osvaldasvalutis

self.addEventListener('fetch', event => {
  event.respondWith(
    // try fetching a resource from the network
    fetch(event.request).then(response => {
      // cache the resource and serve it
      let responseCopy = response.clone();
      addToCache(event.request, responseCopy); // this is a custom function, I'll elaborate on it later
      return response;
    })
    .catch(() => {

osvaldasvalutis

const otherResources = [
        '/about/',
        '/contact/',
        '/services/'
      ],
      cacheCriticals = () => {
        return caches.open(version).then( cache => {
          cache.addAll(otherResources); // important, but not critical resources
          return cache.addAll(criticalResources); // critical resources
        });

osvaldasvalutis

const criticalResources = [
        '/',
        '/offline/',
        '/assets/css/main.css',
        '/assets/js/main.js'
      ],
      cacheCriticals = () => {
        return caches.open(version).then( cache => {
          return cache.addAll(criticalResources);
        });

osvaldasvalutis

self.addEventListener('fetch', event => {
  // ...
});

osvaldasvalutis

self.addEventListener('activate', event => {
  // ...
});

osvaldasvalutis

self.addEventListener('install', event => {
  // ...
});

osvaldasvalutis

if('serviceWorker' in navigator) {
  window.addEventListener('load', function() {
    navigator.serviceWorker.register('/serviceworker.js');
  });
}

osvaldasvalutis

if('serviceWorker' in navigator) {
  document.querySelector('.hero').addEventListener('animationend', function () {
    // service worker is registered only when the animation ends
    navigator.serviceWorker.register('/serviceworker.js');
  });
}
// ---
App.init({
  // config
  complete: function() {

osvaldasvalutis

// a check if the technology is supported by browser
if('serviceWorker' in navigator) {
  navigator.serviceWorker.register('/serviceworker.js');
}