sw.js

const APP_PREFIX = 'secure-wallet'
const VERSION = '0.0.1.3'
const CACHE_NAME = APP_PREFIX + VERSION
const URLS = [
  '/secure-wallet/',
  '/secure-wallet/index.html',
  '/secure-wallet/main.css',
  '/secure-wallet/main.js',
  '/secure-wallet/manifest.json',
  '/secure-wallet/images/favicon-16x16.png',
  '/secure-wallet/sw.js',
]
self.addEventListener('install', e => e.waitUntil(swInstall()))
self.addEventListener('activate', e => e.waitUntil(swActivate()))
self.addEventListener('fetch', e => e.respondWith(swFetch(e)))


async function swFetch(e) {
  console.log('sw[fetch]')
  let request = await caches.match(e.request);
  return request || fetchAndCache(e.request);
}


async function swInstall() {
  console.log('sw[install]')
  const cache = await caches.open(CACHE_NAME);
  let options = { headers: { 'cache-control': 'no-cache' }};
  let requests = URLS.map(url => new Request(url, options))
  await cache.addAll(requests);
  await self.skipWaiting();
}


async function swActivate() {
  console.log('sw[activate]')
  let keyList = await caches.keys();
  let cacheWhitelist = keyList.filter(key => key.indexOf(APP_PREFIX));
  cacheWhitelist.push(CACHE_NAME)
  return Promise.all(keyList.map(function (key, i) {
    if (cacheWhitelist.indexOf(key) === -1) {
      console.log('deleting cache : ' + keyList[i])
      return caches.delete(keyList[i])
    }
  }))
}


async function fetchAndCache(request){
  const res = await fetch(request);
  const cache = await caches.open(CACHE_NAME);
  cache.put(request, res.clone());
  return res;
}