经典webpack入门（讲的很透彻）
<p style="margin-top: 18px; margin-bottom: 18px; color: rgb(51, 51, 51); font-family: "helvetica neue", tahoma, "hiragino sans gb", stheiti, "wenquanyi micro hei", 微软雅黑, 宋体, sans-serif; font-size: 16px; line-height: 27.2px;"><strong>Webpack your bags</strong><br>原文： <a href="https://blog.madewithlove.be/post/webpack-your-bags/" title="Webpack your bags" target="_blank" style="text-decoration: none; color: rgb(49, 135, 219);">**Webpack your bags**</a>(by <a href="https://twitter.com/anahkiasen" target="_blank" style="text-decoration: none; color: rgb(49, 135, 219); margin-left: 0.25em;">Maxime Fabre</a>)<br>2016年5月28日 杜梁 翻译。 <strong>如果您觉得我的翻译能给你带来点帮助，那就给我点个Star鼓励一下吧^_^,</strong> <a href="https://github.com/starduliang/blog/tree/master/2016.6" target="_blank" style="text-decoration: none; color: rgb(49, 135, 219);">我的github会持续更新</a> <a href="https://github.com/starduliang/blog/tree/master/2016.6/assets/webpack%20your%20bags/source/webpack-your-bags-demo" target="_blank" style="text-decoration: none; color: rgb(49, 135, 219); margin-left: 0.25em;">source here</a></p><p style="margin-top: 18px; margin-bottom: 18px; color: rgb(51, 51, 51); font-family: "helvetica neue", tahoma, "hiragino sans gb", stheiti, "wenquanyi micro hei", 微软雅黑, 宋体, sans-serif; font-size: 16px; line-height: 27.2px;"><img src="https://webpack.github.io/assets/what-is-webpack.png" alt="" style="max-width: 50em; margin-top: 1em; margin-bottom: 1em;"></p><p style="margin-top: 18px; margin-bottom: 18px; color: rgb(51, 51, 51); font-family: "helvetica neue", tahoma, "hiragino sans gb", stheiti, "wenquanyi micro hei", 微软雅黑, 宋体, sans-serif; font-size: 16px; line-height: 27.2px;">Webpack your bags</p><p style="margin-top: 18px; margin-bottom: 18px; color: rgb(51, 51, 51); font-family: "helvetica neue", tahoma, "hiragino sans gb", stheiti, "wenquanyi micro hei", 微软雅黑, 宋体, sans-serif; font-size: 16px; line-height: 27.2px;">之前你可能已经听说过这个很酷的叫webpack工具，如果你没仔细了解过这个工具，你可能会有些困惑，因为有人说他它是像<strong>Gulp</strong>之类构建工具，也有人说它是像<strong>Browserify</strong>之类的bundler，如果你仔细了解一下，你可能还是会不明白是怎么回事儿，因为官网上把webpack说成是这两者。</p><p style="margin-top: 18px; margin-bottom: 18px; color: rgb(51, 51, 51); font-family: "helvetica neue", tahoma, "hiragino sans gb", stheiti, "wenquanyi micro hei", 微软雅黑, 宋体, sans-serif; font-size: 16px; line-height: 27.2px;">说实话，开始的时候对于**“webpack到底是什么“很模糊，感觉很受挫，然后我直接就把网页关了，毕竟我已经有一个构建系统了，而且我用得也非常哈皮，如果你紧赶javascript的时髦的话，像我这样，你可能在估计很快因为在各种流行的东西中频繁地跳来跳去而烧的灰飞烟灭了。<br>现在我有些经验了，我觉得我应该写这篇文章给那些还处在混沌中的小伙伴儿，更清楚解释一下webpack到底是什么，更重要的是它的什么地方那么棒以至于值得我们投入更多的精力。</p><h2 style="font-size: 26px; margin-top: 20px; margin-bottom: 20px; counter-reset: section 0; font-weight: normal; color: rgb(51, 51, 51); font-family: "helvetica neue", tahoma, "hiragino sans gb", stheiti, "wenquanyi micro hei", 微软雅黑, 宋体, sans-serif;">Webpack是什么？</h2><p style="margin-top: 18px; margin-bottom: 18px; color: rgb(51, 51, 51); font-family: "helvetica neue", tahoma, "hiragino sans gb", stheiti, "wenquanyi micro hei", 微软雅黑, 宋体, sans-serif; font-size: 16px; line-height: 27.2px;">好的，下面我们来回答一下，介绍里面提到的那个问题，Webpack是一个构建系统还是一个模块bundler（捆绑器），恩-，两个都是 - 我不是说它两个事儿都干，我的意思是它把两者连接起来了，webpack不是先构建你的资源（assets），然后再bundle你的模块，它把你的资源本身当做模块。</p><p style="margin-top: 18px; margin-bottom: 18px; color: rgb(51, 51, 51); font-family: "helvetica neue", tahoma, "hiragino sans gb", stheiti, "wenquanyi micro hei", 微软雅黑, 宋体, sans-serif; font-size: 16px; line-height: 27.2px;">更准确的说，它不是先编译你的所有的Sass文件，再优化所有的图片，再在一个地方include进来，然后bundle所有的模块，在另一个地方include到你的page上。假设你在是下面这样：</p><pre style="font-family: consolas, monaco, menlo, "courier new", courier, monospace; border: 1px solid rgb(221, 221, 221); font-size: 12px; line-height: 18px; overflow: auto; padding: 6px 10px; border-radius: 3px; word-break: break-all; color: rgb(51, 51, 51); background-color: rgb(248, 248, 248);"><code style="font-family: consolas, monaco, menlo, "courier new", courier, monospace; display: inline-block; line-height: 1.5; border: 0px none; border-radius: 0px; font-size: inherit; background: none;">import stylesheet from 'styles/my-styles.scss';import logo from 'img/my-logo.svg';
import someTemplate from 'html/some-template.html';
console.log(stylesheet); // "body{font-size:12px}"
console.log(logo); // "data:image/svg+xml;base64,PD94bWwgdmVyc2lvbj0iMS4wIiBlbmNvZGluZz0iVVRGLTgiIHN0YW5kYWxvbmU9Im5[...]"
console.log(someTemplate) // "<html><body><h1>Hello</h1></body></html>"
</code></pre><p style="margin-top: 18px; margin-bottom: 18px; color: rgb(51, 51, 51); font-family: "helvetica neue", tahoma, "hiragino sans gb", stheiti, "wenquanyi micro hei", 微软雅黑, 宋体, sans-serif; font-size: 16px; line-height: 27.2px;">你的所有的资源本身被当成模块，这些模块可以被import，modify，manipulate（操作），最后被打包到你最后的bundle</p><p style="margin-top: 18px; margin-bottom: 18px; color: rgb(51, 51, 51); font-family: "helvetica neue", tahoma, "hiragino sans gb", stheiti, "wenquanyi micro hei", 微软雅黑, 宋体, sans-serif; font-size: 16px; line-height: 27.2px;">为了达到这个目的，得在webpack configuration里注册loaders，loader就是当你遇到某种文件的时候，对它做相应的一种处理的一种插件，下面是一些loader的例子：</p><pre style="font-family: consolas, monaco, menlo, "courier new", courier, monospace; border: 1px solid rgb(221, 221, 221); font-size: 12px; line-height: 18px; overflow: auto; padding: 6px 10px; border-radius: 3px; word-break: break-all; color: rgb(51, 51, 51); background-color: rgb(248, 248, 248);"><code style="font-family: consolas, monaco, menlo, "courier new", courier, monospace; display: inline-block; line-height: 1.5; border: 0px none; border-radius: 0px; font-size: inherit; background: none;">{
// When you import a .ts file, parse it with Typescript
test: /\.ts/,
loader: 'typescript',
},
{
// When you encounter images, compress them with image-webpack (wrapper around imagemin)
// and then inline them as data64 URLs
test: /\.(png|jpg|svg)/,
loaders: ['url', 'image-webpack'],
},
{
// When you encounter SCSS files, parse them with node-sass, then pass autoprefixer on them
// then return the results as a string of CSS
test: /\.scss/,
loaders: ['css', 'autoprefixer', 'sass'],
}
</code></pre><p style="margin-top: 18px; margin-bottom: 18px; color: rgb(51, 51, 51); font-family: "helvetica neue", tahoma, "hiragino sans gb", stheiti, "wenquanyi micro hei", 微软雅黑, 宋体, sans-serif; font-size: 16px; line-height: 27.2px;">最后在食物链的终点所有的loader返回的都是string，这样可以使webpack把资源最后包装成javascript模块。这个例子里你的Sass文件被loaders转换后，里面看起来差不多是这样。</p><pre style="font-family: consolas, monaco, menlo, "courier new", courier, monospace; border: 1px solid rgb(221, 221, 221); font-size: 12px; line-height: 18px; overflow: auto; padding: 6px 10px; border-radius: 3px; word-break: break-all; color: rgb(51, 51, 51); background-color: rgb(248, 248, 248);"><code style="font-family: consolas, monaco, menlo, "courier new", courier, monospace; display: inline-block; line-height: 1.5; border: 0px none; border-radius: 0px; font-size: inherit; background: none;">export default 'body{font-size:12px}';
</code></pre><p style="margin-top: 18px; margin-bottom: 18px; color: rgb(51, 51, 51); font-family: "helvetica neue", tahoma, "hiragino sans gb", stheiti, "wenquanyi micro hei", 微软雅黑, 宋体, sans-serif; font-size: 16px; line-height: 27.2px;"><img src="http://i.imgur.com/iK7sL6Z.gif" alt="" style="max-width: 50em; margin-top: 1em; margin-bottom: 1em;"></p><h2 style="font-size: 26px; margin-top: 20px; margin-bottom: 20px; counter-reset: section 0; font-weight: normal; color: rgb(51, 51, 51); font-family: "helvetica neue", tahoma, "hiragino sans gb", stheiti, "wenquanyi micro hei", 微软雅黑, 宋体, sans-serif;">那你究竟为什么要用它呢？</h2><p style="margin-top: 18px; margin-bottom: 18px; color: rgb(51, 51, 51); font-family: "helvetica neue", tahoma, "hiragino sans gb", stheiti, "wenquanyi micro hei", 微软雅黑, 宋体, sans-serif; font-size: 16px; line-height: 27.2px;">一旦你明白webpack是做什么的，很有可能就会想到第二个问题：用它能有什么好处呢？images和CSS？还在我的JS里？玩啥呢哥们儿。好的，看下这个：很长时间我一直被告诉要把所有文件都放在一个文件里，这样来保证不浪费我们的request。</p><p style="margin-top: 18px; margin-bottom: 18px; color: rgb(51, 51, 51); font-family: "helvetica neue", tahoma, "hiragino sans gb", stheiti, "wenquanyi micro hei", 微软雅黑, 宋体, sans-serif; font-size: 16px; line-height: 27.2px;">但这样导致一个最大的缺点，就是现在大多数人都把所有的资源（assets）bundle到一个单独的app.js文件里，然后把他include每一个页面，这就意味着渲染任意一个页面的时候大部分时间都浪费在加载一大堆根本用不上的资源上。如果你不这么做，那么你很有可能得手动把这些资源include到指定的页面，这就会引出一大团乱遭的依赖树去维护和跟踪如：哪些页面这个需要依赖？哪些页面style A 和Style B 起作用。</p><p style="margin-top: 18px; margin-bottom: 18px; color: rgb(51, 51, 51); font-family: "helvetica neue", tahoma, "hiragino sans gb", stheiti, "wenquanyi micro hei", 微软雅黑, 宋体, sans-serif; font-size: 16px; line-height: 27.2px;">这两个方法都不对，也都不是错的。我们把webpack当做一个中间者-他不仅仅是一个构建（build）系统或者一个bundler，它是一个邪恶小精灵般的智能打包（packing）系统，正确地配置后，它甚至比你都了解你的系统栈（stack），而且它比你清楚怎么样最优优化你的系统。</p><h2 style="font-size: 26px; margin-top: 20px; margin-bottom: 20px; counter-reset: section 0; font-weight: normal; color: rgb(51, 51, 51); font-family: "helvetica neue", tahoma, "hiragino sans gb", stheiti, "wenquanyi micro hei", 微软雅黑, 宋体, sans-serif;">我们来做一个小的app</h2><p style="margin-top: 18px; margin-bottom: 18px; color: rgb(51, 51, 51); font-family: "helvetica neue", tahoma, "hiragino sans gb", stheiti, "wenquanyi micro hei", 微软雅黑, 宋体, sans-serif; font-size: 16px; line-height: 27.2px;">为了让你更容易地理解webpack带来的好处，我们做一个小的app，然后用它来bundle 资源（assets），在本篇文章里我建议用Node 4 (或 5)和NPM 3因为扁平的依赖树在你用webpack的时候会避免很多让人头疼的麻烦，如果你还没有NPM3,你可以通过 <code style="font-family: consolas, monaco, menlo, "courier new", courier, monospace; display: inline-block; line-height: normal; margin-right: 0.25em; margin-left: 0.25em; padding-right: 0.4em; padding-left: 0.4em; border: 1px solid rgb(221, 221, 221); border-radius: 3px; background-color: rgb(248, 248, 248);">npm install npm@3 -g</code> 来安装。</p><pre style="font-family: consolas, monaco, menlo, "courier new", courier, monospace; border: 1px solid rgb(221, 221, 221); font-size: 12px; line-height: 18px; overflow: auto; padding: 6px 10px; border-radius: 3px; word-break: break-all; color: rgb(51, 51, 51); background-color: rgb(248, 248, 248);"><code style="font-family: consolas, monaco, menlo, "courier new", courier, monospace; display: inline-block; line-height: 1.5; border: 0px none; border-radius: 0px; font-size: inherit; background: none;">$ node --version
