17 KiB
17 KiB
This example show how to use Code Splitting with the ES6 module syntax.
The standard import is sync.
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 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 import("c/" + name) creates two additional chunks (one for each file in node_modules/c/). This is called "async context".
example.js
import a from "a";
import("b").then(function(b) {
console.log("b loaded", b);
})
function loadC(name) {
return import("c/" + name);
}
Promise.all([loadC("1"), loadC("2")]).then(function(arr) {
console.log("c/1 and c/2 loaded", arr);
});
dist/output.js
/******/ (() => { // webpackBootstrap
/******/ var __webpack_modules__ = ([
/* 0 */
/*!********************!*\
!*** ./example.js ***!
\********************/
/*! exports [not provided] [no usage info] */
/*! runtime requirements: __webpack_require__, __webpack_require__.n, __webpack_require__.r, __webpack_exports__, __webpack_require__.e, __webpack_require__.t, __webpack_require__.* */
/***/ ((__unused_webpack_module, __webpack_exports__, __webpack_require__) => {
"use strict";
__webpack_require__.r(__webpack_exports__);
/* harmony import */ var a__WEBPACK_IMPORTED_MODULE_0__ = __webpack_require__(/*! a */ 1);
/* harmony import */ var a__WEBPACK_IMPORTED_MODULE_0___default = /*#__PURE__*/__webpack_require__.n(a__WEBPACK_IMPORTED_MODULE_0__);
__webpack_require__.e(/*! import() */ 644).then(__webpack_require__.t.bind(__webpack_require__, /*! b */ 3, 7)).then(function(b) {
console.log("b loaded", b);
})
function loadC(name) {
return __webpack_require__(2)("./" + name);
}
Promise.all([loadC("1"), loadC("2")]).then(function(arr) {
console.log("c/1 and c/2 loaded", arr);
});
/***/ }),
/* 1 */
/*!***************************!*\
!*** ./node_modules/a.js ***!
\***************************/
/*! exports [maybe provided (runtime-defined)] [no usage info] */
/*! runtime requirements: */
/***/ (() => {
// module a
/***/ }),
/* 2 */
/*!*******************************************************!*\
!*** ./node_modules/c lazy ^\.\/.*$ namespace object ***!
\*******************************************************/
/*! exports [maybe provided (runtime-defined)] [no usage info] */
/*! runtime requirements: module, __webpack_require__, __webpack_require__.e, __webpack_require__.t, __webpack_require__.* */
/***/ ((module, __unused_webpack_exports, __webpack_require__) => {
var map = {
"./1": [
4,
346
],
"./1.js": [
4,
346
],
"./2": [
5,
98
],
"./2.js": [
5,
98
]
};
function webpackAsyncContext(req) {
if(!Object.prototype.hasOwnProperty.call(map, req)) {
return Promise.resolve().then(() => {
var e = new Error("Cannot find module '" + req + "'");
e.code = 'MODULE_NOT_FOUND';
throw e;
});
}
var ids = map[req], id = ids[0];
return __webpack_require__.e(ids[1]).then(() => {
return __webpack_require__.t(id, 7);
});
}
webpackAsyncContext.keys = function webpackAsyncContextKeys() {
return Object.keys(map);
};
webpackAsyncContext.id = 2;
module.exports = webpackAsyncContext;
/***/ })
/******/ ]);
/************************************************************************/
/******/ // The module cache
/******/ var __webpack_module_cache__ = {};
/******/
/******/ // The require function
/******/ function __webpack_require__(moduleId) {
/******/ // Check if module is in cache
/******/ if(__webpack_module_cache__[moduleId]) {
/******/ return __webpack_module_cache__[moduleId].exports;
/******/ }
/******/ // Create a new module (and put it into the cache)
/******/ var module = __webpack_module_cache__[moduleId] = {
/******/ i: moduleId,
/******/ l: false,
/******/ exports: {}
/******/ };
/******/
/******/ // Execute the module function
/******/ __webpack_modules__[moduleId](module, module.exports, __webpack_require__);
/******/
/******/ // Flag the module as loaded
/******/ module.l = true;
/******/
/******/ // Return the exports of the module
/******/ return module.exports;
/******/ }
/******/
/******/ // expose the modules object (__webpack_modules__)
/******/ __webpack_require__.m = __webpack_modules__;
/******/
/************************************************************************/
/******/ /* webpack/runtime/compat get default export */
/******/ !function() {
/******/ // getDefaultExport function for compatibility with non-harmony modules
/******/ __webpack_require__.n = (module) => {
/******/ var getter = module && module.__esModule ?
