<!-- register service worker -->
        <script>

          if ('serviceWorker' in navigator) 
          {
          window.addEventListener('load', function() {
            navigator.serviceWorker.register('/service-worker.js')
            .then(function() { console.log("Service Worker Registered, Cheers to PWA Fire!"); });
          }
          );
        }  
        </script> 
    <!-- end of service worker -->

            
        // PWA Fire Bundle
        // url : https://www.pwafire.org 
                  
        // after a service worker is installed and the user navigates to a different page or 
        // refreshes,the service worker will begin to receive fetch events
                      
        self.addEventListener('fetch', function(event) {
        event.respondWith(caches.open('cache').then(function(cache) {
        return cache.match(event.request).then(function(response) {
        console.log("cache request: " + event.request.url);
        var fetchPromise = fetch(event.request).then(function(networkResponse) {           
        // if we got a response from the cache, update the cache                   
        console.log("fetch completed: " + event.request.url, networkResponse);
        if (networkResponse) {
            console.debug("updated cached page: " + event.request.url, networkResponse);
              cache.put(event.request, networkResponse.clone());}
                return networkResponse;
                  }, function (event) {   
        // rejected promise - just ignore it, we're offline!   
                  console.log("Error in fetch()", event);
                  event.waitUntil(
                  caches.open('cache').then(function(cache) { 
        // our cache is named *cache* in the caches.open() above
                  return cache.addAll
                  ([            
        //cache.addAll(), takes a list of URLs, then fetches them from the server
        // and adds the response to the cache.           
        // add your entire site to the cache- as in the code below; for offline access
        // If you have some build process for your site, perhaps that could 
        // generate the list of possible URLs that a user might load.               
                '/', // do not remove this
                '/index.html', //default
                '/index.html?homescreen=1', //default
                '/?homescreen=1', //default
                '/assets/css/main.css',// configure as by your site ; just an example
                '/images/*',// choose images to keep offline; just an example
        // Do not replace/delete/edit the and manifest.js paths below
                '/manifest.js',
        //These are links to the extenal social media buttons that should be cached;
        // we have used twitter's as an example
                'https://platform.twitter.com/widgets.js',       
                ]);
                })
                );
                });
        // respond from the cache, or the network
          return response || fetchPromise;
        });
        }));
        }); 

        {
          "background_color": "#fff",
          "display": "standalone",
          "orientation":"portrait",
          "theme_color": "#fff",           
          "short_name": "PWA Fire",
          "name": "PWA Fire",
          "description": "description or purpose of your progressive web app",
          "lang": "en-US",
          "icons": [
          {
            "src": "images/icons/icon-72x72.png",
            "sizes": "72x72",
            "type": "image/png"
          },
          {
            "src": "images/icons/icon-96x96.png",
            "sizes": "96x96",
            "type": "image/png"
          },
          {
            "src": "images/icons/icon-128x128.png",
            "sizes": "128x128",
            "type": "image/png"
          },
          {
            "src": "images/icons/icon-144x144.png",
            "sizes": "144x144",
            "type": "image/png"
          },
          {
            "src": "images/icons/icon-152x152.png",
            "sizes": "152x152",
            "type": "image/png"
          },
          {
            "src": "images/icons/icon-192x192.png",
            "sizes": "192x192",
            "type": "image/png"
          },
          {
            "src": "images/icons/icon-384x384.png",
            "sizes": "384x384",
            "type": "image/png"
          },
          {
            "src": "images/icons/icon-512x512.png",
            "sizes": "512x512",
            "type": "image/png"
          }
          ],
          "start_url": "index.html?launcher=true",
        }