v5.7.1
$ npm --version
3.6.0
</code></pre><p style="margin-top: 18px; margin-bottom: 18px; color: rgb(51, 51, 51); font-family: "helvetica neue", tahoma, "hiragino sans gb", stheiti, "wenquanyi micro hei", 微软雅黑, 宋体, sans-serif; font-size: 16px; line-height: 27.2px;">同时我也建议你把 <code style="font-family: consolas, monaco, menlo, "courier new", courier, monospace; display: inline-block; line-height: normal; margin-right: 0.25em; margin-left: 0.25em; padding-right: 0.4em; padding-left: 0.4em; border: 1px solid rgb(221, 221, 221); border-radius: 3px; background-color: rgb(248, 248, 248);">node_modules/.bin</code> 加到你的PATH variable（环境变量里）以避免每次都手动打 <code style="font-family: consolas, monaco, menlo, "courier new", courier, monospace; display: inline-block; line-height: normal; margin-right: 0.25em; margin-left: 0.25em; padding-right: 0.4em; padding-left: 0.4em; border: 1px solid rgb(221, 221, 221); border-radius: 3px; background-color: rgb(248, 248, 248);">node_modules/.bin/webpack</code> ，后面的所有例子都不会显示我要执行的命令行的 <code style="font-family: consolas, monaco, menlo, "courier new", courier, monospace; display: inline-block; line-height: normal; margin-right: 0.25em; margin-left: 0.25em; padding-right: 0.4em; padding-left: 0.4em; border: 1px solid rgb(221, 221, 221); border-radius: 3px; background-color: rgb(248, 248, 248);">node_modules/.bin</code> 部分。</p><p style="margin-top: 18px; margin-bottom: 18px; color: rgb(51, 51, 51); font-family: "helvetica neue", tahoma, "hiragino sans gb", stheiti, "wenquanyi micro hei", 微软雅黑, 宋体, sans-serif; font-size: 16px; line-height: 27.2px;"><strong>基本引导</strong><br>我们开始，先创建个project，安装上webpack，我们也加上jquery好在后面证明一些东西。</p><pre style="font-family: consolas, monaco, menlo, "courier new", courier, monospace; border: 1px solid rgb(221, 221, 221); font-size: 12px; line-height: 18px; overflow: auto; padding: 6px 10px; border-radius: 3px; word-break: break-all; color: rgb(51, 51, 51); background-color: rgb(248, 248, 248);"><code style="font-family: consolas, monaco, menlo, "courier new", courier, monospace; display: inline-block; line-height: 1.5; border: 0px none; border-radius: 0px; font-size: inherit; background: none;">$ npm init -y
$ npm install jquery --save
$ npm install webpack --save-dev
</code></pre><p style="margin-top: 18px; margin-bottom: 18px; color: rgb(51, 51, 51); font-family: "helvetica neue", tahoma, "hiragino sans gb", stheiti, "wenquanyi micro hei", 微软雅黑, 宋体, sans-serif; font-size: 16px; line-height: 27.2px;">现在来我们创建一个app入口，用纯ES5 （in plain ES5）</p><p style="margin-top: 18px; margin-bottom: 18px; color: rgb(51, 51, 51); font-family: "helvetica neue", tahoma, "hiragino sans gb", stheiti, "wenquanyi micro hei", 微软雅黑, 宋体, sans-serif; font-size: 16px; line-height: 27.2px;"><strong>src/index.js</strong></p><pre style="font-family: consolas, monaco, menlo, "courier new", courier, monospace; border: 1px solid rgb(221, 221, 221); font-size: 12px; line-height: 18px; overflow: auto; padding: 6px 10px; border-radius: 3px; word-break: break-all; color: rgb(51, 51, 51); background-color: rgb(248, 248, 248);"><code style="font-family: consolas, monaco, menlo, "courier new", courier, monospace; display: inline-block; line-height: 1.5; border: 0px none; border-radius: 0px; font-size: inherit; background: none;">var $ = require('jquery');
$('body').html('Hello');
</code></pre><p style="margin-top: 18px; margin-bottom: 18px; color: rgb(51, 51, 51); font-family: "helvetica neue", tahoma, "hiragino sans gb", stheiti, "wenquanyi micro hei", 微软雅黑, 宋体, sans-serif; font-size: 16px; line-height: 27.2px;">在一个webpack.config.js文件里建webpack configuration，webpack configuration是javascript，需要export 一个object</p><p style="margin-top: 18px; margin-bottom: 18px; color: rgb(51, 51, 51); font-family: "helvetica neue", tahoma, "hiragino sans gb", stheiti, "wenquanyi micro hei", 微软雅黑, 宋体, sans-serif; font-size: 16px; line-height: 27.2px;"><strong>webpack.config.js</strong></p><pre style="font-family: consolas, monaco, menlo, "courier new", courier, monospace; border: 1px solid rgb(221, 221, 221); font-size: 12px; line-height: 18px; overflow: auto; padding: 6px 10px; border-radius: 3px; word-break: break-all; color: rgb(51, 51, 51); background-color: rgb(248, 248, 248);"><code style="font-family: consolas, monaco, menlo, "courier new", courier, monospace; display: inline-block; line-height: 1.5; border: 0px none; border-radius: 0px; font-size: inherit; background: none;">module.exports = {
entry:'./src',
output: {
path: 'builds',
filename: 'bundle.js',
},
};
</code></pre><p style="margin-top: 18px; margin-bottom: 18px; color: rgb(51, 51, 51); font-family: "helvetica neue", tahoma, "hiragino sans gb", stheiti, "wenquanyi micro hei", 微软雅黑, 宋体, sans-serif; font-size: 16px; line-height: 27.2px;">这里，entry告诉webpack那个文件是你的app的入口点。这些是你的主文件，他们在依赖树的顶端，然后我们告诉它编译我们的bundle 到<code style="font-family: consolas, monaco, menlo, "courier new", courier, monospace; display: inline-block; line-height: normal; margin-right: 0.25em; margin-left: 0.25em; padding-right: 0.4em; padding-left: 0.4em; border: 1px solid rgb(221, 221, 221); border-radius: 3px; background-color: rgb(248, 248, 248);">bundle.js</code>文件放在<code style="font-family: consolas, monaco, menlo, "courier new", courier, monospace; display: inline-block; line-height: normal; margin-right: 0.25em; margin-left: 0.25em; padding-right: 0.4em; padding-left: 0.4em; border: 1px solid rgb(221, 221, 221); border-radius: 3px; background-color: rgb(248, 248, 248);">builds</code>目录下，再创建相应的index HTML</p><pre style="font-family: consolas, monaco, menlo, "courier new", courier, monospace; border: 1px solid rgb(221, 221, 221); font-size: 12px; line-height: 18px; overflow: auto; padding: 6px 10px; border-radius: 3px; word-break: break-all; color: rgb(51, 51, 51); background-color: rgb(248, 248, 248);"><code style="font-family: consolas, monaco, menlo, "courier new", courier, monospace; display: inline-block; line-height: 1.5; border: 0px none; border-radius: 0px; font-size: inherit; background: none;"><!DOCTYPE html>
<html>
<body>
<h1>My title</h1>
<a>Click me</a>
<script src="builds/bundle.js"></script>
</body>
</html>
</code></pre><p style="margin-top: 18px; margin-bottom: 18px; color: rgb(51, 51, 51); font-family: "helvetica neue", tahoma, "hiragino sans gb", stheiti, "wenquanyi micro hei", 微软雅黑, 宋体, sans-serif; font-size: 16px; line-height: 27.2px;">跑一下webpack，如果一切正常，会看见一个信息告诉我们正确地编译了<code style="font-family: consolas, monaco, menlo, "courier new", courier, monospace; display: inline-block; line-height: normal; margin-right: 0.25em; margin-left: 0.25em; padding-right: 0.4em; padding-left: 0.4em; border: 1px solid rgb(221, 221, 221); border-radius: 3px; background-color: rgb(248, 248, 248);">bundle.js</code></p><pre style="font-family: consolas, monaco, menlo, "courier new", courier, monospace; border: 1px solid rgb(221, 221, 221); font-size: 12px; line-height: 18px; overflow: auto; padding: 6px 10px; border-radius: 3px; word-break: break-all; color: rgb(51, 51, 51); background-color: rgb(248, 248, 248);"><code style="font-family: consolas, monaco, menlo, "courier new", courier, monospace; display: inline-block; line-height: 1.5; border: 0px none; border-radius: 0px; font-size: inherit; background: none;">$ webpack
Hash: d41fc61f5b9d72c13744
Version: webpack 1.12.14
Time: 301ms
AssetSizeChunks Chunk Names
bundle.js268 kB 0main
./src/index.js 53 bytes {0}
+ 1 hidden modules
</code></pre><p style="margin-top: 18px; margin-bottom: 18px; color: rgb(51, 51, 51); font-family: "helvetica neue", tahoma, "hiragino sans gb", stheiti, "wenquanyi micro hei", 微软雅黑, 宋体, sans-serif; font-size: 16px; line-height: 27.2px;">这里webpack告诉你你的bundle.js包含了我们的入口点（index.js）和一个隐藏的模块，这个就是jquery，默认情况下webpack把不是你的模块会隐藏掉，如果想看见webpack编译的所有的模块 ，我们可以加<code style="font-family: consolas, monaco, menlo, "courier new", courier, monospace; display: inline-block; line-height: normal; margin-right: 0.25em; margin-left: 0.25em; padding-right: 0.4em; padding-left: 0.4em; border: 1px solid rgb(221, 221, 221); border-radius: 3px; background-color: rgb(248, 248, 248);">--display-modules</code> 参数</p><pre style="font-family: consolas, monaco, menlo, "courier new", courier, monospace; border: 1px solid rgb(221, 221, 221); font-size: 12px; line-height: 18px; overflow: auto; padding: 6px 10px; border-radius: 3px; word-break: break-all; color: rgb(51, 51, 51); background-color: rgb(248, 248, 248);"><code style="font-family: consolas, monaco, menlo, "courier new", courier, monospace; display: inline-block; line-height: 1.5; border: 0px none; border-radius: 0px; font-size: inherit; background: none;">$ webpack --display-modules
bundle.js268 kB 0main
./src/index.js 53 bytes {0}
./~/jquery/dist/jquery.js 259 kB {0}
