Merge pull request #2354 from PrismLibrary/di-navservice-fix

Fixing DI NavigationService resolution

e2e/Forms/src/HelloWorld.Android/HelloWorld.Android.csproj

@@ -105,4 +105,9 @@
     </ProjectReference>
   </ItemGroup>
   <Import Project="$(MSBuildExtensionsPath)\Xamarin\Android\Xamarin.Android.CSharp.targets" />
+  <ProjectExtensions>
+    <VisualStudio>
+      <UserProperties TriggeredFromHotReload="False" />
+    </VisualStudio>
+  </ProjectExtensions>
 </Project>

e2e/Forms/src/HelloWorld/App.xaml.cs

@@ -62,7 +62,7 @@ protected override void OnInitialized()
         {
             InitializeComponent();
 
-            NavigationService.NavigateAsync($"MyMasterDetail/MyTabbedPage").OnNavigationError(OnNavigationError);
+            NavigationService.NavigateAsync($"MyTabbedPage").OnNavigationError(OnNavigationError);
         }
 
         private void OnNavigationError(Exception ex)

e2e/Forms/src/ModuleA/ViewModels/ViewAViewModel.cs

@@ -79,7 +79,8 @@ private void Save()
         async void Navigate()
         {
             CanNavigate = false;
-            await _navigationService.SelectTabAsync("ViewC");
+            //await _navigationService.SelectTabAsync("ViewC");
+            await _navigationService.NavigateAsync("ViewC");
             CanNavigate = true;
         }
 

src/Forms/Prism.Forms/Navigation/Xaml/Navigation.cs

@@ -95,15 +95,7 @@ public static INavigationService GetNavigationService(Page page)
                 if (!currentScope.IsAttached)
                     page.SetValue(NavigationScopeProperty, currentScope);
 
-                currentScope.IsAttached = true;
-
-                navService = currentScope.Resolve<INavigationService>();
-                if (navService is IPageAware pa)
-                {
-                    pa.Page = page;
-                }
-
-                page.SetValue(NavigationServiceProperty, navService);
+                navService = CreateNavigationService(currentScope, page);
             }
             else if(navService is IPageAware pa && pa.Page != page)
             {
@@ -116,6 +108,25 @@ public static INavigationService GetNavigationService(Page page)
             return navService;
         }
 
+        private static INavigationService CreateNavigationService(IScopedProvider scope, Page page)
+        {
+            var navService = scope.Resolve<INavigationService>();
+            switch(navService)
+            {
+                case IPageAware pa when pa.Page is null:
+                    pa.Page = page;
+                    break;
+                case IPageAware pa1 when pa1.Page != page:
+                    return CreateNavigationService(ContainerLocator.Container.CreateScope(), page);
+            }
+
+            page.SetValue(NavigationScopeProperty, scope);
+            scope.IsAttached = true;
+            page.SetValue(NavigationServiceProperty, navService);
+
+            return navService;
+        }
+
         internal static Action GetRaiseCanExecuteChangedInternal(BindableObject view) => (Action)view.GetValue(RaiseCanExecuteChangedInternalProperty);
 
         internal static void SetRaiseCanExecuteChangedInternal(BindableObject view, Action value) => view.SetValue(RaiseCanExecuteChangedInternalProperty, value);