/******/ () => module['default'] :
/******/ () => module;
/******/ __webpack_require__.d(getter, { a: getter });
/******/ return getter;
/******/ };
/******/ }();
/******/
/******/ /* webpack/runtime/create fake namespace object */
/******/ !function() {
/******/ // create a fake namespace object
/******/ // mode & 1: value is a module id, require it
/******/ // mode & 2: merge all properties of value into the ns
/******/ // mode & 4: return value when already ns object
/******/ // mode & 8|1: behave like require
/******/ __webpack_require__.t = function(value, mode) {
/******/ if(mode & 1) value = this(value);
/******/ if(mode & 8) return value;
/******/ if((mode & 4) && typeof value === 'object' && value && value.__esModule) return value;
/******/ var ns = Object.create(null);
/******/ __webpack_require__.r(ns);
/******/ var def = {};
/******/ if(mode & 2 && typeof value == 'object' && value) {
/******/ for(const key in value) def[key] = () => value[key];
/******/ }
/******/ def['default'] = () => value;
/******/ __webpack_require__.d(ns, def);
/******/ return ns;
/******/ };
/******/ }();
/******/
/******/ /* webpack/runtime/define property getters */
/******/ !function() {
/******/ // define getter functions for harmony exports
/******/ var hasOwnProperty = Object.prototype.hasOwnProperty;
/******/ __webpack_require__.d = (exports, definition) => {
/******/ for(var key in definition) {
/******/ if(hasOwnProperty.call(definition, key) && !hasOwnProperty.call(exports, key)) {
/******/ Object.defineProperty(exports, key, { enumerable: true, get: definition[key] });
/******/ }
/******/ }
/******/ };
/******/ }();
/******/
/******/ /* webpack/runtime/ensure chunk */
/******/ !function() {
/******/ __webpack_require__.f = {};
/******/ // This file contains only the entry chunk.
/******/ // The chunk loading function for additional chunks
/******/ __webpack_require__.e = (chunkId) => {
/******/ return Promise.all(Object.keys(__webpack_require__.f).reduce((promises, key) => {
/******/ __webpack_require__.f[key](chunkId, promises);
/******/ return promises;
/******/ }, []));
/******/ };
/******/ }();
/******/
/******/ /* webpack/runtime/get javascript chunk filename */
/******/ !function() {
/******/ // This function allow to reference async chunks
/******/ __webpack_require__.u = (chunkId) => {
/******/ // return url for filenames based on template
/******/ return "" + chunkId + ".output.js";
/******/ };
/******/ }();
/******/
/******/ /* webpack/runtime/make namespace object */
/******/ !function() {
/******/ // define __esModule on exports
/******/ __webpack_require__.r = (exports) => {
/******/ if(typeof Symbol !== 'undefined' && Symbol.toStringTag) {
/******/ Object.defineProperty(exports, Symbol.toStringTag, { value: 'Module' });
/******/ }
/******/ Object.defineProperty(exports, '__esModule', { value: true });
/******/ };
/******/ }();
/******/
/******/ /* webpack/runtime/publicPath */
/******/ !function() {
/******/ __webpack_require__.p = "dist/";
/******/ }();
/******/
/******/ /* webpack/runtime/jsonp chunk loading */
/******/ !function() {
/******/
/******/
/******/ // object to store loaded and loading chunks
/******/ // undefined = chunk not loaded, null = chunk preloaded/prefetched
/******/ // Promise = chunk loading, 0 = chunk loaded
/******/ var installedChunks = {
/******/ 179: 0
/******/ };
/******/
/******/
/******/
/******/
/******/ __webpack_require__.f.j = (chunkId, promises) => {
/******/ // JSONP chunk loading for javascript
/******/ var installedChunkData = Object.prototype.hasOwnProperty.call(installedChunks, chunkId) ? installedChunks[chunkId] : undefined;
/******/ if(installedChunkData !== 0) { // 0 means "already installed".
