navigate with parameters

src/MAUI/TinyMvvm.Maui/ITinyViewModel.cs

@@ -15,9 +15,10 @@ public interface ITinyViewModel : INotifyPropertyChanged
     Task Initialize();
 
     /// <summary>
-    /// This method will run after navigating back.
+    /// This method runs when navigation parameters are set.
     /// </summary>
-    Task Returning();
+    /// <returns></returns>
+    Task ParameterSet();
 
     /// <summary>
     /// This method will run every time the view is apperaing.
@@ -44,10 +45,6 @@ public interface ITinyViewModel : INotifyPropertyChanged
     /// </summary>
     Task OnApplicationSleep();
 
-    /// <summary>
-    /// Parameter that passed to this ViewModel when navigating back to it.
-    /// </summary>
-    object? ReturningParameter { get; set; }
 
     /// <summary>
     /// Parameter that passed to this ViewModel when navigated, will not be available in the constructor, use it when Initialize is running or later. 

src/MAUI/TinyMvvm.Maui/TinyView.cs

@@ -2,7 +2,7 @@
 
 public abstract class TinyView : ContentPage
 {
-    internal SemaphoreSlim ReadLock { get; private set; } = new SemaphoreSlim(1, 1);
+    internal SemaphoreSlim InternalLock { get; private set; } = new SemaphoreSlim(1, 1);
 
     protected override void OnBindingContextChanged()
     {
@@ -16,7 +16,7 @@ protected override void OnBindingContextChanged()
                 {
                     MainThread.BeginInvokeOnMainThread(async () =>
                     {
-                        await ReadLock.WaitAsync();
+                        await InternalLock.WaitAsync();
                         await viewModel.Initialize();
 
                         viewModel.IsInitialized = true;
@@ -25,7 +25,7 @@ protected override void OnBindingContextChanged()
             }
             finally
             {
-                ReadLock.Release();
+                InternalLock.Release();
             }
         }
     }
@@ -38,7 +38,7 @@ protected override void OnAppearing()
         {
             MainThread.BeginInvokeOnMainThread(async () =>
             {
-                await ReadLock.WaitAsync();
+                await InternalLock.WaitAsync();
 
                 if (!viewModel.IsInitialized)
                 {
@@ -48,7 +48,7 @@ protected override void OnAppearing()
 
                 await viewModel.OnAppearing();
 
-                ReadLock.Release();
+                InternalLock.Release();
             });
 
         }
@@ -62,11 +62,11 @@ protected override void OnDisappearing()
         {
             MainThread.BeginInvokeOnMainThread(async () =>
             {
-                await ReadLock.WaitAsync();
+                await InternalLock.WaitAsync();
 
                 await viewModel.OnDisappearing();
 
-                ReadLock.Release();
+                InternalLock.Release();
             });
         }
     }

src/MAUI/TinyMvvm.Maui/TinyViewModel.cs

@@ -32,8 +32,9 @@ public TinyViewModel()
     /// <inheritdoc />
     public virtual Task Initialize() => Task.CompletedTask;
 
+
     /// <inheritdoc />
-    public virtual Task Returning() => Task.CompletedTask;
+    public virtual Task ParameterSet() => Task.CompletedTask;
 
     /// <inheritdoc />
     public virtual Task OnAppearing()
@@ -42,12 +43,8 @@ public virtual Task OnAppearing()
         if (!hasAppeared)
         {
 
-           MainThread.BeginInvokeOnMainThread(async () => await OnFirstAppear());
-
-        }
-        else
-        {
-            MainThread.BeginInvokeOnMainThread(async () => await Returning());
+            MainThread.BeginInvokeOnMainThread(async () => await OnFirstAppear());
+
         }
 
         hasAppeared = true;
@@ -67,9 +64,6 @@ public virtual Task OnAppearing()
     /// <inheritdoc />
     public virtual Task OnApplicationSleep() => Task.CompletedTask;
 
-    /// <inheritdoc />
-    public object? ReturningParameter { get; set; }
-
     /// <inheritdoc />
     public object? NavigationParameter { get; set; }
 
@@ -104,10 +98,10 @@ public bool IsBusy
         {
             var updated = Set(ref _isBusy, value);
 
-            if(updated)
+            if (updated)
             {
                 RaisePropertyChanged(nameof(IsNotBusy));
-            }            
+            }
         }
     }
 
