| commit | author | age | ||
| bae328 | 1 | // This optional code is used to register a service worker. |
| JR | 2 | // register() is not called by default. |
| 3 | ||
| 4 | // This lets the app load faster on subsequent visits in production, and gives | |
| 5 | // it offline capabilities. However, it also means that developers (and users) | |
| 6 | // will only see deployed updates on subsequent visits to a page, after all the | |
| 7 | // existing tabs open on the page have been closed, since previously cached | |
| 8 | // resources are updated in the background. | |
| 9 | ||
| 10 | // To learn more about the benefits of this model and instructions on how to | |
| 11 | // opt-in, read https://bit.ly/CRA-PWA | |
| 12 | ||
| 13 | const isLocalhost = Boolean( | |
| 14 | window.location.hostname === "localhost" || | |
| 15 | // [::1] is the IPv6 localhost address. | |
| 16 | window.location.hostname === "[::1]" || | |
| 17 | // 127.0.0.0/8 are considered localhost for IPv4. | |
| 18 | window.location.hostname.match( | |
| 19 | /^127(?:\.(?:25[0-5]|2[0-4][0-9]|[01]?[0-9][0-9]?)){3}$/ | |
| 20 | ) | |
| 21 | ); | |
| 22 | ||
| 23 | type Config = { | |
| 24 | onSuccess?: (registration: ServiceWorkerRegistration) => void; | |
| 25 | onUpdate?: (registration: ServiceWorkerRegistration) => void; | |
| 26 | }; | |
| 27 | ||
| 28 | export function register(config?: Config) { | |
| 29 | if (process.env.NODE_ENV === "production" && "serviceWorker" in navigator) { | |
| 30 | // The URL constructor is available in all browsers that support SW. | |
| 31 | const publicUrl = new URL( | |
| 32 | process.env.PUBLIC_URL, | |
| 33 | window.location.href | |
| 34 | ); | |
| 35 | if (publicUrl.origin !== window.location.origin) { | |
| 36 | // Our service worker won't work if PUBLIC_URL is on a different origin | |
| 37 | // from what our page is served on. This might happen if a CDN is used to | |
| 38 | // serve assets; see https://github.com/facebook/create-react-app/issues/2374 | |
| 39 | return; | |
| 40 | } | |
| 41 | ||
| 42 | window.addEventListener("load", () => { | |
| 43 | const swUrl = `${process.env.PUBLIC_URL}/service-worker.js`; | |
| 44 | ||
| 45 | if (isLocalhost) { | |
| 46 | // This is running on localhost. Let's check if a service worker still | |
| 47 | // exists or not. | |
| 48 | checkValidServiceWorker(swUrl, config); | |
| 49 | ||
| 50 | // Add some additional logging to localhost, pointing developers to the | |
| 51 | // service worker/PWA documentation. | |
| 52 | navigator.serviceWorker.ready.then(() => { | |
| 53 | console.log( | |
| 54 | "This web app is being served cache-first by a service " + | |
| 55 | "worker. To learn more, visit https://bit.ly/CRA-PWA" | |
| 56 | ); | |
| 57 | }); | |
| 58 | } else { | |
| 59 | // Is not localhost. Just register service worker | |
| 60 | registerValidSW(swUrl, config); | |
| 61 | } | |
| 62 | }); | |
| 63 | } | |
| 64 | } | |
| 65 | ||
| 66 | function registerValidSW(swUrl: string, config?: Config) { | |
| 67 | navigator.serviceWorker | |
| 68 | .register(swUrl) | |
| 69 | .then(registration => { | |
| 70 | registration.onupdatefound = () => { | |
| 71 | const installingWorker = registration.installing; | |
| 72 | if (installingWorker == null) { | |
| 73 | return; | |
| 74 | } | |
| 75 | installingWorker.onstatechange = () => { | |
| 76 | if (installingWorker.state === "installed") { | |
| 77 | if (navigator.serviceWorker.controller) { | |
| 78 | // At this point, the updated precached content has been fetched, | |
| 79 | // but the previous service worker will still serve the older | |
| 80 | // content until all client tabs are closed. | |
| 81 | console.log( | |
| 82 | "New content is available and will be used when all " + | |
| 83 | "tabs for this page are closed. See https://bit.ly/CRA-PWA." | |
| 84 | ); | |
| 85 | ||
| 86 | // Execute callback | |
| 87 | if (config && config.onUpdate) { | |
| 88 | config.onUpdate(registration); | |
| 89 | } | |
| 90 | } else { | |
| 91 | // At this point, everything has been precached. | |
| 92 | // It's the perfect time to display a | |
| 93 | // "Content is cached for offline use." message. | |
| 94 | console.log("Content is cached for offline use."); | |
| 95 | ||
| 96 | // Execute callback | |
| 97 | if (config && config.onSuccess) { | |
| 98 | config.onSuccess(registration); | |
| 99 | } | |
| 100 | } | |
| 101 | } | |
| 102 | }; | |
| 103 | }; | |
| 104 | }) | |
| 105 | .catch(error => { | |
| 106 | console.error("Error during service worker registration:", error); | |
| 107 | }); | |
| 108 | } | |
| 109 | ||
| 110 | function checkValidServiceWorker(swUrl: string, config?: Config) { | |
| 111 | // Check if the service worker can be found. If it can't reload the page. | |
| 112 | fetch(swUrl, { | |
| 113 | headers: { "Service-Worker": "script" } | |
| 114 | }) | |
| 115 | .then(response => { | |
| 116 | // Ensure service worker exists, and that we really are getting a JS file. | |
| 117 | const contentType = response.headers.get("content-type"); | |
| 118 | if ( | |
| 119 | response.status === 404 || | |
| 120 | (contentType != null && contentType.indexOf("javascript") === -1) | |
| 121 | ) { | |
| 122 | // No service worker found. Probably a different app. Reload the page. | |
| 123 | navigator.serviceWorker.ready.then(registration => { | |
| 124 | registration.unregister().then(() => { | |
| 125 | window.location.reload(); | |
| 126 | }); | |
| 127 | }); | |
| 128 | } else { | |
| 129 | // Service worker found. Proceed as normal. | |
| 130 | registerValidSW(swUrl, config); | |
| 131 | } | |
| 132 | }) | |
| 133 | .catch(() => { | |
| 134 | console.log( | |
| 135 | "No internet connection found. App is running in offline mode." | |
| 136 | ); | |
| 137 | }); | |
| 138 | } | |
| 139 | ||
| 140 | export function unregister() { | |
| 141 | if ("serviceWorker" in navigator) { | |
| 142 | navigator.serviceWorker.ready | |
| 143 | .then(registration => { | |
| 144 | registration.unregister(); | |
| 145 | }) | |
| 146 | .catch(error => { | |
| 147 | console.error(error.message); | |
| 148 | }); | |
| 149 | } | |
| 150 | } | |