</code></pre><p style="margin-top: 18px; margin-bottom: 18px; color: rgb(51, 51, 51); font-family: "helvetica neue", tahoma, "hiragino sans gb", stheiti, "wenquanyi micro hei", 微软雅黑, 宋体, sans-serif; font-size: 16px; line-height: 27.2px;">你也可以运行 <code style="font-family: consolas, monaco, menlo, "courier new", courier, monospace; display: inline-block; line-height: normal; margin-right: 0.25em; margin-left: 0.25em; padding-right: 0.4em; padding-left: 0.4em; border: 1px solid rgb(221, 221, 221); border-radius: 3px; background-color: rgb(248, 248, 248);">webpack --watch</code> 来自动监视文件的变化，如果有变化，自动重新编译。<br>搭建我们的第一个loader<br>现在还记得我们怎么讨论webpack可以导入CSS和HTML还有各种文件的吗？什么时候能排上用场呢？好的，如果你跟随着过去几年朝着web组件方向的大跃进（Angular 2, Vue, React, Polymer, X-Tag, etc.）估计你听过这样一个观点：你的app是如果用一套可重用，自包含的UI组件搭建的话相比较于一个单独的内聚的UI将会变得更容易维护，这个可重用的组件就是web 组件（在这里我说的比较简单），现在为了让组件变成真正的自包含，需要把组件需要的所有的东西封装到他们自己的内部，我们来考虑一个button，它里面肯定有一些HTML，而且还有一些JS来保证它的交互性，还得来一些style，这些东西如果需要的时候一起加载进来会非常棒，只有在我们导入button组件的时候，我们才会得到所有的这些资源文件（asset）。</p><p style="margin-top: 18px; margin-bottom: 18px; color: rgb(51, 51, 51); font-family: "helvetica neue", tahoma, "hiragino sans gb", stheiti, "wenquanyi micro hei", 微软雅黑, 宋体, sans-serif; font-size: 16px; line-height: 27.2px;">来我们写一个button，首先我先假设你们已经熟悉了ES2015 ，我们先加入babel这个loader。想要在webpack里安装一个loader，有两步需要做：1.<code style="font-family: consolas, monaco, menlo, "courier new", courier, monospace; display: inline-block; line-height: normal; margin-right: 0.25em; margin-left: 0.25em; padding-right: 0.4em; padding-left: 0.4em; border: 1px solid rgb(221, 221, 221); border-radius: 3px; background-color: rgb(248, 248, 248);">npm install {whatever}-loader</code>,2.把它加到你的Webpack configuration里的<code style="font-family: consolas, monaco, menlo, "courier new", courier, monospace; display: inline-block; line-height: normal; margin-right: 0.25em; margin-left: 0.25em; padding-right: 0.4em; padding-left: 0.4em; border: 1px solid rgb(221, 221, 221); border-radius: 3px; background-color: rgb(248, 248, 248);">module.loaders</code>部分，我们开始，现在我们要加babel，所以：</p><pre style="font-family: consolas, monaco, menlo, "courier new", courier, monospace; border: 1px solid rgb(221, 221, 221); font-size: 12px; line-height: 18px; overflow: auto; padding: 6px 10px; border-radius: 3px; word-break: break-all; color: rgb(51, 51, 51); background-color: rgb(248, 248, 248);"><code style="font-family: consolas, monaco, menlo, "courier new", courier, monospace; display: inline-block; line-height: 1.5; border: 0px none; border-radius: 0px; font-size: inherit; background: none;">$ npm install babel-loader --save-dev
</code></pre><p style="margin-top: 18px; margin-bottom: 18px; color: rgb(51, 51, 51); font-family: "helvetica neue", tahoma, "hiragino sans gb", stheiti, "wenquanyi micro hei", 微软雅黑, 宋体, sans-serif; font-size: 16px; line-height: 27.2px;">我们也得安装Babel ，因为现在我们这个case，loader不会安装它，我们需要装<code style="font-family: consolas, monaco, menlo, "courier new", courier, monospace; display: inline-block; line-height: normal; margin-right: 0.25em; margin-left: 0.25em; padding-right: 0.4em; padding-left: 0.4em; border: 1px solid rgb(221, 221, 221); border-radius: 3px; background-color: rgb(248, 248, 248);">babel-core package</code> 和 <code style="font-family: consolas, monaco, menlo, "courier new", courier, monospace; display: inline-block; line-height: normal; margin-right: 0.25em; margin-left: 0.25em; padding-right: 0.4em; padding-left: 0.4em; border: 1px solid rgb(221, 221, 221); border-radius: 3px; background-color: rgb(248, 248, 248);">es2015 preset</code>:</p><pre style="font-family: consolas, monaco, menlo, "courier new", courier, monospace; border: 1px solid rgb(221, 221, 221); font-size: 12px; line-height: 18px; overflow: auto; padding: 6px 10px; border-radius: 3px; word-break: break-all; color: rgb(51, 51, 51); background-color: rgb(248, 248, 248);"><code style="font-family: consolas, monaco, menlo, "courier new", courier, monospace; display: inline-block; line-height: 1.5; border: 0px none; border-radius: 0px; font-size: inherit; background: none;">$ npm install babel-core babel-preset-es2015 --save-dev.
</code></pre><p style="margin-top: 18px; margin-bottom: 18px; color: rgb(51, 51, 51); font-family: "helvetica neue", tahoma, "hiragino sans gb", stheiti, "wenquanyi micro hei", 微软雅黑, 宋体, sans-serif; font-size: 16px; line-height: 27.2px;">我们现在创建<code style="font-family: consolas, monaco, menlo, "courier new", courier, monospace; display: inline-block; line-height: normal; margin-right: 0.25em; margin-left: 0.25em; padding-right: 0.4em; padding-left: 0.4em; border: 1px solid rgb(221, 221, 221); border-radius: 3px; background-color: rgb(248, 248, 248);">.babelrc</code>文件，告诉bable用那个preset，这是一个json文件让你配置Babel在你的code上执行哪种变体，我们现在这个我们我告诉它用<code style="font-family: consolas, monaco, menlo, "courier new", courier, monospace; display: inline-block; line-height: normal; margin-right: 0.25em; margin-left: 0.25em; padding-right: 0.4em; padding-left: 0.4em; border: 1px solid rgb(221, 221, 221); border-radius: 3px; background-color: rgb(248, 248, 248);">es2015</code>preset</p><p style="margin-top: 18px; margin-bottom: 18px; color: rgb(51, 51, 51); font-family: "helvetica neue", tahoma, "hiragino sans gb", stheiti, "wenquanyi micro hei", 微软雅黑, 宋体, sans-serif; font-size: 16px; line-height: 27.2px;"><strong>.babelrc</strong> <code style="font-family: consolas, monaco, menlo, "courier new", courier, monospace; display: inline-block; line-height: normal; margin-right: 0.25em; margin-left: 0.25em; padding-right: 0.4em; padding-left: 0.4em; border: 1px solid rgb(221, 221, 221); border-radius: 3px; background-color: rgb(248, 248, 248);">{ "presets": ["es2015"] }</code></p><p style="margin-top: 18px; margin-bottom: 18px; color: rgb(51, 51, 51); font-family: "helvetica neue", tahoma, "hiragino sans gb", stheiti, "wenquanyi micro hei", 微软雅黑, 宋体, sans-serif; font-size: 16px; line-height: 27.2px;">现在babel配完了，我们可以更新我们的配置：我们想要什么？我们想babel在我们所有的.js结尾的文件上运行，<strong>但是</strong>由于webpack遍历所有的依赖，我们想避免babel运行在第三方代码上，如jquery，所以我们可以再稍微过滤一下，loaders既可以有<code style="font-family: consolas, monaco, menlo, "courier new", courier, monospace; display: inline-block; line-height: normal; margin-right: 0.25em; margin-left: 0.25em; padding-right: 0.4em; padding-left: 0.4em; border: 1px solid rgb(221, 221, 221); border-radius: 3px; background-color: rgb(248, 248, 248);">include</code>也可以由<code style="font-family: consolas, monaco, menlo, "courier new", courier, monospace; display: inline-block; line-height: normal; margin-right: 0.25em; margin-left: 0.25em; padding-right: 0.4em; padding-left: 0.4em; border: 1px solid rgb(221, 221, 221); border-radius: 3px; background-color: rgb(248, 248, 248);">exclude</code>，可以是string，regex（正则表达式），一个callback（回调），随便用哪个。因为我们想让babel值运行在我们的文件上，所以我们只include我们自己的source目录：</p><pre style="font-family: consolas, monaco, menlo, "courier new", courier, monospace; border: 1px solid rgb(221, 221, 221); font-size: 12px; line-height: 18px; overflow: auto; padding: 6px 10px; border-radius: 3px; word-break: break-all; color: rgb(51, 51, 51); background-color: rgb(248, 248, 248);"><code style="font-family: consolas, monaco, menlo, "courier new", courier, monospace; display: inline-block; line-height: 1.5; border: 0px none; border-radius: 0px; font-size: inherit; background: none;">module.exports = {
entry:'./src',
output: {
path: 'builds',
filename: 'bundle.js',
},
module: {
loaders: [
{
test: /\.js/,
loader: 'babel',
include: __dirname + '/src',
}
],
}
};
</code></pre><p style="margin-top: 18px; margin-bottom: 18px; color: rgb(51, 51, 51); font-family: "helvetica neue", tahoma, "hiragino sans gb", stheiti, "wenquanyi micro hei", 微软雅黑, 宋体, sans-serif; font-size: 16px; line-height: 27.2px;">我们可以用ES6重写一下我们的<code style="font-family: consolas, monaco, menlo, "courier new", courier, monospace; display: inline-block; line-height: normal; margin-right: 0.25em; margin-left: 0.25em; padding-right: 0.4em; padding-left: 0.4em; border: 1px solid rgb(221, 221, 221); border-radius: 3px; background-color: rgb(248, 248, 248);">index.js</code>这个小文件，由于我们引入了babel，从这里开始后面的所有例子都用ES6.</p><pre style="font-family: consolas, monaco, menlo, "courier new", courier, monospace; border: 1px solid rgb(221, 221, 221); font-size: 12px; line-height: 18px; overflow: auto; padding: 6px 10px; border-radius: 3px; word-break: break-all; color: rgb(51, 51, 51); background-color: rgb(248, 248, 248);"><code style="font-family: consolas, monaco, menlo, "courier new", courier, monospace; display: inline-block; line-height: 1.5; border: 0px none; border-radius: 0px; font-size: inherit; background: none;">import $ from 'jquery';
$('body').html('Hello');
</code></pre><p style="margin-top: 18px; margin-bottom: 18px; color: rgb(51, 51, 51); font-family: "helvetica neue", tahoma, "hiragino sans gb", stheiti, "wenquanyi micro hei", 微软雅黑, 宋体, sans-serif; font-size: 16px; line-height: 27.2px;"><strong>写个小组件</strong><br>我们来写一个小的Button 组件，它有一些SCSS style，一个HTML template，和一些behavior，那么我们安装一些我们需要的东西。首先我们用一个非常轻量的模板包Mustache ，我们也需要给Sass和HTML用的loaders，因为结果会通过管道（pipe）从一个loader传到另一个，我们需要一个Sass loader，现在一旦我们有了css，会有多种方式处理它，当前阶段，我们用一个叫<code style="font-family: consolas, monaco, menlo, "courier new", courier, monospace; display: inline-block; line-height: normal; margin-right: 0.25em; margin-left: 0.25em; padding-right: 0.4em; padding-left: 0.4em; border: 1px solid rgb(221, 221, 221); border-radius: 3px; background-color: rgb(248, 248, 248);">style-loader</code>的loader，它会接收一段CSS，然后动态地把它插入到页面。</p><pre style="font-family: consolas, monaco, menlo, "courier new", courier, monospace; border: 1px solid rgb(221, 221, 221); font-size: 12px; line-height: 18px; overflow: auto; padding: 6px 10px; border-radius: 3px; word-break: break-all; color: rgb(51, 51, 51); background-color: rgb(248, 248, 248);"><code style="font-family: consolas, monaco, menlo, "courier new", courier, monospace; display: inline-block; line-height: 1.5; border: 0px none; border-radius: 0px; font-size: inherit; background: none;">$ npm install mustache --save
