reactjs - 启用组件特定的热重载？

Question

我使用以下方法创建了一个 React 应用:

create-react-app my-app --scripts-version=react-scripts-ts

来自以下示例:https://github.com/wmonk/create-react-app-typescript

我尝试添加:

if (module.hot) {
  module.hot.accept();
}

到我的 index.tsx 但我只在更改嵌套组件时刷新整页。

例如我创建了这样一个组件:

const MediaGrid = (props: any) => {
    return (<div>hello</div>);
}

并将其放在根组件中:

class Home extends Component<{ }, { }>{

    render() {
        return <div>
<h2>some stuff</h2>
            <MediaGrid />
        </div>;
    }
}

如果我更改 MediaGrid，则只会刷新整个页面，包括主页和主页中的所有其他组件。

我已经看到 React 项目具有特定于组件的热重载，并希望获得相同的结果，以便如果我仅更改 MediaGird，它就会刷新。

我尝试按照此处的步骤进行 typescript :https://github.com/wmonk/create-react-app-typescript/pull/312#issuecomment-387974687

我的 webpack.config.dev.js:

'use strict';

const autoprefixer = require('autoprefixer');
const path = require('path');
const webpack = require('webpack');
const HtmlWebpackPlugin = require('html-webpack-plugin');
const CaseSensitivePathsPlugin = require('case-sensitive-paths-webpack-plugin');
const InterpolateHtmlPlugin = require('react-dev-utils/InterpolateHtmlPlugin');
const WatchMissingNodeModulesPlugin = require('react-dev-utils/WatchMissingNodeModulesPlugin');
const ModuleScopePlugin = require('react-dev-utils/ModuleScopePlugin');
const ForkTsCheckerWebpackPlugin = require('fork-ts-checker-webpack-plugin');
const getClientEnvironment = require('./env');
const paths = require('./paths');
const TsconfigPathsPlugin = require('tsconfig-paths-webpack-plugin');

// Webpack uses `publicPath` to determine where the app is being served from.
// In development, we always serve from the root. This makes config easier.
const publicPath = '/';
// `publicUrl` is just like `publicPath`, but we will provide it to our app
// as %PUBLIC_URL% in `index.html` and `process.env.PUBLIC_URL` in JavaScript.
// Omit trailing slash as %PUBLIC_PATH%/xyz looks better than %PUBLIC_PATH%xyz.
const publicUrl = '';
// Get environment variables to inject into our app.
const env = getClientEnvironment(publicUrl);

// This is the development configuration.
// It is focused on developer experience and fast rebuilds.
// The production configuration is different and lives in a separate file.
module.exports = {
  // You may want 'eval' instead if you prefer to see the compiled output in DevTools.
  // See the discussion in https://github.com/facebookincubator/create-react-app/issues/343.
  devtool: 'cheap-module-source-map',
  // These are the "entry points" to our application.
  // This means they will be the "root" imports that are included in JS bundle.
  // The first two entry points enable "hot" CSS and auto-refreshes for JS.
  entry: [
    // We ship a few polyfills by default:
    require.resolve('./polyfills'),
    // Include an alternative client for WebpackDevServer. A client's job is to
    // connect to WebpackDevServer by a socket and get notified about changes.
    // When you save a file, the client will either apply hot updates (in case
    // of CSS changes), or refresh the page (in case of JS changes). When you
    // make a syntax error, this client will display a syntax error overlay.
    // Note: instead of the default WebpackDevServer client, we use a custom one
    // to bring better experience for Create React App users. You can replace
    // the line below with these two lines if you prefer the stock client:
    // require.resolve('webpack-dev-server/client') + '?/',
    // require.resolve('webpack/hot/dev-server'),
    require.resolve('react-dev-utils/webpackHotDevClient'),
    // Finally, this is your app's code:
    paths.appIndexJs,
    // We include the app code last so that if there is a runtime error during
    // initialization, it doesn't blow up the WebpackDevServer client, and
    // changing JS code would still trigger a refresh.
  ],
  output: {
    // Add /* filename */ comments to generated require()s in the output.
    pathinfo: true,
    // This does not produce a real file. It's just the virtual path that is
    // served by WebpackDevServer in development. This is the JS bundle
    // containing code from all our entry points, and the Webpack runtime.
    filename: 'static/js/bundle.js',
    // There are also additional JS chunk files if you use code splitting.
    chunkFilename: 'static/js/[name].chunk.js',
    // This is the URL that app is served from. We use "/" in development.
    publicPath: publicPath,
    // Point sourcemap entries to original disk location (format as URL on Windows)
    devtoolModuleFilenameTemplate: info =>
      path.resolve(info.absoluteResourcePath).replace(/\\/g, '/'),
  },
  resolve: {
    // This allows you to set a fallback for where Webpack should look for modules.
    // We placed these paths second because we want `node_modules` to "win"
    // if there are any conflicts. This matches Node resolution mechanism.
    // https://github.com/facebookincubator/create-react-app/issues/253
    modules: ['node_modules', paths.appNodeModules].concat(
      // It is guaranteed to exist because we tweak it in `env.js`
      process.env.NODE_PATH.split(path.delimiter).filter(Boolean)
    ),
    // These are the reasonable defaults supported by the Node ecosystem.
    // We also include JSX as a common component filename extension to support
    // some tools, although we do not recommend using it, see:
    // https://github.com/facebookincubator/create-react-app/issues/290
    // `web` extension prefixes have been added for better support
    // for React Native Web.
    extensions: [
      '.mjs',
      '.web.ts',
      '.ts',
      '.web.tsx',
      '.tsx',
      '.web.js',
      '.js',
      '.json',
      '.web.jsx',
      '.jsx',
    ],
    alias: {

