webpack 从入门到上树
colinshen
8年前
<h2>webpack 是什么</h2> <p><img src="https://simg.open-open.com/show/47f33d3ec28f9800b3af7fab96329d79.png"></p> <p>一项技术、一个工具的出现，肯定是为了解决问题的。那么，webpack 是为什么解决什么问题？答案是： <strong>文件依赖管理</strong> 。我们在浏览器中的 js 中，不能直接引用其它 js, css 等文件（或说，模块）。而 webpack 就是用来解决这个问题的，让你的项目可以很好地分文件、分模块，而且它对外部文件的引入同时支持 cmd, amd 和 commondJs 这三种形式，够有诚意。</p> <p>或许你要说了，解决文件依赖，早在 require.js 和 sea.js 的时候，都已经解决了呀！那么，webpack 在这方面，有哪些新的突破：</p> <ol> <li> <p>支持依赖各种拓展名的文件</p> </li> <li> <p>能够在不依赖 gulp 或 grunt 的情况下直接产出打包文件</p> </li> <li> <p>支持实时编译，浏览器同步刷新</p> </li> </ol> <p>这个时候，是不是很想唱一下王力宏的《唯一》：确定你就是我的唯一！</p> <p>OK，进入正题。</p> <h2>安装与运行</h2> <p>目前，我们的项目目录结构是这样的：</p> <div contenteditable="false" tabindex="-1"> <pre data-widget="codeSnippet"> <code class="language-basic hljs">webpack_demo |<span class="hljs-comment">--src</span> | |<span class="hljs-comment">--pages</span> | | |<span class="hljs-comment">--index</span> | | | |<span class="hljs-comment">--index.js</span> |<span class="hljs-comment">--views_dev</span> | |<span class="hljs-comment">--index.html</span> |<span class="hljs-comment">--webpack.config.js</span> |<span class="hljs-comment">--package.json</span></code></pre> <img src="data:image/gif;base64,R0lGODlhAQABAPABAP///wAAACH5BAEKAAAALAAAAAABAAEAAAICRAEAOw=="> <span style="background:rgba(220, 220, 220, 0.5) url("http://www.open-open.com/lib/ckeditor/plugins/widget/images/handle.png") repeat scroll 0% 0%; display:block; left:0px; top:-15px"><img height="15" src="data:image/gif;base64,R0lGODlhAQABAPABAP///wAAACH5BAEKAAAALAAAAAABAAEAAAICRAEAOw==" title="点击并拖拽以移动" width="15"></span> </div> <h3>安装</h3> <p>在项目的根目录执行：</p> <div contenteditable="false" tabindex="-1"> <pre data-widget="codeSnippet"> <code class="language-basic hljs">$ npm init <span class="hljs-comment">// 生成项目依赖文件配置 package.json</span> $ npm install webpack -g <span class="hljs-comment">// 全局安装webpack</span> $ touch webpack.config.js <span class="hljs-comment">// 在项目根目录下，新建 webpack.config.js 文件</span></code></pre> <img src="data:image/gif;base64,R0lGODlhAQABAPABAP///wAAACH5BAEKAAAALAAAAAABAAEAAAICRAEAOw=="> <span style="background:rgba(220, 220, 220, 0.5) url("http://www.open-open.com/lib/ckeditor/plugins/widget/images/handle.png") repeat scroll 0% 0%; display:block; left:0px; top:-15px"><img height="15" src="data:image/gif;base64,R0lGODlhAQABAPABAP///wAAACH5BAEKAAAALAAAAAABAAEAAAICRAEAOw==" title="点击并拖拽以移动" width="15"></span> </div> <h3>配置</h3> <p>然后，在以下3个文件，输入内容：</p> <ol> <li> <p>页面 HTML 文件</p> <div contenteditable="false" tabindex="-1"> <pre data-widget="codeSnippet"> <code class="language-basic hljs">// views_dev/index.html <span class="hljs-doctype"><!DOCTYPE html></span> <span class="hljs-tag"><<span class="hljs-title">html</span>></span> <span class="hljs-tag"><<span class="hljs-title">head</span>></span> <span class="hljs-tag"><<span class="hljs-title">meta</span> <span class="hljs-attribute">charset</span>=<span class="hljs-value">"utf-8"</span>></span> <span class="hljs-tag"><<span class="hljs-title">title</span>></span>首页<span class="hljs-tag"></<span class="hljs-title">title</span>></span> <span class="hljs-tag"></<span class="hljs-title">head</span>></span> <span class="hljs-tag"><<span