$ npm install css-loader style-loader html-loader sass-loader node-sass --save-dev
</code></pre><p style="margin-top: 18px; margin-bottom: 18px; color: rgb(51, 51, 51); font-family: "helvetica neue", tahoma, "hiragino sans gb", stheiti, "wenquanyi micro hei", 微软雅黑, 宋体, sans-serif; font-size: 16px; line-height: 27.2px;">为了让webpack用管道（pipe）把东西从一个loader传到另一个loader，我们简传入几个loader方向由右到左，用一个<code style="font-family: consolas, monaco, menlo, "courier new", courier, monospace; display: inline-block; line-height: normal; margin-right: 0.25em; margin-left: 0.25em; padding-right: 0.4em; padding-left: 0.4em; border: 1px solid rgb(221, 221, 221); border-radius: 3px; background-color: rgb(248, 248, 248);">！</code>分开，或者你可以用一个数组通过<code style="font-family: consolas, monaco, menlo, "courier new", courier, monospace; display: inline-block; line-height: normal; margin-right: 0.25em; margin-left: 0.25em; padding-right: 0.4em; padding-left: 0.4em; border: 1px solid rgb(221, 221, 221); border-radius: 3px; background-color: rgb(248, 248, 248);">loaders</code>属性，不是<code style="font-family: consolas, monaco, menlo, "courier new", courier, monospace; display: inline-block; line-height: normal; margin-right: 0.25em; margin-left: 0.25em; padding-right: 0.4em; padding-left: 0.4em; border: 1px solid rgb(221, 221, 221); border-radius: 3px; background-color: rgb(248, 248, 248);">loader</code></p><pre style="font-family: consolas, monaco, menlo, "courier new", courier, monospace; border: 1px solid rgb(221, 221, 221); font-size: 12px; line-height: 18px; overflow: auto; padding: 6px 10px; border-radius: 3px; word-break: break-all; color: rgb(51, 51, 51); background-color: rgb(248, 248, 248);"><code style="font-family: consolas, monaco, menlo, "courier new", courier, monospace; display: inline-block; line-height: 1.5; border: 0px none; border-radius: 0px; font-size: inherit; background: none;">{
test:/\.js/,
loader:'babel',
include: __dirname + '/src',
},
{
test: /\.scss/,
loader: 'style!css!sass',
// Or
loaders: ['style', 'css', 'sass'],
},
{
test: /\.html/,
loader: 'html',
}
</code></pre><p style="margin-top: 18px; margin-bottom: 18px; color: rgb(51, 51, 51); font-family: "helvetica neue", tahoma, "hiragino sans gb", stheiti, "wenquanyi micro hei", 微软雅黑, 宋体, sans-serif; font-size: 16px; line-height: 27.2px;">现在我们把loaders准备好了，我们来写一个button：</p><p style="margin-top: 18px; margin-bottom: 18px; color: rgb(51, 51, 51); font-family: "helvetica neue", tahoma, "hiragino sans gb", stheiti, "wenquanyi micro hei", 微软雅黑, 宋体, sans-serif; font-size: 16px; line-height: 27.2px;"><strong>src/Components/Button.scss</strong></p><p style="margin-top: 18px; margin-bottom: 18px; color: rgb(51, 51, 51); font-family: "helvetica neue", tahoma, "hiragino sans gb", stheiti, "wenquanyi micro hei", 微软雅黑, 宋体, sans-serif; font-size: 16px; line-height: 27.2px;">.button {<br>background: tomato; color: white; }</p><p style="margin-top: 18px; margin-bottom: 18px; color: rgb(51, 51, 51); font-family: "helvetica neue", tahoma, "hiragino sans gb", stheiti, "wenquanyi micro hei", 微软雅黑, 宋体, sans-serif; font-size: 16px; line-height: 27.2px;"><strong>src/Components/Button.html</strong></p><pre style="font-family: consolas, monaco, menlo, "courier new", courier, monospace; border: 1px solid rgb(221, 221, 221); font-size: 12px; line-height: 18px; overflow: auto; padding: 6px 10px; border-radius: 3px; word-break: break-all; color: rgb(51, 51, 51); background-color: rgb(248, 248, 248);"><code style="font-family: consolas, monaco, menlo, "courier new", courier, monospace; display: inline-block; line-height: 1.5; border: 0px none; border-radius: 0px; font-size: inherit; background: none;"><a class="button" href="{{link}}">{{text}}</a>
</code></pre><p style="margin-top: 18px; margin-bottom: 18px; color: rgb(51, 51, 51); font-family: "helvetica neue", tahoma, "hiragino sans gb", stheiti, "wenquanyi micro hei", 微软雅黑, 宋体, sans-serif; font-size: 16px; line-height: 27.2px;"><strong>src/Components/Button.js</strong></p><p style="margin-top: 18px; margin-bottom: 18px; color: rgb(51, 51, 51); font-family: "helvetica neue", tahoma, "hiragino sans gb", stheiti, "wenquanyi micro hei", 微软雅黑, 宋体, sans-serif; font-size: 16px; line-height: 27.2px;">import $ from 'jquery';<br>import template from './Button.html';<br>import Mustache from 'mustache';<br>import './Button.scss';</p><p style="margin-top: 18px; margin-bottom: 18px; color: rgb(51, 51, 51); font-family: "helvetica neue", tahoma, "hiragino sans gb", stheiti, "wenquanyi micro hei", 微软雅黑, 宋体, sans-serif; font-size: 16px; line-height: 27.2px;">import $ from 'jquery';<br>import template from './Button.html';<br>import Mustache from 'mustache';<br>import './Button.scss';</p><p style="margin-top: 18px; margin-bottom: 18px; color: rgb(51, 51, 51); font-family: "helvetica neue", tahoma, "hiragino sans gb", stheiti, "wenquanyi micro hei", 微软雅黑, 宋体, sans-serif; font-size: 16px; line-height: 27.2px;">export default class Button {<br>constructor(link) {<br>this.link = link;<br>}</p><p style="margin-top: 18px; margin-bottom: 18px; color: rgb(51, 51, 51); font-family: "helvetica neue", tahoma, "hiragino sans gb", stheiti, "wenquanyi micro hei", 微软雅黑, 宋体, sans-serif; font-size: 16px; line-height: 27.2px;">onClick(event) {<br>event.preventDefault();<br>alert(this.link);<br>}</p><p style="margin-top: 18px; margin-bottom: 18px; color: rgb(51, 51, 51); font-family: "helvetica neue", tahoma, "hiragino sans gb", stheiti, "wenquanyi micro hei", 微软雅黑, 宋体, sans-serif; font-size: 16px; line-height: 27.2px;">render(node) {<br>const text = $(node).text();</p><p style="margin-top: 18px; margin-bottom: 18px; color: rgb(51, 51, 51); font-family: "helvetica neue", tahoma, "hiragino sans gb", stheiti, "wenquanyi micro hei", 微软雅黑, 宋体, sans-serif; font-size: 16px; line-height: 27.2px;">// Render our button<br>$(node).html(Mustache.render(template, {text}));</p><p style="margin-top: 18px; margin-bottom: 18px; color: rgb(51, 51, 51); font-family: "helvetica neue", tahoma, "hiragino sans gb", stheiti, "wenquanyi micro hei", 微软雅黑, 宋体, sans-serif; font-size: 16px; line-height: 27.2px;">// Attach our listeners<br>$('.button').click(this.onClick.bind(this));<br>}<br>}</p><p style="margin-top: 18px; margin-bottom: 18px; color: rgb(51, 51, 51); font-family: "helvetica neue", tahoma, "hiragino sans gb", stheiti, "wenquanyi micro hei", 微软雅黑, 宋体, sans-serif; font-size: 16px; line-height: 27.2px;">你的Button现在是百分之百自包含的，无论什么时候导入，无论运行在什么context，它有所有需要的东西，然后正确地render（渲染），现在我们只需要把我们的Button render到我们的网页上（page）：</p><p style="margin-top: 18px; margin-bottom: 18px; color: rgb(51, 51, 51); font-family: "helvetica neue", tahoma, "hiragino sans gb", stheiti, "wenquanyi micro hei", 微软雅黑, 宋体, sans-serif; font-size: 16px; line-height: 27.2px;"><strong>src/index.js</strong></p><pre style="font-family: consolas, monaco, menlo, "courier new", courier, monospace; border: 1px solid rgb(221, 221, 221); font-size: 12px; line-height: 18px; overflow: auto; padding: 6px 10px; border-radius: 3px; word-break: break-all; color: rgb(51, 51, 51); background-color: rgb(248, 248, 248);"><code style="font-family: consolas, monaco, menlo, "courier new", courier, monospace; display: inline-block; line-height: 1.5; border: 0px none; border-radius: 0px; font-size: inherit; background: none;">js import Button from ‘./Components/Button’;
const button = new Button(‘google.com’); button.render(‘a’);
</code></pre><p style="margin-top: 18px; margin-bottom: 18px; color: rgb(51, 51, 51); font-family: "helvetica neue", tahoma, "hiragino sans gb", stheiti, "wenquanyi micro hei", 微软雅黑, 宋体, sans-serif; font-size: 16px; line-height: 27.2px;">我们来运行一下webpack，然后刷新一下页面，你应该就能看见你的挺丑的button出来了。 <img src="http://i.imgur.com/8Ov1x2P.png" alt="" style="max-width: 50em; margin-top: 1em; margin-bottom: 1em;"></p><p style="margin-top: 18px; margin-bottom: 18px; color: rgb(51, 51, 51); font-family: "helvetica neue", tahoma, "hiragino sans gb", stheiti, "wenquanyi micro hei", 微软雅黑, 宋体, sans-serif; font-size: 16px; line-height: 27.2px;">现在你已经学了怎么配置loader和怎么给你的app的每一个部分定义dependency（依赖），现在可能看起来不太重要这些，但现在我们来把我们的例子再做一下改进：</p><p style="margin-top: 18px; margin-bottom: 18px; color: rgb(51, 51, 51); font-family: "helvetica neue", tahoma, "hiragino sans gb", stheiti, "wenquanyi micro hei", 微软雅黑, 宋体, sans-serif; font-size: 16px; line-height: 27.2px;">code 分片（splitting）</p><p style="margin-top: 18px; margin-bottom: 18px; color: rgb(51, 51, 51); font-family: "helvetica neue", tahoma, "hiragino sans gb", stheiti, "wenquanyi micro hei", 微软雅黑, 宋体, sans-serif; font-size: 16px; line-height: 27.2px;">这个例子还不错什么都有，但可能我们不总需要我们的Button，可能有些界面不会有 <code style="font-family: consolas, monaco, menlo, "courier new", courier, monospace; display: inline-block; line-height: normal; margin-right: 0.25em; margin-left: 0.25em; padding-right: 0.4em; padding-left: 0.4em; border: 1px solid rgb(221, 221, 221); border-radius: 3px; background-color: rgb(248, 248, 248);">a</code>（link）来让我们渲染Button用，在这中情况下，我们不需要导入所有的Button的style（式样），template（模板），Mustache 和一切相关的东西，对吧？“Monolithic bundle”（单片绑定） VS “Unmaintainable manual imports”（不好维护的手动导入）. 这种idea是，你在你的代码里定义split point（分割点）：你的code中可以轻松拆分开到单独文件中的部分，然后按需加载，语法非常简单：</p><pre style="font-family: consolas, monaco, menlo, "courier new", courier, monospace; border: 1px solid rgb(221, 221, 221); font-size: 12px; line-height: 18px; overflow: auto; padding: 6px 10px; border-radius: 3px; word-break: break-all; color: rgb(51, 51, 51); background-color: rgb(248, 248, 248);"><code style="font-family: consolas, monaco, menlo, "courier new", courier, monospace; display: inline-block; line-height: 1.5; border: 0px none; border-radius: 0px; font-size: inherit; background: none;">import $ from 'jquery';