tests/Forms/Prism.DI.Forms.Tests/Fixtures/Navigation/NavigationServiceFixture.cs

@@ -0,0 +1,177 @@
+using Prism.Common;
+using Prism.DI.Forms.Tests.Mocks.ViewModels;
+using Prism.DI.Forms.Tests.Mocks.Views;
+using Xamarin.Forms;
+using Xunit;
+using Xunit.Abstractions;
+
+namespace Prism.DI.Forms.Tests.Fixtures.Navigation
+{
+    public class NavigationServiceFixture : FixtureBase
+    {
+        public NavigationServiceFixture(ITestOutputHelper testOutputHelper)
+            : base(testOutputHelper)
+        {
+        }
+
+        [Fact]
+        public void ContentPage_GetsCorrectNavService()
+        {
+            var app = CreateMockApplication();
+            app.NavigationService.NavigateAsync("XamlViewMockA");
+
+            var mainPage = app.MainPage;
+            var vm = mainPage.BindingContext as XamlViewMockAViewModel;
+
+            Assert.IsType<XamlViewMockA>(mainPage);
+            Assert.NotNull(vm);
+
+            var page = ((IPageAware)vm.NavigationService).Page;
+            Assert.IsType<XamlViewMockA>(mainPage);
+            Assert.Same(mainPage, page);
+        }
+
+        [Fact]
+        public void ContentPage_InNavigationPage_GetsCorrectNavService()
+        {
+            var app = CreateMockApplication();
+            app.NavigationService.NavigateAsync("NavigationPage/XamlViewMockA");
+
+            var mainPage = app.MainPage;
+            Assert.IsType<NavigationPage>(mainPage);
+
+            var view = mainPage.Navigation.NavigationStack[0] as XamlViewMockA;
+            Assert.NotNull(view);
+
+            var vm = view.BindingContext as XamlViewMockAViewModel;
+            Assert.NotNull(vm);
+
+            var page = ((IPageAware)vm.NavigationService).Page;
+            Assert.IsType<XamlViewMockA>(page);
+            Assert.Same(view, page);
+        }
+
+        [Fact]
+        public void TabbedPage_GetsCorrectNavService()
+        {
+            var app = CreateMockApplication();
+            app.NavigationService.NavigateAsync("XamlTabbedViewMock");
+
+            var tp = app.MainPage as TabbedPage;
+            Assert.NotNull(tp);
+
+            var tpVm = tp.BindingContext as XamlTabbedViewMockViewModel;
+            Assert.NotNull(tpVm);
+
+            var page = ((IPageAware)tpVm.NavigationService).Page;
+            Assert.IsType<XamlTabbedViewMock>(page);
+            Assert.Same(tp, page);
+        }
+
+        [Fact]
+        public void TabbedPage_ContentPage_NestedNavigationPage_GetsCorrectNavService()
+        {
+            var app = CreateMockApplication();
+            app.NavigationService.NavigateAsync("XamlTabbedViewMock");
+
+            var tp = app.MainPage as TabbedPage;
+            Assert.NotNull(tp);
+
+            var tab = tp.Children[0];
+            Assert.NotNull(tab);
+
+            var navPage = tab as NavigationPage;
+            Assert.NotNull(navPage);
+
+            var view = navPage.CurrentPage;
+            Assert.NotNull(view);
+
+            var vm = view.BindingContext as XamlViewMockAViewModel;
+            Assert.NotNull(vm);
+
+            var page = ((IPageAware)vm.NavigationService).Page;
+            Assert.IsType<XamlViewMockA>(page);
+            Assert.Same(view, page);
+        }
+
+        [Fact]
+        public void TabbedPage_ContentPage_GetsCorrectNavService()
+        {
+            var app = CreateMockApplication();
+            app.NavigationService.NavigateAsync("XamlTabbedViewMock");
+
+            var tp = app.MainPage as TabbedPage;
+            Assert.NotNull(tp);
+
+            var view = tp.Children[1];
+            Assert.NotNull(view);
+
+            var vm = view.BindingContext as XamlViewMockAViewModel;
+            Assert.NotNull(vm);
+
+            var page = ((IPageAware)vm.NavigationService).Page;
+            Assert.IsType<XamlViewMockA>(page);
+            Assert.Same(view, page);
+        }
+
+        [Fact]
+        public void TabbedPage_InNavigationPage_GetsCorrectNavService()
+        {
+            var app = CreateMockApplication();
+            app.NavigationService.NavigateAsync("NavigationPage/XamlTabbedViewMock");
+
+            var mainPage = app.MainPage;
+            Assert.IsType<NavigationPage>(mainPage);
+
+            var tp = mainPage.Navigation.NavigationStack[0] as TabbedPage;
+            Assert.NotNull(tp);
+
+            var tpVm = tp.BindingContext as XamlTabbedViewMockViewModel;
+            Assert.NotNull(tpVm);
+
+            var page = ((IPageAware)tpVm.NavigationService).Page;
+            Assert.IsType<XamlTabbedViewMock>(page);
+            Assert.Same(tp, page);
+        }
+
+        [Fact]
+        public void MasterDetail_GetsCorrectNavService()
+        {
+            var app = CreateMockApplication();
+            app.NavigationService.NavigateAsync("XamlMasterDetailViewMock");
+
+            var mainPage = app.MainPage;
+            Assert.IsType<XamlMasterDetailViewMock>(mainPage);
+
+            var vm = mainPage.BindingContext as XamlMasterDetailViewMockViewModel;
+            Assert.NotNull(vm);
+
+            var page = ((IPageAware)vm.NavigationService).Page;
+            Assert.IsType<XamlMasterDetailViewMock>(page);
+            Assert.Same(mainPage, page);
+        }
+
+        [Fact]
+        public void MasterDetail_Detail_GetsCorrectNavService()
+        {
+            var app = CreateMockApplication();
+            app.NavigationService.NavigateAsync("XamlMasterDetailViewMock");
+
+            var mainPage = app.MainPage as XamlMasterDetailViewMock;
+            Assert.NotNull(mainPage);
+
+            var detail = mainPage.Detail as NavigationPage;
+            Assert.NotNull(detail);
+
+            var view = detail.CurrentPage as XamlViewMockA;
+            Assert.NotNull(view);
+
+            var vm = view.BindingContext as XamlViewMockAViewModel;
+            Assert.NotNull(vm);
+
+            var page = ((IPageAware)vm.NavigationService).Page;
+            Assert.IsType<XamlViewMockA>(page);
+            Assert.Same(view, page);
+        }
+    }
+}

