Add check for Focusing tab button during pre-rendering

src/Pure.Blazor.Components/Layout/PureTabButton.razor

@@ -1,13 +1,14 @@
 @using System.Text
 @inherits PureComponent
-<button @ref="_elementReference" tabindex="@(IsActive ? 0 : -1)" @onclick="@((e) => { Console.WriteLine("clicked"); OnClick.InvokeAsync(e); })" class="@ApplyStyle(InternalCss)" @onkeyup="OnKeyUp" role="tab">
+<button @ref="_elementReference" @key="Title" tabindex="@(IsActive ? 0 : -1)" @onclick="@((e) => { Console.WriteLine("clicked"); OnClick.InvokeAsync(e); })" class="@ApplyStyle(InternalCss)" @onkeyup="OnKeyUp" role="tab">
     <!-- todo: icon -->
     @Title
 </button>
 
 @code {
-    private ElementReference? _elementReference;
+    private ElementReference _elementReference;
     private bool prevStateActive = false;
+    [Inject] public required ILogger<PureTabButton> Logger { get; set; }
     [Parameter] public string Title { get; set; } = string.Empty;
 
     [Parameter] public bool IsActive { get; set; }
@@ -28,23 +29,24 @@
     }
 
     private string InternalCss { get; set; } = string.Empty;
-
     protected override async Task OnParametersSetAsync()
     {
-        if (_elementReference is null)
-        {
-            return;
-        }
-
+        // If the button is not active yet, but the parameter is set to active, focus on the button.
+        // This is to ensure that the button is focused when it becomes active the first time.
         if (!prevStateActive && IsActive)
         {
             try
             {
-                await _elementReference.Value.FocusAsync();
+                // Context is null when pre-rendering or when using static rendering
+                if (_elementReference.Context is not null)
+                {
+                    await Task.Run(async () => await _elementReference.FocusAsync());
+                }
             }
             catch (Exception e)
             {
-                Console.WriteLine(e);
+                // Log the error and continue
+                Logger.LogWarning(e, "Failed to focus on tab button");
             }
         }