// This is a split point
require.ensure([], () => {
// All the code in here, and everything that is imported
// will be in a separate file
const library = require('some-big-library');
$('foo').click(() => library.doSomething());
});
</code></pre><p style="margin-top: 18px; margin-bottom: 18px; color: rgb(51, 51, 51); font-family: "helvetica neue", tahoma, "hiragino sans gb", stheiti, "wenquanyi micro hei", 微软雅黑, 宋体, sans-serif; font-size: 16px; line-height: 27.2px;">在<code style="font-family: consolas, monaco, menlo, "courier new", courier, monospace; display: inline-block; line-height: normal; margin-right: 0.25em; margin-left: 0.25em; padding-right: 0.4em; padding-left: 0.4em; border: 1px solid rgb(221, 221, 221); border-radius: 3px; background-color: rgb(248, 248, 248);">require.ensure</code> callback 里的任何东西都会被拆分成chunk（代码块）-一个webpack需要的时候会通过ajax单独加载的bundle，这意味着我们基本上有这些：</p><pre style="font-family: consolas, monaco, menlo, "courier new", courier, monospace; border: 1px solid rgb(221, 221, 221); font-size: 12px; line-height: 18px; overflow: auto; padding: 6px 10px; border-radius: 3px; word-break: break-all; color: rgb(51, 51, 51); background-color: rgb(248, 248, 248);"><code style="font-family: consolas, monaco, menlo, "courier new", courier, monospace; display: inline-block; line-height: 1.5; border: 0px none; border-radius: 0px; font-size: inherit; background: none;">bundle.js
|- jquery.js
|- index.js // our main file
chunk1.js
|- some-big-libray.js
|- index-chunk.js // the code in the callback
</code></pre><p style="margin-top: 18px; margin-bottom: 18px; color: rgb(51, 51, 51); font-family: "helvetica neue", tahoma, "hiragino sans gb", stheiti, "wenquanyi micro hei", 微软雅黑, 宋体, sans-serif; font-size: 16px; line-height: 27.2px;">你无需导入<code style="font-family: consolas, monaco, menlo, "courier new", courier, monospace; display: inline-block; line-height: normal; margin-right: 0.25em; margin-left: 0.25em; padding-right: 0.4em; padding-left: 0.4em; border: 1px solid rgb(221, 221, 221); border-radius: 3px; background-color: rgb(248, 248, 248);">chunk1.js</code>。webpack只有在需要它的时候才会加载它，这意味着你可以把你的code按照各种逻辑分成多块，我们将在下面的例子中这么做，我们只想在page里有link的的时候才需要Button</p><p style="margin-top: 18px; margin-bottom: 18px; color: rgb(51, 51, 51); font-family: "helvetica neue", tahoma, "hiragino sans gb", stheiti, "wenquanyi micro hei", 微软雅黑, 宋体, sans-serif; font-size: 16px; line-height: 27.2px;"><strong>src/index.js</strong></p><pre style="font-family: consolas, monaco, menlo, "courier new", courier, monospace; border: 1px solid rgb(221, 221, 221); font-size: 12px; line-height: 18px; overflow: auto; padding: 6px 10px; border-radius: 3px; word-break: break-all; color: rgb(51, 51, 51); background-color: rgb(248, 248, 248);"><code style="font-family: consolas, monaco, menlo, "courier new", courier, monospace; display: inline-block; line-height: 1.5; border: 0px none; border-radius: 0px; font-size: inherit; background: none;">if (document.querySelectorAll('a').length) {
require.ensure([], () => {
const Button = require('./Components/Button').default;
const button = new Button('google.com');
button.render('a');
});
}
</code></pre><p style="margin-top: 18px; margin-bottom: 18px; color: rgb(51, 51, 51); font-family: "helvetica neue", tahoma, "hiragino sans gb", stheiti, "wenquanyi micro hei", 微软雅黑, 宋体, sans-serif; font-size: 16px; line-height: 27.2px;">注意，用<code style="font-family: consolas, monaco, menlo, "courier new", courier, monospace; display: inline-block; line-height: normal; margin-right: 0.25em; margin-left: 0.25em; padding-right: 0.4em; padding-left: 0.4em; border: 1px solid rgb(221, 221, 221); border-radius: 3px; background-color: rgb(248, 248, 248);">require</code>的时候，如果你想default export 你需要通过<code style="font-family: consolas, monaco, menlo, "courier new", courier, monospace; display: inline-block; line-height: normal; margin-right: 0.25em; margin-left: 0.25em; padding-right: 0.4em; padding-left: 0.4em; border: 1px solid rgb(221, 221, 221); border-radius: 3px; background-color: rgb(248, 248, 248);">.default</code>手动获取它，<br>因为<code style="font-family: consolas, monaco, menlo, "courier new", courier, monospace; display: inline-block; line-height: normal; margin-right: 0.25em; margin-left: 0.25em; padding-right: 0.4em; padding-left: 0.4em; border: 1px solid rgb(221, 221, 221); border-radius: 3px; background-color: rgb(248, 248, 248);">require</code>不会同时处理default 和 normal（正常） exports，所以你必须指定返回哪个，不过<code style="font-family: consolas, monaco, menlo, "courier new", courier, monospace; display: inline-block; line-height: normal; margin-right: 0.25em; margin-left: 0.25em; padding-right: 0.4em; padding-left: 0.4em; border: 1px solid rgb(221, 221, 221); border-radius: 3px; background-color: rgb(248, 248, 248);">import</code>有一个系统处理这个，所以它已经知道了(例如： <code style="font-family: consolas, monaco, menlo, "courier new", courier, monospace; display: inline-block; line-height: normal; margin-right: 0.25em; margin-left: 0.25em; padding-right: 0.4em; padding-left: 0.4em; border: 1px solid rgb(221, 221, 221); border-radius: 3px; background-color: rgb(248, 248, 248);">import foo from 'bar'</code>)vs <code style="font-family: consolas, monaco, menlo, "courier new", courier, monospace; display: inline-block; line-height: normal; margin-right: 0.25em; margin-left: 0.25em; padding-right: 0.4em; padding-left: 0.4em; border: 1px solid rgb(221, 221, 221); border-radius: 3px; background-color: rgb(248, 248, 248);">import {baz} from 'bar').</code></p><p style="margin-top: 18px; margin-bottom: 18px; color: rgb(51, 51, 51); font-family: "helvetica neue", tahoma, "hiragino sans gb", stheiti, "wenquanyi micro hei", 微软雅黑, 宋体, sans-serif; font-size: 16px; line-height: 27.2px;">webpack的output现在应该会相应地不同了，我们来用<code style="font-family: consolas, monaco, menlo, "courier new", courier, monospace; display: inline-block; line-height: normal; margin-right: 0.25em; margin-left: 0.25em; padding-right: 0.4em; padding-left: 0.4em; border: 1px solid rgb(221, 221, 221); border-radius: 3px; background-color: rgb(248, 248, 248);">--display-chunks</code> flag 来运行一下，来看一下哪个模块在哪个chunk里</p><pre style="font-family: consolas, monaco, menlo, "courier new", courier, monospace; border: 1px solid rgb(221, 221, 221); font-size: 12px; line-height: 18px; overflow: auto; padding: 6px 10px; border-radius: 3px; word-break: break-all; color: rgb(51, 51, 51); background-color: rgb(248, 248, 248);"><code style="font-family: consolas, monaco, menlo, "courier new", courier, monospace; display: inline-block; line-height: 1.5; border: 0px none; border-radius: 0px; font-size: inherit; background: none;">$ webpack --display-modules --display-chunks
Hash: 43b51e6cec5eb6572608
Version: webpack 1.12.14
Time: 1185ms
Asset SizeChunks Chunk Names
bundle.js3.82 kB 0main
1.bundle.js 300 kB 1
chunk{0} bundle.js (main) 235 bytes
./src/index.js 235 bytes {0}
chunk{1} 1.bundle.js 290 kB {0}
./src/Components/Button.js 1.94 kB {1}
./~/jquery/dist/jquery.js 259 kB {1}
./src/Components/Button.html 72 bytes {1}
./~/mustache/mustache.js 19.4 kB {1}
./src/Components/Button.scss 1.05 kB {1}
./~/css-loader!./~/sass-loader!./src/Components/Button.scss 212 bytes {1}
./~/css-loader/lib/css-base.js 1.51 kB {1}
./~/style-loader/addStyles.js 7.21 kB {1}
</code></pre><p style="margin-top: 18px; margin-bottom: 18px; color: rgb(51, 51, 51); font-family: "helvetica neue", tahoma, "hiragino sans gb", stheiti, "wenquanyi micro hei", 微软雅黑, 宋体, sans-serif; font-size: 16px; line-height: 27.2px;">可以看到我们的入口（<code style="font-family: consolas, monaco, menlo, "courier new", courier, monospace; display: inline-block; line-height: normal; margin-right: 0.25em; margin-left: 0.25em; padding-right: 0.4em; padding-left: 0.4em; border: 1px solid rgb(221, 221, 221); border-radius: 3px; background-color: rgb(248, 248, 248);">bundle.js</code>）现在只有一些webpack的逻辑，其它的东西(jQuery, Mustache, Button) 都在<code style="font-family: consolas, monaco, menlo, "courier new", courier, monospace; display: inline-block; line-height: normal; margin-right: 0.25em; margin-left: 0.25em; padding-right: 0.4em; padding-left: 0.4em; border: 1px solid rgb(221, 221, 221); border-radius: 3px; background-color: rgb(248, 248, 248);">1.bundle.js</code>,只有page上有anchor （锚：超链接的意思）的时候才会加载，为了让webpack知道用ajax加载的时候在哪能找到chunks，我们必须在我们的配置中加几行:</p><pre style="font-family: consolas, monaco, menlo, "courier new", courier, monospace; border: 1px solid rgb(221, 221, 221); font-size: 12px; line-height: 18px; overflow: auto; padding: 6px 10px; border-radius: 3px; word-break: break-all; color: rgb(51, 51, 51); background-color: rgb(248, 248, 248);"><code style="font-family: consolas, monaco, menlo, "courier new", courier, monospace; display: inline-block; line-height: 1.5; border: 0px none; border-radius: 0px; font-size: inherit; background: none;">path: 'builds',
filename: 'bundle.js',
publicPath: 'builds/',