tests/Forms/Prism.DI.Forms.Tests/Mocks/PrismApplicationMock.cs

@@ -57,6 +57,8 @@ protected override void RegisterTypes(IContainerRegistry containerRegistry)
             containerRegistry.RegisterForNavigation<XamlViewMock>();
             containerRegistry.RegisterForNavigation<XamlViewMockB, XamlViewMockBViewModel>();
             containerRegistry.RegisterForNavigation<XamlViewMockA, XamlViewMockAViewModel>();
+            containerRegistry.RegisterForNavigation<XamlTabbedViewMock, XamlTabbedViewMockViewModel>();
+            containerRegistry.RegisterForNavigation<XamlMasterDetailViewMock, XamlMasterDetailViewMockViewModel>();
 
             ViewModelLocationProvider.Register<PartialView, PartialViewModel>();
         }

tests/Forms/Prism.DI.Forms.Tests/Mocks/ViewModels/XamlMasterDetailViewMockViewModel.cs

@@ -0,0 +1,14 @@
+using Prism.Navigation;
+
+namespace Prism.DI.Forms.Tests.Mocks.ViewModels
+{
+    public class XamlMasterDetailViewMockViewModel
+    {
+        public INavigationService NavigationService { get; }
+
+        public XamlMasterDetailViewMockViewModel(INavigationService navigationService)
+        {
+            NavigationService = navigationService;
+        }        
+    }
+}

tests/Forms/Prism.DI.Forms.Tests/Mocks/ViewModels/XamlTabbedViewMockViewModel.cs

@@ -0,0 +1,15 @@
+using Prism.Mvvm;
+using Prism.Navigation;
+
+namespace Prism.DI.Forms.Tests.Mocks.ViewModels
+{
+    public class XamlTabbedViewMockViewModel : BindableBase
+    {
+        public INavigationService NavigationService { get; }
+
+        public XamlTabbedViewMockViewModel(INavigationService navigationService)
+        {
+            NavigationService = navigationService;
+        }
+    }
+}

tests/Forms/Prism.DI.Forms.Tests/Mocks/ViewModels/XamlViewMockAViewModel.cs

@@ -20,6 +20,13 @@ public string Test
             set => SetProperty(ref _test, value);
         }
 
