text: const CACHE_NAME = "ppdbsda-2019-1";
  var urlsToCache = [
      "icon.png",
      "wallpaper.png",
      "pengumuman.png",
      "manifest.json",
      "nav.html",
      "index.html",
      "pages/home.html",
      "pages/ketentuan.html",
      "pages/prosedur.html",
      "pages/jadwal.html",
      "css/materialize.min.css",
      "js/materialize.min.js",
      "js/nav.js"
  ];
  
  self.addEventListener("install", function(event) {
      event.waitUntil(
          caches.open(CACHE_NAME).then(function(cache) {
              return cache.addAll(urlsToCache);
          })
      );
  });
  
  self.addEventListener("fetch", function (event) {
      event.respondWith(caches.match(event.request, {cacheName: CACHE_NAME})
          .then(function (response) {
              if (response){
                  console.log("ServiceWorker: Gunakan aset dari cache: ", response.url)
                  return response
              }
              console.log("ServiceWorker: Memuat aset dari server: ", event.request.url)
              return fetch(event.request)
          })
      )
  })
  
  self.addEventListener("activate", function(event) {
      event.waitUntil(caches.keys().then(function(cacheNames) {
          return Promise.all(cacheNames.map(function(cacheName) {
              if (cacheName != CACHE_NAME) {
                  console.log("ServiceWorker: cache " + cacheName + " dihapus");
                  return caches.delete(cacheName);
              }})
          );
      }));
  });