</code></pre><p style="margin-top: 18px; margin-bottom: 18px; color: rgb(51, 51, 51); font-family: "helvetica neue", tahoma, "hiragino sans gb", stheiti, "wenquanyi micro hei", 微软雅黑, 宋体, sans-serif; font-size: 16px; line-height: 27.2px;"><code style="font-family: consolas, monaco, menlo, "courier new", courier, monospace; display: inline-block; line-height: normal; margin-right: 0.25em; margin-left: 0.25em; padding-right: 0.4em; padding-left: 0.4em; border: 1px solid rgb(221, 221, 221); border-radius: 3px; background-color: rgb(248, 248, 248);">output.publicPath</code>选项告诉webpack相对于当前的page（我们的case是在 /builds/）在哪能找到built（构建后的）assets （资源），现在访问我们的page我们会看到一切都正常工作，但更重要的是，我们能看到，由于页面上有anchor （锚：超链接的意思），webpack实时地加载加载了chunk：</p><p style="margin-top: 18px; margin-bottom: 18px; color: rgb(51, 51, 51); font-family: "helvetica neue", tahoma, "hiragino sans gb", stheiti, "wenquanyi micro hei", 微软雅黑, 宋体, sans-serif; font-size: 16px; line-height: 27.2px;"><img src="http://i.imgur.com/rPvIRiB.png" alt="" style="max-width: 50em; margin-top: 1em; margin-bottom: 1em;"></p><p style="margin-top: 18px; margin-bottom: 18px; color: rgb(51, 51, 51); font-family: "helvetica neue", tahoma, "hiragino sans gb", stheiti, "wenquanyi micro hei", 微软雅黑, 宋体, sans-serif; font-size: 16px; line-height: 27.2px;">如果我们page上没有anchor，只有<code style="font-family: consolas, monaco, menlo, "courier new", courier, monospace; display: inline-block; line-height: normal; margin-right: 0.25em; margin-left: 0.25em; padding-right: 0.4em; padding-left: 0.4em; border: 1px solid rgb(221, 221, 221); border-radius: 3px; background-color: rgb(248, 248, 248);">bundle.js</code>会被加载 ，这点可以让你智能地把你的app里的大片逻辑拆分开，让每个页面值加载它真正需要的，我们也可以给我们的split point命名，不用<code style="font-family: consolas, monaco, menlo, "courier new", courier, monospace; display: inline-block; line-height: normal; margin-right: 0.25em; margin-left: 0.25em; padding-right: 0.4em; padding-left: 0.4em; border: 1px solid rgb(221, 221, 221); border-radius: 3px; background-color: rgb(248, 248, 248);">1.bundle.js</code>，我们可以用更有语义的名字，你可以通过传给<code style="font-family: consolas, monaco, menlo, "courier new", courier, monospace; display: inline-block; line-height: normal; margin-right: 0.25em; margin-left: 0.25em; padding-right: 0.4em; padding-left: 0.4em; border: 1px solid rgb(221, 221, 221); border-radius: 3px; background-color: rgb(248, 248, 248);">require.ensure</code>第三个参数来指定:</p><pre style="font-family: consolas, monaco, menlo, "courier new", courier, monospace; border: 1px solid rgb(221, 221, 221); font-size: 12px; line-height: 18px; overflow: auto; padding: 6px 10px; border-radius: 3px; word-break: break-all; color: rgb(51, 51, 51); background-color: rgb(248, 248, 248);"><code style="font-family: consolas, monaco, menlo, "courier new", courier, monospace; display: inline-block; line-height: 1.5; border: 0px none; border-radius: 0px; font-size: inherit; background: none;">require.ensure([], () => {
const Button = require('./Components/Button').default;
const button = new Button('google.com');
button.render('a');
}, 'button');
</code></pre><p style="margin-top: 18px; margin-bottom: 18px; color: rgb(51, 51, 51); font-family: "helvetica neue", tahoma, "hiragino sans gb", stheiti, "wenquanyi micro hei", 微软雅黑, 宋体, sans-serif; font-size: 16px; line-height: 27.2px;">这样就会生成<code style="font-family: consolas, monaco, menlo, "courier new", courier, monospace; display: inline-block; line-height: normal; margin-right: 0.25em; margin-left: 0.25em; padding-right: 0.4em; padding-left: 0.4em; border: 1px solid rgb(221, 221, 221); border-radius: 3px; background-color: rgb(248, 248, 248);">button.bundle.js</code>而不是<code style="font-family: consolas, monaco, menlo, "courier new", courier, monospace; display: inline-block; line-height: normal; margin-right: 0.25em; margin-left: 0.25em; padding-right: 0.4em; padding-left: 0.4em; border: 1px solid rgb(221, 221, 221); border-radius: 3px; background-color: rgb(248, 248, 248);">1.bundle.js.</code><br>加入第二个组件<br>现在啥都有了非常cool了已经，我们再来加一个组件来看看好不好使：</p><p style="margin-top: 18px; margin-bottom: 18px; color: rgb(51, 51, 51); font-family: "helvetica neue", tahoma, "hiragino sans gb", stheiti, "wenquanyi micro hei", 微软雅黑, 宋体, sans-serif; font-size: 16px; line-height: 27.2px;"><strong>src/Components/Header.scss</strong></p><pre style="font-family: consolas, monaco, menlo, "courier new", courier, monospace; border: 1px solid rgb(221, 221, 221); font-size: 12px; line-height: 18px; overflow: auto; padding: 6px 10px; border-radius: 3px; word-break: break-all; color: rgb(51, 51, 51); background-color: rgb(248, 248, 248);"><code style="font-family: consolas, monaco, menlo, "courier new", courier, monospace; display: inline-block; line-height: 1.5; border: 0px none; border-radius: 0px; font-size: inherit; background: none;">.header {
font-size: 3rem;
}
</code></pre><p style="margin-top: 18px; margin-bottom: 18px; color: rgb(51, 51, 51); font-family: "helvetica neue", tahoma, "hiragino sans gb", stheiti, "wenquanyi micro hei", 微软雅黑, 宋体, sans-serif; font-size: 16px; line-height: 27.2px;"><strong>src/Components/Header.html</strong></p><pre style="font-family: consolas, monaco, menlo, "courier new", courier, monospace; border: 1px solid rgb(221, 221, 221); font-size: 12px; line-height: 18px; overflow: auto; padding: 6px 10px; border-radius: 3px; word-break: break-all; color: rgb(51, 51, 51); background-color: rgb(248, 248, 248);"><code style="font-family: consolas, monaco, menlo, "courier new", courier, monospace; display: inline-block; line-height: 1.5; border: 0px none; border-radius: 0px; font-size: inherit; background: none;"><header class="header">{{text}}</header>
</code></pre><p style="margin-top: 18px; margin-bottom: 18px; color: rgb(51, 51, 51); font-family: "helvetica neue", tahoma, "hiragino sans gb", stheiti, "wenquanyi micro hei", 微软雅黑, 宋体, sans-serif; font-size: 16px; line-height: 27.2px;"><strong>src/Components/Header.js</strong></p><p style="margin-top: 18px; margin-bottom: 18px; color: rgb(51, 51, 51); font-family: "helvetica neue", tahoma, "hiragino sans gb", stheiti, "wenquanyi micro hei", 微软雅黑, 宋体, sans-serif; font-size: 16px; line-height: 27.2px;">import $ from 'jquery';<br>import Mustache from 'mustache';<br>import template from './Header.html';<br>import './Header.scss';</p><p style="margin-top: 18px; margin-bottom: 18px; color: rgb(51, 51, 51); font-family: "helvetica neue", tahoma, "hiragino sans gb", stheiti, "wenquanyi micro hei", 微软雅黑, 宋体, sans-serif; font-size: 16px; line-height: 27.2px;">export default class Header {<br>render(node) {<br>const text = $(node).text();</p><p style="margin-top: 18px; margin-bottom: 18px; color: rgb(51, 51, 51); font-family: "helvetica neue", tahoma, "hiragino sans gb", stheiti, "wenquanyi micro hei", 微软雅黑, 宋体, sans-serif; font-size: 16px; line-height: 27.2px;">$(node).html(<br>Mustache.render(template, {text})<br>);<br>}<br>}</p><p style="margin-top: 18px; margin-bottom: 18px; color: rgb(51, 51, 51); font-family: "helvetica neue", tahoma, "hiragino sans gb", stheiti, "wenquanyi micro hei", 微软雅黑, 宋体, sans-serif; font-size: 16px; line-height: 27.2px;">我们在我们的application里把它render（渲染）一下：</p><pre style="font-family: consolas, monaco, menlo, "courier new", courier, monospace; border: 1px solid rgb(221, 221, 221); font-size: 12px; line-height: 18px; overflow: auto; padding: 6px 10px; border-radius: 3px; word-break: break-all; color: rgb(51, 51, 51); background-color: rgb(248, 248, 248);"><code style="font-family: consolas, monaco, menlo, "courier new", courier, monospace; display: inline-block; line-height: 1.5; border: 0px none; border-radius: 0px; font-size: inherit; background: none;">// If we have an anchor, render the Button component on it
if (document.querySelectorAll('a').length) {
require.ensure([], () => {
const Button = require('./Components/Button').default;
const button = new Button('google.com');
button.render('a');
});
}
// If we have a title, render the Header component on it
if (document.querySelectorAll('h1').length) {
require.ensure([], () => {
const Header = require('./Components/Header').default;
new Header().render('h1');
});
}
</code></pre><p style="margin-top: 18px; margin-bottom: 18px; color: rgb(51, 51, 51); font-family: "helvetica neue", tahoma, "hiragino sans gb", stheiti, "wenquanyi micro hei", 微软雅黑, 宋体, sans-serif; font-size: 16px; line-height: 27.2px;">现在用<code style="font-family: consolas, monaco, menlo, "courier new", courier, monospace; display: inline-block; line-height: normal; margin-right: 0.25em; margin-left: 0.25em; padding-right: 0.4em; padding-left: 0.4em; border: 1px solid rgb(221, 221, 221); border-radius: 3px; background-color: rgb(248, 248, 248);">--display-chunks --display-modules</code> flags（参数标记）来看一下webpack的output：</p><p style="margin-top: 18px; margin-bottom: 18px; color: rgb(51, 51, 51); font-family: "helvetica neue", tahoma, "hiragino sans gb", stheiti, "wenquanyi micro hei", 微软雅黑, 宋体, sans-serif; font-size: 16px; line-height: 27.2px;">$ webpack --display-modules --display-chunks<br>Hash: 178b46d1d1570ff8bceb<br>Version: webpack 1.12.14<br>Time: 1548ms<br>Asset Size Chunks Chunk Names bundle.js 4.16 kB 0 main 1.bundle.js 300 kB 1 <br>2.bundle.js 299 kB 2 <br>chunk{0} bundle.js (main) 550 bytes <br> ./src/index.js 550 bytes {0} <br>chunk{1} 1.bundle.js 290 kB {0} <br> ./src/Components/Button.js 1.94 kB {1} <br> ./~/jquery/dist/jquery.js 259 kB {1} {2} <br> ./src/Components/Button.html 72 bytes {1} <br> ./~/mustache/mustache.js 19.4 kB {1} {2} <br> ./src/Components/Button.scss 1.05 kB {1} <br> ./~/css-loader!./~/sass-loader!./src/Components/Button.scss 212 bytes {1} <br> ./~/css-loader/lib/css-base.js 1.51 kB {1} {2} <br> ./~/style-loader/addStyles.js 7.21 kB {1} {2} <br>chunk{2} 2.bundle.js 290 kB {0} <br> ./~/jquery/dist/jquery.js 259 kB {1} {2} <br> ./~/mustache/mustache.js 19.4 kB {1} {2} <br> ./~/css-loader/lib/css-base.js 1.51 kB {1} {2} <br> ./~/style-loader/addStyles.js 7.21 kB {1} {2} <br> ./src/Components/Header.js 1.62 kB {2} <br> ./src/Components/Header.html 64 bytes {2} ./src/Components/Header.scss 1.05 kB {2} ./~/css-loader!./~/sass-loader!./src/Components/Header.scss 192 bytes {2} </p><p style="margin-top: 18px; margin-bottom: 18px; color: rgb(51, 51, 51); font-family: "helvetica neue", tahoma, "hiragino sans gb", stheiti, "wenquanyi micro hei", 微软雅黑, 宋体, sans-serif; font-size: 16px; line-height: 27.2px;">能看见这里有一个主要问题：我们的两个组件都会用到jQuery 和 Mustache，也就是说这两个依赖会在chunk里有重复，wepack默认做很少优化，但是他会以plugin的形式来给webpack提供强大的功能。