class="hljs-title">body</span>></span> <span class="hljs-tag"><<span class="hljs-title">div</span>></span>哈喽，world<span class="hljs-tag"></<span class="hljs-title">div</span>></span> <span class="hljs-tag"><<span class="hljs-title">script</span> <span class="hljs-attribute">src</span>=<span class="hljs-value">"../asset/dev/main.js"</span>></span><span class="hljs-tag"></<span class="hljs-title">script</span>></span> <span class="hljs-tag"></<span class="hljs-title">body</span>></span> <span class="hljs-tag"></<span class="hljs-title">html</span>></span></code></pre> <img src="data:image/gif;base64,R0lGODlhAQABAPABAP///wAAACH5BAEKAAAALAAAAAABAAEAAAICRAEAOw=="> <span style="background:rgba(220, 220, 220, 0.5) url("http://www.open-open.com/lib/ckeditor/plugins/widget/images/handle.png") repeat scroll 0% 0%; display:block; left:0px; top:-15px"><img height="15" src="data:image/gif;base64,R0lGODlhAQABAPABAP///wAAACH5BAEKAAAALAAAAAABAAEAAAICRAEAOw==" title="点击并拖拽以移动" width="15"></span> </div> </li> <li> <p>页面引用的 js 文件</p> <div contenteditable="false" tabindex="-1"> <pre data-widget="codeSnippet"> <code class="language-basic hljs">// src/pages/<span class="hljs-keyword">index</span>/<span class="hljs-keyword">index</span>.js console.<span class="hljs-keyword">log</span>(<span class="hljs-string">'I am in index/index.js, haha4'</span>);</code></pre> <img src="data:image/gif;base64,R0lGODlhAQABAPABAP///wAAACH5BAEKAAAALAAAAAABAAEAAAICRAEAOw=="> <span style="background:rgba(220, 220, 220, 0.5) url("http://www.open-open.com/lib/ckeditor/plugins/widget/images/handle.png") repeat scroll 0% 0%; display:block; left:0px; top:-15px"><img height="15" src="data:image/gif;base64,R0lGODlhAQABAPABAP///wAAACH5BAEKAAAALAAAAAABAAEAAAICRAEAOw==" title="点击并拖拽以移动" width="15"></span> </div> </li> <li> <p>webpack 打包配置</p> <div contenteditable="false" tabindex="-1"> <pre data-widget="codeSnippet"> <code class="language-basic hljs"><span class="hljs-comment">// webpack.config.js</span> module.exports = { <span class="hljs-comment">// 入口：要进行处理的实例（js）</span> entry: <span class="hljs-string">'./src/pages/index/index.js'</span>, <span class="hljs-comment">// 出口：输出配置</span> output: { <span class="hljs-comment">// 输出到哪个目录</span> path: <span class="hljs-string">'./asset/dev/'</span>, <span class="hljs-comment">// 静态资源的引用路径</span> publicpath: <span class="hljs-string">'/asset/dev/'</span>, <span class="hljs-comment">// 实例最终输出的名字</span> filename: <span class="hljs-string">'[name].js'</span> } };</code></pre> <img src="data:image/gif;base64,R0lGODlhAQABAPABAP///wAAACH5BAEKAAAALAAAAAABAAEAAAICRAEAOw=="> <span style="background:rgba(220, 220, 220, 0.5) url("http://www.open-open.com/lib/ckeditor/plugins/widget/images/handle.png") repeat scroll 0% 0%; display:block; left:0px; top:-15px"><img height="15" src="data:image/gif;base64,R0lGODlhAQABAPABAP///wAAACH5BAEKAAAALAAAAAABAAEAAAICRAEAOw==" title="点击并拖拽以移动" width="15"></span> </div> </li> </ol> <h3>运行</h3> <p>运行 webpack 命令，进行打包。