fix: Check if navigating back is possible to update state

src/Uno.Extensions.Hosting.UI/AppHostingEnvironment.cs

@@ -16,15 +16,14 @@ internal class AppHostingEnvironment : HostingEnvironment, IAppHostEnvironment,
 	public Assembly? HostAssembly { get; init; }
 
 #if __WASM__
-	public async Task UpdateAddressBar(Uri applicationUri)
+	public async Task UpdateAddressBar(Uri applicationUri, bool canGoBack)
 	{
 		CoreApplication.MainView?.DispatcherQueue.TryEnqueue(() =>
 					{
 						var state = 1;
 						if (PlatformHelper.IsWebAssembly)
 						{
-							var currentView = SystemNavigationManager.GetForCurrentView();
-							state = currentView?.AppViewBackButtonVisibility == AppViewBackButtonVisibility.Visible ? 1 : 0;
+							state = canGoBack ? 1 : 0;
 						}
 
 						var href = Imports.GetLocation();

src/Uno.Extensions.Hosting/IHasAddressBar.cs

@@ -12,8 +12,11 @@ public interface IHasAddressBar
 	/// <param name="applicationUri">
 	/// The URI to update the address bar with.
 	/// </param>
+	/// <param name="canGoBack">
+	/// Whether it is possible to navigate back or not.
+	/// </param>
 	/// <returns>
 	/// A task that completes when the address bar has been updated.
 	/// </returns>
-	Task UpdateAddressBar(Uri applicationUri);
+	Task UpdateAddressBar(Uri applicationUri, bool canGoBack);
 }

src/Uno.Extensions.Navigation.UI/BrowserAddressBarService.cs

@@ -72,12 +72,14 @@ private async void RouteChanged(object? sender, RouteChangedEventArgs e)
 				return;
 			}
 
+			var canGoBack = rootRegion.Navigator() is { } navigator && await navigator.CanGoBack();
+
 			var url = new UriBuilder
 			{
 				Query = route.Query(),
 				Path = route.FullPath()?.Replace("+", "/")
 			};
-			await _addressbarHost!.UpdateAddressBar(url.Uri);
+			await _addressbarHost!.UpdateAddressBar(url.Uri, canGoBack);
 		}
 		catch (Exception ex)
 		{

testing/TestHarness/TestHarness.Shared/Ext/Navigation/PageNavigation/PageNavigationOnePage.xaml

@@ -1,75 +1,76 @@
 <Page x:Class="TestHarness.Ext.Navigation.PageNavigation.PageNavigationOnePage"
 	  xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
 	  xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
-	  xmlns:local="using:TestHarness.Ext.Navigation.PageNavigation"
 	  xmlns:d="http://schemas.microsoft.com/expression/blend/2008"
+	  xmlns:local="using:TestHarness.Ext.Navigation.PageNavigation"
 	  xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006"
-	  mc:Ignorable="d"
+	  xmlns:muxc="using:Microsoft.UI.Xaml.Controls"
 	  xmlns:uen="using:Uno.Extensions.Navigation.UI"
 	  xmlns:utu="using:Uno.Toolkit.UI"
-	  xmlns:muxc="using:Microsoft.UI.Xaml.Controls"
-	  Background="{ThemeResource ApplicationPageBackgroundThemeBrush}">
+	  Background="{ThemeResource ApplicationPageBackgroundThemeBrush}"
+	  mc:Ignorable="d">
 