</p><p style="margin-top: 18px; margin-bottom: 18px; color: rgb(51, 51, 51); font-family: "helvetica neue", tahoma, "hiragino sans gb", stheiti, "wenquanyi micro hei", 微软雅黑, 宋体, sans-serif; font-size: 16px; line-height: 27.2px;">plugin跟laoder不同，它不是对指定的文件像pipe一样执行一些操作，他们对所有文件进行处理，做一些更高级的操作，但不一定非得是transformation（转换），webpack有一把plugin可以做各种优化，此时我们比较感兴趣的一个是CommonChunksPlugin：它分析你的chunk的递归依赖，然后把它们抽出来放在别的地方，可以使一个完全独立的文件（如<code style="font-family: consolas, monaco, menlo, "courier new", courier, monospace; display: inline-block; line-height: normal; margin-right: 0.25em; margin-left: 0.25em; padding-right: 0.4em; padding-left: 0.4em; border: 1px solid rgb(221, 221, 221); border-radius: 3px; background-color: rgb(248, 248, 248);">vendor.js</code>）或者也可以是你的主（main）文件。</p><p style="margin-top: 18px; margin-bottom: 18px; color: rgb(51, 51, 51); font-family: "helvetica neue", tahoma, "hiragino sans gb", stheiti, "wenquanyi micro hei", 微软雅黑, 宋体, sans-serif; font-size: 16px; line-height: 27.2px;">我们现在的case，我们需要把公用的依赖移到我们的entry（入口） 文件，如果所有的文件需要jQuery 和 Mustache,我们也可以把它往上层移动，我们来更新一下我们的configuration：</p><p style="margin-top: 18px; margin-bottom: 18px; color: rgb(51, 51, 51); font-family: "helvetica neue", tahoma, "hiragino sans gb", stheiti, "wenquanyi micro hei", 微软雅黑, 宋体, sans-serif; font-size: 16px; line-height: 27.2px;">var webpack = require('webpack');</p><p style="margin-top: 18px; margin-bottom: 18px; color: rgb(51, 51, 51); font-family: "helvetica neue", tahoma, "hiragino sans gb", stheiti, "wenquanyi micro hei", 微软雅黑, 宋体, sans-serif; font-size: 16px; line-height: 27.2px;">module.exports = {<br>entry: './src', output: { // ... }, plugins: [ new webpack.optimize.CommonsChunkPlugin({ name: 'main', // Move dependencies to our main file children: true, // Look for common dependencies in all children, minChunks: 2, // How many times a dependency must come up before being extracted }), ], module: { // ... } };</p><p style="margin-top: 18px; margin-bottom: 18px; color: rgb(51, 51, 51); font-family: "helvetica neue", tahoma, "hiragino sans gb", stheiti, "wenquanyi micro hei", 微软雅黑, 宋体, sans-serif; font-size: 16px; line-height: 27.2px;">如果我们重新run一下 Webpack，我们可以看到现在比之前好多了，这里的<code style="font-family: consolas, monaco, menlo, "courier new", courier, monospace; display: inline-block; line-height: normal; margin-right: 0.25em; margin-left: 0.25em; padding-right: 0.4em; padding-left: 0.4em; border: 1px solid rgb(221, 221, 221); border-radius: 3px; background-color: rgb(248, 248, 248);">main</code>是默认chunk的名字</p><p style="margin-top: 18px; margin-bottom: 18px; color: rgb(51, 51, 51); font-family: "helvetica neue", tahoma, "hiragino sans gb", stheiti, "wenquanyi micro hei", 微软雅黑, 宋体, sans-serif; font-size: 16px; line-height: 27.2px;">chunk {0} bundle.js (main) 287 kB <br> ./src/index.js 550 bytes {0} ./~/jquery/dist/jquery.js 259 kB {0} ./~/mustache/mustache.js 19.4 kB {0} ./~/css-loader/lib/css-base.js 1.51 kB {0} ./~/style-loader/addStyles.js 7.21 kB {0} chunk {1} 1.bundle.js 3.28 kB {0} <br> ./src/Components/Button.js 1.94 kB {1} ./src/Components/Button.html 72 bytes {1} ./src/Components/Button.scss 1.05 kB {1} ./~/css-loader!./~/sass-loader!./src/Components/Button.scss 212 bytes {1} chunk {2} 2.bundle.js 2.92 kB {0} <br> ./src/Components/Header.js 1.62 kB {2} ./src/Components/Header.html 64 bytes {2} ./src/Components/Header.scss 1.05 kB {2} ./~/css-loader!./~/sass-loader!./src/Components/Header.scss 192 bytes {2} </p><p style="margin-top: 18px; margin-bottom: 18px; color: rgb(51, 51, 51); font-family: "helvetica neue", tahoma, "hiragino sans gb", stheiti, "wenquanyi micro hei", 微软雅黑, 宋体, sans-serif; font-size: 16px; line-height: 27.2px;">如果我们把名字制定为如<code style="font-family: consolas, monaco, menlo, "courier new", courier, monospace; display: inline-block; line-height: normal; margin-right: 0.25em; margin-left: 0.25em; padding-right: 0.4em; padding-left: 0.4em; border: 1px solid rgb(221, 221, 221); border-radius: 3px; background-color: rgb(248, 248, 248);">name: 'vendor':</code></p><p style="margin-top: 18px; margin-bottom: 18px; color: rgb(51, 51, 51); font-family: "helvetica neue", tahoma, "hiragino sans gb", stheiti, "wenquanyi micro hei", 微软雅黑, 宋体, sans-serif; font-size: 16px; line-height: 27.2px;">new webpack.optimize.CommonsChunkPlugin({<br>name: 'vendor', children: true, minChunks: 2, }),</p><p style="margin-top: 18px; margin-bottom: 18px; color: rgb(51, 51, 51); font-family: "helvetica neue", tahoma, "hiragino sans gb", stheiti, "wenquanyi micro hei", 微软雅黑, 宋体, sans-serif; font-size: 16px; line-height: 27.2px;">由于vendor 这个 chunk还不存在，webpack会创建一个<code style="font-family: consolas, monaco, menlo, "courier new", courier, monospace; display: inline-block; line-height: normal; margin-right: 0.25em; margin-left: 0.25em; padding-right: 0.4em; padding-left: 0.4em; border: 1px solid rgb(221, 221, 221); border-radius: 3px; background-color: rgb(248, 248, 248);">builds/vendor.js</code>,我们手动把它导入到我们的HTML：</p><p style="margin-top: 18px; margin-bottom: 18px; color: rgb(51, 51, 51); font-family: "helvetica neue", tahoma, "hiragino sans gb", stheiti, "wenquanyi micro hei", 微软雅黑, 宋体, sans-serif; font-size: 16px; line-height: 27.2px;">你也可以通过不提供一个公用的（common） chunk name或者是指定<code style="font-family: consolas, monaco, menlo, "courier new", courier, monospace; display: inline-block; line-height: normal; margin-right: 0.25em; margin-left: 0.25em; padding-right: 0.4em; padding-left: 0.4em; border: 1px solid rgb(221, 221, 221); border-radius: 3px; background-color: rgb(248, 248, 248);">async: true</code>来让公用的dependency被异步加载，webpack有非常多的只能优化。我不可能全列出来，但作为练习我们来给我们的app建一个product version</p><p style="margin-top: 18px; margin-bottom: 18px; color: rgb(51, 51, 51); font-family: "helvetica neue", tahoma, "hiragino sans gb", stheiti, "wenquanyi micro hei", 微软雅黑, 宋体, sans-serif; font-size: 16px; line-height: 27.2px;">To production and beyond（超越）</p><p style="margin-top: 18px; margin-bottom: 18px; color: rgb(51, 51, 51); font-family: "helvetica neue", tahoma, "hiragino sans gb", stheiti, "wenquanyi micro hei", 微软雅黑, 宋体, sans-serif; font-size: 16px; line-height: 27.2px;">好首先，我们加几个plugin到configuration，但我们想只有在NODE_ENV 等于production才加载这些plugin，所以让我们来给configuration加一些逻辑，因为只是一个js 文件，所以比较简单：</p><p style="margin-top: 18px; margin-bottom: 18px; color: rgb(51, 51, 51); font-family: "helvetica neue", tahoma, "hiragino sans gb", stheiti, "wenquanyi micro hei", 微软雅黑, 宋体, sans-serif; font-size: 16px; line-height: 27.2px;">var webpack = require('webpack');<br>var production = process.env.NODE_ENV === 'production';</p><p style="margin-top: 18px; margin-bottom: 18px; color: rgb(51, 51, 51); font-family: "helvetica neue", tahoma, "hiragino sans gb", stheiti, "wenquanyi micro hei", 微软雅黑, 宋体, sans-serif; font-size: 16px; line-height: 27.2px;">var plugins = [<br>new webpack.optimize.CommonsChunkPlugin({ name: 'main', // Move dependencies to our main file children: true, // Look for common dependencies in all children, minChunks: 2, // How many times a dependency must come up before being extracted }), ];</p><p style="margin-top: 18px; margin-bottom: 18px; color: rgb(51, 51, 51); font-family: "helvetica neue", tahoma, "hiragino sans gb", stheiti, "wenquanyi micro hei", 微软雅黑, 宋体, sans-serif; font-size: 16px; line-height: 27.2px;">if (production) {<br>plugins = plugins.concat([ // Production plugins go here ]); }</p><p style="margin-top: 18px; margin-bottom: 18px; color: rgb(51, 51, 51); font-family: "helvetica neue", tahoma, "hiragino sans gb", stheiti, "wenquanyi micro hei", 微软雅黑, 宋体, sans-serif; font-size: 16px; line-height: 27.2px;">module.exports = {<br>entry: './src', output: { path: 'builds', filename: 'bundle.js', publicPath: 'builds/', }, plugins: plugins, // ... };</p><p style="margin-top: 18px; margin-bottom: 18px; color: rgb(51, 51, 51); font-family: "helvetica neue", tahoma, "hiragino sans gb", stheiti, "wenquanyi micro hei", 微软雅黑, 宋体, sans-serif; font-size: 16px; line-height: 27.2px;">再把几个webpack的设置在production上关掉：</p><p style="margin-top: 18px; margin-bottom: 18px; color: rgb(51, 51, 51); font-family: "helvetica neue", tahoma, "hiragino sans gb", stheiti, "wenquanyi micro hei", 微软雅黑, 宋体, sans-serif; font-size: 16px; line-height: 27.2px;">module.exports = {<br>debug: !production, devtool: production ? false : 'eval',</p><p style="margin-top: 18px; margin-bottom: 18px; color: rgb(51, 51, 51); font-family: "helvetica neue", tahoma, "hiragino sans gb", stheiti, "wenquanyi micro hei", 微软雅黑, 宋体, sans-serif; font-size: 16px; line-height: 27.2px;">第一个设置把转为非debug模式，非debug模式会去掉debug模式中产生的方便调试的code，第2个是控制sourcemap 生成的，webpack有几个方法可以render sourcemap，自带的里面<code style="font-family: consolas, monaco, menlo, "courier new", courier, monospace; display: inline-block; line-height: normal; margin-right: 0.25em; margin-left: 0.25em; padding-right: 0.4em; padding-left: 0.4em; border: 1px solid rgb(221, 221, 221); border-radius: 3px; background-color: rgb(248, 248, 248);">eval</code>是最好的，生产环境我们不太关心sourcemap的事，我们把它disable掉，下面加一下production plugins：</p><p style="margin-top: 18px; margin-bottom: 18px; color: rgb(51, 51, 51); font-family: "helvetica neue", tahoma, "hiragino sans gb", stheiti, "wenquanyi micro hei", 微软雅黑, 宋体, sans-serif; font-size: 16px; line-height: 27.2px;">if (production) {<br>plugins = plugins.concat([</p><pre style="font-family: consolas, monaco, menlo, "courier new", courier, monospace; border: 1px solid rgb(221, 221, 221); font-size: 12px; line-height: 18px; overflow: auto; padding: 6px 10px; border-radius: 3px; word-break: break-all; color: rgb(51, 51, 51); background-color: rgb(248, 248, 248);"><code style="font-family: consolas, monaco, menlo, "courier new", courier, monospace; display: inline-block; line-height: 1.5; border: 0px none; border-radius: 0px; font-size: inherit; background: none;"> // This plugin looks for similar chunks and files
