service-worker.js

var dataCacheName = 'boothData-v2';
var cacheName = 'boothPWA-v2';
var filesToCache = [
  '/',
  '/index.html',

  '/scripts/app.js',
  '/scripts/qrdecode.min.js',
  '/scripts/rsa.min.js',

  '/data/initial_data.jsonp',

  '/styles/inline.css',
  '/images/lock.png',
  '/images/star.png',
  '/images/icon_cloud_download.svg',
  '/images/icon_lock_rounded_open.svg',
  '/images/icon_checkered_flag.svg'
];

self.addEventListener('install', function(e) {
  console.log('[ServiceWorker] Install');
  e.waitUntil(
    caches.open(cacheName).then(function(cache) {
      console.log('[ServiceWorker] Caching app shell');
      return cache.addAll(filesToCache);
    })
  );
});

self.addEventListener('activate', function(e) {
  console.log('[ServiceWorker] Activate');
  e.waitUntil(
    caches.keys().then(function(keyList) {
      return Promise.all(keyList.map(function(key) {
        if (key !== cacheName) {
          console.log('[ServiceWorker] Removing old cache', key);
          return caches.delete(key);
        }
      }));
    })
  );
});

self.addEventListener('fetch', function(e) {
  console.log('[ServiceWorker] Fetch', e.request.url);
  var dataUrl = 'https://earthday.firebaseio.com/';
  if (e.request.url.indexOf(dataUrl) === 0) {
    e.respondWith(
      fetch(e.request)
        .then(function(response) {
          return caches.open(dataCacheName).then(function(cache) {
            cache.put(e.request.url, response.clone());
            console.log('[ServiceWorker] Fetched&Cached Data');
            return response;
          });
        })
    );
  } else {
    e.respondWith(
      caches.match(e.request).then(function(response) {
        return response || fetch(e.request);
      })
    );
  }
});