| 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 * as React from 'react'; |
| 10 | // import {renderToString} from 'react-dom/server'; |
| 11 | import {renderToPipeableStream} from 'react-dom/server'; |
| 12 | import App from '../src/App'; |
| 13 | import {DataProvider} from '../src/data'; |
| 14 | import {API_DELAY, ABORT_DELAY} from './delays'; |
| 15 | |
| 16 | // In a real setup, you'd read it from webpack build stats. |
| 17 | let assets = { |
| 18 | 'main.js': '/main.js', |
| 19 | 'main.css': '/main.css', |
| 20 | }; |
| 21 | |
| 22 | module.exports = function render(url, res) { |
| 23 | const data = createServerData(); |
| 24 | // This is how you would wire it up previously: |
| 25 | // |
| 26 | // res.send( |
| 27 | // '<!DOCTYPE html>' + |
| 28 | // renderToString( |
| 29 | // <DataProvider data={data}> |
| 30 | // <App assets={assets} /> |
| 31 | // </DataProvider>, |
| 32 | // ) |
| 33 | // ); |
| 34 | |
| 35 | // The new wiring is a bit more involved. |
| 36 | res.socket.on('error', error => { |
| 37 | console.error('Fatal', error); |
| 38 | }); |
| 39 | let didError = false; |
| 40 | const {pipe, abort} = renderToPipeableStream( |
| 41 | <DataProvider data={data}> |
| 42 | <App assets={assets} /> |
| 43 | </DataProvider>, |
| 44 | { |
| 45 | bootstrapScripts: [assets['main.js']], |
| 46 | onAllReady() { |
| 47 | // Full completion. |
| 48 | // You can use this for SSG or crawlers. |
| 49 | }, |
| 50 | onShellReady() { |
| 51 | // If something errored before we started streaming, we set the error code appropriately. |
| 52 | res.statusCode = didError ? 500 : 200; |
| 53 | res.setHeader('Content-type', 'text/html'); |
| 54 | pipe(res); |
| 55 | }, |
| 56 | onShellError(x) { |
| 57 | // Something errored before we could complete the shell so we emit an alternative shell. |
| 58 | res.statusCode = 500; |
| 59 | res.send('<!doctype><p>Error</p>'); |
| 60 | }, |
| 61 | onError(x) { |
| 62 | didError = true; |
| 63 | console.error(x); |
| 64 | }, |
| 65 | } |
| 66 | ); |
| 67 | // Abandon and switch to client rendering if enough time passes. |
| 68 | // Try lowering this to see the client recover. |
| 69 | setTimeout(abort, ABORT_DELAY); |
| 70 | }; |
| 71 | |
| 72 | // Simulate a delay caused by data fetching. |
| 73 | // We fake this because the streaming HTML renderer |
| 74 | // is not yet integrated with real data fetching strategies. |
| 75 | function createServerData() { |
| 76 | let done = false; |
| 77 | let promise = null; |
| 78 | return { |
| 79 | read() { |
| 80 | if (done) { |
| 81 | return; |
| 82 | } |
| 83 | if (promise) { |
| 84 | throw promise; |
| 85 | } |
| 86 | promise = new Promise(resolve => { |
| 87 | setTimeout(() => { |
| 88 | done = true; |
| 89 | promise = null; |
| 90 | resolve(); |
| 91 | }, API_DELAY); |
| 92 | }); |
| 93 | throw promise; |
| 94 | }, |
| 95 | }; |
| 96 | } |