// and merges them for better caching by the user
new webpack.optimize.DedupePlugin(),
// This plugins optimizes chunks and modules by
// how much they are used in your app
new webpack.optimize.OccurenceOrderPlugin(),
// This plugin prevents Webpack from creating chunks
// that would be too small to be worth loading separately
new webpack.optimize.MinChunkSizePlugin({
minChunkSize: 51200, // ~50kb
}),
// This plugin minifies all the Javascript code of the final bundle
new webpack.optimize.UglifyJsPlugin({
mangle: true,
compress: {
warnings: false, // Suppress uglification warnings
},
}),
// This plugins defines various variables that we can set to false
// in production to avoid code related to them from being compiled
// in our final bundle
new webpack.DefinePlugin({
__SERVER__: !production,
__DEVELOPMENT__: !production,
__DEVTOOLS__: !production,
'process.env': {
BABEL_ENV: JSON.stringify(process.env.NODE_ENV),
},
}),
]);
</code></pre><p style="margin-top: 18px; margin-bottom: 18px; color: rgb(51, 51, 51); font-family: "helvetica neue", tahoma, "hiragino sans gb", stheiti, "wenquanyi micro hei", 微软雅黑, 宋体, sans-serif; font-size: 16px; line-height: 27.2px;">}</p><p style="margin-top: 18px; margin-bottom: 18px; color: rgb(51, 51, 51); font-family: "helvetica neue", tahoma, "hiragino sans gb", stheiti, "wenquanyi micro hei", 微软雅黑, 宋体, sans-serif; font-size: 16px; line-height: 27.2px;">上面这几个是我最长用的，不过webpack提供很多plugin用来优化处理你的modules和chunks，NPM上也有个人用户写的plugin，有各种功能的插件，自行按需选择。</p><p style="margin-top: 18px; margin-bottom: 18px; color: rgb(51, 51, 51); font-family: "helvetica neue", tahoma, "hiragino sans gb", stheiti, "wenquanyi micro hei", 微软雅黑, 宋体, sans-serif; font-size: 16px; line-height: 27.2px;">另关于production assets的另一个方面是，我们有时想给asset加版本，还记得在上面我把<code style="font-family: consolas, monaco, menlo, "courier new", courier, monospace; display: inline-block; line-height: normal; margin-right: 0.25em; margin-left: 0.25em; padding-right: 0.4em; padding-left: 0.4em; border: 1px solid rgb(221, 221, 221); border-radius: 3px; background-color: rgb(248, 248, 248);">output.filename</code>设置为<code style="font-family: consolas, monaco, menlo, "courier new", courier, monospace; display: inline-block; line-height: normal; margin-right: 0.25em; margin-left: 0.25em; padding-right: 0.4em; padding-left: 0.4em; border: 1px solid rgb(221, 221, 221); border-radius: 3px; background-color: rgb(248, 248, 248);">bundle.js</code>吧，这有几个变量可以在option里用，其中一个是<code style="font-family: consolas, monaco, menlo, "courier new", courier, monospace; display: inline-block; line-height: normal; margin-right: 0.25em; margin-left: 0.25em; padding-right: 0.4em; padding-left: 0.4em; border: 1px solid rgb(221, 221, 221); border-radius: 3px; background-color: rgb(248, 248, 248);"></code>代表最后bundle文件的版本，同时用<code style="font-family: consolas, monaco, menlo, "courier new", courier, monospace; display: inline-block; line-height: normal; margin-right: 0.25em; margin-left: 0.25em; padding-right: 0.4em; padding-left: 0.4em; border: 1px solid rgb(221, 221, 221); border-radius: 3px; background-color: rgb(248, 248, 248);">output.chunkFilename</code>给chunk也加上版本：</p><p style="margin-top: 18px; margin-bottom: 18px; color: rgb(51, 51, 51); font-family: "helvetica neue", tahoma, "hiragino sans gb", stheiti, "wenquanyi micro hei", 微软雅黑, 宋体, sans-serif; font-size: 16px; line-height: 27.2px;">output: {<br>path: 'builds', filename: production ? '-.js' : 'bundle.js', chunkFilename: '-.js', publicPath: 'builds/', },</p><p style="margin-top: 18px; margin-bottom: 18px; color: rgb(51, 51, 51); font-family: "helvetica neue", tahoma, "hiragino sans gb", stheiti, "wenquanyi micro hei", 微软雅黑, 宋体, sans-serif; font-size: 16px; line-height: 27.2px;">由于没有什么特别好的办法能动态地获取这个简化版app编译后的bundle的名字（由于加了版本号），所以只是在production上给asset加版本，多次编译后目录里带版本的bundle会越来越多，还得加一个第三方插件来每次production build 之前清理一下build folder（output 里面的path）：</p><pre style="font-family: consolas, monaco, menlo, "courier new", courier, monospace; border: 1px solid rgb(221, 221, 221); font-size: 12px; line-height: 18px; overflow: auto; padding: 6px 10px; border-radius: 3px; word-break: break-all; color: rgb(51, 51, 51); background-color: rgb(248, 248, 248);"><code style="font-family: consolas, monaco, menlo, "courier new", courier, monospace; display: inline-block; line-height: 1.5; border: 0px none; border-radius: 0px; font-size: inherit; background: none;">$ npm install clean-webpack-plugin --save-dev
</code></pre><p style="margin-top: 18px; margin-bottom: 18px; color: rgb(51, 51, 51); font-family: "helvetica neue", tahoma, "hiragino sans gb", stheiti, "wenquanyi micro hei", 微软雅黑, 宋体, sans-serif; font-size: 16px; line-height: 27.2px;">把它加到configuration里</p><p style="margin-top: 18px; margin-bottom: 18px; color: rgb(51, 51, 51); font-family: "helvetica neue", tahoma, "hiragino sans gb", stheiti, "wenquanyi micro hei", 微软雅黑, 宋体, sans-serif; font-size: 16px; line-height: 27.2px;">var webpack = require('webpack');<br>var CleanPlugin = require('clean-webpack-plugin');</p><p style="margin-top: 18px; margin-bottom: 18px; color: rgb(51, 51, 51); font-family: "helvetica neue", tahoma, "hiragino sans gb", stheiti, "wenquanyi micro hei", 微软雅黑, 宋体, sans-serif; font-size: 16px; line-height: 27.2px;">// ...</p><p style="margin-top: 18px; margin-bottom: 18px; color: rgb(51, 51, 51); font-family: "helvetica neue", tahoma, "hiragino sans gb", stheiti, "wenquanyi micro hei", 微软雅黑, 宋体, sans-serif; font-size: 16px; line-height: 27.2px;">if (production) {<br>plugins = plugins.concat([</p><pre style="font-family: consolas, monaco, menlo, "courier new", courier, monospace; border: 1px solid rgb(221, 221, 221); font-size: 12px; line-height: 18px; overflow: auto; padding: 6px 10px; border-radius: 3px; word-break: break-all; color: rgb(51, 51, 51); background-color: rgb(248, 248, 248);"><code style="font-family: consolas, monaco, menlo, "courier new", courier, monospace; display: inline-block; line-height: 1.5; border: 0px none; border-radius: 0px; font-size: inherit; background: none;"> // Cleanup the builds/ folder before
// compiling our final assets
new CleanPlugin('builds'),
</code></pre><p style="margin-top: 18px; margin-bottom: 18px; color: rgb(51, 51, 51); font-family: "helvetica neue", tahoma, "hiragino sans gb", stheiti, "wenquanyi micro hei", 微软雅黑, 宋体, sans-serif; font-size: 16px; line-height: 27.2px;">欧了，做完了几个小优化，下面比较一下结果：</p><p style="margin-top: 18px; margin-bottom: 18px; color: rgb(51, 51, 51); font-family: "helvetica neue", tahoma, "hiragino sans gb", stheiti, "wenquanyi micro hei", 微软雅黑, 宋体, sans-serif; font-size: 16px; line-height: 27.2px;">$ webpack<br>bundle.js 314 kB 0 main 1-21660ec268fe9de7776c.js 4.46 kB 1 <br>2-fcc95abf34773e79afda.js 4.15 kB 2 </p><p style="margin-top: 18px; margin-bottom: 18px; color: rgb(51, 51, 51); font-family: "helvetica neue", tahoma, "hiragino sans gb", stheiti, "wenquanyi micro hei", 微软雅黑, 宋体, sans-serif; font-size: 16px; line-height: 27.2px;">.</p><p style="margin-top: 18px; margin-bottom: 18px; color: rgb(51, 51, 51); font-family: "helvetica neue", tahoma, "hiragino sans gb", stheiti, "wenquanyi micro hei", 微软雅黑, 宋体, sans-serif; font-size: 16px; line-height: 27.2px;">$ NODE_ENV=production webpack<br>main-937cc23ccbf192c9edd6.js 97.2 kB 0 main</p><p style="margin-top: 18px; margin-bottom: 18px; color: rgb(51, 51, 51); font-family: "helvetica neue", tahoma, "hiragino sans gb", stheiti, "wenquanyi micro hei", 微软雅黑, 宋体, sans-serif; font-size: 16px; line-height: 27.2px;">to be done ................（last update 2016.6.8 ） <a href="https://github.com/starduliang/blog/tree/master/2016.6" target="_blank" style="text-decoration: none; color: rgb(49, 135, 219);">我的github会对这篇持续更新,以后还会加入更多有营养的内容</a> <a href="https://github.com/starduliang/blog/tree/master/2016.6/assets/webpack%20your%20bags/source/webpack-your-bags-demo" target="_blank" style="text-decoration: none; color: rgb(49, 135, 219); margin-left: 0.25em;">source</a> <strong>如果您觉得我的翻译能给你带来点帮助，那就给我点个Star鼓励一下吧^_^,</strong></p><p style="margin-top: 18px; margin-bottom: 18px; color: rgb(51, 51, 51); font-family: "helvetica neue", tahoma, "hiragino sans gb", stheiti, "wenquanyi micro hei", 微软雅黑, 宋体, sans-serif; font-size: 16px; line-height: 27.2px;"><strong><br></strong></p><p style="margin-top: 18px; margin-bottom: 18px;"><strong style="color: rgb(51, 51, 51); font-family: "helvetica neue", tahoma, "hiragino sans gb", stheiti, "wenquanyi micro hei", 微软雅黑, 宋体, sans-serif; font-size: 16px; line-height: 27.2px;">来源：</strong><font color="#333333" face="helvetica neue, tahoma, hiragino sans gb, stheiti, wenquanyi micro hei, 微软雅黑, 宋体, sans-serif"><span style="font-size: 16px; line-height: 27.2px;"><b>http://div.io/topic/1752</b></span></font></p><p></p>
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