feature(#86): Add Blazor Component Rendering Service

docs/Email/README.md

@@ -2,8 +2,14 @@
 
 - [Email](#email)
   - [Setup](#setup)
-  - [Create and send an email](#create-and-send-an-email)
-  - [View locations](#view-locations)
+  - [Razor Views (MVC)](#razor-views-mvc) 
+    - [Create and send an email](#create-and-send-an-email)
+    - [View locations](#view-locations)
+    - [Set a Subject](#set-a-subject)
+  - [Razor Components (Blazor)](#razor-components-blazor) 
+    - [Create and send an email](#create-and-send-an-email-1)
+    - [Component locations](#component-locations)
+    - [Set a Subject](#set-a-subject-1)
   - [Attachments](#attachments)
   - [Headers](#headers)
 
@@ -16,7 +22,9 @@ The settings contain sender Email and name, SMTP settings, Debug settings and CS
 container.RegisterEmail(options => Configuration.GetSection("Email").Bind(options));
 ```
 
-## Create and send an email
+## Razor Views (MVC)
+
+### Create and send an email
 
 To add new emails, following steps need to be done:
 
@@ -28,7 +36,7 @@ To add new emails, following steps need to be done:
 
 To check the visuals of the view file, use the [Swagger API](./api.md) to access the methods of the `EmailController`.
 
-## View locations
+### View locations
 
 The views that are used for the emails are configured on the `EmailViewAttribute`. To find the view, the Razor view engine looks in the folder `Views` by default. A view path of `Emails/FancyEmail` matches to `Views/Emails/FancyEmail.cshtml`.
 
@@ -38,6 +46,30 @@ If you want to place the Views in other folders, for example `/Emails`, you can
 services.Configure<RazorViewEngineOptions>(options => options.ViewLocationFormats.Add("/Emails/{0}" + RazorViewEngine.ViewExtension));
 ```
 
+### Set a Subject
+Per default the SubjectKey is "Subject" and it is being tried to resolve from the corresponding resource file. If you want to use a different key, you can set it in the `EmailViewAttribute` like this: `[EmailView("Emails/Registration", SubjectKey = "RegistrationSubject")]`. If no value could be found it will fallback to the the SubjectKey.
+
+## Razor Components (Blazor)
+
+### Create and send an email
+
+To add new emails, following steps need to be done:
+
+1) Add a new Component (`.razor`) in the directory `Components/Emails/`.
+2) Add a new ComponentModel in the same namespace as the business logic that needs to send the mail.
+3) Implement the `IComponentModel<T>` interface in the ComponentModel, where `T` is the type of the Component.
+4) Extend the `EmailController` with a new method to render the razor file and return the contents.
+5) To send the mail in the business logic use the MediatR-command `SendEmail` and supply it with the view model. SendEmail renders the mail based on the component model and the `IComponentModel<T>`.
+
+To check the visuals of the view file, use the [Swagger API](./api.md) to access the methods of the `EmailController`.
+
+### Component locations
+
+In contrast to the classic Razor Views, the Razor Components can be placed in any folder, even in a different assembly, as long as you can reference it in the `IComponentModel<T>`.
+
+### Set a Subject
+Per default the SubjectKey is "Subject" and it is being tried to resolve from the corresponding resource file. If you want to use a different key, you can optionally implement the `IProvideEmailSubject` interface like this `string IProvideEmailSubject.SubjectKey => "RegistrationSubject";`. If no value could be found it will fallback to the the SubjectKey.
+
 ## Attachments
 
 By default, only attachments in file://-Uris are supported. To allow adding attachments from other sources (eg. AWS S3), implement `IEmailAttachmentResolver` and register it SimpleInjector with

