Fixed #6 by using a web worker for the loop cycles instead of a plain for(;;) loop. Bug was due to tab hibernation (most browsers throttle inactive tabs' resources to a point where the generated TOTP codes would no longer be correct after a few minutes of inactivity).

Author: GlitchedPolygons

TFACGUI.BlazorWebApp/Constants.cs

@@ -53,6 +53,9 @@ public static class InteropFunctionNames
         public const string ALERT_DIALOG = "alert";
         public const string CONFIRM_DIALOG = "confirm";
         public const string SHOW_TOAST = "ShowToast";
+        public const string START_LOOP_WORKER = "StartLoopWorker";
+        public const string STOP_LOOP_WORKER = "StopLoopWorker";
+        public const string IS_WORKER_AVAILABLE = "WorkerAvailable";
         public const string GET_INPUT_VALUE = "GetInputValue";
         public const string GET_INPUT_VALUE_RADIO_BOX = "GetRadioBoxValue";
         public const string SET_INPUT_VALUE = "SetInputValue";
@@ -68,6 +71,7 @@ public static class InteropFunctionNames
         public const string GET_WINDOW_INNER_WIDTH = "GetWindowInnerWidth";
         public const string GET_WINDOW_INNER_HEIGHT = "GetWindowInnerHeight";
         public const string BLUT_ACTIVE_ELEMENT = "document.activeElement.blur";
+        
     }
 
     public static class AesGcm

TFACGUI.BlazorWebApp/Pages/Home.razor

@@ -572,6 +572,8 @@
     private string qrCodeScannerWidth = "90%";
 
     private readonly string manualRegistrationDescTooltip = "Manually registering a 2FA secret is useful for example if your device has no camera to scan the QR code with, or if you want more control over how the entry is going to be labelled inside your TFACGUI chain.\n\nMake sure to enter everything correctly and label everything in an easily recognizable fashion!";
+    
+    private static event Action? Looped;
 
     protected override async Task OnInitializedAsync()
     {
@@ -581,21 +583,32 @@
 
         gridView = await JS.InvokeAsync<string>(Constants.InteropFunctionNames.GET_LOCALSTORAGE_VALUE, Constants.LocalStorageIds.GRID_VIEW, "true") != "false";
 
-        for (;;)
+        bool workerApiSupported = await JS.InvokeAsync<bool>(Constants.InteropFunctionNames.IS_WORKER_AVAILABLE);
+
+        if (workerApiSupported)
         {
-            if (changedFocusedState)
-            {
-                changedFocusedState = false;
+            await JS.InvokeVoidAsync(Constants.InteropFunctionNames.START_LOOP_WORKER);
 
-                if (focused)
+            Looped += OnLoopCycle;
+        }
+        else
+        {
+            for (;;)
+            {
+                if (changedFocusedState)
                 {
-                    userData = await UserDataService.GetUserData();
+                    changedFocusedState = false;
+
+                    if (focused)
+                    {
+                        userData = await UserDataService.GetUserData();
+                    }
                 }
-            }
 
-            StateHasChanged();
+                StateHasChanged();
 
-            await Task.Delay(focused ? 128 : 256);
+                await Task.Delay(focused ? 128 : 256);
+            }
         }
     }
 
@@ -612,6 +625,34 @@
         changedFocusedState = true;
     }
 
+    [JSInvokable]
+    public static void OnLoopCycleWorkerCallback(string eventArgs)
+    {
+#if DEBUG
+        Console.WriteLine($"Loop cycle occurred. Event args: {eventArgs}");
+#endif
+        
+        Looped?.Invoke();
+    }
+
+    private void OnLoopCycle()
+    {
+        if (changedFocusedState)
+        {
+            changedFocusedState = false;
+
+            if (focused)
+            {
+                Task.Run(async () =>
+                {
+                    userData = await UserDataService.GetUserData();
+                });
+            }
+        }
+        
+        StateHasChanged();
+    }
+
     private async Task ResetManualRegistrationModalForm()
     {
         await JS.InvokeVoidAsync(Constants.InteropFunctionNames.SET_INPUT_VALUE, Constants.ElementIds.TOTP_CONFIG_ENTRY_NAME, string.Empty);

TFACGUI.BlazorWebApp/TFACGUI.BlazorWebApp.csproj

@@ -5,8 +5,8 @@
         <Nullable>enable</Nullable>
         <ImplicitUsings>enable</ImplicitUsings>
         <Company>Glitched Polygons</Company>
-        <AssemblyVersion>1.0.0</AssemblyVersion>
-        <FileVersion>1.0.0</FileVersion>
+        <AssemblyVersion>1.0.1</AssemblyVersion>
+        <FileVersion>1.0.1</FileVersion>
         <ApplicationIcon>wwwroot\favicon.ico</ApplicationIcon>
         <!-- The following two are necessary until Microsoft fixes https://github.com/dotnet/runtime/issues/90710 -->
         <RunAOTCompilation>false</RunAOTCompilation>

TFACGUI.BlazorWebApp/wwwroot/index.html

@@ -37,6 +37,7 @@
     <script src="js/toaster.js"></script>
     <script src="js/window.js"></script>
     <script src="js/focus.js"></script>
+    <script src="js/loop.js"></script>
 </body>
 
 </html>

TFACGUI.BlazorWebApp/wwwroot/js/focus.js

@@ -6,5 +6,5 @@ function IsDocumentHidden()
 
 document.addEventListener("visibilitychange", () => 
 {
-    DotNet.invokeMethodAsync('TFACGUI.BlazorWebApp', 'OnChangeVisibilityState', document.hidden)
+    DotNet.invokeMethodAsync('TFACGUI.BlazorWebApp', 'OnChangeVisibilityState', document.hidden);
 });

TFACGUI.BlazorWebApp/wwwroot/js/loop.js

@@ -0,0 +1,35 @@
+let loopWorker = undefined;
+
+function WorkerAvailable()
+{
+    return typeof(Worker) !== 'undefined';
+}
+
+function StartLoopWorker() 
+{
+    if (WorkerAvailable()) 
+    {
+        if (typeof(loopWorker) == 'undefined') 
+        {
+            loopWorker = new Worker('js/loopworker.js');
+        }
+        
+        loopWorker.onmessage = function (event) 
+        {
+            DotNet.invokeMethodAsync('TFACGUI.BlazorWebApp', 'OnLoopCycleWorkerCallback', '');
+        };
+    } 
+    else 
+    {
+        console.error('Sorry, your browser does not support web workers... Please use a browser that does in order to make full use of TFACGUI!');
+    }
+}
+
+function StopLoopWorker() 
+{
+    if (loopWorker)
+    {
+        loopWorker.terminate();
+        loopWorker = undefined;
+    }
+}

TFACGUI.BlazorWebApp/wwwroot/js/loopworker.js

@@ -0,0 +1,8 @@
+
+function Loop() 
+{
+    postMessage('');
+    setTimeout('Loop()',128);
+}
+
+Loop();