Broadcast channel

frontend/src/routes/+layout.svelte

@@ -11,14 +11,21 @@
 				navigator.serviceWorker.register('/service-worker.js');
 			});
 
+			if (BroadcastChannel) {
 				const channel = new BroadcastChannel('sw-messages');
 				channel.addEventListener('message', (event) => {
+					console.log(event.data);
 					new Toast({ target: node });
 				});
+			} else {
+				navigator.serviceWorker.addEventListener('message', (evt) => {
+					console.log(evt.data);
+					new Toast({ target: node });
+				});
+			}
 
 			navigator.serviceWorker.ready.then((registration) => {
-				console.log(registration);
-				console.log('registered service worker');
+				registration.active?.postMessage('Save client');
 			});
 		}
 	});