src/AspNetCore/src/Blazor/BlazorRenderingService.cs

@@ -0,0 +1,50 @@
+// Copyright (c) Fusonic GmbH. All rights reserved.
+// Licensed under the MIT License. See LICENSE file in the project root for license information.
+
+using System.Globalization;
+using System.Reflection;
+using Microsoft.AspNetCore.Components;
+using Microsoft.AspNetCore.Components.Web;
+
+namespace Fusonic.Extensions.AspNetCore.Blazor;
+
+public class BlazorRenderingService(HtmlRenderer htmlRenderer) : IBlazorRenderingService
+{
+    public async Task<string> RenderComponent(IComponentModel model, CultureInfo culture)
+    {
+        var modelType = model.GetType();
+        var componentType = model.ComponentType;
+
+        var modelProperty = componentType.GetProperties(BindingFlags.Public | BindingFlags.Instance)
+                                         .FirstOrDefault(p => p.PropertyType == modelType)
+            ?? throw new ArgumentNullException($"The Component {componentType.Name} is missing a property of type {modelType.Name}.");
+
+        return await RenderComponent(componentType, culture, new() { [modelProperty.Name] = model }, beforeRender: null);
+    }
+
+    public Task<string> RenderComponent<T>(CultureInfo culture, Dictionary<string, object?>? dictionary = null) where T : IComponent
+        => RenderComponentBase(typeof(T), culture, dictionary is null ? ParameterView.Empty : ParameterView.FromDictionary(dictionary), beforeRender: null);
+
+    public Task<string> RenderComponent(Type componentType, CultureInfo culture, Dictionary<string, object?>? dictionary = null, Action? beforeRender = null)
+        => RenderComponentBase(componentType, culture, dictionary is null ? ParameterView.Empty : ParameterView.FromDictionary(dictionary), beforeRender);
+
+    private async Task<string> RenderComponentBase(Type componentType, CultureInfo culture, ParameterView parameters, Action? beforeRender)
+        => await htmlRenderer.Dispatcher.InvokeAsync(async () =>
+        {
+            var currentCulture = (CultureInfo.CurrentCulture, CultureInfo.CurrentUICulture);
+            try
+            {
+                // The razor renderer takes the culture from the current thread culture.
+                CultureInfo.CurrentCulture = CultureInfo.CurrentUICulture = culture;
+
+                beforeRender?.Invoke();
+
+                var output = await htmlRenderer.RenderComponentAsync(componentType, parameters);
+                return output.ToHtmlString();
+            }
+            finally
+            {
+                (CultureInfo.CurrentCulture, CultureInfo.CurrentUICulture) = currentCulture;
+            }
+        });
+}

src/AspNetCore/src/Blazor/IBlazorRenderingService.cs

@@ -0,0 +1,14 @@
+// Copyright (c) Fusonic GmbH. All rights reserved.
+// Licensed under the MIT License. See LICENSE file in the project root for license information.
+
+using System.Globalization;
+using Microsoft.AspNetCore.Components;
+
+namespace Fusonic.Extensions.AspNetCore.Blazor;
+
+public interface IBlazorRenderingService
+{
+    Task<string> RenderComponent(IComponentModel model, CultureInfo culture);
+    Task<string> RenderComponent<T>(CultureInfo culture, Dictionary<string, object?>? dictionary = null) where T : IComponent;
+    Task<string> RenderComponent(Type componentType, CultureInfo culture, Dictionary<string, object?>? dictionary = null, Action? beforeRender = null);
+}

src/AspNetCore/src/Blazor/IComponentModel.cs

@@ -0,0 +1,11 @@
+using Microsoft.AspNetCore.Components;
+
+public interface IComponentModel<T> : IComponentModel where T : IComponent
+{
+    Type IComponentModel.ComponentType => typeof(T);
+}
+
+public interface IComponentModel
+{
+    Type ComponentType { get; }
+}

src/AspNetCore/src/Razor/RazorViewModelAttribute.cs

@@ -6,7 +6,6 @@ namespace Fusonic.Extensions.AspNetCore.Razor;
 [AttributeUsage(AttributeTargets.Class, Inherited = false)]
 public sealed class RazorViewModelAttribute(string viewPath) : Attribute
 {
-
     /// <summary>
     /// Path to the view within the razor search paths.
     /// Example: A value of "Feature/FancyPage" usually finds the View "Views/Feature/FancyPage.cshtml"

