Fix service worker

cmd/fastgallery/assets/serviceWorker.js

@@ -1,21 +1,22 @@
-self.addEventListener('install', (event) => {
-    console.log("Service worker installed")
+self.addEventListener("install", (event) => {
+    console.log("Service worker installed");
 });
 
-self.addEventListener('activate', (event) => {
-    console.log("Service worker activated")
+self.addEventListener("activate", (event) => {
+    console.log("Service worker activated");
 });
 
-self.addEventListener('fetch', (event) => {
-    try {
-        return fetch(event.request)
-    } catch (error) {
-        return new Response(
-            "<h1>No network connection</h1>Retrying...<script>setTimeout(() => { window.location.reload(1); }, 5000);</script>",
-            {
-                headers: {
-                    'Content-type': 'text/html'
+self.addEventListener("fetch", (event) => {
+    if (event.request.mode === "navigate") {
+        event.respondWith(
+            (async () => {
+                try {
+                    return await fetch(event.request);
+                } catch (error) {
+                    return new Response("<h1>No network connection</h1>Retrying...<script>setTimeout(() => { window.location.reload(1); }, 5000);</script>",
+                        { status: 200, headers: { 'Content-type': 'text/html' } })
                 }
-            })
+            })()
+        );
     }
 });

cmd/fastgallery/main.go

@@ -637,6 +637,8 @@ func copyFile(source string, destination string) {
 }
 */
 
+// TODO document function
+// TODO icons without transparent backgrounds
 func isIcon(iconPath string) bool {
 	re := regexp.MustCompile(`^icon`)
 	iconPath = filepath.Base(iconPath)
@@ -877,6 +879,8 @@ func createHTML(depth int, source directory, galleryDirectory string, dryRun boo
 			log.Println("couldn't parse HTML template", templatePath, ":", err.Error())
 			exit(1)
 		}
+		// TODO apple-touch-icon to template
+		// TODO simplify service worker
 
 		htmlFileHandle, err := os.Create(htmlFilePath)
 		if err != nil {