sw.js

gistfile1.js

importScripts('./cachepolyfill.js');

var CACHE_VERSION = 1;
var CACHE = `cache-v${ CACHE_VERSION }`;

const assetsToCache = [
  // CDNs AND 3rd parties
  '//cdnjs.cloudflare.com/ajax/libs/socket.io/1.7.2/socket.io.min.js',
  '//cdnjs.cloudflare.com/ajax/libs/jquery/3.1.1/jquery.min.js',
  '//cdnjs.cloudflare.com/ajax/libs/twitter-bootstrap/3.3.5/css/bootstrap.min.css',
  // FONTS
  '/fonts/proximanova-regular-webfont.woff',
  '/fonts/ProximaNova-Bold.otf',
  '/fonts/proximanova-semibold-webfont.woff',
  // LOCAL FILES
  '/js/ie-unsupported-ver.js',
];

// On install, cache some resources.
self.addEventListener('install', function(evt) {
  console.info('SW: The service worker is being installed. Version:', CACHE_VERSION);

  // Ask the service worker to keep installing until the returning promise
  // resolves.
  evt.waitUntil(precache());
});

// On fetch, use cache but update the entry with the latest contents
// from the server.
self.addEventListener('fetch', function(evt) {
  // Try cache, if the resource is not there check network
  evt.respondWith(fromCache(evt.request)
    .catch(function () {
      return fromNetwork(evt.request);
    })
  );
});

// Open a cache and use `addAll()` with an array of assets to add all of them
// to the cache. Return a promise resolving when all the assets are added.
function precache() {
  return caches.open(CACHE).then(function (cache) {
    return cache.addAll(assetsToCache)
      .then(function(){
        console.info('SW: Assets cached')
      })
      .catch(function(){
        console.info('SW: Error on caching assets.')
      });
  });
}

// Update consists in opening the cache, performing a network request and
// storing the new response data.
function update(request) {
  return caches.open(CACHE).then(function (cache) {
    return fetch(request).then(function (response) {
      cache.put(request, response.clone())
        .catch(function(){
          console.info('SW: Error in putting something on the cache');
        })
      return response;
    });
  });
}

// Time limited network request. If the network fails or the response is not
// served before timeout, the promise is rejected.
function fromNetwork(request) {
  return new Promise(function (fulfill, reject) {
    // Fulfill in case of success.
    fetch(request).then(function (response) {
      // Cache images
      if(request.url.indexOf('/img/') > -1 || request.url.indexOf('cloudfront') > -1
         || request.url.indexOf('hires') > -1){
        update(request)
        .then(fulfill)
      }
      else {
        fulfill(response);
      }
    // Reject also if network fetch rejects.
    }, reject);
  });
}

// Open the cache where the assets were stored and search for the requested
// resource. Notice that in case of no matching, the promise still resolves
// but it does with `undefined` as value.
function fromCache(request) {
  return caches.open(CACHE).then(function (cache) {
    return cache.match(request).then(function (matching) {
      return matching || Promise.reject('no-match');
    });
  });
}


self.addEventListener('activate', function(event){
  // Delete previous caches
  event.waitUntil(
    self.clients.claim()
      .then(function() {
        caches.keys().then(function(cacheNames){
          return Promise.all(
            cacheNames.map(function(cacheName){
              if (CACHE.indexOf(cacheName) === -1) {
                // Delete it
                return caches.delete(cacheName);
              }
              return cacheName;
            })
          );
        });
      })
  );
});