sw.js

var CACHE_STATIC_NAME = 'static-v4';
var CACHE_DYNAMIC_NAME = 'dynamic-v2';

self.addEventListener('install', function (event) {
    console.log('[Service Worker] Installing Service Worker ...', event);
    event.waitUntil(
        caches.open(CACHE_STATIC_NAME)
        .then(function (cache) {
            console.log('[Service Worker] Precaching App Shell');
            cache.addAll([
          '/',
          '/index.html',
          '/form.html',
          '/style.css',
          '/style1.css',
          '/js/animframe_polyfill.js',
          '/js/application.js',
          '/js/bind_polyfill.js',
          '/js/classlist_polyfill.js',
          '/js/game_manager.js',
          '/js/grid.js',
          '/js/html_actuator.js',
          '/js/keyboard_input_manager.js',
          '/js/local_storage_manager.js',
          '/js/tile.js',
          '/apple-touch-icon.png',
          '/promise.js',
          '/fetch.js',
          '/insert.php',
          '/register.js',
          'https://fonts.googleapis.com/css?family=Montserrat',
        ]);
        })
    )
});
//comments
self.addEventListener('activate', function (event) {
    console.log('[Service Worker] Activating Service Worker ....', event);
    event.waitUntil(
        caches.keys()
        .then(function (keyList) {
            return Promise.all(keyList.map(function (key) {
                if (key !== CACHE_STATIC_NAME && key !== CACHE_DYNAMIC_NAME) {
                    console.log('[Service Worker] Removing old cache.', key);
                    return caches.delete(key);
                }
            }));
        })
    );
    return self.clients.claim();
});

self.addEventListener('fetch', function (event) {
    event.respondWith(
        caches.match(event.request)
        .then(function (response) {
            if (response) {
                return response;
            } else {
                return fetch(event.request)
                    .then(function (res) {
                        return caches.open(CACHE_DYNAMIC_NAME)
                            .then(function (cache) {
                                cache.put(event.request.url, res.clone());
                                return res;
                            })
                    })
                    .catch(function (err) {

                    });
            }
        })
    );
});