| 1 | import React from 'react'; |
| 2 | import {renderToPipeableStream} from 'react-dom/server'; |
| 3 | import {Writable} from 'stream'; |
| 4 | |
| 5 | import App from '../src/components/App'; |
| 6 | |
| 7 | let assets; |
| 8 | if (process.env.NODE_ENV === 'development') { |
| 9 | // Use the bundle from create-react-app's server in development mode. |
| 10 | assets = { |
| 11 | 'main.js': '/static/js/bundle.js', |
| 12 | 'main.css': '', |
| 13 | }; |
| 14 | } else { |
| 15 | assets = require('../build/asset-manifest.json'); |
| 16 | } |
| 17 | |
| 18 | class ThrottledWritable extends Writable { |
| 19 | constructor(destination) { |
| 20 | super(); |
| 21 | this.destination = destination; |
| 22 | this.delay = 10; |
| 23 | } |
| 24 | |
| 25 | _write(chunk, encoding, callback) { |
| 26 | let o = 0; |
| 27 | const write = () => { |
| 28 | this.destination.write(chunk.slice(o, o + 100), encoding, x => { |
| 29 | o += 100; |
| 30 | if (o < chunk.length) { |
| 31 | setTimeout(write, this.delay); |
| 32 | } else { |
| 33 | callback(x); |
| 34 | } |
| 35 | }); |
| 36 | }; |
| 37 | setTimeout(write, this.delay); |
| 38 | } |
| 39 | |
| 40 | _final(callback) { |
| 41 | setTimeout(() => { |
| 42 | this.destination.end(callback); |
| 43 | }, this.delay); |
| 44 | } |
| 45 | } |
| 46 | |
| 47 | export default function render(url, res) { |
| 48 | res.socket.on('error', error => { |
| 49 | // Log fatal errors |
| 50 | console.error('Fatal', error); |
| 51 | }); |
| 52 | let didError = false; |
| 53 | const {pipe, abort} = renderToPipeableStream(<App assets={assets} />, { |
| 54 | bootstrapScripts: [assets['main.js']], |
| 55 | progressiveChunkSize: 1024, |
| 56 | onShellReady() { |
| 57 | // If something errored before we started streaming, we set the error code appropriately. |
| 58 | res.statusCode = didError ? 500 : 200; |
| 59 | res.setHeader('Content-type', 'text/html'); |
| 60 | // To test the actual chunks taking time to load over the network, we throttle |
| 61 | // the stream a bit. |
| 62 | const throttledResponse = new ThrottledWritable(res); |
| 63 | pipe(throttledResponse); |
| 64 | }, |
| 65 | onShellError(x) { |
| 66 | // Something errored before we could complete the shell so we emit an alternative shell. |
| 67 | res.statusCode = 500; |
| 68 | res.send('<!doctype><p>Error</p>'); |
| 69 | }, |
| 70 | onError(x) { |
| 71 | didError = true; |
| 72 | console.error(x); |
| 73 | }, |
| 74 | }); |
| 75 | // Abandon and switch to client rendering after 5 seconds. |
| 76 | // Try lowering this to see the client recover. |
| 77 | setTimeout(abort, 5000); |
| 78 | } |