</p> <div contenteditable="false" tabindex="-1"> <pre data-widget="codeSnippet"> <code class="language-basic hljs"><span class="hljs-variable">$ </span>webpack</code></pre> <img src="data:image/gif;base64,R0lGODlhAQABAPABAP///wAAACH5BAEKAAAALAAAAAABAAEAAAICRAEAOw=="> <span style="background:rgba(220, 220, 220, 0.5) url("http://www.open-open.com/lib/ckeditor/plugins/widget/images/handle.png") repeat scroll 0% 0%; display:block; left:0px; top:-15px"><img height="15" src="data:image/gif;base64,R0lGODlhAQABAPABAP///wAAACH5BAEKAAAALAAAAAABAAEAAAICRAEAOw==" title="点击并拖拽以移动" width="15"></span> </div> <p>然后，搞定了，此时在浏览器中打开 views_dev/index.html ，你会发现，打包成功了！</p> <p><img src="https://simg.open-open.com/show/f3528c010c0e3d4d563331a8d97a613b.png"></p> <p>好的，你入门了的，哈哈！接下去，我会详细介绍单个页面打包、多个页面打包，以及最后的发布上线。Now, go ~</p> <h2>单个页面打包</h2> <p>这里，你将学到：</p> <ol> <li> <p>引入其它 js 文件。是的，你将学会 <strong>模块化</strong> 。</p> </li> <li> <p>引入其它类型的文件，以 css 为例。</p> </li> <li> <p>实时编译 + 浏览器同步刷新。爽！</p> </li> </ol> <p>现在，我们的项目目录，是这样：</p> <div contenteditable="false" tabindex="-1"> <pre data-widget="codeSnippet"> <code class="language-basic hljs">webpack_demo |<span class="hljs-comment">--src</span> | |<span class="hljs-comment">--pages</span> | | |<span class="hljs-comment">--index</span> | | | |<span class="hljs-comment">--index.js</span> | | | |<span class="hljs-comment">--test.js</span> | | | |<span class="hljs-comment">--index.css</span> | |<span class="hljs-comment">--plugins</span> | | |<span class="hljs-comment">--dialog</span> | | | |<span class="hljs-comment">--dialog.css</span> | | | |<span class="hljs-comment">--dialog.js</span> |<span class="hljs-comment">--views_dev</span> | |<span class="hljs-comment">--index.html</span> |<span class="hljs-comment">--webpack.config.js</span> |<span class="hljs-comment">--package.json</span></code></pre> <img src="data:image/gif;base64,R0lGODlhAQABAPABAP///wAAACH5BAEKAAAALAAAAAABAAEAAAICRAEAOw=="> <span style="background:rgba(220, 220, 220, 0.5) url("http://www.open-open.com/lib/ckeditor/plugins/widget/images/handle.png") repeat scroll 0% 0%; display:block; left:0px; top:-15px"><img height="15" src="data:image/gif;base64,R0lGODlhAQABAPABAP///wAAACH5BAEKAAAALAAAAAABAAEAAAICRAEAOw==" title="点击并拖拽以移动" width="15"></span> </div> <h3>引入其它 js 文件</h3> <ol> <li> <p>使用相对路径</p> <p>现在，我们要在 src/pages/index.js 里面引入 src/pages/test.js 文件。这样做就可以了：</p> <div contenteditable="false" tabindex="-1"> <pre data-widget="codeSnippet"> <code class="language-basic hljs"><span class="hljs-keyword">var</span> Test = <span class="hljs-built_in">require</span>(<span class="hljs-string">'./test.js'</span>);</code></pre> <img src="data:image/gif;base64,R0lGODlhAQABAPABAP///wAAACH5BAEKAAAALAAAAAABAAEAAAICRAEAOw=="> <span style="background-image:url(http://www.open-open.com/lib/ckeditor/plugins/widget/images/handle.png); background:rgba(220,220,220,0.5)"><img height="15" src="data:image/gif;base64,R0lGODlhAQABAPABAP///wAAACH5BAEKAAAALAAAAAABAAEAAAICRAEAOw==" title="点击并拖拽以移动" width="15"></span> </div> <p>你也许会问，此时， var Test 这个变量，得到的是什么？换个说法，怎么控制 test.js 被导出到外部的内容。答案是：通过 module.exports . 例如：</p> <div contenteditable="false" tabindex="-1"> <pre data-widget="codeSnippet"> <code class="language-basic hljs"><span class="hljs-regexp">//</span> index/test.js <span class="hljs-reserved">var</span> str = <span class="hljs-string">"I am in test.js"</span>; <span class="hljs-built_in">module</span>.