1 files changed, 55 insertions, 0 deletions
diff --git a/static/js/sw.js b/static/js/sw.js
new file mode 100755
index 0000000..4b3b1e2
--- /dev/null
+++ b/static/js/sw.js
@@ -0,0 +1,55 @@
+//This is the service worker with the combined offline experience (Offline page + Offline copy of pages)
+
+//Install stage sets up the offline page in the cache and opens a new cache
+self.addEventListener('install', function(event) {
+  event.waitUntil(preLoad());
+});
+
+var preLoad = function(){
+  console.log('[PWA Builder] Install Event processing');
+  return caches.open('pwabuilder-offline').then(function(cache) {
+    console.log('[PWA Builder] Cached index and offline page during Install');
+    return cache.addAll(['/offline.html', '/index.html']);
+  });
+}
+
+self.addEventListener('fetch', function(event) {
+  console.log('[PWA Builder] The service worker is serving the asset.');
+  event.respondWith(checkResponse(event.request).catch(function() {
+    return returnFromCache(event.request)}
+  ));
+  event.waitUntil(addToCache(event.request));
+});
+
+var checkResponse = function(request){
+  return new Promise(function(fulfill, reject) {
+    fetch(request).then(function(response){
+      if(response.status !== 404) {
+        fulfill(response)
+      } else {
+        reject()
+      }
+    }, reject)
+  });
+};
+
+var addToCache = function(request){
+  return caches.open('pwabuilder-offline').then(function (cache) {
+    return fetch(request).then(function (response) {
+      console.log('[PWA Builder] add page to offline'+response.url)
+      return cache.put(request, response);
+    });
+  });
+};
+
+var returnFromCache = function(request){
+  return caches.open('pwabuilder-offline').then(function (cache) {
+    return cache.match(request).then(function (matching) {
+     if(!matching || matching.status == 404) {
+       return cache.match('offline.html')
+     } else {
+       return matching
+     }
+    });
+  });
+};