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Diffstat (limited to 'src/tools/emcoui/src/serviceWorker.js')
| -rw-r--r-- | src/tools/emcoui/src/serviceWorker.js | 155 |
1 files changed, 155 insertions, 0 deletions
diff --git a/src/tools/emcoui/src/serviceWorker.js b/src/tools/emcoui/src/serviceWorker.js new file mode 100644 index 00000000..dfc5034e --- /dev/null +++ b/src/tools/emcoui/src/serviceWorker.js @@ -0,0 +1,155 @@ +//======================================================================= +// Copyright (c) 2017-2020 Aarna Networks, Inc. +// All rights reserved. +// ====================================================================== +// Licensed under the Apache License, Version 2.0 (the "License"); +// you may not use this file except in compliance with the License. +// You may obtain a copy of the License at +// http://www.apache.org/licenses/LICENSE-2.0 +// Unless required by applicable law or agreed to in writing, software +// distributed under the License is distributed on an "AS IS" BASIS, +// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. +// See the License for the specific language governing permissions and +// limitations under the License. +// ======================================================================== +// 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://bit.ly/CRA-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://bit.ly/CRA-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://bit.ly/CRA-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); + }); + } +} |