      // Support React Native Web
      // https://www.smashingmagazine.com/2016/08/a-glimpse-into-the-future-with-react-native-for-web/
      'react-native': 'react-native-web',
    },
    plugins: [
      // Prevents users from importing files from outside of src/ (or node_modules/).
      // This often causes confusion because we only process files within src/ with babel.
      // To fix this, we prevent you from importing files out of src/ -- if you'd like to,
      // please link the files into your node_modules/ and let module-resolution kick in.
      // Make sure your source files are compiled, as they will not be processed in any way.
      new ModuleScopePlugin(paths.appSrc, [paths.appPackageJson]),
      new TsconfigPathsPlugin({ configFile: paths.appTsConfig }),
    ],
  },
  module: {
    strictExportPresence: true,
    rules: [
      // TODO: Disable require.ensure as it's not a standard language feature.
      // We are waiting for https://github.com/facebookincubator/create-react-app/issues/2176.
      // { parser: { requireEnsure: false } },

      {
        test: /\.(js|jsx|mjs)$/,
        loader: require.resolve('source-map-loader'),
        enforce: 'pre',
        include: paths.appSrc,
      },
      {
        // "oneOf" will traverse all following loaders until one will
        // match the requirements. When no loader matches it will fall
        // back to the "file" loader at the end of the loader list.
        oneOf: [
          // "url" loader works like "file" loader except that it embeds assets
          // smaller than specified limit in bytes as data URLs to avoid requests.
          // A missing `test` is equivalent to a match.
          {
            test: [/\.bmp$/, /\.gif$/, /\.jpe?g$/, /\.png$/],
            loader: require.resolve('url-loader'),
            options: {
              limit: 10000,
              name: 'static/media/[name].[hash:8].[ext]',
            },
          },
          {
            test: /\.(js|jsx|mjs)$/,
            include: paths.appSrc,
            loader: require.resolve('babel-loader'),
            options: {

              compact: true,
            },
          },

          // Compile .tsx?

          {
            test: /\.tsx?$/,
            use: [
              {
                loader: 'babel-loader',
                options: {
                  babelrc: false,
                  plugins: ['react-hot-loader/babel'],
                },
              },
              'ts-loader', // (or awesome-typescript-loader)
            ],
          },
          // "postcss" loader applies autoprefixer to our CSS.
          // "css" loader resolves paths in CSS and adds assets as dependencies.
          // "style" loader turns CSS into JS modules that inject <style> tags.
          // In production, we use a plugin to extract that CSS to a file, but
          // in development "style" loader enables hot editing of CSS.
          {
            test: /\.css$/,
            use: [
              require.resolve('style-loader'),
              {
                loader: require.resolve('css-loader'),
                options: {
                  importLoaders: 1,
                },
              },
              {
                loader: require.resolve('postcss-loader'),
                options: {
                  // Necessary for external CSS imports to work
                  // https://github.com/facebookincubator/create-react-app/issues/2677
                  ident: 'postcss',
                  plugins: () => [
                    require('postcss-flexbugs-fixes'),
                    autoprefixer({
                      browsers: [
                        '>1%',
                        'last 4 versions',
                        'Firefox ESR',
                        'not ie < 9', // React doesn't support IE8 anyway
                      ],
                      flexbox: 'no-2009',
                    }),
                  ],
                },
              },
            ],
          },
          // "file" loader makes sure those assets get served by WebpackDevServer.
          // When you `import` an asset, you get its (virtual) filename.
          // In production, they would get copied to the `build` folder.
          // This loader doesn't use a "test" so it will catch all modules
          // that fall through the other loaders.
          {
            // Exclude `js` files to keep "css" loader working as it injects
            // its runtime that would otherwise processed through "file" loader.
            // Also exclude `html` and `json` extensions so they get processed
            // by webpacks internal loaders.
            exclude: [/\.(js|jsx|mjs)$/, /\.html$/, /\.json$/],
            loader: require.resolve('file-loader'),
            options: {
              name: 'static/media/[name].[hash:8].[ext]',
            },
          },
        ],
      },
      // ** STOP ** Are you adding a new loader?
      // Make sure to add the new loader(s) before the "file" loader.
    ],
  },
  plugins: [
    // Makes some environment variables available in index.html.
    // The public URL is available as %PUBLIC_URL% in index.html, e.g.:
    // <link rel="shortcut icon" href="%PUBLIC_URL%/favicon.ico">
    // In development, this will be an empty string.
    new InterpolateHtmlPlugin(env.raw),
    // Generates an `index.html` file with the <script> injected.
    new HtmlWebpackPlugin({
      inject: true,
      template: paths.appHtml,
    }),
    // Add module names to factory functions so they appear in browser profiler.
    new webpack.NamedModulesPlugin(),
    // Makes some environment variables available to the JS code, for example:
    // if (process.env.NODE_ENV === 'development') { ... }. See `./env.js`.
    new webpack.DefinePlugin(env.stringified),
    // This is necessary to emit hot updates (currently CSS only):
    new webpack.HotModuleReplacementPlugin(),
    // Watcher doesn't work well if you mistype casing in a path so we use
    // a plugin that prints an error when you attempt to do this.
    // See https://github.com/facebookincubator/create-react-app/issues/240
    new CaseSensitivePathsPlugin(),
    // If you require a missing module and then `npm install` it, you still have
    // to restart the development server for Webpack to discover it. This plugin
    // makes the discovery automatic so you don't have to restart.
    // See https://github.com/facebookincubator/create-react-app/issues/186
    new WatchMissingNodeModulesPlugin(paths.appNodeModules),
    // Moment.js is an extremely popular library that bundles large locale files
    // by default due to how Webpack interprets its code. This is a practical
    // solution that requires the user to opt into importing specific locales.
    // https://github.com/jmblog/how-to-optimize-momentjs-with-webpack
    // You can remove this if you don't use Moment.js:
    new webpack.IgnorePlugin(/^\.\/locale$/, /moment$/),
    // Perform type checking and linting in a separate process to speed up compilation
    new ForkTsCheckerWebpackPlugin({
      async: false,
      watch: paths.appSrc,
      tsconfig: paths.appTsConfig,
      tslint: paths.appTsLint,
    }),
  ],
  // Some libraries import Node modules but don't use them in the browser.
  // Tell Webpack to provide empty mocks for them so importing them works.
  node: {
    dgram: 'empty',
    fs: 'empty',
    net: 'empty',
    tls: 'empty',
    child_process: 'empty',
  },
  // Turn off performance hints during development because we don't do any
  // splitting or minification in interest of speed. These warnings become
  // cumbersome.
  performance: {
    hints: false,
  },
};