/******/
/******/ // a Promise means "currently loading".
/******/ if(installedChunkData) {
/******/ promises.push(installedChunkData[2]);
/******/ } else {
/******/ if(true) { // all chunks have JS
/******/ // setup Promise in chunk cache
/******/ var promise = new Promise((resolve, reject) => {
/******/ installedChunkData = installedChunks[chunkId] = [resolve, reject];
/******/ });
/******/ promises.push(installedChunkData[2] = promise);
/******/
/******/ // start chunk loading
/******/ var url = __webpack_require__.p + __webpack_require__.u(chunkId);
/******/ var loadingEnded = () => {
/******/ if(Object.prototype.hasOwnProperty.call(installedChunks, chunkId)) {
/******/ installedChunkData = installedChunks[chunkId];
/******/ if(installedChunkData !== 0) installedChunks[chunkId] = undefined;
/******/ if(installedChunkData) return installedChunkData[1];
/******/ }
/******/ };
/******/ var script = document.createElement('script');
/******/ var onScriptComplete;
/******/
/******/ script.charset = 'utf-8';
/******/ script.timeout = 120;
/******/ if (__webpack_require__.nc) {
/******/ script.setAttribute("nonce", __webpack_require__.nc);
/******/ }
/******/ script.src = url;
/******/
/******/ // create error before stack unwound to get useful stacktrace later
/******/ var error = new Error();
/******/ onScriptComplete = function (event) {
/******/ onScriptComplete = function() {};
/******/ // avoid mem leaks in IE.
/******/ script.onerror = script.onload = null;
/******/ clearTimeout(timeout);
/******/ var reportError = loadingEnded();
/******/ if(reportError) {
/******/ var errorType = event && (event.type === 'load' ? 'missing' : event.type);
/******/ var realSrc = event && event.target && event.target.src;
/******/ error.message = 'Loading chunk ' + chunkId + ' failed.\n(' + errorType + ': ' + realSrc + ')';
/******/ error.name = 'ChunkLoadError';
/******/ error.type = errorType;
/******/ error.request = realSrc;
/******/ reportError(error);
/******/ }
/******/ };
/******/ var timeout = setTimeout(function(){
/******/ onScriptComplete({ type: 'timeout', target: script });
/******/ }, 120000);
/******/ script.onerror = script.onload = onScriptComplete;
/******/ document.head.appendChild(script);
/******/ } else installedChunks[chunkId] = 0;
/******/
/******/ // no HMR
/******/ }
/******/ }
/******/
/******/ // no chunk preloading needed
/******/ };
/******/
/******/ // no prefetching
/******/
/******/ // no HMR
/******/
/******/ // no HMR manifest
/******/
/******/ // no deferred startup or startup prefetching
/******/
/******/ // install a JSONP callback for chunk loading
/******/ function webpackJsonpCallback(data) {
/******/ var chunkIds = data[0];
/******/ var moreModules = data[1];
/******/
/******/ var runtime = data[3];
/******/
/******/ // 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(Object.prototype.hasOwnProperty.call(installedChunks, chunkId) && installedChunks[chunkId]) {
/******/ resolves.push(installedChunks[chunkId][0]);
/******/ }
/******/ installedChunks[chunkId] = 0;
/******/ }
/******/ for(moduleId in moreModules) {
/******/ if(Object.prototype.hasOwnProperty.call(moreModules, moduleId)) {
/******/ __webpack_require__.m[moduleId] = moreModules[moduleId];
/******/ }
/******/ }
/******/ if(runtime) runtime(__webpack_require__);
/******/ if(parentJsonpFunction) parentJsonpFunction(data);
/******/
/******/ while(resolves.length) {
/******/ resolves.shift()();
/******/ }
/******/
/******/ };
/******/
/******/ var jsonpArray = window["webpackJsonp"] = window["webpackJsonp"] || [];
