[Blazor] Add an API to describe the render mode (if any) a component …

…is running in (#55577)

src/Components/Components/src/ComponentBase.cs

@@ -22,6 +22,7 @@ namespace Microsoft.AspNetCore.Components;
 public abstract class ComponentBase : IComponent, IHandleEvent, IHandleAfterRender
 {
     private readonly RenderFragment _renderFragment;
+    private (IComponentRenderMode? mode, bool cached) _renderMode;
     private RenderHandle _renderHandle;
     private bool _initialized;
     private bool _hasNeverRendered = true;
@@ -41,6 +42,27 @@ public ComponentBase()
         };
     }
 
+    /// <summary>
+    /// Gets the <see cref="ComponentPlatform"/> the component is running on.
+    /// </summary>
+    protected ComponentPlatform Platform => _renderHandle.Platform;
+
+    /// <summary>
+    /// Gets the <see cref="IComponentRenderMode"/> assigned to this component.
+    /// </summary>
+    protected IComponentRenderMode? AssignedRenderMode
+    {
+        get
+        {
+            if (!_renderMode.cached)
+            {
+                _renderMode = (_renderHandle.RenderMode, true);
+            }
+
+            return _renderMode.mode;
+        }
+    }
+
     /// <summary>
     /// Renders the component to the supplied <see cref="RenderTreeBuilder"/>.
     /// </summary>

src/Components/Components/src/PublicAPI.Unshipped.txt

@@ -1,3 +1,12 @@
 #nullable enable
+Microsoft.AspNetCore.Components.ComponentBase.AssignedRenderMode.get -> Microsoft.AspNetCore.Components.IComponentRenderMode?
+Microsoft.AspNetCore.Components.ComponentBase.Platform.get -> Microsoft.AspNetCore.Components.ComponentPlatform!
+Microsoft.AspNetCore.Components.ComponentPlatform
+Microsoft.AspNetCore.Components.ComponentPlatform.ComponentPlatform(string! platformName, bool isInteractive) -> void
+Microsoft.AspNetCore.Components.ComponentPlatform.IsInteractive.get -> bool
+Microsoft.AspNetCore.Components.ComponentPlatform.Name.get -> string!
 Microsoft.AspNetCore.Components.ExcludeFromInteractiveRoutingAttribute
 Microsoft.AspNetCore.Components.ExcludeFromInteractiveRoutingAttribute.ExcludeFromInteractiveRoutingAttribute() -> void
+Microsoft.AspNetCore.Components.RenderHandle.Platform.get -> Microsoft.AspNetCore.Components.ComponentPlatform!
+Microsoft.AspNetCore.Components.RenderHandle.RenderMode.get -> Microsoft.AspNetCore.Components.IComponentRenderMode?
+virtual Microsoft.AspNetCore.Components.RenderTree.Renderer.ComponentPlatform.get -> Microsoft.AspNetCore.Components.ComponentPlatform!

src/Components/Components/src/RenderHandle.cs

@@ -51,6 +51,28 @@ public Dispatcher Dispatcher
     internal bool IsRendererDisposed => _renderer?.Disposed
         ?? throw new InvalidOperationException("No renderer has been initialized.");
 
+    /// <summary>
+    /// Gets the <see cref="ComponentPlatform"/> the component is running on.
+    /// </summary>
+    public ComponentPlatform Platform => _renderer?.ComponentPlatform ?? throw new InvalidOperationException("No renderer has been initialized.");
+
+    /// <summary>
+    /// Retrieves the <see cref="IComponentRenderMode"/> assigned to the component.
+    /// </summary>
+    /// <returns>The <see cref="IComponentRenderMode"/> assigned to the component.</returns>
+    public IComponentRenderMode? RenderMode
+    {
+        get
+        {
+            if (_renderer == null)
+            {
+                throw new InvalidOperationException("No renderer has been initialized.");
+            }
+
+            return _renderer.GetComponentRenderMode(_componentId);
+        }
+    }
+
     /// <summary>
     /// Notifies the renderer that the component should be rendered.
     /// </summary>