src/AspNetCore/test/Blazor/BlazorRenderingServiceTests.cs

@@ -0,0 +1,69 @@
+// Copyright (c) Fusonic GmbH. All rights reserved.
+// Licensed under the MIT License. See LICENSE file in the project root for license information.
+
+using System.Globalization;
+using System.Text.RegularExpressions;
+using System.Web;
+using FluentAssertions;
+using Fusonic.Extensions.AspNetCore.Blazor;
+using Xunit;
+
+namespace Fusonic.Extensions.AspNetCore.Tests.Blazor;
+
+public partial class BlazorRenderingServiceTests : TestBase
+{
+    private readonly BlazorRenderingService blazorRenderingService;
+
+    public BlazorRenderingServiceTests(TestFixture fixture) : base(fixture)
+    {
+        blazorRenderingService = GetInstance<BlazorRenderingService>();
+    }
+
+    [Fact]
+    public async Task Succeeds()
+    {
+        // Arrange
+        var component = new TestComponent.ComponentModel("Hello World!");
+
+        // Act
+        var html = await blazorRenderingService.RenderComponent(component, CultureInfo.CurrentCulture);
+
+        // Assert
+        html.Should().Be("<body>Hello World!</body>");
+    }
+
+    [Theory]
+    [InlineData("de-CH")]
+    [InlineData("de-AT")]
+    [InlineData("fr-CH")]
+    [InlineData("it-CH")]
+    [InlineData("en-CH")]
+    public async Task Rendering_RespectsCulture(string cultureName)
+    {
+        // Arrange
+        var cultureInfo = new CultureInfo(cultureName);
+
+        var viewModel = new TestCultureComponent.ComponentModel(new(2019, 1, 9), 12345678.89);
+
+        var expectedDate = AsString($"{viewModel.Date:d}");
+        var expectedMonth = AsString($"{viewModel.Date:MMMM}");
+        var expectedNumber = AsString($"{viewModel.Number:n}");
+
+        // Act
+        var body = await blazorRenderingService.RenderComponent(viewModel, cultureInfo);
+
+        // Assert
+        var regex = GetHtmlParagraphContentsRegex();
+        var matches = regex.Matches(body);
+
+        Match(0).Should().Be(expectedDate);
+        Match(1).Should().Be(expectedMonth);
+        Match(2).Should().Be(expectedNumber);
+
+        string Match(int idx) => HttpUtility.HtmlDecode(matches[idx].Groups[1].Value);
+        string AsString(IFormattable f) => f.ToString(null, cultureInfo);
+    }
+
+    [GeneratedRegex("<p>(.*?)<\\/p>")]
+    private static partial Regex GetHtmlParagraphContentsRegex();
+}

src/AspNetCore/test/Blazor/TestComponent.razor

@@ -0,0 +1,10 @@
+@using Fusonic.Extensions.AspNetCore.Razor
+
+<body>@Model.Name</body>
+
+@code {
+    [Parameter]
+    public required ComponentModel Model { get; init; }
+
+    public record ComponentModel(string Name) : IComponentModel<TestComponent>;
+}

src/AspNetCore/test/Blazor/TestCultureComponent.razor

@@ -0,0 +1,19 @@
+@using Fusonic.Extensions.AspNetCore.Razor
+
+<html>
+<head>
+    <meta charset="UTF-8" />
+</head>
+<body>
+    <p>@($"{Model.Date:d}")</p>
+    <p>@($"{Model.Date:MMMM}")</p>
+    <p>@($"{Model.Number:N}")</p>
+</body>
+</html>
+
+@code {
+    [Parameter]
+    public required ComponentModel Model { get; init; }
+
+    public record ComponentModel(DateTime Date, double Number) : IComponentModel<TestCultureComponent>;
+}

src/AspNetCore/test/TestFixture.cs

@@ -3,11 +3,14 @@
 
 using System.Diagnostics;
 using System.Reflection;
+using Fusonic.Extensions.AspNetCore.Blazor;
 using Fusonic.Extensions.AspNetCore.Razor;
 using Fusonic.Extensions.UnitTests.SimpleInjector;
+using Microsoft.AspNetCore.Components.Web;
 using Microsoft.AspNetCore.Hosting;
 using Microsoft.AspNetCore.Mvc.ApplicationParts;
 using Microsoft.AspNetCore.Mvc.Localization;
+using Microsoft.Extensions.Configuration;
 using Microsoft.Extensions.DependencyInjection;
 using SimpleInjector;
 
@@ -20,13 +23,19 @@ protected sealed override void RegisterCoreDependencies(Container container)
         base.RegisterCoreDependencies(container);
 
         container.Register<RazorViewRenderingService>();
+        container.Register<BlazorRenderingService>();
 
         var services = new ServiceCollection();
+
+        services.AddRazorComponents();
         services.AddRazorPages()
                 .ConfigureApplicationPartManager(apm => apm.ApplicationParts.Add(new CompiledRazorAssemblyPart(Assembly.GetExecutingAssembly())));
 
         services.AddLogging();
         services.AddLocalization(options => options.ResourcesPath = "Resources");
+        services.AddSingleton<IConfiguration>(_ => new ConfigurationBuilder().Build());
+        services.AddScoped<HtmlRenderer>();
+
         services.AddScoped<IViewLocalizer, ViewLocalizer>();
         services.AddScoped<IHtmlLocalizerFactory, HtmlLocalizerFactory>();
         services.AddSingleton<IWebHostEnvironment, TestWebHostEnvironment>();