tsconfig.json:

{
  "compilerOptions": {
    "baseUrl": ".",
    "outDir": "build/dist",
    "module": "esnext",
    "target": "es5",
    "lib": ["es6", "dom"],
    "sourceMap": true,
    "allowJs": true,
    "jsx": "react",
    "moduleResolution": "node",
    "rootDir": "src",
    "forceConsistentCasingInFileNames": true,
    "noImplicitReturns": true,
    "noImplicitThis": true,
    "noImplicitAny": true,
    "strictNullChecks": true,
    "suppressImplicitAnyIndexErrors": true,
    "noUnusedLocals": true
  },
  "exclude": [
    "node_modules",
    "build",
    "scripts",
    "acceptance-tests",
    "webpack",
    "jest",
    "src/setupTests.ts"
  ]
}

我的应用程序.tsx:

import * as React from 'react';
import { Provider } from 'react-redux'

import rootStore from './redux/store'

import './App.css';

import AppContext from './context/AppContext';
import Header from './components/header';
import LoginPopup from './components/LoginPopup';
import Home from './pages/Home';

import logo from './logo.svg';
import { hot } from 'react-hot-loader';



import * as firebase from 'firebase';
import SubmitPopup from './components/SubmitPopup';
var firebaseConfig = {
  apiKey: "snip",
  authDomain: "hadaka-2.firebaseapp.com",
  databaseURL: "https://hadaka-2.firebaseio.com",
  projectId: "hadaka-2",
  storageBucket: "hadaka-2.appspot.com",
  messagingSenderId: "305148376063"
};

firebase.initializeApp(firebaseConfig)

class App extends React.Component {
  public render() {
    return (<Provider store={rootStore}>
      <div className="App">
        <AppContext>
          <LoginPopup />
          <SubmitPopup />
          <Header />
          <header className="App-header">
            <img src={logo} className="App-logo" alt="logo" />
            <h1 className="App-title">Welcome to React</h1>
          </header>

          <Home />
          <p className="App-intro">
            To get started, edit <code>src/App.tsx</code> and save to reload.
        </p>
        </AppContext>
      </div>
    </Provider>
    );
  }
}


export default hot(module)(App);

有时它可以工作，但更常见的是整个页面重新加载...

它似乎每两次都有效，例如，如果我添加一个像 hello 这样的新 div，组件本身会重新加载，如果我添加另一个像 hello 2 这样的 div 或删除我添加的 div，整个页面都会重新加载，这让我觉得有些东西其他在这里玩尝试做一个全屏刷新..

Answer 1

您必须使用 react-hot-loader模块。只需按照入门部分进行操作即可。

此外，不要忘记将 npm start 脚本修改为 node scripts/start.js -- --hot

我为此创建了一个演示库。请看这个:https://github.com/shishiranshuman/react-ts-hot-reloading-example

演示: