From 68b43bec328bdbddbe1c1534e28bda381d976f96 Mon Sep 17 00:00:00 2001
From: Candid Dauth <cdauth@cdauth.eu>
Date: Sat, 29 May 2021 16:43:46 +0200
Subject: [PATCH] Add service worker to allow installing as a PWA

---
 frontend/src/map/map.ts    |  3 +++
 frontend/static/sw.js      | 26 ++++++++++++++++++++++++++
 frontend/webpack.config.ts |  1 +
 3 files changed, 30 insertions(+)
 create mode 100644 frontend/static/sw.js

diff --git a/frontend/src/map/map.ts b/frontend/src/map/map.ts
index 37bcd698..666cec96 100644
--- a/frontend/src/map/map.ts
+++ b/frontend/src/map/map.ts
@@ -44,6 +44,9 @@ $(document).on("click", "a", function() {
 	}
 });
 
+if ('serviceWorker' in navigator)
+	navigator.serviceWorker.register('./sw.js');
+
 const queryParams = decodeQueryString(location.search);
 const toBoolean = (val: string, def: boolean) => (val == null ? def : val != "0" && val != "false" && val != "no");
 
diff --git a/frontend/static/sw.js b/frontend/static/sw.js
new file mode 100644
index 00000000..1a4282e4
--- /dev/null
+++ b/frontend/static/sw.js
@@ -0,0 +1,26 @@
+// For now we just add offline support for index.html so that FacilMap can be installed as a PWA
+
+const version = "v1";
+
+self.addEventListener('install', (e) => {
+	e.waitUntil(caches.open(version).then((cache) => cache.addAll(["/"])));
+});
+
+self.addEventListener('activate', event => {
+	event.waitUntil(
+		caches.keys().then((keyList) => {
+			return Promise.all(keyList.map((key) => {
+				if(key != version)
+					return caches.delete(key);
+			}));
+		})
+	);
+});
+
+self.addEventListener('fetch', (event) => {
+	event.respondWith(caches.open(version).then((cache) => {
+		return fetch(event.request).catch(() => {
+			return cache.match(event.request, { ignoreSearch: true });
+		});
+	}));
+});
diff --git a/frontend/webpack.config.ts b/frontend/webpack.config.ts
index 31f8f998..a45b1f47 100644
--- a/frontend/webpack.config.ts
+++ b/frontend/webpack.config.ts
@@ -136,6 +136,7 @@ module.exports = (env: any, argv: any): Configuration[] => {
 						"favicon.ico",
 						"favicon.svg",
 						"manifest.json",
+						"sw.js",
 						"opensearch.xml"
 					].map((file) => ({ from: `${__dirname}/static/${file}` }))
 				}),