src/Email/src/BlazorEmailRenderingService.cs

@@ -0,0 +1,59 @@
+// Copyright (c) Fusonic GmbH. All rights reserved.
+// Licensed under the MIT License. See LICENSE file in the project root for license information.
+
+using System.Globalization;
+using System.Reflection;
+using Fusonic.Extensions.AspNetCore.Blazor;
+using Microsoft.Extensions.Localization;
+
+namespace Fusonic.Extensions.Email;
+
+public class BlazorEmailRenderingService(IBlazorRenderingService blazorRenderingService, IStringLocalizerFactory stringLocalizerFactory) : IEmailRenderingService
+{
+    private const string DefaultSubjectKey = "Subject";
+
+    public bool Supports(object model) => model is IComponentModel;
+
+    /// <inheritdoc />
+    public async Task<(string Subject, string Body)> RenderAsync(
+        object model,
+        CultureInfo culture,
+        string? subjectKey,
+        object[]? subjectFormatParameters = null)
+    {
+        var modelType = model.GetType();
+
+        if (model is not IComponentModel componentModel)
+            throw new ArgumentException($"The type {modelType.Name} does not implement {nameof(IComponentModel)}.", nameof(model));
+
+        var componentType = componentModel.ComponentType;
+        var modelProperty = componentType.GetProperties(BindingFlags.Public | BindingFlags.Instance)
+                                         .FirstOrDefault(p => p.PropertyType == modelType)
+            ?? throw new ArgumentNullException(nameof(model), $"The Component {componentType.Name} is missing a property of type {modelType.Name}.");
+
+        subjectKey ??= (componentModel as IProvideEmailSubject)?.SubjectKey ?? DefaultSubjectKey;
+        var subject = subjectKey;
+
+        var body = await RenderAsync(
+            componentType,
+            modelProperty.Name,
+            componentModel,
+            culture,
+            beforeRender: SetSubject);
+
+        return (subject, body);
+
+        void SetSubject()
+        {
+            var subjectLocalization = stringLocalizerFactory.Create(componentType).GetString(subjectKey, subjectFormatParameters ?? []);
+            subject = subjectLocalization.ResourceNotFound ? subjectKey : subjectLocalization.Value;
+        }
+    }
+
+    private async Task<string> RenderAsync(Type componentType, string modelPropertyName, IComponentModel model, CultureInfo culture, Action beforeRender)
+    {
+        var content = await blazorRenderingService.RenderComponent(componentType, culture, new() { [modelPropertyName] = model }, beforeRender);
+        content = CssInliner.Inline(content);
+        return content;
+    }
+}

src/Email/src/ContainerExtensions.cs

@@ -2,9 +2,11 @@
 // Licensed under the MIT License. See LICENSE file in the project root for license information.
 
 using System.Reflection;
+using Fusonic.Extensions.AspNetCore.Blazor;
 using Fusonic.Extensions.AspNetCore.Razor;
 using Fusonic.Extensions.Mediator;
 using Microsoft.AspNetCore.Mvc.Localization;
+using Microsoft.Extensions.Localization;
 using SimpleInjector;
 
 namespace Fusonic.Extensions.Email;
@@ -32,9 +34,15 @@ public static void RegisterEmail(this Container container, Action<EmailOptions>
         container.RegisterInstance(options);
 
         container.RegisterInstance(new CssInliner(options));
-        container.Register<IEmailRenderingService, RazorEmailRenderingService>();
-        container.Register<IRazorViewRenderingService, RazorViewRenderingService>();
+
         container.RegisterInstance(container.GetInstance<IViewLocalizer>);
+        container.RegisterInstance(container.GetInstance<IStringLocalizerFactory>);
+
+        container.Register<IRazorViewRenderingService, RazorViewRenderingService>();
+        container.Register<IBlazorRenderingService, BlazorRenderingService>();
+
+        container.Collection.Append<IEmailRenderingService, RazorEmailRenderingService>();
+        container.Collection.Append<IEmailRenderingService, BlazorEmailRenderingService>();
 
         container.Register<ISmtpClient, SmtpClient>();
         container.Collection.Append<IEmailAttachmentResolver, FileAttachmentResolver>(Lifestyle.Singleton);