1 files changed, 40 insertions, 0 deletions
diff --git a/app/public/sw2.js b/app/public/sw2.js
new file mode 100644
index 0000000..0dabb13
--- /dev/null
+++ b/app/public/sw2.js
@@ -0,0 +1,40 @@
+// https://googlechrome.github.io/samples/service-worker/basic/
+
+const PRECACHE = "notes-precache-v1";
+const RUNTIME = "notes-runtime";
+
+const PRECACHE_URLS = [
+  "./", // Alias for index.html
+  "index.html",
+  "style.css",
+  "main.js"
+];
+
+self.addEventListener("install", e => e.waitUntil(
+  caches.open(PRECACHE)
+    .then(cache => cache.addAll(PRECACHE_URLS))
+    .then(self.skipWaiting())));
+
+self.addEventListener("activate", e => {
+  const currentCaches = [PRECACHE, RUNTIME];
+  e.waitUntil( // Clean up old caches
+    caches.keys().then(cacheNames =>
+      cacheNames.filter(cacheName => !currentCaches.includes(cacheName))
+    ).then(cachesToDelete => Promise.all(cachesToDelete.map(cacheToDelete =>
+      caches.delete(cacheToDelete)))
+    ).then(() => self.clients.claim())
+  );
+});
+
+self.addEventListener("fetch", e => {
+  if (e.request.url.startsWith(self.location.origin)) {
+    e.respondWith(caches.match(e.request).then(cachedResponse =>
+      cachedResponse? cachedResponse
+      : caches.open(RUNTIME).then(cache =>
+        fetch(e.request).then(res =>
+          cache.put(e.request, res.clone()).then(() => res)
+        )
+      )
+    ));
+  }
+});