@@ -120,7 +114,7 @@ public bool IsNotBusy
         }
     }
 
-    
+
     private bool _isInitialized;
     /// <inheritdoc />
     public bool IsInitialized
@@ -177,15 +171,37 @@ protected bool Set<T>(ref T field, T newValue, [CallerMemberName] string? proper
     }
 
     /// <inheritdoc />
-    public void ApplyQueryAttributes(IDictionary<string, object> query)
+    public async void ApplyQueryAttributes(IDictionary<string, object> query)
     {
-        if(query.ContainsKey("tinyParameter"))
+        if(query == null || query.Count == 0)
+        {
+            return;
+        }
+
+        if (query.ContainsKey("tinyParameter"))
         {
             NavigationParameter = query["tinyParameter"];
         }
         else
         {
             QueryParameters = query;
         }
+
+        async Task RunParameterSet()
+        {
+            await ParameterSet();
+        }
+
+        if (MainThread.IsMainThread)
+        {
+            await RunParameterSet();
+        }
+        else
+        {
+            MainThread.BeginInvokeOnMainThread(async () =>
+            {
+                await RunParameterSet();
+            });
+        }
     }
 }

src/MAUI/TinyMvvm.Sample/Services/CityService.cs

@@ -48,7 +48,7 @@ private async Task<List<City>> Load()
         using var stream = await FileSystem.OpenAppPackageFileAsync("cities.json");
         using var reader = new StreamReader(stream);
 
-        var contents = reader.ReadToEnd();
+        var contents = await reader.ReadToEndAsync();
 
         cities = JsonSerializer.Deserialize<List<City>>(contents, new JsonSerializerOptions() { PropertyNameCaseInsensitive = true });
 

src/MAUI/TinyMvvm.Sample/ViewModels/DetailsViewModel.cs

@@ -10,7 +10,7 @@ public DetailsViewModel(ICityService cityService)
             this.cityService = cityService;
         }
 
-        public override async Task Initialize()
+        public override async Task ParameterSet()
         {
             IsBusy = true;
 

src/MAUI/TinyMvvm.Sample/ViewModels/MainViewModel.cs

@@ -27,6 +27,8 @@ public string Text
     {
         IsBusy = true;
 
+        var isMain = MainThread.IsMainThread;
+
         var result = await cityService.Search(Text);
 
         Cities = new ObservableCollection<City>(result);

src/MAUI/TinyMvvm.Sample/Views/DetailsView.xaml

@@ -4,9 +4,9 @@
              xmlns:mvvm="clr-namespace:TinyMvvm;assembly=TinyMvvm.Maui"
              x:Class="TinyMvvm.Sample.Views.DetailsView"
              Title="DetailsView">
-    <VerticalStackLayout>
+    <VerticalStackLayout Padding="10">
         <Label 
-            Text="Welcome to .NET MAUI!"
+            Text="{Binding City.Name}"
             VerticalOptions="Center" 
             HorizontalOptions="Center" />
     </VerticalStackLayout>

src/MAUI/TinyMvvm.Sample/Views/ListView.xaml

@@ -4,7 +4,7 @@
              xmlns:mvvm="clr-namespace:TinyMvvm;assembly=TinyMvvm.Maui"
              x:Class="TinyMvvm.Sample.Views.ListView"
              Title="ListView">
-    <Grid>
+    <Grid Padding="10">
         <ActivityIndicator HorizontalOptions="Center" VerticalOptions="Center" IsRunning="{Binding IsBusy}" />
         <CollectionView x:Name="CityList" ItemsSource="{Binding Cities}" IsVisible="{Binding IsNotBusy}">
             <CollectionView.ItemTemplate>

src/MAUI/TinyMvvm.Sample/Views/MainView.xaml

@@ -9,7 +9,7 @@
             <Entry Text="{Binding Text}" Placeholder="Search city" />
             <Button Command="{Binding Search}" Text="Search" />
         </VerticalStackLayout>
-        <ActivityIndicator Grid.Row="1" HorizontalOptions="Center" VerticalOptions="Center" IsRunning="{Binding IsBusy}" />
+        <ActivityIndicator Grid.Row="1" HorizontalOptions="Center" VerticalOptions="Center" IsRunning="{Binding IsBusy}" IsVisible="{Binding IsBusy}" />
         <CollectionView Grid.Row="1" x:Name="CityList" ItemsSource="{Binding Cities}" IsVisible="{Binding IsNotBusy}">
             <CollectionView.ItemTemplate>
                 <DataTemplate>