First commit

public_html/sw.js

@@ -0,0 +1,33 @@
+/* Cache-first: once installed the clock never touches the network again. */
+const CACHE = "bgclock-v1";
+const FILES = [
+  "./",
+  "./index.html",
+  "./manifest.webmanifest",
+  "./icon-192.png",
+  "./icon-512.png",
+  "./icon-maskable-512.png"
+];
+
+self.addEventListener("install", (e) => {
+  e.waitUntil(caches.open(CACHE).then((c) => c.addAll(FILES)).then(() => self.skipWaiting()));
+});
+
+self.addEventListener("activate", (e) => {
+  e.waitUntil(
+    caches.keys()
+      .then((keys) => Promise.all(keys.filter((k) => k !== CACHE).map((k) => caches.delete(k))))
+      .then(() => self.clients.claim())
+  );
+});
+
+self.addEventListener("fetch", (e) => {
+  if (e.request.method !== "GET") return;
+  e.respondWith(
+    caches.match(e.request).then((hit) => hit || fetch(e.request).then((res) => {
+      const copy = res.clone();
+      caches.open(CACHE).then((c) => c.put(e.request, copy)).catch(() => {});
+      return res;
+    }).catch(() => caches.match("./index.html")))
+  );
+});