src/Components/Components/src/RenderTree/ComponentPlatform.cs

@@ -0,0 +1,31 @@
+// Licensed to the .NET Foundation under one or more agreements.
+// The .NET Foundation licenses this file to you under the MIT license.
+
+namespace Microsoft.AspNetCore.Components;
+
+/// <summary>
+/// Provides information about the platform that the component is running on.
+/// </summary>
+public sealed class ComponentPlatform
+{
+    /// <summary>
+    /// Constructs a new instance of <see cref="ComponentPlatform"/>.
+    /// </summary>
+    /// <param name="platformName">The name of the platform.</param>
+    /// <param name="isInteractive">A flag to indicate if the platform is interactive.</param>
+    public ComponentPlatform(string platformName, bool isInteractive)
+    {
+        Name = platformName;
+        IsInteractive = isInteractive;
+    }
+
+    /// <summary>
+    /// Gets the name of the platform.
+    /// </summary>
+    public string Name { get; }
+
+    /// <summary>
+    /// Gets a flag to indicate if the platform is interactive.
+    /// </summary>
+    public bool IsInteractive { get; }
+}

src/Components/Components/src/RenderTree/Renderer.cs

@@ -142,6 +142,9 @@ protected ComponentState GetComponentState(int componentId)
     protected internal virtual IComponentRenderMode? GetComponentRenderMode(IComponent component)
         => null;
 
+    internal IComponentRenderMode? GetComponentRenderMode(int componentId)
+        => GetComponentRenderMode(GetRequiredComponentState(componentId).Component);
+
     /// <summary>
     /// Resolves the component state for a given <see cref="IComponent"/> instance.
     /// </summary>
@@ -150,6 +153,11 @@ protected ComponentState GetComponentState(int componentId)
     protected internal ComponentState GetComponentState(IComponent component)
         => _componentStateByComponent.GetValueOrDefault(component);
 
+    /// <summary>
+    /// Gets the <see cref="ComponentPlatform"/> associated with this <see cref="Renderer"/>.
+    /// </summary>
+    protected internal virtual ComponentPlatform ComponentPlatform { get; }
+
     private async void RenderRootComponentsOnHotReload()
     {
         // Before re-rendering the root component, also clear any well-known caches in the framework

src/Components/Server/src/Circuits/RemoteRenderer.cs

@@ -18,6 +18,7 @@ internal partial class RemoteRenderer : WebRenderer
 #pragma warning restore CA1852 // Seal internal types
 {
     private static readonly Task CanceledTask = Task.FromCanceled(new CancellationToken(canceled: true));
+    private static readonly ComponentPlatform _componentPlatform = new("Server", isInteractive: true);
 
     private readonly CircuitClientProxy _client;
     private readonly CircuitOptions _options;
@@ -56,6 +57,10 @@ internal partial class RemoteRenderer : WebRenderer
 
     public override Dispatcher Dispatcher { get; } = Dispatcher.CreateDefault();
 
+    protected override ComponentPlatform ComponentPlatform => _componentPlatform;
+
+    protected override IComponentRenderMode? GetComponentRenderMode(IComponent component) => RenderMode.InteractiveServer;
+
     public Task AddComponentAsync(Type componentType, ParameterView parameters, string domElementSelector)
     {
         var componentId = AddRootComponent(componentType, domElementSelector);

src/Components/Web/src/HtmlRendering/StaticHtmlRenderer.cs

@@ -19,6 +19,8 @@ namespace Microsoft.AspNetCore.Components.HtmlRendering.Infrastructure;
 /// </summary>
 public partial class StaticHtmlRenderer : Renderer
 {
+    private static readonly ComponentPlatform _componentPlatform = new ComponentPlatform("Static", isInteractive: false);
+
     private static readonly Task CanceledRenderTask = Task.FromCanceled(new CancellationToken(canceled: true));
     private readonly NavigationManager? _navigationManager;
 
