Exclude persistent views in designer mode

StabilityMatrix.Avalonia/ViewLocator.cs

@@ -21,7 +21,8 @@ public class ViewLocator : IDataTemplate, INavigationPageFactory
     /// <inheritdoc />
     public Control Build(object? data)
     {
-        if (data is null) throw new ArgumentNullException(nameof(data));
+        if (data is null)
+            throw new ArgumentNullException(nameof(data));
 
         var type = data.GetType();
 
@@ -31,10 +32,7 @@ public class ViewLocator : IDataTemplate, INavigationPageFactory
             return GetView(viewType, data, viewAttr.IsPersistent);
         }
 
-        return new TextBlock
+        return new TextBlock { Text = "View Model Not Found: " + data.GetType().FullName };
-        {
-            Text = "View Model Not Found: " + data.GetType().FullName
-        };
     }
 
     private Control GetView(Type viewType)
@@ -44,21 +42,25 @@ public class ViewLocator : IDataTemplate, INavigationPageFactory
             return view;
         }
 
-        return new TextBlock
+        return new TextBlock { Text = "View Not Found: " + viewType.FullName };
-        {
-            Text = "View Not Found: " + viewType.FullName
-        };
     }
 
     private Control GetView(Type viewType, object context, bool persistent)
     {
+        // Disregard persistent settings in design mode
+        if (Design.IsDesignMode)
+        {
+            persistent = false;
+        }
+
         if (persistent)
         {
             // Check assignable from IPersistentViewProvider
             if (context is not IPersistentViewProvider persistentViewProvider)
             {
                 throw new InvalidOperationException(
-                    $"View {viewType.Name} is marked as persistent but does not implement IPersistentViewProvider");
+                    $"View {viewType.Name} is marked as persistent but does not implement IPersistentViewProvider"
+                );
             }
 
             // Try get from context
@@ -87,10 +89,7 @@ public class ViewLocator : IDataTemplate, INavigationPageFactory
             }
         }
 
-        return new TextBlock
+        return new TextBlock { Text = "View Not Found: " + viewType.FullName };
-        {
-            Text = "View Not Found: " + viewType.FullName
-        };
     }
 
     /// <inheritdoc />
@@ -102,8 +101,10 @@ public class ViewLocator : IDataTemplate, INavigationPageFactory
     /// <inheritdoc />
     public Control? GetPage(Type srcType)
     {
-        if (Attribute.GetCustomAttribute(srcType, typeof(ViewAttribute)) is not ViewAttribute
+        if (
-            viewAttr)
+            Attribute.GetCustomAttribute(srcType, typeof(ViewAttribute))
+            is not ViewAttribute viewAttr
+        )
         {
             throw new InvalidOperationException("View not found for " + srcType.FullName);
         }
@@ -118,8 +119,10 @@ public class ViewLocator : IDataTemplate, INavigationPageFactory
     /// <inheritdoc />
     public Control GetPageFromObject(object target)
     {
-        if (Attribute.GetCustomAttribute(target.GetType(), typeof(ViewAttribute)) is not
+        if (
-            ViewAttribute viewAttr)
+            Attribute.GetCustomAttribute(target.GetType(), typeof(ViewAttribute))
+            is not ViewAttribute viewAttr
+        )
         {
             throw new InvalidOperationException("View not found for " + target.GetType().FullName);
         }