diff --git a/_src/_includes/scripts.html b/_src/_includes/scripts.html
index 2c4276ee..1b726675 100644
--- a/_src/_includes/scripts.html
+++ b/_src/_includes/scripts.html
@@ -1,3 +1,8 @@
+
diff --git a/_src/service-worker.js b/_src/service-worker.js
new file mode 100644
index 00000000..f90519fe
--- /dev/null
+++ b/_src/service-worker.js
@@ -0,0 +1,202 @@
+---
+---
+
+"use strict";
+
+console.log('WORKER: executing.');
+
+/* A version number is useful when updating the worker logic,
+ allowing you to remove outdated cache entries during the update.
+*/
+var version = 'v{{ site.time | date: "%Y%m%d%H%M%S" }}::';
+
+/* These resources will be downloaded and cached by the service worker
+ during the installation process. If any resource fails to be downloaded,
+ then the service worker won't be installed either.
+*/
+var offlineFundamentals = [
+ '',
+ 'assets/css/kremalicious3.min.css',
+ 'assets/js/kremalicious3.min.js'
+];
+
+/* The install event fires when the service worker is first installed.
+ You can use this event to prepare the service worker to be able to serve
+ files while visitors are offline.
+*/
+self.addEventListener("install", function(event) {
+ console.log('WORKER: install event in progress.');
+ /* Using event.waitUntil(p) blocks the installation process on the provided
+ promise. If the promise is rejected, the service worker won't be installed.
+ */
+ event.waitUntil(
+ /* The caches built-in is a promise-based API that helps you cache responses,
+ as well as finding and deleting them.
+ */
+ caches
+ /* You can open a cache by name, and this method returns a promise. We use
+ a versioned cache name here so that we can remove old cache entries in
+ one fell swoop later, when phasing out an older service worker.
+ */
+ .open(version + 'fundamentals')
+ .then(function(cache) {
+ /* After the cache is opened, we can fill it with the offline fundamentals.
+ The method below will add all resources in `offlineFundamentals` to the
+ cache, after making requests for them.
+ */
+ return cache.addAll(offlineFundamentals);
+ })
+ .then(function() {
+ console.log('WORKER: install completed');
+ })
+ );
+});
+
+/* The fetch event fires whenever a page controlled by this service worker requests
+ a resource. This isn't limited to `fetch` or even XMLHttpRequest. Instead, it
+ comprehends even the request for the HTML page on first load, as well as JS and
+ CSS resources, fonts, any images, etc.
+*/
+self.addEventListener("fetch", function(event) {
+ console.log('WORKER: fetch event in progress.');
+
+ /* We should only cache GET requests, and deal with the rest of method in the
+ client-side, by handling failed POST,PUT,PATCH,etc. requests.
+ */
+ if (event.request.method !== 'GET') {
+ /* If we don't block the event as shown below, then the request will go to
+ the network as usual.
+ */
+ console.log('WORKER: fetch event ignored.', event.request.method, event.request.url);
+ return;
+ }
+ /* Similar to event.waitUntil in that it blocks the fetch event on a promise.
+ Fulfillment result will be used as the response, and rejection will end in a
+ HTTP response indicating failure.
+ */
+ event.respondWith(
+ caches
+ /* This method returns a promise that resolves to a cache entry matching
+ the request. Once the promise is settled, we can then provide a response
+ to the fetch request.
+ */
+ .match(event.request)
+ .then(function(cached) {
+ /* Even if the response is in our cache, we go to the network as well.
+ This pattern is known for producing "eventually fresh" responses,
+ where we return cached responses immediately, and meanwhile pull
+ a network response and store that in the cache.
+
+ Read more:
+ https://ponyfoo.com/articles/progressive-networking-serviceworker
+ */
+ var networked = fetch(event.request)
+ // We handle the network request with success and failure scenarios.
+ .then(fetchedFromNetwork, unableToResolve)
+ // We should catch errors on the fetchedFromNetwork handler as well.
+ .catch(unableToResolve);
+
+ /* We return the cached response immediately if there is one, and fall
+ back to waiting on the network as usual.
