diff --git a/web/cashtab/src/index.js b/web/cashtab/src/index.js --- a/web/cashtab/src/index.js +++ b/web/cashtab/src/index.js @@ -6,6 +6,7 @@ import { HashRouter as Router } from 'react-router-dom'; import GA from './utils/GoogleAnalytics'; import 'antd/dist/antd.min.css'; +import * as serviceWorkerRegistration from './serviceWorkerRegistration'; ReactDOM.render( @@ -19,6 +20,11 @@ document.getElementById('root'), ); +// If you want your app to work offline and load faster, you can change +// unregister() to register() below. Note this comes with some pitfalls. +// Learn more about service workers: https://cra.link/PWA +serviceWorkerRegistration.register(); + if (module.hot) { module.hot.accept(); } diff --git a/web/cashtab/src/service-worker.js b/web/cashtab/src/service-worker.js new file mode 100644 --- /dev/null +++ b/web/cashtab/src/service-worker.js @@ -0,0 +1,73 @@ +/* eslint-disable no-restricted-globals */ + +// This service worker can be customized! +// See https://developers.google.com/web/tools/workbox/modules +// for the list of available Workbox modules, or add any other +// code you'd like. +// You can also remove this file if you'd prefer not to use a +// service worker, and the Workbox build step will be skipped. + +import { clientsClaim } from 'workbox-core'; +import { ExpirationPlugin } from 'workbox-expiration'; +import { precacheAndRoute, createHandlerBoundToURL } from 'workbox-precaching'; +import { registerRoute } from 'workbox-routing'; +import { StaleWhileRevalidate } from 'workbox-strategies'; + +clientsClaim(); + +// Precache all of the assets generated by your build process. +// Their URLs are injected into the manifest variable below. +// This variable must be present somewhere in your service worker file, +// even if you decide not to use precaching. See https://cra.link/PWA +precacheAndRoute(self.__WB_MANIFEST); + +// Set up App Shell-style routing, so that all navigation requests +// are carried out with your index.html shell. Learn more at +// https://developers.google.com/web/fundamentals/architecture/app-shell +const fileExtensionRegexp = new RegExp('/[^/?]+\\.[^/]+$'); +registerRoute( + // Return false to exempt requests from being carried out by index.html. + ({ request, url }) => { + // If this isn't a navigation, skip. + if (request.mode !== 'navigate') { + return false; + } // If this is a URL that starts with /_, skip. + + if (url.pathname.startsWith('/_')) { + return false; + } // If this looks like a URL for a resource, because it contains // a file extension, skip. + + if (url.pathname.match(fileExtensionRegexp)) { + return false; + } // Return true to signal that we want to use the handler. + + return true; + }, + createHandlerBoundToURL(process.env.PUBLIC_URL + '/index.html'), +); + +// An example runtime caching route for requests that aren't handled by the +// precache, in this case same-origin .png requests like those from in public/ +registerRoute( + // Add in any other file extensions or routing criteria as needed. + ({ url }) => + url.origin === self.location.origin && url.pathname.endsWith('.png'), // Customize this strategy as needed, e.g., by changing to CacheFirst. + new StaleWhileRevalidate({ + cacheName: 'images', + plugins: [ + // Ensure that once this runtime cache reaches a maximum size the + // least-recently used images are removed. + new ExpirationPlugin({ maxEntries: 50 }), + ], + }), +); + +// This allows the web app to trigger skipWaiting via +// registration.waiting.postMessage({type: 'SKIP_WAITING'}) +self.addEventListener('message', event => { + if (event.data && event.data.type === 'SKIP_WAITING') { + self.skipWaiting(); + } +}); + +// Any other custom service worker logic can go here. diff --git a/web/cashtab/src/serviceWorkerRegistration.js b/web/cashtab/src/serviceWorkerRegistration.js new file mode 100644 --- /dev/null +++ b/web/cashtab/src/serviceWorkerRegistration.js @@ -0,0 +1,142 @@ +// This optional code is used to register a service worker. +// register() is not called by default. + +// This lets the app load faster on subsequent visits in production, and gives +// it offline capabilities. However, it also means that developers (and users) +// will only see deployed updates on subsequent visits to a page, after all the +// existing tabs open on the page have been closed, since previously cached +// resources are updated in the background. + +// To learn more about the benefits of this model and instructions on how to +// opt-in, read https://cra.link/PWA + +const isLocalhost = Boolean( + window.location.hostname === 'localhost' || + // [::1] is the IPv6 localhost address. + window.location.hostname === '[::1]' || + // 127.0.0.0/8 are considered localhost for IPv4. + window.location.hostname.match( + /^127(?:\.