Sample interactive render mode

Author: javiercn

src/Components/Components/src/ComponentBase.cs

@@ -23,6 +23,7 @@ namespace Microsoft.AspNetCore.Components;
 public abstract class ComponentBase : IComponent, IHandleEvent, IHandleAfterRender
 {
     private readonly RenderFragment _renderFragment;
+    private IComponentRenderMode? _interactiveRenderMode;
     private RenderHandle _renderHandle;
     private bool _initialized;
     private bool _hasNeverRendered = true;
@@ -47,6 +48,11 @@ public ComponentBase()
     /// </summary>
     protected ComponentPlatform Platform => _renderHandle.Platform;
 
+    /// <summary>
+    /// Gets the <see cref="IComponentRenderMode"/> the component is rendering or will render in when it becomes interactive.
+    /// </summary>
+    protected IComponentRenderMode? InteractiveRenderMode => _interactiveRenderMode ??= _renderHandle.GetInteractiveRenderMode();
+
     /// <summary>
     /// Renders the component to the supplied <see cref="RenderTreeBuilder"/>.
     /// </summary>

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

@@ -1,4 +1,5 @@
 #nullable enable
+Microsoft.AspNetCore.Components.ComponentBase.InteractiveRenderMode.get -> Microsoft.AspNetCore.Components.IComponentRenderMode?
 Microsoft.AspNetCore.Components.ComponentBase.Platform.get -> Microsoft.AspNetCore.Components.RenderTree.ComponentPlatform!
 Microsoft.AspNetCore.Components.ExcludeFromInteractiveRoutingAttribute
 Microsoft.AspNetCore.Components.ExcludeFromInteractiveRoutingAttribute.ExcludeFromInteractiveRoutingAttribute() -> void

src/Components/Components/src/RenderHandle.cs

@@ -56,6 +56,16 @@ public Dispatcher Dispatcher
     /// </summary>
     public ComponentPlatform Platform => _renderer?.ComponentPlatform ?? throw new InvalidOperationException("No renderer has been initialized.");
 
+    internal IComponentRenderMode? GetInteractiveRenderMode()
+    {
+        if (_renderer == null)
+        {
+            throw new InvalidOperationException("No renderer has been initialized.");
+        }
+
+        return _renderer.ComponentPlatform.RenderMode ?? _renderer.GetComponentRenderMode(_componentId);
+    }
+
     /// <summary>
     /// Notifies the renderer that the component should be rendered.
     /// </summary>

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>