<span class="hljs-built_in">exports</span> = str;</code></pre> <img src="data:image/gif;base64,R0lGODlhAQABAPABAP///wAAACH5BAEKAAAALAAAAAABAAEAAAICRAEAOw=="> <span style="background:rgba(220, 220, 220, 0.5) url("http://www.open-open.com/lib/ckeditor/plugins/widget/images/handle.png") repeat scroll 0% 0%; display:block; left:0px; top:-15px"><img height="15" src="data:image/gif;base64,R0lGODlhAQABAPABAP///wAAACH5BAEKAAAALAAAAAABAAEAAAICRAEAOw==" title="点击并拖拽以移动" width="15"></span> </div> <p>那么， require('./test.js') 的值就是 "I am in test.js" 这个字符串。 module.exports 可以导出任何值。比如，我们要导出 Object.</p> <div contenteditable="false" tabindex="-1"> <pre data-widget="codeSnippet"> <code class="language-basic hljs">module.exports = { aa: <span class="hljs-string">'axxx'</span>, b: <span class="hljs-function"><span class="hljs-keyword">function</span><span class="hljs-params">()</span> {</span>} };</code></pre> <img src="data:image/gif;base64,R0lGODlhAQABAPABAP///wAAACH5BAEKAAAALAAAAAABAAEAAAICRAEAOw=="> <span style="background:rgba(220, 220, 220, 0.5) url("http://www.open-open.com/lib/ckeditor/plugins/widget/images/handle.png") repeat scroll 0% 0%; display:block; left:0px; top:-15px"><img height="15" src="data:image/gif;base64,R0lGODlhAQABAPABAP///wAAACH5BAEKAAAALAAAAAABAAEAAAICRAEAOw==" title="点击并拖拽以移动" width="15"></span> </div> </li> <li> <p>使用绝对路径（别名的使用）</p> <p>如果只能使用相对路径，那 webpack 就太不靠谱了。因为将有可能出现这样 ../../../../libs/libs-tost/toast.js , 啊，想死！那么，怎么使用呢？假如，我们想引入 src/plugins/dialog/dialog.js 这个弹窗。</p> <ul> <li> <p>在 webpack.config.js 中，配置别名</p> <div contenteditable="false" tabindex="-1"> <pre data-widget="codeSnippet"> <code class="language-basic hljs"><span class="hljs-comment">// webpack.config.js</span> module.exports = { resolve: { <span class="hljs-comment">// 定义别名</span> alias: { plugins: <span class="hljs-string">'D:/your/path/webpack_demo/src/plugins'</span> } } }</code></pre> <img src="data:image/gif;base64,R0lGODlhAQABAPABAP///wAAACH5BAEKAAAALAAAAAABAAEAAAICRAEAOw=="> <span style="background-image:url(http://www.open-open.com/lib/ckeditor/plugins/widget/images/handle.png); background:rgba(220,220,220,0.5)"><img height="15" src="data:image/gif;base64,R0lGODlhAQABAPABAP///wAAACH5BAEKAAAALAAAAAABAAEAAAICRAEAOw==" title="点击并拖拽以移动" width="15"></span> </div> </li> <li> <p>可以使用了</p> <div contenteditable="false" tabindex="-1"> <pre data-widget="codeSnippet"> <code class="language-basic hljs"><span class="hljs-comment">// src/index/index.js</span> <span class="hljs-keyword">var</span> Dialog = <span class="hljs-built_in">require</span>(<span class="hljs-string">'plugins/dialog/dialog.js'</span>);</code></pre> <img src="data:image/gif;base64,R0lGODlhAQABAPABAP///wAAACH5BAEKAAAALAAAAAABAAEAAAICRAEAOw=="> <span style="background-image:url(http://www.open-open.com/lib/ckeditor/plugins/widget/images/handle.png); background:rgba(220,220,220,0.5)"><img height="15" src="data:image/gif;base64,R0lGODlhAQABAPABAP///wAAACH5BAEKAAAALAAAAAABAAEAAAICRAEAOw==" title="点击并拖拽以移动" width="15"></span> </div> <p>当 require() 的第一单词是 alias 中的，将被匹配。</p> </li> </ul> </li> </ol> <h3>引入其它类型的文件</h3> <p>webpack 的强大之处是，它允许你引入任何文件，比如：css, jpg, png. 那么，问题来了，对于不同的文件，它要怎么知道该如何分开处理呢？