NextJS

NextJS

Tips

  • 注意
    • getInitialProps
      • 只能用于页面组件不能用于子组件
      • 在第一次渲染会执行，之后会在客户端做转换
      • 不要能服务端的模块，通过 API 实现调用
    • 请求推荐使用 isomorphic-unfetch
  • 页面自定义
    • 默认特殊页面内容
    • _document.js
      • 自定义文档内容 - HTML
      • 在 <Main/> 之外的组建都不会在页面初始化 - 只做 SSR
      • 不要在这里做应用逻辑 - 在 app 做
      • 不要在这里做布局
      • 不要在这里用事件
      • 不能在这里导入 CSS
    • _app.js
      • 自定义应用
  • 问题
    • #8311 - Setting-Up Socket.io-based Serverless API Route
    • #9965 - Server-Sent Events don't work in Next API routes
    • #9524 - Static Generation / SSG Improvements
    • #706 - Add support to transpile modules inside node_modules
      • 跨项目转译 - martpie/next-transpile-modules
      • 配合 lerna 使用有问题
      • 被转译模块不能使用绝对路径，除非添加 package
        • import 'libs/utils' 不可以
        • import './utils' 可以
        • import '@wener/core/libs/utils' 可以
    • #5054 - Truly static pages without react app
      • PR #11949
        • 页面导出 const config={unstable_runtimeJS: false}
  • 参考

快速开始

# 初始化项目
mkdir my-web && cd my-web
# 依赖
# npm install --save next react react-dom
# npm install --save-dev typescript @types/react @types/node
yarn add [email protected] [email protected] [email protected]
yarn add --dev typescript @types/react @types/node
# 首页
mkdir pages
cat <<INDEX >pages/index.tsx
import React from 'react'
function Home({ pid }) {
return <div>NextJS Running on {pid}!</div>
}
Home.getInitialProps = function () {
return { pid: process.pid }
}
export default Home
INDEX
# 启动服务
./node_modules/.bin/next
# 访问 http://localhost:3000
# 其它常用目录
mkdir -p public libs hooks types components modules reducers hooks

Tips

# 基础依赖
yarn add [email protected] [email protected] [email protected]
yarn add --dev typescript @types/react @types/node
# Next 扩展增强插件
# 已内建
# yarn add @zeit/next-css @zeit/next-sass @next/mdx
yarn add next-transpile-modules @next/bundle-analyzer
# 已内建
# yarn add dotenv tsconfig-paths-webpack-plugin
yarn add --dev @babel/plugin-proposal-decorators @babel/plugin-proposal-class-properties
yarn add --dev babel-plugin-import
# 服务端开发
# isomorphic-unfetch isomorphic-ws
# 常用工具
yarn add moment lodash date-fns
yarn add --dev @types/lodash
# UI 框架
yarn add antd
# 测试
yarn add --dev ts-node jest ts-jest @types/jest

提示

目录结构

  • next.config.js - 配置文件
  • next-env.d.ts - 针对 TS 的类型定义
  • pages - 页面 - 可直接访问
    • _document.js
    • _app.js
    • api - 接口 - 通过 /api/* 访问

自定义 _app.js

function MyApp({ Component, pageProps }) {
return <Component {...pageProps} />
}
// Only uncomment this method if you have blocking data requirements for
// every single page in your application. This disables the ability to
// perform automatic static optimization, causing every page in your app to
// be server-side rendered.
//
// MyApp.getInitialProps = async (appContext) => {
// // calls page's `getInitialProps` and fills `appProps.pageProps`
// const appProps = await App.getInitialProps(appContext);
//
// return { ...appProps }
// }
export default MyApp

自定义 _document.js

// _document is only rendered on the server side and not on the client side
// Event handlers like onClick can't be added to this file
// ./pages/_document.js
import Document, { Html, Head, Main, NextScript } from 'next/document'
class MyDocument extends Document {
static async getInitialProps(ctx) {
const initialProps = await Document.getInitialProps(ctx)
return { ...initialProps }
}
render() {
return (
<Html>
<Head />
<body>
<Main />
<NextScript />
</body>
</Html>
)
}
}
export default MyDocument

自定义 _error.js

接口

修改 pages/api/test.ts 为以下内容

import { NextApiRequest, NextApiResponse } from 'next'
export default (req: NextApiRequest, res: NextApiResponse) => {
res.status(200).json({ title: 'From server side' })
}

然后访问 http://localhost:3000/api/test

接口配置

export const config = {
api: {
// 默认会解析 1mb 的 body - 可以关闭
bodyParser: false,
// 修改配置
bodyParser: {
sizeLimit: '1mb'
}
},
}

支持 CORS

import Cors from 'micro-cors'
const cors = Cors({
allowedMethods: ['GET', 'HEAD'],
})
function Endpoint(req, res) {
res.json({ message: 'Hello Everyone!' })
}
export default cors(Endpoint)