@@ -38,6 +40,9 @@ public StaticHtmlRenderer(IServiceProvider serviceProvider, ILoggerFactory logge
     /// <inheritdoc/>
     public override Dispatcher Dispatcher { get; } = Dispatcher.CreateDefault();
 
+    /// <inheritdoc/>
+    protected internal override ComponentPlatform ComponentPlatform => _componentPlatform;
+
     /// <summary>
     /// Adds a root component of the specified type and begins rendering it.
     /// </summary>

src/Components/Web/src/PublicAPI.Unshipped.txt

@@ -3,3 +3,4 @@ Microsoft.AspNetCore.Components.Web.Internal.IInternalWebJSInProcessRuntime
 Microsoft.AspNetCore.Components.Web.Internal.IInternalWebJSInProcessRuntime.InvokeJS(string! identifier, string? argsJson, Microsoft.JSInterop.JSCallResultType resultType, long targetInstanceId) -> string!
 Microsoft.AspNetCore.Components.Web.KeyboardEventArgs.IsComposing.get -> bool
 Microsoft.AspNetCore.Components.Web.KeyboardEventArgs.IsComposing.set -> void
+override Microsoft.AspNetCore.Components.HtmlRendering.Infrastructure.StaticHtmlRenderer.ComponentPlatform.get -> Microsoft.AspNetCore.Components.ComponentPlatform!

src/Components/WebAssembly/WebAssembly/src/Rendering/WebAssemblyRenderer.cs

@@ -24,6 +24,7 @@ internal sealed partial class WebAssemblyRenderer : WebRenderer
     private readonly ILogger _logger;
     private readonly Dispatcher _dispatcher;
     private readonly IInternalJSImportMethods _jsMethods;
+    private static readonly ComponentPlatform _componentPlatform = new("WebAssembly", isInteractive: true);
 
     public WebAssemblyRenderer(IServiceProvider serviceProvider, ILoggerFactory loggerFactory, JSComponentInterop jsComponentInterop)
         : base(serviceProvider, loggerFactory, DefaultWebAssemblyJSRuntime.Instance.ReadJsonSerializerOptions(), jsComponentInterop)
@@ -72,11 +73,15 @@ private void OnUpdateRootComponents(RootComponentOperationBatch batch)
         NotifyEndUpdateRootComponents(batch.BatchId);
     }
 
+    protected override IComponentRenderMode? GetComponentRenderMode(IComponent component) => RenderMode.InteractiveWebAssembly;
+
     public void NotifyEndUpdateRootComponents(long batchId)
     {
         _jsMethods.EndUpdateRootComponents(batchId);
     }
 
+    protected override ComponentPlatform ComponentPlatform => _componentPlatform;
+
     public override Dispatcher Dispatcher => _dispatcher;
 
     public Task AddComponentAsync([DynamicallyAccessedMembers(Component)] Type componentType, ParameterView parameters, string domElementSelector)

src/Components/WebView/WebView/src/Services/WebViewRenderer.cs

@@ -9,6 +9,7 @@ namespace Microsoft.AspNetCore.Components.WebView.Services;
 
 internal sealed class WebViewRenderer : WebRenderer
 {
+    private static readonly ComponentPlatform _componentPlatform = new("WebView", isInteractive: true);
     private readonly Queue<UnacknowledgedRenderBatch> _unacknowledgedRenderBatches = new();
     private readonly Dispatcher _dispatcher;
     private readonly IpcSender _ipcSender;
@@ -31,6 +32,8 @@ internal sealed class WebViewRenderer : WebRenderer
 
     public override Dispatcher Dispatcher => _dispatcher;
 
+    protected override ComponentPlatform ComponentPlatform => _componentPlatform;
+
     protected override int GetWebRendererId() => (int)WebRendererId.WebView;
 
     protected override void HandleException(Exception exception)
@@ -81,7 +84,7 @@ public void NotifyRenderCompleted(long batchId)
     private sealed class UnacknowledgedRenderBatch
     {
         public long BatchId { get; init; }
-        
+
         public TaskCompletionSource CompletionSource { get; init; }
     }
 }

src/Components/benchmarkapps/Wasm.Performance/ConsoleHost/Scenarios/GridScenario.cs