(?:25[0-5]|2[0-4][0-9]|[01]?[0-9][0-9]?)){3}$/, + ), +); + +export function register(config) { + if (process.env.NODE_ENV === 'production' && 'serviceWorker' in navigator) { + // The URL constructor is available in all browsers that support SW. + const publicUrl = new URL(process.env.PUBLIC_URL, window.location.href); + if (publicUrl.origin !== window.location.origin) { + // Our service worker won't work if PUBLIC_URL is on a different origin + // from what our page is served on. This might happen if a CDN is used to + // serve assets; see https://github.com/facebook/create-react-app/issues/2374 + return; + } + + window.addEventListener('load', () => { + const swUrl = `${process.env.PUBLIC_URL}/service-worker.js`; + + if (isLocalhost) { + // This is running on localhost. Let's check if a service worker still exists or not. + checkValidServiceWorker(swUrl, config); + + // Add some additional logging to localhost, pointing developers to the + // service worker/PWA documentation. + navigator.serviceWorker.ready.then(() => { + console.log( + 'This web app is being served cache-first by a service ' + + 'worker. To learn more, visit https://cra.link/PWA', + ); + }); + } else { + // Is not localhost. Just register service worker + registerValidSW(swUrl, config); + } + }); + } +} + +function registerValidSW(swUrl, config) { + navigator.serviceWorker + .register(swUrl) + .then(registration => { + registration.onupdatefound = () => { + const installingWorker = registration.installing; + if (installingWorker == null) { + return; + } + installingWorker.onstatechange = () => { + if (installingWorker.state === 'installed') { + if (navigator.serviceWorker.controller) { + // At this point, the updated precached content has been fetched, + // but the previous service worker will still serve the older + // content until all client tabs are closed. + console.log( + 'New content is available and will be used when all ' + + 'tabs for this page are closed. See https://cra.link/PWA.', + ); + + // Execute callback + if (config && config.onUpdate) { + config.onUpdate(registration); + } + } else { + // At this point, everything has been precached. + // It's the perfect time to display a + // "Content is cached for offline use." message. + console.log('Content is cached for offline use.'); + + // Execute callback + if (config && config.onSuccess) { + config.onSuccess(registration); + } + } + } + }; + }; + }) + .catch(error => { + console.error('Error during service worker registration:', error); + }); +} + +function checkValidServiceWorker(swUrl, config) { + // Check if the service worker can be found. If it can't reload the page. + fetch(swUrl, { + headers: { 'Service-Worker': 'script' }, + }) + .then(response => { + // Ensure service worker exists, and that we really are getting a JS file. + const contentType = response.headers.get('content-type'); + if ( + response.status === 404 || + (contentType != null && + contentType.indexOf('javascript') === -1) + ) { + // No service worker found. Probably a different app. Reload the page. + navigator.serviceWorker.ready.then(registration => { + registration.unregister().then(() => { + window.location.reload(); + }); + }); + } else { + // Service worker found. Proceed as normal. + registerValidSW(swUrl, config); + } + }) + .catch(() => { + console.log( + 'No internet connection found. App is running in offline mode.', + ); + }); +} + +export function unregister() { + if ('serviceWorker' in navigator) { + navigator.serviceWorker.ready + .then(registration => { + registration.unregister(); + }) + .catch(error => { + console.error(error.message); + }); + } +}