Added simple messenger configuration for generic view models #28

src/BuildingBlocks/BuildingBlocks.Application/ViewModels/GenericViewModel.cs

@@ -0,0 +1,26 @@
+using BuildingBlocks.Application.ViewModels.Messages;
+using CommunityToolkit.Mvvm.ComponentModel;
+using CommunityToolkit.Mvvm.Input;
+using CommunityToolkit.Mvvm.Messaging;
+
+namespace BuildingBlocks.Application.ViewModels;
+
+public partial class GenericItemViewModel<TModel> : ObservableObject
+    where TModel : ObservableObject, new()
+{
+    private readonly IMessenger _messenger;
+
+    [ObservableProperty]
+    private TModel item = new();
+
+    public GenericItemViewModel(IMessenger messenger)
+    {
+        _messenger = messenger;
+    }
+
+    [RelayCommand]
+    protected virtual void Save()
+    {
+        _messenger.Send(new NewGenericItemCreatedMessage<TModel>(item));
+    }
+}

src/Inventory.Application/ViewModels/Product/ProductViewModel.cs

@@ -1,19 +1,18 @@
-using CommunityToolkit.Mvvm.ComponentModel;
+using BuildingBlocks.Application.ViewModels;
+using CommunityToolkit.Mvvm.Messaging;
 using Inventory.Application.DomainOperations.Product.GetProductById;
 using Inventory.Application.Models;
 using Inventory.Application.Services.Navigation;
 using MediatR;
 
 namespace Inventory.Application.ViewModels.Product;
 
-public sealed partial class ProductViewModel : ObservableObject, INavigationAware
+public sealed partial class ProductViewModel : GenericItemViewModel<ProductModel>, INavigationAware
 {
     private readonly IMediator _mediator;
 
-    [ObservableProperty]
-    private ProductModel? product;
-
-    public ProductViewModel(IMediator mediator)
+    public ProductViewModel(IMediator mediator, IMessenger messenger)
+        : base(messenger)
     {
         _mediator = mediator;
     }
@@ -29,6 +28,7 @@ public async void OnNavigatedTo(object parameter)
             return;
         }
 
-        Product = await _mediator.Send(new GetProductByIdQuery(productId));
+        var product = await _mediator.Send(new GetProductByIdQuery(productId));
+        Item = product ?? new ProductModel() { Name = "Product name" };
     }
 }

src/Inventory.Application/ViewModels/Products/ProductsViewModel.cs

@@ -1,6 +1,5 @@
-using System.Collections.ObjectModel;
+using System.Threading.Tasks;
 using BuildingBlocks.Application.ViewModels;
-using CommunityToolkit.Mvvm.ComponentModel;
 using CommunityToolkit.Mvvm.Input;
 using Inventory.Application.DomainOperations.Product.GetProducts;
 using Inventory.Application.Models;
@@ -19,6 +18,7 @@ public ProductsViewModel(IMediator mediator, INavigationService navigationServic
     {
         _mediator = mediator;
         _navigationService = navigationService;
+        IsActive = true;
     }
 
     protected override void OnCreateNewItem()
@@ -27,7 +27,7 @@ protected override void OnCreateNewItem()
     }
 
     [RelayCommand]
-    private async void Loaded()
+    private async Task Loaded()
     {
         await foreach (var item in _mediator.CreateStream(new GetProductsStreamQuery()))
         {

src/Inventory.Infrastructure/AutofacModules/NavigationModule.cs

@@ -43,7 +43,7 @@ protected override void Load(ContainerBuilder builder)
         builder.RegisterType<ContentGridViewModel>().InstancePerDependency();
         builder.RegisterType<ListDetailsViewModel>().InstancePerDependency();
         builder.RegisterType<WebViewViewModel>().InstancePerDependency();
-        builder.RegisterType<ProductsViewModel>().InstancePerDependency();
+        builder.RegisterType<ProductsViewModel>().SingleInstance();
         builder.RegisterType<ProductViewModel>().InstancePerDependency();
     }
 }

src/Inventory.Infrastructure/AutofacModules/ServicesModule.cs

@@ -1,4 +1,5 @@
 using Autofac;
+using CommunityToolkit.Mvvm.Messaging;
 using CommunityToolkit.WinUI.Helpers;
 using Inventory.Application.Services.SampleData;
 using Inventory.Application.Services.ThemeSelector;
@@ -20,5 +21,6 @@ protected override void Load(ContainerBuilder builder)
 
         builder.RegisterType<SampleDataService>().As<ISampleDataService>().SingleInstance();
         builder.RegisterType<ThemeSelectorService>().As<IThemeSelectorService>().SingleInstance();
+        builder.RegisterInstance<IMessenger>(WeakReferenceMessenger.Default).SingleInstance();
     }
 }

src/Inventory.Presentation/Views/Product/ProductView.xaml

@@ -11,6 +11,9 @@
     <Grid x:Name="ContentArea">
         <ScrollViewer IsTabStop="True">
             <StackPanel x:Name="contentPanel">
+
+                <Button Content="Save" Command="{x:Bind ViewModel.SaveCommand}"/>
+
                 <RelativePanel>
                     <Grid
                         x:Name="itemHero"
@@ -26,7 +29,7 @@
                         <Image
                             HorizontalAlignment="Center"
                             VerticalAlignment="Center"
-                            Source="{x:Bind ViewModel.Product.ImageSource, Mode=OneWay}" />
+                            Source="{x:Bind ViewModel.Item.ImageSource, Mode=OneWay}" />
                     </Grid>
 
                     <TextBlock
@@ -35,11 +38,11 @@
                         RelativePanel.AlignTopWithPanel="True"
                         RelativePanel.RightOf="itemHero"
                         Style="{ThemeResource TitleTextBlockStyle}"
-                        Text="{x:Bind ViewModel.Product.Category, Mode=OneWay}" />
+                        Text="{x:Bind ViewModel.Item.Category, Mode=OneWay}" />
 
                     <StackPanel x:Name="propertiesGroup1" RelativePanel.Below="itemHero">
 
-                        <TextBlock Text="{x:Bind ViewModel.Product.Name}" />
+                        <TextBlock Text="{x:Bind ViewModel.Item.Name}" />
 
                         <StackPanel x:Name="statusGroup" Margin="{StaticResource SmallTopMargin}">
                             <TextBlock Style="{ThemeResource SubtitleTextBlockStyle}" Text="Status" />

src/Inventory.Presentation/Views/Products/ProductsView.xaml

@@ -26,7 +26,7 @@
         animations:Connected.ListItemKey="animationKeyContentGrid"
         IsItemClickEnabled="True"
         ItemClickCommand="{x:Bind ViewModel.ItemClickedCommand}"
-        ItemsSource="{x:Bind ViewModel.Products, Mode=OneWay}"
+        ItemsSource="{x:Bind ViewModel.Items, Mode=OneWay}"
         SelectionMode="None"
         StretchContentForSingleRow="False">