Merge pull request #1780 from unoplatform/mergify/bp/legacy/2x/pr-1756

fix: FeedView not initializing properly if not visible on first load (backport #1756)

src/Uno.Extensions.Reactive.UI.Tests/Given_FeedView.cs

@@ -6,6 +6,7 @@
 using System.Threading.Tasks;
 using FluentAssertions;
 using Microsoft.UI.Xaml;
+using Microsoft.UI.Xaml.Controls;
 using Microsoft.VisualStudio.TestTools.UnitTesting;
 using Uno.Extensions.Reactive.Core;
 using Uno.Extensions.Reactive.Testing;
@@ -41,6 +42,28 @@ public async Task When_Loading()
 		await UIHelper.WaitFor(() => isLoadingValues.Count > 0, CT);
 	}
 
+	[TestMethod]
+	public async Task When_NotVisible_Then_DoesNotSubscribeToSource()
+	{
+		// This tests will also ensure that is the FeedView will not try to GoToState while it does not have any template yet.
+
+		var isLoaded = false;
+		var src = Feed.Async(async ct => isLoaded = true);
+		var sut = new FeedView { Source = src };
+		var root = new Grid { Visibility = Visibility.Collapsed, Children = { sut } };
+
+		await UIHelper.Load(root, CT);
+
+		isLoaded.Should().BeFalse("The FeedView should not have subscribed to the source while it is not visible.");
+
+		root.Visibility = Visibility.Visible;
+
+		await UIHelper.WaitFor(() => isLoaded, CT);
+
+		isLoaded.Should().BeTrue("The FeedView should have subscribed to the source when it became visible.");
+	}
+
+
 	[TestMethod]
 	public async Task When_GetSource_Then_ContextContainsDispatcher()
 	{

src/Uno.Extensions.Reactive.UI/View/FeedView.cs

@@ -200,9 +200,18 @@ public FeedViewRefreshState RefreshingState
 	} 
 	#endregion
 
-	private bool _isReady;
+	private ControlState _state;
 	private Subscription? _subscription;
 
+	[Flags]
+	private enum ControlState
+	{
+		IsLoaded = 1 << 0,
+		HasTemplate = 1 << 1,
+
+		IsReady = IsLoaded | HasTemplate,
+	}
+
 	/// <summary>
 	/// Gets a command which request to refresh the source when executed.
 	/// </summary>
@@ -236,7 +245,7 @@ private static void Enable(object snd, RoutedEventArgs _)
 	{
 		if (snd is FeedView that)
 		{
-			that._isReady = true;
+			that._state |= ControlState.IsLoaded;
 			if (that.Source is ISignal<IMessage> feed)
 			{
 				that.Subscribe(feed);
@@ -248,16 +257,28 @@ private static void Disable(object snd, RoutedEventArgs _)
 	{
 		if (snd is FeedView that)
 		{
-			that._isReady = false;
+			that._state &= ~ControlState.IsLoaded;
 			that._subscription?.Dispose();
 		}
 	}
 
+	/// <inheritdoc />
+	protected override void OnApplyTemplate()
+	{
+		base.OnApplyTemplate();
+
+		_state |= ControlState.HasTemplate;
+		if (Source is ISignal<IMessage> feed)
+		{
+			Subscribe(feed);
+		}
+	}
+
 	private void Subscribe(ISignal<IMessage>? feed)
 	{
-		if (feed is null || !_isReady)
+		if (feed is null || _state is not ControlState.IsReady)
 		{
-			SetIsLoading(!_isReady); // If we set the Source to null while we are already ready, we clear the loading flag.
+			SetIsLoading(_state is not ControlState.IsReady); // If we set the Source to null while we are already ready, we clear the loading flag.
 			_subscription?.Dispose();
 
 			return;

src/Uno.Extensions.RuntimeTests/Uno.Extensions.RuntimeTests.Shared/App.xaml.cs

@@ -45,13 +45,13 @@ protected override void OnLaunched(Microsoft.UI.Xaml.LaunchActivatedEventArgs ar
 		{
 #if NET6_0_OR_GREATER && WINDOWS && !HAS_UNO
 			_window = new Window();
-			_window.Activate();
 #else
 			_window = Microsoft.UI.Xaml.Window.Current;
 #endif
 
 			ForceAssemblyLoading();
 			_window.Content ??= new Uno.UI.RuntimeTests.UnitTestsControl();
+			_window.Activate();
 		}
 
 		/// <summary>

src/Uno.Extensions.RuntimeTests/Uno.Extensions.RuntimeTests.Windows/Properties/launchsettings.json

@@ -0,0 +1,10 @@
+{
+  "profiles": {
+	"RuntimeTests.Windows (Package)": {
+	  "commandName": "MsixPackage"
+	},
+	"RuntimeTests.Windows (Unpackaged)": {
+	  "commandName": "Project"
+	}
+  }
+}

src/Uno.Extensions.RuntimeTests/Uno.Extensions.RuntimeTests.Windows/Uno.Extensions.RuntimeTests.Windows.csproj

@@ -12,6 +12,11 @@
 		<EnableMsixTooling>true</EnableMsixTooling>
 		<ManagePackageVersionsCentrally>false</ManagePackageVersionsCentrally>
 		<DefineConstants>$(DefineConstants);WINDOWS_WINUI;WINUI</DefineConstants>
+
+		<!-- Comment this out if you want to handle distributing the WinAppSdk -->
+		<WindowsAppSDKSelfContained>true</WindowsAppSDKSelfContained>
+		<!-- Uncomment for to package dotnet in addition to WinAppSdk -->
+		<!-- <SelfContained>true</SelfContained>-->
 	</PropertyGroup>
 
 	<ItemGroup>