 	<Grid>
 		<Grid.RowDefinitions>
 			<RowDefinition Height="Auto" />
 			<RowDefinition Height="Auto" />
 			<RowDefinition />
 		</Grid.RowDefinitions>
-		<utu:NavigationBar Content="Page Navigation - One"
-						   AutomationProperties.AutomationId="PageNavigationOne" />
-		<StackPanel HorizontalAlignment="Center"
-					VerticalAlignment="Center"
-					Grid.Row="1">
+		<utu:NavigationBar AutomationProperties.AutomationId="PageNavigationOne" Content="Page Navigation - One" />
+		<StackPanel Grid.Row="1"
+					HorizontalAlignment="Center"
+					VerticalAlignment="Center">
 			<TextBlock>
 				<Run Text="Created on UI Thread: " /><Run Text="{Binding CreatedOnUIThread}" />
 			</TextBlock>
-			<Button AutomationProperties.AutomationId="OnePageToTwoPageButton"
-					Content="Two"
-					uen:Navigation.Request="PageNavigationTwo" />
+			<Button uen:Navigation.Request="PageNavigationTwo"
+					AutomationProperties.AutomationId="OnePageToTwoPageButton"
+					Content="Two" />
 			<Button AutomationProperties.AutomationId="OnePageToTwoPageCodebehindButton"
-					Content="Two (Codebehind)"
-					Click="OnePageToTwoPageCodebehindClick" />
+					Click="OnePageToTwoPageCodebehindClick"
+					Content="Two (Codebehind)" />
 			<Button AutomationProperties.AutomationId="OnePageToTwoPageViewModelButton"
-					Content="Two (ViewModel)"
-					Click="{x:Bind ViewModel.GoToTwo}" />
+					Click="{x:Bind ViewModel.GoToTwo}"
+					Content="Two (ViewModel)" />
 			<Button AutomationProperties.AutomationId="RapidSettingsWriteTestButton"
-					Content="Settings Write Test"
-					Click="{x:Bind ViewModel.SettingsWriteTest}" />
+					Click="{x:Bind ViewModel.SettingsWriteTest}"
+					Content="Settings Write Test" />
+			<TextBlock x:Name="TxtUrl" AutomationProperties.AutomationId="OnePageTxtUrlFromBrowser" />
+			<Button AutomationProperties.AutomationId="OnePageGetUrlFromBrowser"
+					Click="GetUrlFromBrowser"
+					Content="Get URL" />
 		</StackPanel>
 		<ScrollViewer Grid.Row="2">
-			<muxc:ItemsRepeater ItemsSource="{Binding Items}"
-								uen:Navigation.Request="PageNavigationTwo">
+			<muxc:ItemsRepeater uen:Navigation.Request="PageNavigationTwo" ItemsSource="{Binding Items}">
 				<muxc:ItemsRepeater.ItemTemplate>
 					<DataTemplate>
 						<!--<UserControl>-->
-							<Grid Height="200"
-								  Background="Red">
-								<Border Background="Pink"
-										VerticalAlignment="Top"
-										HorizontalAlignment="Center">
-									<TextBlock Text="{Binding}" />
-								</Border>
-								<utu:CardContentControl Height="50"
-														Width="200"
-														Style="{StaticResource FilledCardContentControlStyle}"
-														HorizontalAlignment="Stretch"
-														HorizontalContentAlignment="Stretch"
-														VerticalContentAlignment="Stretch">
-									<utu:CardContentControl.ContentTemplate>
-										<DataTemplate>
-											<Border Background="Green"
+						<Grid Height="200" Background="Red">
+							<Border HorizontalAlignment="Center"
+									VerticalAlignment="Top"
+									Background="Pink">
+								<TextBlock Text="{Binding}" />
+							</Border>
+							<utu:CardContentControl Width="200"
 													Height="50"
-													Width="200">
-												<TextBlock Text="Inner card" />
-											</Border>
-										</DataTemplate>
-									</utu:CardContentControl.ContentTemplate>
-								</utu:CardContentControl>
-								<Button VerticalAlignment="Bottom"
-										Content="Go to Three"
-										uen:Navigation.Request="PageNavigationThree" />
-							</Grid>
+													HorizontalAlignment="Stretch"
+													HorizontalContentAlignment="Stretch"
+													VerticalContentAlignment="Stretch"
+													Style="{StaticResource FilledCardContentControlStyle}">
+								<utu:CardContentControl.ContentTemplate>
+									<DataTemplate>
+										<Border Width="200"
+												Height="50"
+												Background="Green">
+											<TextBlock Text="Inner card" />
+										</Border>
+									</DataTemplate>
+								</utu:CardContentControl.ContentTemplate>
+							</utu:CardContentControl>
+							<Button VerticalAlignment="Bottom"
+									uen:Navigation.Request="PageNavigationThree"
+									Content="Go to Three" />
+						</Grid>
 						<!--</UserControl>-->
 					</DataTemplate>
 				</muxc:ItemsRepeater.ItemTemplate>

testing/TestHarness/TestHarness.Shared/Ext/Navigation/PageNavigation/PageNavigationOnePage.xaml.cs

