| 1 | /** |
| 2 | * Copyright (c) Meta Platforms, Inc. and affiliates. |
| 3 | * |
| 4 | * This source code is licensed under the MIT license found in the |
| 5 | * LICENSE file in the root directory of this source tree. |
| 6 | * |
| 7 | */ |
| 8 | |
| 9 | import {Writable} from 'stream'; |
| 10 | import * as React from 'react'; |
| 11 | import {renderToPipeableStream} from 'react-dom/server'; |
| 12 | import App from '../src/App'; |
| 13 | import {ABORT_DELAY} from './delays'; |
| 14 | |
| 15 | // In a real setup, you'd read it from webpack build stats. |
| 16 | let assets = { |
| 17 | 'main.js': '/main.js', |
| 18 | 'main.css': '/main.css', |
| 19 | }; |
| 20 | |
| 21 | function HtmlWritable(options) { |
| 22 | Writable.call(this, options); |
| 23 | this.chunks = []; |
| 24 | this.html = ''; |
| 25 | } |
| 26 | |
| 27 | HtmlWritable.prototype = Object.create(Writable.prototype); |
| 28 | HtmlWritable.prototype.getHtml = function getHtml() { |
| 29 | return this.html; |
| 30 | }; |
| 31 | HtmlWritable.prototype._write = function _write(chunk, encoding, callback) { |
| 32 | this.chunks.push(chunk); |
| 33 | callback(); |
| 34 | }; |
| 35 | HtmlWritable.prototype._final = function _final(callback) { |
| 36 | this.html = Buffer.concat(this.chunks).toString(); |
| 37 | callback(); |
| 38 | }; |
| 39 | |
| 40 | module.exports = function render(url, res) { |
| 41 | let writable = new HtmlWritable(); |
| 42 | res.socket.on('error', error => { |
| 43 | console.error('Fatal', error); |
| 44 | }); |
| 45 | let didError = false; |
| 46 | let didFinish = false; |
| 47 | |
| 48 | writable.on('finish', () => { |
| 49 | // If something errored before we started streaming, we set the error code appropriately. |
| 50 | res.statusCode = didError ? 500 : 200; |
| 51 | res.setHeader('Content-type', 'text/html'); |
| 52 | res.send(writable.getHtml()); |
| 53 | }); |
| 54 | |
| 55 | const {pipe, abort} = renderToPipeableStream(<App assets={assets} />, { |
| 56 | bootstrapScripts: [assets['main.js']], |
| 57 | onAllReady() { |
| 58 | // Full completion. |
| 59 | // You can use this for SSG or crawlers. |
| 60 | didFinish = true; |
| 61 | }, |
| 62 | onShellReady() { |
| 63 | // If something errored before we started streaming, we set the error code appropriately. |
| 64 | pipe(writable); |
| 65 | }, |
| 66 | onShellError(x) { |
| 67 | // Something errored before we could complete the shell so we emit an alternative shell. |
| 68 | res.statusCode = 500; |
| 69 | res.send('<!doctype><p>Error</p>'); |
| 70 | }, |
| 71 | onError(x) { |
| 72 | didError = true; |
| 73 | console.error(x); |
| 74 | }, |
| 75 | }); |
| 76 | // Abandon and switch to client rendering if enough time passes. |
| 77 | // Try lowering this to see the client recover. |
| 78 | setTimeout(() => { |
| 79 | if (!didFinish) { |
| 80 | abort(); |
| 81 | } |
| 82 | }, ABORT_DELAY); |
| 83 | }; |