常用脚本

packages.json

{
"scripts": {
"test": "jest --passWithNoTests",
"dev": "next",
"build": "next build",
"start": "next start"
}
}

支持自定义端口

Heroku 部署需要这样

{
"scripts": {
"test": "jest --passWithNoTests",
"dev": "next dev -p ${PORT:-3000}",
"build": "next build",
"start": "next start -p ${PORT:-3000}"
}
}

workspace

{
"scripts": {
"test": "yarn --cwd packages/server test",
"dev": "yarn --cwd packages/server dev",
"build": "yarn --cwd packages/server build",
"start": "yarn --cwd packages/server start"
}
}

配置

module.exports = {
// 自定义环境变量
env: { customKey: 'my-value', },
// 页面扩展名
pageExtensions: ['mdx', 'jsx', 'js', 'ts', 'tsx'],
// 资源路径替换
assetPrefix: isProd ? 'https://cdn.mydomain.com' : '',
// 支持 server 和 serverless
target: 'serverless',
// 自定义 webpack 配置
webpack: (config, { buildId, dev, isServer, defaultLoaders, webpack }) => {
// Note: we provide webpack above so you should not `require` it
// Perform customizations to webpack config
// Important: return the modified config
config.plugins.push(new webpack.IgnorePlugin(/\/__tests__\//))
return config
},
webpackDevMiddleware: config => {
// Perform customizations to webpack dev middleware config
// Important: return the modified config
return config
},
// target 为 server 支持压缩
// 如果前端后 web 服务可以不考虑开启
compress: false,
// 自动静态优化的提示 - 闪电图标
devIndicators: {
autoPrerender: false,
},
// 关闭 X-Powered-By 头
poweredByHeader: false,
// 生成 ETag - 默认开启
generateEtags: false,
// 构建目录
distDir: 'build',
// 生成构建 ID
generateBuildId: async () => {
// You can, for example, get the latest git commit hash here
return 'my-build-id'
},
onDemandEntries: {
// period (in ms) where the server will keep pages in the buffer
maxInactiveAge: 25 * 1000,
// number of pages that should be kept simultaneously without being disposed
pagesBufferLength: 2,
},
typescript: {
// 忽略开发时的 typescript 错误
ignoreDevErrors: true,
},
// 静态导出的路径 - next export
exportPathMap: async function(
defaultPathMap,
{ dev, dir, outDir, distDir, buildId }
) {
return {
'/': { page: '/' },
'/about': { page: '/about' },
'/p/hello-nextjs': { page: '/post', query: { title: 'hello-nextjs' } },
'/p/learn-nextjs': { page: '/post', query: { title: 'learn-nextjs' } },
'/p/deploy-nextjs': { page: '/post', query: { title: 'deploy-nextjs' } },
}
},
// 会导出为 about/index.html 而不是 about.html
exportTrailingSlash: true,
}
const { PHASE_DEVELOPMENT_SERVER } = require('next/constants')
module.exports = (phase, { defaultConfig }) => {
if (phase === PHASE_DEVELOPMENT_SERVER) {
return {
/* development only config options here */
}
}
return {
/* config options for all phases except development here */
}
}

针对服务端配置 fs:empty

module.exports = {
webpack: (config, { isServer }) => {
if (!isServer) {
config.node = {
fs: 'empty'
}
}
return config
}
}

支持 CSS

⚠️ 9.2 后内建支持 css

const withCSS = require('@zeit/next-css')
module.exports = withCSS({})

apollo

FAQ

检测在浏览器

// Webpack 定义 - 会根据依赖来移除代码
// https://github.com/zeit/next.js/pull/5159
process.browser
// 通用逻辑
typeof window === 'undefined'

如何在 getInitialProps 引入服务端模块

  • 如果直接 require 是会导致被打包到客户端代码的
const faker = eval("require('faker')")

这个方式是最简单的，其他方式参考 SSR and Server Only Modules

Invalid left-hand side in assignment "MyModule*" = namespaces;

分析服务端代码和SSR代码

安装依赖

npm install --save-dev webpack-bundle-analyzer @zeit/next-bundle-analyzer

next.config.js

const withBundleAnalyzer = require('@zeit/next-bundle-analyzer')
const nextConfig = {
analyzeServer: ['server', 'both'].includes(process.env.BUNDLE_ANALYZE),
analyzeBrowser: ['browser', 'both'].includes(process.env.BUNDLE_ANALYZE),
bundleAnalyzerConfig: {
server: {
analyzerMode: 'static',
reportFilename: '../bundles/server.html',
},
browser: {
analyzerMode: 'static',
reportFilename: '../bundles/client.html',
},
},
webpack(config) {
return config
},
}
module.exports = withBundleAnalyzer(nextConfig)

添加脚本

添加到 package.json

"analyze": "BUNDLE_ANALYZE=both next build",
"analyze:server": "BUNDLE_ANALYZE=server next build",
"analyze:browser": "BUNDLE_ANALYZE=browser next build"

执行分析

npm run analyze
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