ssr with react和express并要求stats.json解释

Question

我正在查看底部的代码示例,这是一个反应ssr示例:

在configureProduction函数中,它有这一行:

const clientStats = require('./assets/stats.json');

这个stats.json文件是什么？

import express from 'express';
import { join } from 'path';
import { log } from 'winston';

/**
 * Configures hot reloading and assets paths for local development environment.
 * Use the `npm start` command to start the local development server.
 *
 * @param app Express app
 */
const configureDevelopment = app => {
    const clientConfig = require('../webpack/client');
    const serverConfig = require('../webpack/server');
    const publicPath = clientConfig.output.publicPath;
    const outputPath = clientConfig.output.path;

    const multiCompiler = require('webpack')([clientConfig, serverConfig]);
    const clientCompiler = multiCompiler.compilers[0];

    app.use(require('webpack-dev-middleware')(multiCompiler, {publicPath}));
    app.use(require('webpack-hot-middleware')(clientCompiler));

    app.use(publicPath, express.static(outputPath));

    app.use(require('webpack-hot-server-middleware')(multiCompiler, {
        serverRendererOptions: { outputPath }
    }));

    app.set('views', join(__dirname, '../public/views'));
};

/**
 * Configures assets paths for production environment.
 * This environment is used in deployment and inside the docker container.
 * Use the `npm run build` command to create a production build.
 *
 * @param app Express app
 */
const configureProduction = app => {
    const clientStats = require('./assets/stats.json');
    const serverRender = require('./assets/app.server.js').default;
    const publicPath = '/';
    const outputPath = join(__dirname, 'assets');

    app.use(publicPath, express.static(outputPath));
    app.use(serverRender({
        clientStats,
        outputPath
    }));

    app.set('views', join(__dirname, 'views'));
};

const app = express();

log('info', `Configuring server for environment: ${process.env.NODE_ENV}...`);
if (process.env.NODE_ENV === 'development') {
    configureDevelopment(app);
} else {
    configureProduction(app);
}

log('info', 'Configuring server engine...');
app.set('view engine', 'ejs');
app.set('port', process.env.PORT || 3000);

app.listen(app.get('port'), () => log('info', `Server listening on port ${app.get('port')}...`));

Answer 1

这可能是由 webpack 插件（https://github.com/danethurber/webpack-manifest-plugin）在构建客户端包后生成的文件，该文件名经过哈希处理，并且对服务器来说是必需的，因此它知道如何渲染基本模板，然后引导客户端。

当然，这是猜测，因为我们无权访问您的json文件、webpack配置或package.json..

该存储库使用类似的方法：https://github.com/CheesecakeLabs/react-redux-boilerplate/ 它构建客户端，生成相同类型的文件，然后使用该 JSON 文件作为信息点构建服务器包以了解如何客户端包已命名。

JSON 文件应与此类似：

{
  "apple-touch-icon.png": "114dec1694406188ff0cb2698607cbca.png",
  "production.css": "production.fbee6dc76218b122f7ff.css",
  "production.css.map": "production.fbee6dc76218b122f7ff.css.map",
  "production.js": "production.fbee6dc76218b122f7ff.js",
  "production.js.map": "production.fbee6dc76218b122f7ff.js.map",
  "safari-pinned-tab.svg": "f157afc1cf258044878dab6647d2800b.svg"
}