) 440 bytes [rendered]
> main [4] ./example.js
[0] ./~/a.js 11 bytes {2} [built]
harmony import a [4] ./example.js 1:0-18
[1] ./~/c async ^\.\/.*$ 160 bytes {2} [built]
System.import context c [4] ./example.js 8:8-34
[4] ./example.js 269 bytes {2} [built]
chunk {3} 3.js 11 bytes {2} [rendered]
> [4] ./example.js 3:0-18
[5] ./~/b.js 11 bytes {3} [built]
System.import b [4] ./example.js 3:0-18