bin/template/www/cordova-sw.js

// Note, these will be updated automatically at build time
var CACHE_VERSION = '%CACHE_VERSION%';
var CACHE_LIST = ['CACHE_VALUES'];

this.addEventListener('install', function (event) {
    // Perform install steps
    console.log('cordova service worker is installing.');
    event.waitUntil(caches.open(CACHE_VERSION) /* eslint no-undef : 0 */
        .then(function (cache) {
            return cache.addAll(CACHE_LIST);
        }));
});

this.addEventListener('activate', function (event) {
    // Perform activate steps
    console.log('cordova service worker is activated.');
});

this.addEventListener('fetch', function (event) {
    console.log('cordova service worker : fetch : ' + event.request.url);

    event.respondWith(caches.match(event.request).then(function (response) { /* eslint no-undef : 0 */
        // Cache hit? return response else fetch it
        return response || fetch(event.request); /* eslint no-undef : 0 */
    }));
});