/******/ var oldJsonpFunction = jsonpArray.push.bind(jsonpArray);
/******/ jsonpArray.push = webpackJsonpCallback;
/******/
/******/ var parentJsonpFunction = oldJsonpFunction;
/******/ }();
/******/
/************************************************************************/
/******/ // startup
/******/ // Load entry module
/******/ __webpack_require__(0);
/******/ // This entry module used 'exports' so it can't be inlined
/******/ })()
;
Info
Unoptimized
Hash: 0a1b2c3d4e5f6a7b8c9d
Version: webpack 5.0.0-beta.6
Asset Size
346.output.js 325 bytes [emitted]
644.output.js 317 bytes [emitted]
98.output.js 324 bytes [emitted]
output.js 12.3 KiB [emitted] [name: main]
Entrypoint main = output.js
chunk 98.output.js 13 bytes [rendered]
> ./2 ./node_modules/c lazy ^\.\/.*$ namespace object ./2
> ./2.js ./node_modules/c lazy ^\.\/.*$ namespace object ./2.js
./node_modules/c/2.js 13 bytes [optional] [built]
[used exports unknown]
context element ./2 ./node_modules/c lazy ^\.\/.*$ namespace object ./2
context element ./2.js ./node_modules/c lazy ^\.\/.*$ namespace object ./2.js
chunk output.js (main) 414 bytes (javascript) 5.77 KiB (runtime) [entry] [rendered]
> ./example.js main
./example.js 243 bytes [built]
[no exports]
[used exports unknown]
entry ./example.js main
./node_modules/a.js 11 bytes [built]
[used exports unknown]
harmony side effect evaluation a ./example.js 1:0-18
./node_modules/c lazy ^\.\/.*$ namespace object 160 bytes [built]
[used exports unknown]
import() context lazy c ./example.js 8:8-27
+ 8 hidden chunk modules
chunk 346.output.js 13 bytes [rendered]
> ./1 ./node_modules/c lazy ^\.\/.*$ namespace object ./1
> ./1.js ./node_modules/c lazy ^\.\/.*$ namespace object ./1.js
./node_modules/c/1.js 13 bytes [optional] [built]
[used exports unknown]
context element ./1 ./node_modules/c lazy ^\.\/.*$ namespace object ./1
context element ./1.js ./node_modules/c lazy ^\.\/.*$ namespace object ./1.js
chunk 644.output.js 11 bytes [rendered]
> b ./example.js 3:0-11
./node_modules/b.js 11 bytes [built]
[used exports unknown]
import() b ./example.js 3:0-11
Production mode
Hash: 0a1b2c3d4e5f6a7b8c9d
Version: webpack 5.0.0-beta.6
Asset Size
346.output.js 73 bytes [emitted]
644.output.js 73 bytes [emitted]
98.output.js 71 bytes [emitted]
output.js 2.62 KiB [emitted] [name: main]
Entrypoint main = output.js
chunk 98.output.js 13 bytes [rendered]
> ./2 ./node_modules/c lazy ^\.\/.*$ namespace object ./2
> ./2.js ./node_modules/c lazy ^\.\/.*$ namespace object ./2.js
./node_modules/c/2.js 13 bytes [optional] [built]
context element ./2 ./node_modules/c lazy ^\.\/.*$ namespace object ./2
context element ./2.js ./node_modules/c lazy ^\.\/.*$ namespace object ./2.js
chunk output.js (main) 414 bytes (javascript) 5.77 KiB (runtime) [entry] [rendered]
> ./example.js main
./example.js 243 bytes [built]
[no exports]
[no exports used]
entry ./example.js main
./node_modules/a.js 11 bytes [built]
[no exports used]
harmony side effect evaluation a ./example.js 1:0-18
./node_modules/c lazy ^\.\/.*$ namespace object 160 bytes [built]
import() context lazy c ./example.js 8:8-27
+ 8 hidden chunk modules
chunk 346.output.js 13 bytes [rendered]
> ./1 ./node_modules/c lazy ^\.\/.*$ namespace object ./1
> ./1.js ./node_modules/c lazy ^\.\/.*$ namespace object ./1.js
./node_modules/c/1.js 13 bytes [optional] [built]
context element ./1 ./node_modules/c lazy ^\.\/.*$ namespace object ./1
context element ./1.js ./node_modules/c lazy ^\.\/.*$ namespace object ./1.js
chunk 644.output.js 11 bytes [rendered]
> b ./example.js 3:0-11
./node_modules/b.js 11 bytes [built]
import() b ./example.js 3:0-11