cupper-hugo-theme/static/js/service-worker-registration.js
2019-01-31 18:19:20 -06:00

63 lines
2.8 KiB
JavaScript

/**
* Copyright 2015 Google 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.
*/
/* eslint-env browser */
'use strict';
if ('serviceWorker' in navigator) {
// Delay registration until after the page has loaded, to ensure that our
// precaching requests don't degrade the first visit experience.
// See https://developers.google.com/web/fundamentals/instant-and-offline/service-worker/registration
window.addEventListener('load', function() {
// Your service-worker.js *must* be located at the top-level directory relative to your site.
// It won't be able to control pages unless it's located at the same level or higher than them.
// *Don't* register service worker file in, e.g., a scripts/ sub-directory!
// See https://github.com/slightlyoff/ServiceWorker/issues/468
navigator.serviceWorker.register('service-worker.js').then(function(reg) {
// updatefound is fired if service-worker.js changes.
reg.onupdatefound = function() {
// The updatefound event implies that reg.installing is set; see
// https://w3c.github.io/ServiceWorker/#service-worker-registration-updatefound-event
var installingWorker = reg.installing;
installingWorker.onstatechange = function() {
switch (installingWorker.state) {
case 'installed':
if (navigator.serviceWorker.controller) {
// At this point, the old content will have been purged and the fresh content will
// have been added to the cache.
// It's the perfect time to display a "New content is available; please refresh."
// message in the page's interface.
console.log('New or updated content is available.');
} 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 now available offline!');
}
break;
case 'redundant':
console.error('The installing service worker became redundant.');
break;
}
};
};
}).catch(function(e) {
console.error('Error during service worker registration:', e);
});
});
}