+        public INavigationService NavigationService { get; set; }
+
+        public XamlViewMockAViewModel(INavigationService navigationService)
+        {
+            NavigationService = navigationService;
+        }
+
         public void OnNavigatedFrom(INavigationParameters parameters)
         {
         }

tests/Forms/Prism.DI.Forms.Tests/Mocks/Views/XamlMasterDetailViewMock.xaml

@@ -0,0 +1,23 @@
+<?xml version="1.0" encoding="utf-8" ?>
+<MasterDetailPage xmlns="http://xamarin.com/schemas/2014/forms"
+                  xmlns:x="http://schemas.microsoft.com/winfx/2009/xaml"
+                  xmlns:prism="http://prismlibrary.com"
+                  xmlns:local="clr-namespace:Prism.DI.Forms.Tests.Mocks.Views"
+                  prism:ViewModelLocator.AutowireViewModel="True"
+                  x:Class="Prism.DI.Forms.Tests.Mocks.Views.XamlMasterDetailViewMock">
+
+  <MasterDetailPage.Master>
+    <ContentPage Title="Master">
+
+    </ContentPage>
+  </MasterDetailPage.Master>
+
+  <MasterDetailPage.Detail>
+    <NavigationPage>
+      <x:Arguments>
+        <local:XamlViewMockA Title="View A" />
+      </x:Arguments>
+    </NavigationPage>
+  </MasterDetailPage.Detail>
+
+</MasterDetailPage>

tests/Forms/Prism.DI.Forms.Tests/Mocks/Views/XamlMasterDetailViewMock.xaml.cs

@@ -0,0 +1,12 @@
+using Xamarin.Forms;
+
+namespace Prism.DI.Forms.Tests.Mocks.Views
+{
+    public partial class XamlMasterDetailViewMock : MasterDetailPage
+    {
+        public XamlMasterDetailViewMock()
+        {
+            InitializeComponent();
+        }
+    }
+}

tests/Forms/Prism.DI.Forms.Tests/Mocks/Views/XamlTabbedViewMock.xaml

@@ -0,0 +1,17 @@
+<?xml version="1.0" encoding="utf-8" ?>
+<TabbedPage xmlns="http://xamarin.com/schemas/2014/forms"
+            xmlns:x="http://schemas.microsoft.com/winfx/2009/xaml"
+            xmlns:prism="http://prismlibrary.com"
+            xmlns:local="clr-namespace:Prism.DI.Forms.Tests.Mocks.Views"
+            prism:ViewModelLocator.AutowireViewModel="True"
+            x:Class="Prism.DI.Forms.Tests.Mocks.Views.XamlTabbedViewMock">
+
+  <NavigationPage Title="View A">
+    <x:Arguments>
+      <local:XamlViewMockA Title="View A" />
+    </x:Arguments>
+  </NavigationPage>
+
+  <local:XamlViewMockA Title="View B" />
+
+</TabbedPage>

tests/Forms/Prism.DI.Forms.Tests/Mocks/Views/XamlTabbedViewMock.xaml.cs

@@ -0,0 +1,12 @@
+using Xamarin.Forms;
+
+namespace Prism.DI.Forms.Tests.Mocks.Views
+{
+    public partial class XamlTabbedViewMock : TabbedPage
+    {
+        public XamlTabbedViewMock()
+        {
+            InitializeComponent();
+        }
+    }
+}

tests/Forms/Prism.DI.Forms.Tests/Mocks/Views/XamlViewMockA.xaml

@@ -1,15 +1,16 @@
 <?xml version="1.0" encoding="UTF-8" ?>
-<ContentPage
+<ContentPage x:Class="Prism.DI.Forms.Tests.Mocks.Views.XamlViewMockA"
     xmlns="http://xamarin.com/schemas/2014/forms"
     xmlns:x="http://schemas.microsoft.com/winfx/2009/xaml"
     xmlns:xaml="clr-namespace:Prism.Navigation.Xaml;assembly=Prism.Forms"
-    Title="{Binding Title}"
-    x:Class="Prism.DI.Forms.Tests.Mocks.Views.XamlViewMockA">
+    xmlns:prism="http://prismlibrary.com"
+    prism:ViewModelLocator.AutowireViewModel="True"
+    Title="{Binding Title}" >
 <Button x:Name="testButton"  Command="{xaml:NavigateTo 'XamlViewMockB'}">
     <Button.CommandParameter>
         <xaml:NavigationParameters>
             <xaml:NavigationParameter Key="Foo" Value="Bar"/>
         </xaml:NavigationParameters>
     </Button.CommandParameter>
 </Button>
-</ContentPage>
+</ContentPage>