</p> <div contenteditable="false" tabindex="-1"> <pre data-widget="codeSnippet"> <code class="language-basic hljs"><span class="hljs-regexp">//</span> webpack.config.js <span class="hljs-built_in">module</span>.<span class="hljs-built_in">exports</span> = { <span class="hljs-attribute">module</span>: { <span class="hljs-attribute">loaders</span>: [{ <span class="hljs-attribute">test</span>: <span class="hljs-regexp">/\.css$/</span>, <span class="hljs-attribute">loader</span>: <span class="hljs-string">'style!css'</span> }, { <span class="hljs-attribute">test</span>: <span class="hljs-regexp">/\.js$/</span>, <span class="hljs-attribute">loader</span>: <span class="hljs-string">'babel'</span> }] } };</code></pre> <img src="data:image/gif;base64,R0lGODlhAQABAPABAP///wAAACH5BAEKAAAALAAAAAABAAEAAAICRAEAOw=="> <span style="background-image:url(http://www.open-open.com/lib/ckeditor/plugins/widget/images/handle.png); background:rgba(220,220,220,0.5)"><img height="15" src="data:image/gif;base64,R0lGODlhAQABAPABAP///wAAACH5BAEKAAAALAAAAAABAAEAAAICRAEAOw==" title="点击并拖拽以移动" width="15"></span> </div> <p>上面的配置是说，对于拓展名是 .css 的文件，使用加载器 style!css （这边中间有一个感叹号，意思是：先是用 css 加载器处理，然后使用 style 加载器处理）。完整的写法是： style-loader!css-loader , 其中， -loader 可以省略。而这里的， style-loader 和 css-loader 就需要你 npm 安装下了。</p> <div contenteditable="false" tabindex="-1"> <pre data-widget="codeSnippet"> <code class="language-basic hljs"><span class="hljs-variable">$ </span>npm i style-loader -<span class="hljs-constant">D</span> <span class="hljs-variable">$ </span>npm i css-loader -<span class="hljs-constant">D</span></code></pre> <img src="data:image/gif;base64,R0lGODlhAQABAPABAP///wAAACH5BAEKAAAALAAAAAABAAEAAAICRAEAOw=="> <span style="background-image:url(http://www.open-open.com/lib/ckeditor/plugins/widget/images/handle.png); background:rgba(220,220,220,0.5)"><img height="15" src="data:image/gif;base64,R0lGODlhAQABAPABAP///wAAACH5BAEKAAAALAAAAAABAAEAAAICRAEAOw==" title="点击并拖拽以移动" width="15"></span> </div> <p>对于其它拓展名的处理，也是用同样的方式来处理。</p> <h3>释放双手：自动编译 + 浏览器同步刷新</h3> <p>你肯定希望，这样的功能。那么，开始吧，喝杯咖啡！</p> <ol> <li> <p>自动编译</p> <p>如果你只是想支持自动编译，那么很简单。只要运行 $ webpack -w 就可以开启它的自动编译功能。</p> </li> <li> <p>用 webpack-dev-server 实现：自动编译 + 浏览器同步刷新</p> <ul> <li> <p>首先，你需要安装 webpack-dev-server 这个包。</p> <div contenteditable="false" tabindex="-1"> <pre data-widget="codeSnippet"> <code class="language-basic hljs"><span class="hljs-variable">$ </span>npm i webpack-dev-server -<span class="hljs-constant">D</span></code></pre> <img src="data:image/gif;base64,R0lGODlhAQABAPABAP///wAAACH5BAEKAAAALAAAAAABAAEAAAICRAEAOw=="> <span style="background-image:url(http://www.open-open.com/lib/ckeditor/plugins/widget/images/handle.png); background:rgba(220,220,220,0.5)"><img height="15" src="data:image/gif;base64,R0lGODlhAQABAPABAP///wAAACH5BAEKAAAALAAAAAABAAEAAAICRAEAOw==" title="点击并拖拽以移动" width="15"></span> </div> </li> <li> <p>然后，我简单介绍下它： <a href="/misc/goto?guid=4959676961343349964" rel="nofollow,noindex">webpack-dev-server 文档</a></p> <ul> <li> <p>运行时，它会启动一个本地 Node 服务器，默认端口8080. 即：localhost:8080. 并且自动识别当前目录下的 webpack.config.js 文件，来作为 webpack 配置文件。</p> </li> <li> <p>产出的编译后文件，不在 output.path 里，而在它自己定义的内存。</p> </li> <li> <p>行内参数说明：</p> <ul> <li> <p>inline: 使用命令行模式。