@@ -14,4 +14,22 @@ public async void OnePageToTwoPageCodebehindClick(object sender, RoutedEventArgs
 		await this.Navigator()!.NavigateViewAsync<PageNavigationTwoPage>(this);
 	}
 
+
+	public async void GetUrlFromBrowser(object sender, RoutedEventArgs e)
+	{
+#if __WASM__
+		var url = Imports.GetLocation();
+
+		TxtUrl.Text = url;
+#else
+		TxtUrl.Text = "Not supported";
+#endif
+	}
+}
+#if __WASM__
+internal static partial class Imports
+{
+	[System.Runtime.InteropServices.JavaScript.JSImport("globalThis.Uno.Extensions.Hosting.getLocation")]
+	public static partial string GetLocation();
 }
+#endif

testing/TestHarness/TestHarness.Shared/TestHarness.Shared.shproj

@@ -4,6 +4,9 @@
     <ProjectGuid>6279c845-92f8-4333-ab99-3d213163593c</ProjectGuid>
     <MinimumVisualStudioVersion>14.0</MinimumVisualStudioVersion>
   </PropertyGroup>
+  <PropertyGroup>
+    <AllowUnsafeBlocks>true</AllowUnsafeBlocks>
+  </PropertyGroup>
   <Import Project="$(MSBuildExtensionsPath)\$(MSBuildToolsVersion)\Microsoft.Common.props" Condition="Exists('$(MSBuildExtensionsPath)\$(MSBuildToolsVersion)\Microsoft.Common.props')" />
   <Import Project="$(MSBuildExtensionsPath32)\Microsoft\VisualStudio\v$(VisualStudioVersion)\CodeSharing\Microsoft.CodeSharing.Common.Default.props" />
   <Import Project="$(MSBuildExtensionsPath32)\Microsoft\VisualStudio\v$(VisualStudioVersion)\CodeSharing\Microsoft.CodeSharing.Common.props" />
@@ -37,4 +40,4 @@
     <_Globbled_Page Remove="Ext\Navigation\NavigationView\NavigationViewDataRecipeDetailsPage.xaml" />
     <_Globbled_Page Remove="Ext\Navigation\NavigationView\NavigationViewDataRecipesPage.xaml" />
   </ItemGroup>
-</Project>
+</Project>

testing/TestHarness/TestHarness.UITest/Ext/Navigation/PageNavigation/Given_PageNavigation.cs

@@ -176,4 +176,27 @@ private void OnePageToFivePage()
 		App.WaitThenTap("FourPageToFivePageButton");
 
 	}
+
+	[Test]
+	[ActivePlatforms(Platform.Browser)]
+	public void When_PageNavigationNavigateRootUpdateUrl()
+	{
+		InitTestSection(TestSections.Navigation_PageNavigation);
+
+		App.WaitThenTap("ShowOnePageButton");
+
+		App.WaitThenTap("OnePageGetUrlFromBrowser");
+		App.WaitElement("OnePageTxtUrlFromBrowser");
+		var urlBefore = App.GetText("OnePageTxtUrlFromBrowser");
+
+		App.WaitThenTap("OnePageToTwoPageButton");
+
+		App.WaitThenTap("TwoPageBackButton");
+
+		App.WaitThenTap("OnePageGetUrlFromBrowser");
+		App.WaitElement("OnePageTxtUrlFromBrowser");
+		var urlAfter = App.GetText("OnePageTxtUrlFromBrowser");
+
+		Assert.AreEqual(urlBefore, urlAfter);
+	}
 }