feat(pwa): service worker

Author: Pablo Vieira

_includes/service-worker.html

@@ -0,0 +1,14 @@
+<script>
+  if ('serviceWorker' in navigator) {
+    console.log('ServiceWorker available \\o/');
+    window.addEventListener('load', function() {
+      navigator.serviceWorker.register('/sw.js').then(function(registration) {
+        console.log('ServiceWorker registration successful with scope: ', registration.scope);
+      }, function(err) {
+        console.log('ServiceWorker registration failed: ', err);
+      });
+    });
+  } else {
+    console.log('ServiceWorker not available :(');
+  }
+</script>

_layouts/default.html

@@ -20,5 +20,7 @@
     {% include footer.html %}
 
     {% include analytics.html %}
+
+    {% include service-worker.html %}
   </body>
 </html>

sw.js

@@ -0,0 +1,80 @@
+---
+layout: null
+---
+
+var CACHE_NAME = 'pv8-web-cache-v1';
+
+var urlsToCache = [
+  '/',
+  '/css/main.css',
+  {% for page in site.html_pages %}
+  '{{ page.url }}',
+  {% endfor %}
+  {% for post in site.posts %}
+  '{{ post.url }}',
+  {% endfor %}
+  {% for file in site.static_files %}
+  {% if file.extname == '.js' or file.path contains '/media' %} '{{ file.path }}', {% endif %}
+  {% endfor %}
+];
+
+// {% if file.extname == '.js' or file.path contains '/portfolio/screenshots' or file.path contains '/portfolio/thumbnails' %} '{{ file.path }}', {% endif %}
+
+const CACHE_STATIC = [
+  '/css/main.css',
+  '/media/gamification_balance.png',
+  '/media/gamification_experience.png',
+  '/media/gamification_gameelements.png',
+  '/media/gamification_icon.png',
+  '/media/gamification_journey.png',
+  '/media/gamification_players.png',
+  '/media/Python-logo-notext.png'
+ ];
+
+ const CACHE_APP = [
+    '/',
+    '/index.html',
+    '/posts/',
+    '/contact/'
+ ];
+
+self.addEventListener('install',function(event){
+  event.waitUntil(
+    caches.open(CACHE_NAME)
+      .then(function(cache) {
+        console.log('Opened cache');
+        return cache.addAll(urlsToCache);
+      })
+  );
+});
+
+self.addEventListener('fetch', function(event) {
+  event.respondWith(
+    caches.match(event.request)
+      .then(function(response) {
+        // Cache hit - return response
+        if (response) {
+          return response;
+        }
+        return fetch(event.request);
+      }
+    )
+  );
+});
+
+self.addEventListener('activate', function(event) {
+
+  var cacheWhitelist = [CACHE_NAME];
+
+  event.waitUntil(
+    caches.keys().then(function(cacheNames) {
+      return Promise.all(
+        cacheNames.map(function(cacheName) {
+          if (cacheWhitelist.indexOf(cacheName) === -1) {
+            return caches.delete(cacheName);
+          }
+        })
+      );
+    })
+  );
+});