From 187058899963da8ee5bef62181bc5c81e4e63e86 Mon Sep 17 00:00:00 2001
From: Ardis Lu <ardisglu@gmail.com>
Date: Sun, 28 Mar 2021 19:46:57 -0700
Subject: [PATCH] Add service worker to cache CMS responses

My google-api-proxy takes 1-2 seconds to serve content, which is not acceptable. The service worker will automatically cache and serve the last response from the CMS.
---
 script.js |  4 ++++
 sw.js     | 22 ++++++++++++++++++++++
 2 files changed, 26 insertions(+)
 create mode 100644 sw.js

diff --git a/script.js b/script.js
index dc9fca0..bc757bf 100644
--- a/script.js
+++ b/script.js
@@ -1,3 +1,7 @@
+if ('serviceWorker' in navigator) {
+  navigator.serviceWorker.register('/sw.js');
+}
+
 const main = document.getElementsByTagName("main")[0];
 const initialColumns = Math.max(1, Math.floor(main.clientWidth / 320) - 1);
 
diff --git a/sw.js b/sw.js
new file mode 100644
index 0000000..64122f3
--- /dev/null
+++ b/sw.js
@@ -0,0 +1,22 @@
+const cacheName = 'v1';
+
+self.addEventListener('install', event => {
+  event.waitUntil((async () => {
+    const cache = await caches.open(cacheName);
+    await cache.addAll(['index.html', '404.html', 'style.css', 'script.js', 'favicon.ico', 'github.svg', 'home.svg']);
+  })());
+});
+
+self.addEventListener('fetch', event => {
+  event.respondWith((async () => {
+    const fetchResponseP = fetch(event.request);
+    const fetchResponseCloneP = fetchResponseP.then(r => r.clone());
+
+    event.waitUntil((async () => {
+      const cache = await caches.open(cacheName);
+      await cache.add(event.request.url, await fetchResponseCloneP);
+    })());
+
+    return (await caches.match(event.request.url)) || fetchResponseP;
+  })());
+});
\ No newline at end of file
-- 
2.47.3