extend ConfigurationValueViewModel to write the value back to settings

Toolkit.Foundation/ConfigurationValueViewModel.cs

@@ -7,23 +7,28 @@ public partial class ConfigurationValueViewModel<TConfiguration, TValue>(IServic
     ISubscriber subscriber,
     IDisposer disposer,
     TConfiguration configuration,
-    Func<TConfiguration, TValue> valueDelegate) :
+    IWritableConfiguration<TConfiguration> writer,
+    Func<TConfiguration, TValue?> read,
+    Action<TValue?, TConfiguration> write) :
     ValueViewModel<TValue>(provider, factory, mediator, publisher, subscriber, disposer),
     INotificationHandler<ChangedEventArgs<TConfiguration>>
     where TConfiguration : class
 {
-    private readonly TConfiguration configuration = configuration;
-
-    private readonly Func<TConfiguration, TValue> valueDelegate = valueDelegate;
-
     public Task Handle(ChangedEventArgs<TConfiguration> args)
     {
+
         throw new NotImplementedException();
     }
 
+    protected override void OnChanged(TValue? value)
+    {
+        writer.Write(args => write(value, args));
+        base.OnChanged(value);
+    }
+
     public override Task OnActivated()
     {
-        Value = valueDelegate(configuration);
+        Value = read(configuration);
         return base.OnActivated();
     }
 }