Merge pull request #394 from ashawley/service-worker

Add initial Service Worker

_includes/footer.html

@@ -12,3 +12,8 @@
     anchors.options.visible = 'always';
     anchors.add('article h2, article h3, article h4, article h5, article h6');
 </script>{% endif %}
+<script type="text/javascript">
+    if ("serviceWorker" in navigator) {
+      navigator.serviceWorker.register("{{ '/sw.js' | relative_url }}")
+    }
+</script>

sw.js

@@ -0,0 +1,54 @@
+---
+layout: null
+---
+var CACHE_NAME = "pixyll2-{{site.time | date: '%Y%m%d%H%M%S'}}";
+
+self.addEventListener("install", function(e) {
+  e.waitUntil(
+    caches.open(CACHE_NAME).then(function(cache) {
+      return cache.addAll([
+        "{{ '/css/pixyll.css' | relative_url }}?{{ site.time | date: '%Y%m%d%H%M' }}",
+        "{{ '/' | relative_url }}"
+      ]);
+    })
+  );
+});
+
+self.addEventListener("activate", function(e) {
+  e.waitUntil(
+    caches.keys().then(function(names) {
+      return Promise.all(
+        names.map(function(name) {
+          if (name != CACHE_NAME) {
+            return caches.delete(name);
+          }
+        })
+      );
+    })
+  );
+  return clients.claim();
+});
+
+addEventListener("fetch", function(e) {
+  e.respondWith(
+    caches.match(e.request).then(function(response) {
+        return response || fetch(e.request).then(function(response) {
+        var clonedResponse = response.clone();
+        var hosts = [
+          "https://fonts.googleapis.com",
+          "https://fonts.gstatic.com",
+          "https://maxcdn.bootstrapcdn.com",
+          "https://cdnjs.cloudflare.com"
+        ];
+        hosts.map(function(host) {
+          if (e.request.url.indexOf(host) === 0) {
+            caches.open(CACHE_NAME).then(function(cache) {
+              cache.put(e.request, clonedResponse);
+            });
+          }
+        });
+        return response;
+      });
+    })
+  );
+});