Added OnServiceWorkerUpdateFound event to WebWorkerService to address issue #5.

Author: LostBeard

SpawnDev.BlazorJS.WebWorkers/WebWorkerService.cs

@@ -388,6 +388,10 @@ public void SendEventToParents(string eventName, params object?[]? data)
             }
         }
         /// <summary>
+        /// The updatefound event of the ServiceWorkerRegistration interface is fired any time the ServiceWorkerRegistration.installing property acquires a new service worker.
+        /// </summary>
+        public event Action OnServiceWorkerUpdateFound;
+        /// <summary>
         /// This event fires if this instance is running in a WebWorker when the connection to the parent has been established
         /// </summary>
         public event Action OnDedicatedWorkerParentReady;
@@ -507,13 +511,6 @@ private string GetName()
             if (JS.SharedWorkerThis != null) return JS.SharedWorkerThis.Name ?? "";
             return "";
         }
-        private string GetParentInstanceId()
-        {
-            if (JS.WindowThis != null) return JS.WindowThis.Name ?? "";
-            if (JS.DedicateWorkerThis != null) return JS.DedicateWorkerThis.Name ?? "";
-            if (JS.SharedWorkerThis != null) return JS.SharedWorkerThis.Name ?? "";
-            return "";
-        }
         /// <summary>
         /// Called by BlazorJSRuntime at startup
         /// </summary>
@@ -659,8 +656,13 @@ public async Task RegisterServiceWorker()
                     workerUrl += $"?{queryStr}";
                 }
                 using var registration = await serviceWorker.Register(workerUrl, ServiceWorkerConfig.Options);
+                registration.OnUpdateFound += ServiceWorker_OnUpdateFound;
             }
         }
+        void ServiceWorker_OnUpdateFound()
+        {
+            OnServiceWorkerUpdateFound?.Invoke();
+        }
         /// <summary>
         /// Unregisters a registered service worker
         /// </summary>