@@ -20,8 +20,8 @@ public GridScenario() : base("grid")
     protected override async Task ExecuteAsync(ConsoleHostRenderer renderer, int numCycles)
     {
         var gridType = _gridTypeOption.HasValue()
-            ? (GridRendering.RenderMode)Enum.Parse(typeof(GridRendering.RenderMode), _gridTypeOption.Value(), true)
-            : GridRendering.RenderMode.FastGrid;
+            ? (GridRendering.GridRenderMode)Enum.Parse(typeof(GridRendering.GridRenderMode), _gridTypeOption.Value(), true)
+            : GridRendering.GridRenderMode.FastGrid;
 
         for (var i = 0; i < numCycles; i++)
         {

src/Components/benchmarkapps/Wasm.Performance/TestApp/Pages/GridRendering.razor

@@ -6,9 +6,9 @@
 
 <fieldset>
     <select id="render-mode" @bind="SelectedRenderMode">
-        <option>@RenderMode.FastGrid</option>
-        <option>@RenderMode.PlainTable</option>
-        <option>@RenderMode.ComplexTable</option>
+        <option>@GridRenderMode.FastGrid</option>
+        <option>@GridRenderMode.PlainTable</option>
+        <option>@GridRenderMode.ComplexTable</option>
     </select>
 
     <button id="show" @onclick="Show">Show</button>
@@ -23,7 +23,7 @@
 {
     <p><em>(No data assigned)</em></p>
 }
-else if (SelectedRenderMode == RenderMode.FastGrid)
+else if (SelectedRenderMode == GridRenderMode.FastGrid)
 {
     <p>FastGrid represents a minimal, optimized implementation of a grid.</p>
 
@@ -50,23 +50,23 @@ else if (SelectedRenderMode == RenderMode.FastGrid)
         <GridColumn TRowData="WeatherForecast" Title="Summary">@context.Summary</GridColumn>
     </Grid>
 }
-else if (SelectedRenderMode == RenderMode.PlainTable)
+else if (SelectedRenderMode == GridRenderMode.PlainTable)
 {
     <p>PlainTable represents a minimal but not optimized implementation of a grid.</p>
 
     <Wasm.Performance.TestApp.Shared.PlainTable.TableComponent Data="@forecasts" Columns="@Columns" />
 }
-else if (SelectedRenderMode == RenderMode.ComplexTable)
+else if (SelectedRenderMode == GridRenderMode.ComplexTable)
 {
     <p>ComplexTable represents a maximal, not optimized implementation of a grid, using a wide range of Blazor features at once.</p>
 
     <Wasm.Performance.TestApp.Shared.ComplexTable.TableComponent Data="@forecasts" Columns="@Columns" />
 }
 
 @code {
-    public enum RenderMode { PlainTable, ComplexTable, FastGrid }
+    public enum GridRenderMode { PlainTable, ComplexTable, FastGrid }
 
-    public RenderMode SelectedRenderMode { get; set; } = RenderMode.FastGrid;
+    public GridRenderMode SelectedRenderMode { get; set; } = GridRenderMode.FastGrid;
 
     private WeatherForecast[] forecasts;
     public List<string> Columns { get; set; } = new List<string>

