vuex-help

<!DOCTYPE HTML> <html lang="zh-cn" > <head> <meta charset="UTF-8"> <meta content="text/html; charset=utf-8" http-equiv="Content-Type"> <title>插件 · Vuex</title> <meta http-equiv="X-UA-Compatible" content="IE=edge" /> <meta name="description" content=""> <meta name="generator" content="GitBook 3.2.3"> <link rel="stylesheet" href="../gitbook/style.css"> <link rel="stylesheet" href="../gitbook/gitbook-plugin-prism/prism.css"> <link rel="stylesheet" href="../gitbook/gitbook-plugin-search/search.css"> <link rel="stylesheet" href="../gitbook/gitbook-plugin-theme-vuejs/vue.css"> <meta name="HandheldFriendly" content="true"/> <meta name="viewport" content="width=device-width, initial-scale=1, user-scalable=no"> <meta name="apple-mobile-web-app-capable" content="yes"> <meta name="apple-mobile-web-app-status-bar-style" content="black"> <link rel="apple-touch-icon-precomposed" sizes="152x152" href="../gitbook/images/apple-touch-icon-precomposed-152.png"> <link rel="shortcut icon" 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href="getting-started.html"> 开始 </a> </li> <li class="chapter " data-level="1.6" data-path="core-concepts.html"> <a href="core-concepts.html"> 核心概念 </a> <ul class="articles"> <li class="chapter " data-level="1.6.1" data-path="state.html"> <a href="state.html"> State </a> </li> <li class="chapter " data-level="1.6.2" data-path="getters.html"> <a href="getters.html"> Getter </a> </li> <li class="chapter " data-level="1.6.3" data-path="mutations.html"> <a href="mutations.html"> Mutation </a> </li> <li class="chapter " data-level="1.6.4" data-path="actions.html"> <a href="actions.html"> Action </a> </li> <li class="chapter " data-level="1.6.5" data-path="modules.html"> <a href="modules.html"> Module </a> </li> </ul> </li> <li class="chapter " data-level="1.7" data-path="structure.html"> <a href="structure.html"> 项目结构 </a> </li> <li class="chapter active" data-level="1.8" data-path="plugins.html"> <a href="plugins.html"> 插件 </a> </li> <li class="chapter " data-level="1.9" data-path="strict.html"> <a href="strict.html"> 严格模式 </a> </li> <li class="chapter " data-level="1.10" data-path="forms.html"> <a href="forms.html"> 表单处理 </a> </li> <li class="chapter " data-level="1.11" data-path="testing.html"> <a href="testing.html"> 测试 </a> </li> <li class="chapter " data-level="1.12" data-path="hot-reload.html"> <a href="hot-reload.html"> 热重载 </a> </li> <li class="chapter " data-level="1.13" data-path="api.html"> <a href="api.html"> API 文档 </a> </li> <li class="divider"></li> <li> <a href="https://www.gitbook.com" target="blank" class="gitbook-link"> 本書使用 GitBook 釋出 </a> </li> </ul> </nav> </div> <div class="book-body"> <div class="body-inner"> <div class="book-header" role="navigation">  <h1> <a href="." >插件</a> </h1> </div> <div class="page-wrapper" tabindex="-1" role="main"> <div class="page-inner"> <div id="book-search-results"> <div class="search-noresults"> <section class="normal markdown-section"> <h1 id="插件">插件</h1> Vuex 的 store 接受 <code>plugins</code> 选项，这个选项暴露出每次 mutation 的钩子。Vuex 插件就是一个函数，它接收 store 作为唯一参数： <pre class="language-"><code class="lang-js">const myPlugin = store => { // 当 store 初始化后调用 store.subscribe((mutation, state) => { // 每次 mutation 之后调用 // mutation 的格式为 { type, payload } }) } </code></pre> 然后像这样使用： <pre class="language-"><code class="lang-js">const store = new Vuex.Store({ // ... plugins: [myPlugin] }) </code></pre> <h3 id="在插件内提交-mutation">在插件内提交 Mutation</h3> 在插件中不允许直接修改状态——类似于组件，只能通过提交 mutation 来触发变化。 通过提交 mutation，插件可以用来同步数据源到 store。例如，同步 websocket 数据源到 store（下面是个大概例子，实际上 <code>createPlugin</code> 方法可以有更多选项来完成复杂任务）： <pre class="language-"><code class="lang-js">export default function createWebSocketPlugin (socket) { return store => { socket.on('data', data => { store.commit('receiveData', data) }) store.subscribe(mutation => { if (mutation.type === 'UPDATE_DATA') { socket.emit('update', mutation.payload) } }) } } </code></pre> <pre class="language-"><code class="lang-js">const plugin = createWebSocketPlugin(socket) const store = new Vuex.Store({ state, mutations, plugins: [plugin] }) </code></pre> <h3 id="生成-state-快照">生成 State 快照</h3> 有时候插件需要获得状态的“快照”，比较改变的前后状态。想要实现这项功能，你需要对状态对象进行深拷贝： <pre class="language-"><code class="lang-js">const myPluginWithSnapshot = store => { let prevState = _.cloneDeep(store.state) store.subscribe((mutation, state) => { let nextState = _.cloneDeep(state) // 比较 prevState 和 nextState... // 保存状态，用于下一次 mutation prevState = nextState }) } </code></pre> 生成状态快照的插件应该只在开发阶段使用，使用 webpack 或 Browserify，让构建工具帮我们处理： <pre class="language-"><code class="lang-js">const store = new Vuex.Store({ // ... plugins: process.env.NODE_ENV !== 'production' ? [myPluginWithSnapshot] : [] }) </code></pre> 上面插件会默认启用。