63 lines
2.8 KiB
JavaScript
63 lines
2.8 KiB
JavaScript
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/**
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* Copyright 2015 Google Inc. All rights reserved.
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*
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* Licensed under the Apache License, Version 2.0 (the "License");
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* you may not use this file except in compliance with the License.
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* You may obtain a copy of the License at
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*
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* http://www.apache.org/licenses/LICENSE-2.0
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*
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* Unless required by applicable law or agreed to in writing, software
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* distributed under the License is distributed on an "AS IS" BASIS,
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* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
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* See the License for the specific language governing permissions and
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* limitations under the License.
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*/
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/* eslint-env browser */
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'use strict';
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if ('serviceWorker' in navigator) {
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// Delay registration until after the page has loaded, to ensure that our
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// precaching requests don't degrade the first visit experience.
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// See https://developers.google.com/web/fundamentals/instant-and-offline/service-worker/registration
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window.addEventListener('load', function() {
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// Your service-worker.js *must* be located at the top-level directory relative to your site.
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// It won't be able to control pages unless it's located at the same level or higher than them.
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// *Don't* register service worker file in, e.g., a scripts/ sub-directory!
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// See https://github.com/slightlyoff/ServiceWorker/issues/468
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navigator.serviceWorker.register('service-worker.js').then(function(reg) {
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// updatefound is fired if service-worker.js changes.
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reg.onupdatefound = function() {
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// The updatefound event implies that reg.installing is set; see
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// https://w3c.github.io/ServiceWorker/#service-worker-registration-updatefound-event
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var installingWorker = reg.installing;
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installingWorker.onstatechange = function() {
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switch (installingWorker.state) {
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case 'installed':
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if (navigator.serviceWorker.controller) {
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// At this point, the old content will have been purged and the fresh content will
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// have been added to the cache.
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// It's the perfect time to display a "New content is available; please refresh."
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// message in the page's interface.
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console.log('New or updated content is available.');
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} else {
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// At this point, everything has been precached.
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// It's the perfect time to display a "Content is cached for offline use." message.
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console.log('Content is now available offline!');
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}
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break;
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case 'redundant':
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console.error('The installing service worker became redundant.');
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break;
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}
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};
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};
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}).catch(function(e) {
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console.error('Error during service worker registration:', e);
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});
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});
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}
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