dgrijuela · January 12, 2016 15:17 · Jan 12, 2016
diff --git a/index.html b/index.html
@@ -0,0 +1,22 @@
+<!DOCTYPE html>
+<html lang="en">
+<head>
+  <meta charset="UTF-8">
+  <title></title>
+</head>
+<body>
+  <script>
+    // Test if service workers are supported
+    if ('serviceWorker' in navigator) {
+      // Attempt to register it
+      navigator.serviceWorker.register('/sw.js').then(function() {
+        // Success
+        console.log('ServiceWorker registration successful');
+      }).catch(function(err) {
+        // Fail
+        console.log('ServiceWorker registration failed: ', err);
+      });
+    }
+  </script>
+</body>
+</html>
diff --git a/sw.js b/sw.js
@@ -0,0 +1,75 @@
+// You have to supply a name for your cache, this will
+// allow us to remove an old one to avoid hitting disk
+// space limits and displaying old resources
+var cacheName = 'v1';
+// Change for your sitemap's path if that's what
+// you'll use to get your blog's pages
+var sitemapUrl = '/sitemap.xml';
+// Replace with your assets paths
+var assetsToCache = [
+  '/assets/css/screen.css',
+  '/assets/js/index.js',
+  '/content/images/2015/12/bg-blox.jpg'
+];
+
+self.addEventListener('install', function(event) {
+  // waitUntil() ensures that the Service Worker will not
+  // install until the code inside has successfully occurred
+  event.waitUntil(
+    // Create cache with the name supplied above and
+    // return a promise for it
+    caches.open(cacheName).then(function(cache) {
+      // Add assets supplied above
+      cache.addAll(assetsToCache);
+      // Get your blog's pages and add them to cache
+      cachePages(cache);
+    })
+  );
+});
+
+function cachePages(cache) {
+  // Get sitemap and return the text response
+  fetch(sitemapUrl).then(function(response) {
+    return response.text();
+  }).then(function(text) {
+    // Regex to match xml locations (URLs)
+    var pattern = /<loc>(.+?)</g;
+    // Get all matches within the text
+    var urls = getMatches(text, pattern);
+    // Add them to the previously opened cache
+    cache.addAll(urls);
+  });
+}
+
+// Simple function to get multiple matched groups
+function getMatches(string, regex) {
+  var matches = [];
+  var match;
+  while (match = regex.exec(string)) {
+    matches.push(match[1]);
+  }
+  return matches;
+}
+
+self.addEventListener('fetch', function(event) {
+  // Ignore non-get request like when accessing the admin panel
+  if (event.request.method !== 'GET') { return; }
+  // Don't try to handle non-secure assets because fetch will fail
+  if (/http:/.test(event.request.url)) { return; }
+  event.respondWith(
+    // Open the cache created when install
+    caches.open(CACHE_NAME).then(function(cache) {
+      // Go to the network to ask for that resource
+      return fetch(event.request).then(function(networkResponse) {
+        // Add a copy of the response to the cache (updating the old version)
+        cache.put(event.request, networkResponse.clone());
+        // Respond with it
+        return networkResponse;
+      }).catch(function() {
+        // If there is no internet connection, try to match the request
+        // to some of our cached resources
+        return cache.match(event.request);
+      })
+    })
+  );
+});