</p> </li> <li> <p>content-base: 指定网站的根地址，如果你想指定为项目根目录，那么 --content-base ./</p> </li> <li> <p>hot: 开启热替换。一般用在 React 和 Vue 当中，我们这里不用。</p> </li> </ul> </li> </ul> </li> </ul> <p>好了，那么，启动它吧：</p> <div contenteditable="false" tabindex="-1"> <pre data-widget="codeSnippet"> <code class="language-basic hljs">$ webpack-dev-server --inline --content-<span class="hljs-keyword">base</span> ./</code></pre> <img src="data:image/gif;base64,R0lGODlhAQABAPABAP///wAAACH5BAEKAAAALAAAAAABAAEAAAICRAEAOw=="> <span style="background-image:url(http://www.open-open.com/lib/ckeditor/plugins/widget/images/handle.png); background:rgba(220,220,220,0.5)"><img height="15" src="data:image/gif;base64,R0lGODlhAQABAPABAP///wAAACH5BAEKAAAALAAAAAABAAEAAAICRAEAOw==" title="点击并拖拽以移动" width="15"></span> </div> <p>然后，你在浏览器中，访问 http://localhost:8080/views_dev/index.html 就会发现，你修改代码的时候，实时编译，并且浏览器同步刷新了。</p> </li> </ol> <h2>多页面打包</h2> <p>现在，我们加一点点配置，让它支持多个页面打包。之前，它是这样的：</p> <div contenteditable="false" tabindex="-1"> <pre data-widget="codeSnippet"> <code class="language-basic hljs">module.exports = { <span class="hljs-comment">// 入口：要进行处理的实例（js）</span> entry: <span class="hljs-string">'./src/pages/index/index.js'</span>, <span class="hljs-comment">// 出口：输出配置</span> output: { <span class="hljs-comment">// 输出到哪个目录</span> path: <span class="hljs-string">'./asset/dev/'</span>, <span class="hljs-comment">// 静态资源的引用路径</span> publicpath: <span class="hljs-string">'/asset/dev/'</span>, <span class="hljs-comment">// 实例最终输出的名字</span> filename: <span class="hljs-string">'[name].js'</span> }, <span class="hljs-comment">// 其它配置...</span> };</code></pre> <img src="data:image/gif;base64,R0lGODlhAQABAPABAP///wAAACH5BAEKAAAALAAAAAABAAEAAAICRAEAOw=="> <span style="background-image:url(http://www.open-open.com/lib/ckeditor/plugins/widget/images/handle.png); background:rgba(220,220,220,0.5)"><img height="15" src="data:image/gif;base64,R0lGODlhAQABAPABAP///wAAACH5BAEKAAAALAAAAAABAAEAAAICRAEAOw==" title="点击并拖拽以移动" width="15"></span> </div> <p>现在，我们需要改下 entry 的配置，如下：</p> <div contenteditable="false" tabindex="-1"> <pre data-widget="codeSnippet"> <code class="language-basic hljs"><span class="hljs-tag">entry</span>: <span class="hljs-rules">{ <span class="hljs-rule"><span class="hljs-attribute">index</span>:<span class="hljs-value"> <span class="hljs-string">'./src/pages/index/index.js'</span>, list: <span class="hljs-string">'./src/pages/list/index.js'</span>, common: [ <span class="hljs-string">'./src/base/base.js'</span>, <span class="hljs-string">'./src/base/base.css'</span> ] </span></span></span>}</code></pre> <img src="data:image/gif;base64,R0lGODlhAQABAPABAP///wAAACH5BAEKAAAALAAAAAABAAEAAAICRAEAOw=="> <span style="background-image:url(http://www.open-open.com/lib/ckeditor/plugins/widget/images/handle.png); background:rgba(220,220,220,0.5)"><img height="15" src="data:image/gif;base64,R0lGODlhAQABAPABAP///wAAACH5BAEKAAAALAAAAAABAAEAAAICRAEAOw==" title="点击并拖拽以移动" width="15"></span> </div> <p>上面的配置意思是，会独立打包3个实体。分别是 index, list, common. 知识点如下：</p> <ol> <li> <p>它支持多个文件打包在一起，如这里的 common 的配置。我们一般，用来放公共基础包。</p> </li> <li> <p>我们看到 output.filename = [name].js ，这里的 [name] 取自于 entry 的 key 值。