src/Components/test/E2ETest/Tests/InteractiveHostRendermodeTest.cs

@@ -0,0 +1,57 @@
+// Licensed to the .NET Foundation under one or more agreements.
+// The .NET Foundation licenses this file to you under the MIT license.
+
+using Components.TestServer.RazorComponents;
+using Microsoft.AspNetCore.Components.E2ETest.Infrastructure;
+using Microsoft.AspNetCore.Components.E2ETest.Infrastructure.ServerFixtures;
+using Microsoft.AspNetCore.E2ETesting;
+using OpenQA.Selenium;
+using TestServer;
+using Xunit.Abstractions;
+
+namespace Microsoft.AspNetCore.Components.E2ETests.Tests;
+
+public class InteractiveHostRendermodeTest : ServerTestBase<BasicTestAppServerSiteFixture<RazorComponentEndpointsStartup<App>>>
+{
+    public InteractiveHostRendermodeTest(
+        BrowserFixture browserFixture,
+        BasicTestAppServerSiteFixture<RazorComponentEndpointsStartup<App>> serverFixture,
+        ITestOutputHelper output)
+        : base(browserFixture, serverFixture, output)
+    {
+    }
+
+    [Theory]
+    [InlineData("server")]
+    [InlineData("webassembly")]
+    [InlineData("auto")]
+    [InlineData("static")]
+    public void EmbeddingServerAppInsideIframe_Works(string renderMode)
+    {
+        Navigate($"/subdir/ComponentPlatform?suppress-autostart&ComponentRenderMode={renderMode}");
+
+        Browser.Equal(renderMode, () => Browser.Exists(By.Id("host-render-mode")).Text);
+        Browser.Equal("False", () => Browser.Exists(By.Id("platform-is-interactive")).Text);
+
+        Browser.Click(By.Id("call-blazor-start"));
+
+        if (renderMode == "static")
+        {
+            Browser.Equal("False", () => Browser.Exists(By.Id("platform-is-interactive")).Text);
+        }
+        else
+        {
+            Browser.Equal("True", () => Browser.Exists(By.Id("platform-is-interactive")).Text);
+        }
+
+        if (renderMode != "auto")
+        {
+            Browser.Equal(renderMode, () => Browser.Exists(By.Id("host-render-mode")).Text);
+        }
+        else
+        {
+            Browser.True(() => Browser.Exists(By.Id("host-render-mode")).Text is "server" or "webassembly");
+        }
+    }
+}
+

src/Components/test/testassets/BasicTestApp/Index.razor

@@ -55,6 +55,7 @@
         <option value="BasicTestApp.GracefulTermination">Graceful Termination</option>
         <option value="BasicTestApp.HeadModification">Head Modification</option>
         <option value="BasicTestApp.HierarchicalImportsTest.Subdir.ComponentUsingImports">Imports statement</option>
+        <option value="BasicTestApp.HostRenderMode">Host render mode</option>
         <option value="BasicTestApp.HtmlBlockChildContent">ChildContent HTML Block</option>
         <option value="BasicTestApp.HtmlEncodedChildContent">ChildContent HTML Encoded Block</option>
         <option value="BasicTestApp.HtmlMixedChildContent">ChildContent Mixed Block</option>

src/Components/test/testassets/Components.TestServer/RazorComponents/Pages/ComponentPlatform.razor

@@ -0,0 +1,38 @@
+@page "/componentplatform"
+@using TestContentPackage
+
+<h3>Component platform tests</h3>
+
+<p>
+    Defines a component and applies the render mode in the query string value for ComponentRenderMode.
+    The component prints the render mode and whether its interactive.
+</p>
+
+<ComponentPlatformDetails @rendermode="_renderMode" />
+
+@code {
+    [SupplyParameterFromQuery] public string ComponentRenderMode { get; set; }
+
+    IComponentRenderMode _renderMode;
+
+    protected override void OnInitialized()
+    {
+        switch (ComponentRenderMode)
+        {
+            case "server":
+                _renderMode = RenderMode.InteractiveServer;
+                break;
+            case "webassembly":
+                _renderMode = RenderMode.InteractiveWebAssembly;
+                break;
+            case "auto":
+                _renderMode = RenderMode.InteractiveAuto;
+                break;
+            case "static":
+                _renderMode = null;
+                break;
+            default:
+                throw new InvalidOperationException($"Unknown component render mode: {ComponentRenderMode}");
+        }
+    }
+}