| 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 | * @flow |
| 8 | */ |
| 9 | |
| 10 | import * as React from 'react'; |
| 11 | |
| 12 | function deferred<T>( |
| 13 | timeoutMS: number, |
| 14 | resolvedValue: T, |
| 15 | displayName: string, |
| 16 | ): Promise<T> { |
| 17 | const promise = new Promise<T>(resolve => { |
| 18 | setTimeout(() => resolve(resolvedValue), timeoutMS); |
| 19 | }); |
| 20 | (promise as any).displayName = displayName; |
| 21 | |
| 22 | return promise; |
| 23 | } |
| 24 | |
| 25 | const title = deferred(100, 'Segmented Page Title', 'title'); |
| 26 | const content = deferred( |
| 27 | 400, |
| 28 | 'This is the content of a segmented page. It loads in multiple parts.', |
| 29 | 'content', |
| 30 | ); |
| 31 | function Page(): React.Node { |
| 32 | return ( |
| 33 | <article> |
| 34 | <h1>{title}</h1> |
| 35 | <p>{content}</p> |
| 36 | </article> |
| 37 | ); |
| 38 | } |
| 39 | |
| 40 | function InnerSegment({children}: {children: React.Node}): React.Node { |
| 41 | return ( |
| 42 | <> |
| 43 | <h3>Inner Segment</h3> |
| 44 | <React.Suspense name="InnerSegment" fallback={<p>Loading...</p>}> |
| 45 | <section>{children}</section> |
| 46 | <p>After inner</p> |
| 47 | </React.Suspense> |
| 48 | </> |
| 49 | ); |
| 50 | } |
| 51 | |
| 52 | const cookies = deferred(200, 'Cookies: 🍪🍪🍪', 'cookies'); |
| 53 | function OuterSegment({children}: {children: React.Node}): React.Node { |
| 54 | return ( |
| 55 | <> |
| 56 | <h2>Outer Segment</h2> |
| 57 | <React.Suspense name="OuterSegment" fallback={<p>Loading outer</p>}> |
| 58 | <p>{cookies}</p> |
| 59 | <div>{children}</div> |
| 60 | <p>After outer</p> |
| 61 | </React.Suspense> |
| 62 | </> |
| 63 | ); |
| 64 | } |
| 65 | |
| 66 | function Root({children}: {children: React.Node}): React.Node { |
| 67 | return ( |
| 68 | <> |
| 69 | <h1>Root Segment</h1> |
| 70 | <React.Suspense name="Root" fallback={<p>Loading root</p>}> |
| 71 | <main>{children}</main> |
| 72 | <footer>After root</footer> |
| 73 | </React.Suspense> |
| 74 | </> |
| 75 | ); |
| 76 | } |
| 77 | |
| 78 | const dynamicData = deferred(10, 'Dynamic Data: 📈📉📊', 'dynamicData'); |
| 79 | export default function Segments(): React.Node { |
| 80 | return ( |
| 81 | <> |
| 82 | <p>{dynamicData}</p> |
| 83 | <React.Activity name="root" mode="visible"> |
| 84 | <Root> |
| 85 | <React.Activity name="outer" mode="visible"> |
| 86 | <OuterSegment> |
| 87 | <React.Activity name="inner" mode="visible"> |
| 88 | <InnerSegment> |
| 89 | <React.Activity name="slot" mode="visible"> |
| 90 | <Page /> |
| 91 | </React.Activity> |
| 92 | </InnerSegment> |
| 93 | </React.Activity> |
| 94 | </OuterSegment> |
| 95 | </React.Activity> |
| 96 | </Root> |
| 97 | </React.Activity> |
| 98 | </> |
| 99 | ); |
| 100 | } |