意味着，他们最终打包的输出是：</p> <div contenteditable="false" tabindex="-1"> <pre data-widget="codeSnippet"> <code class="language-basic hljs">webpack_demo |<span class="hljs-comment">--asset</span> | |<span class="hljs-comment">--dev</span> | | |<span class="hljs-comment">--index.js</span> | | |<span class="hljs-comment">--list.js</span> | | |<span class="hljs-comment">--common.js</span></code></pre> <img src="data:image/gif;base64,R0lGODlhAQABAPABAP///wAAACH5BAEKAAAALAAAAAABAAEAAAICRAEAOw=="> <span style="background-image:url(http://www.open-open.com/lib/ckeditor/plugins/widget/images/handle.png); background:rgba(220,220,220,0.5)"><img height="15" src="data:image/gif;base64,R0lGODlhAQABAPABAP///wAAACH5BAEKAAAALAAAAAABAAEAAAICRAEAOw==" title="点击并拖拽以移动" width="15"></span> </div> </li> </ol> <h2>上线</h2> <p>发布上线，需要做什么呢？也许是这样：</p> <ol> <li> <p>把静态资源生成到一个独立的目录下</p> </li> <li> <p>压缩</p> </li> <li> <p>加上 md5</p> </li> <li> <p>html 和 css 中，引用的静态资源需要替换。</p> </li> </ol> <p>哈哈，或许你还能想到很多。我就上面4步来说下实现方式。开始之前，我们一般会这么做：新建一个 webpack 的配置文件，用来做上线发布的配置。比如，我们同样放在根目录下，命名 webpack.config.build.js . 此时，你可以这样做：</p> <div contenteditable="false" tabindex="-1"> <pre data-widget="codeSnippet"> <code class="language-basic hljs"><span class="hljs-variable">$ </span>webpack -p --config webpack.config.build.js</code></pre> <img src="data:image/gif;base64,R0lGODlhAQABAPABAP///wAAACH5BAEKAAAALAAAAAABAAEAAAICRAEAOw=="> <span style="background-image:url(http://www.open-open.com/lib/ckeditor/plugins/widget/images/handle.png); background:rgba(220,220,220,0.5)"><img height="15" src="data:image/gif;base64,R0lGODlhAQABAPABAP///wAAACH5BAEKAAAALAAAAAABAAEAAAICRAEAOw==" title="点击并拖拽以移动" width="15"></span> </div> <p>这里的 -p 是 production 模式的意思，它会对 css, js 文件进行压缩。后面 --config 就是指定此次运行的配置文件。</p> <p>然后，我们来解决上面的4个要求：</p> <ol> <li> <p>把静态资源生成到一个独立的目录下 + md5</p> <div contenteditable="false" tabindex="-1"> <pre data-widget="codeSnippet"> <code class="language-basic hljs"><span class="hljs-comment">// webpack.config.build.js</span> module.exports = { output: { path: <span class="hljs-string">'./asset/build/'</span>, <span class="hljs-comment">// 文件编译输出路径改成 build</span> publicpath: <span class="hljs-string">'http://yourweb.com/asset/build/'</span>, <span class="hljs-comment">// 这里替换成线上实际地址，可以修改 css 中对图片资源的引用路径。</span> filename: <span class="hljs-string">'[name]_[hash:5].js'</span> <span class="hljs-comment">// 生成的文件名字，加上了5位的 hash值。</span> }, <span class="hljs-comment">// 其它配置...</span> };</code></pre> <img src="data:image/gif;base64,R0lGODlhAQABAPABAP///wAAACH5BAEKAAAALAAAAAABAAEAAAICRAEAOw=="> <span style="background:rgba(220, 220, 220, 0.5) url("http://www.open-open.com/lib/ckeditor/plugins/widget/images/handle.png") repeat scroll 0% 0%; display:block; left:0px; top:-15px"><img height="15" src="data:image/gif;base64,R0lGODlhAQABAPABAP///wAAACH5BAEKAAAALAAAAAABAAEAAAICRAEAOw==" title="点击并拖拽以移动" width="15"></span> </div> </li> <li> <p>压缩。已经用 webpack -p 解决了。</p> </li> <li> <p>替换静态资源的路径。可以用 webpack 的插件， html-webpack-plugin 来做。或者，你对 gulp 还是比较熟悉的话，用 gulp-prefix 来实现。这里就不详细写配置了。</p> </li> </ol> <p>然后，恭喜你看完了！</p> <p> </p> <p>来自：https://segmentfault.com/a/1190000006649986</p> <p> </p> <p><span style="color:rgb(255, 255, 255)">Save</span></p>