+ */
+ console.log('WORKER: fetch event', cached ? '(cached)' : '(network)', event.request.url);
+ return cached || networked;
+
+ function fetchedFromNetwork(response) {
+ /* We copy the response before replying to the network request.
+ This is the response that will be stored on the ServiceWorker cache.
+ */
+ var cacheCopy = response.clone();
+
+ console.log('WORKER: fetch response from network.', event.request.url);
+
+ caches
+ // We open a cache to store the response for this request.
+ .open(version + 'pages')
+ .then(function add(cache) {
+ /* We store the response for this request. It'll later become
+ available to caches.match(event.request) calls, when looking
+ for cached responses.
+ */
+ cache.put(event.request, cacheCopy);
+ })
+ .then(function() {
+ console.log('WORKER: fetch response stored in cache.', event.request.url);
+ });
+
+ // Return the response so that the promise is settled in fulfillment.
+ return response;
+ }
+
+ /* When this method is called, it means we were unable to produce a response
+ from either the cache or the network. This is our opportunity to produce
+ a meaningful response even when all else fails. It's the last chance, so
+ you probably want to display a "Service Unavailable" view or a generic
+ error response.
+ */
+ function unableToResolve() {
+ /* There's a couple of things we can do here.
+ - Test the Accept header and then return one of the `offlineFundamentals`
+ e.g: `return caches.match('/some/cached/image.png')`
+ - You should also consider the origin. It's easier to decide what
+ "unavailable" means for requests against your origins than for requests
+ against a third party, such as an ad provider.
+ - Generate a Response programmaticaly, as shown below, and return that.
+ */
+
+ console.log('WORKER: fetch request failed in both cache and network.');
+
+ /* Here we're creating a response programmatically. The first parameter is the
+ response body, and the second one defines the options for the response.
+ */
+ return new Response('Service Unavailable
', {
+ status: 503,
+ statusText: 'Service Unavailable',
+ headers: new Headers({
+ 'Content-Type': 'text/html'
+ })
+ });
+ }
+ })
+ );
+});
+
+/* The activate event fires after a service worker has been successfully installed.
+ It is most useful when phasing out an older version of a service worker, as at
+ this point you know that the new worker was installed correctly. In this example,
+ we delete old caches that don't match the version in the worker we just finished
+ installing.
+*/
+self.addEventListener("activate", function(event) {
+ /* Just like with the install event, event.waitUntil blocks activate on a promise.
+ Activation will fail unless the promise is fulfilled.
+ */
+ console.log('WORKER: activate event in progress.');
+
+ event.waitUntil(
+ caches
+ /* This method returns a promise which will resolve to an array of available
+ cache keys.
+ */
+ .keys()
+ .then(function(keys) {
+ // We return a promise that settles when all outdated caches are deleted.
+ return Promise.all(
+ keys
+ .filter(function(key) {
+ // Filter by keys that don't start with the latest version prefix.
+ return !key.startsWith(version);
+ })
+ .map(function(key) {
+ /* Return a promise that's fulfilled
+ when each outdated cache is deleted.
+ */
+ return caches.delete(key);
+ })
+ );
+ })
+ .then(function() {
+ console.log('WORKER: activate completed.');
+ })
+ );
+});
diff --git a/gulpfile.js b/gulpfile.js
index 6f35c782..c2355424 100644
--- a/gulpfile.js
+++ b/gulpfile.js
@@ -215,8 +215,19 @@ gulp.task('js:project', function() {
.pipe(gulp.dest(DIST + '/assets/js/'))
});
+// Service Worker js
+gulp.task('js:sw', function() {
+ return gulp.src(DIST + '/service-worker.js')
+ .pipe($.if(isProduction, $.uglify({
+ compress: {
+ drop_console: true
+ }
+ }))).on('error', onError)
+ .pipe(gulp.dest(DIST + '/'))
+});
+
// Collect all script tasks
-gulp.task('js', ['js:libraries', 'js:project'])
+gulp.task('js', ['js:libraries', 'js:project', 'js:sw'])
//