在发布阶段，你需要使用 webpack 的 <a href="https://webpack.js.org/plugins/define-plugin/" target="_blank">DefinePlugin</a> 或者是 Browserify 的 <a href="https://github.com/hughsk/envify" target="_blank">envify</a> 使 <code>process.env.NODE_ENV !== 'production'</code> 为 <code>false</code>。 <h3 id="内置-logger-插件">内置 Logger 插件</h3> <blockquote> 如果正在使用 <a href="https://github.com/vuejs/vue-devtools" target="_blank">vue-devtools</a>，你可能不需要此插件。 </blockquote> Vuex 自带一个日志插件用于一般的调试: <pre class="language-"><code class="lang-js">import createLogger from 'vuex/dist/logger' const store = new Vuex.Store({ plugins: [createLogger()] }) </code></pre> <code>createLogger</code> 函数有几个配置项： <pre class="language-"><code class="lang-js">const logger = createLogger({ collapsed: false, // 自动展开记录的 mutation filter (mutation, stateBefore, stateAfter) { // 若 mutation 需要被记录，就让它返回 true 即可 // 顺便，`mutation` 是个 { type, payload } 对象 return mutation.type !== "aBlacklistedMutation" }, transformer (state) { // 在开始记录之前转换状态 // 例如，只返回指定的子树 return state.subTree }, mutationTransformer (mutation) { // mutation 按照 { type, payload } 格式记录 // 我们可以按任意方式格式化 return mutation.type }, logger: console, // 自定义 console 实现，默认为 `console` }) </code></pre> 日志插件还可以直接通过 <code><script></code> 标签引入，它会提供全局方法 <code>createVuexLogger</code>。 要注意，logger 插件会生成状态快照，所以仅在开发环境使用。 </section> </div> <div class="search-results"> <div class="has-results"> <h1 class="search-results-title"> results matching ""</h1> <ul class="search-results-list"></ul> </div> <div class="no-results"> <h1 class="search-results-title">No results matching ""</h1> </div> </div> </div> </div> </div> <script src="//m.servedby-buysellads.com/monetization.js" type="text/javascript"></script> <div class="bsa-cpc"></div> <script> (function(){ if(typeof _bsa !== 'undefined' && _bsa) { _bsa.init('default', 'CKYD62QM', 'placement:vuejsorg', { target: '.bsa-cpc', align: 'horizontal', disable_css: 'true' }); } })(); </script> </div> <a href="structure.html" class="navigation navigation-prev " aria-label="Previous page: 项目结构"> </a> <a href="strict.html" class="navigation navigation-next " aria-label="Next page: 严格模式"> </a> </div> <script> var gitbook = gitbook || []; gitbook.push(function() { gitbook.page.hasChanged({"page":{"title":"插件","level":"1.8","depth":1,"next":{"title":"严格模式","level":"1.9","depth":1,"path":"strict.md","ref":"strict.md","articles":[]},"previous":{"title":"项目结构","level":"1.7","depth":1,"path":"structure.md","ref":"structure.md","articles":[]},"dir":"ltr"},"config":{"plugins":["edit-link","prism","-highlight","github","-highlight","github"],"styles":{"website":"styles/website.css","pdf":"styles/pdf.css","epub":"styles/epub.css","mobi":"styles/mobi.css","ebook":"styles/ebook.css","print":"styles/print.css"},"pluginsConfig":{"prism":{},"github":{"url":"https://github.com/vuejs/vuex/"},"livereload":{},"search":{},"theme-vuejs":{},"lunr":{"maxIndexSize":1000000,"ignoreSpecialCharacters":false},"sharing":{"facebook":false,"twitter":false,"google":false,"weibo":false,"instapaper":false,"vk":false,"all":["facebook","google","twitter","weibo","instapaper"]},"edit-link":{"label":"编辑此页面","base":"https://github.com/vuejs/vuex/tree/dev/docs"},"theme-default":{"styles":{"website":"styles/website.css","pdf":"styles/pdf.css","epub":"styles/epub.css","mobi":"styles/mobi.css","ebook":"styles/ebook.css","print":"styles/print.css"},"showLevel":false}},"theme":"default","pdf":{"pageNumbers":true,"fontSize":12,"fontFamily":"Arial","paperSize":"a4","chapterMark":"pagebreak","pageBreaksBefore":"/","margin":{"right":62,"left":62,"top":56,"bottom":56}},"structure":{"langs":"LANGS.md","readme":"README.md","glossary":"GLOSSARY.md","summary":"SUMMARY.md"},"variables":{},"title":"Vuex","language":"zh-cn","links":{"sharing":{"facebook":false,"twitter":false}},"gitbook":"2.x.x"},"file":{"path":"plugins.md","mtime":"2018-02-17T07:20:49.000Z","type":"markdown"},"gitbook":{"version":"3.2.3","time":"2018-03-02T20:43:43.208Z"},"basePath":".","book":{"language":"zh-cn"}}); }); </script> </div> <script src="../gitbook/gitbook.js"></script> <script src="../gitbook/theme.js"></script> <script src="../gitbook/gitbook-plugin-edit-link/plugin.js"></script> <script src="../gitbook/gitbook-plugin-github/plugin.js"></script> <script src="../gitbook/gitbook-plugin-livereload/plugin.js"></script> <script src="../gitbook/gitbook-plugin-search/search-engine.js"></script> <script src="../gitbook/gitbook-plugin-search/search.js"></script> <script src="../gitbook/gitbook-plugin-lunr/lunr.min.js"></script> <script src="../gitbook/gitbook-plugin-lunr/search-lunr.js"></script> <script src="../gitbook/gitbook-plugin-sharing/buttons.js"></script> </body> </html>