Additional cleanups

Author: javiercn

src/Components/Components/src/Binding/CascadingModelBinder.cs

@@ -22,7 +22,10 @@ public sealed class CascadingModelBinder : IComponent, IDisposable
     [Parameter] public string Name { get; set; } = "";
 
     /// <summary>
-    /// The binding context name.
+    /// If true, indicates that <see cref="ModelBindingContext.BindingContextId"/> will not change.
+    /// This is a performance optimization that allows the framework to skip setting up
+    /// change notifications. Set this flag only if you will not change
+    /// <see cref="Name"/> of this context or its parents' context during the component's lifetime.
     /// </summary>
     [Parameter] public bool IsFixed { get; set; }
 

src/Components/Components/src/RenderTree/RenderTreeDiffBuilder.cs

@@ -40,19 +40,12 @@ public static RenderTreeDiff ComputeDiff(
         // Once a component has defined a named event handler with a concrete name, no other component instance can
         // define a named event handler with that name.
         //
-        // This is only enforced when we are trying to dispatch an event to a named event handler, since in any other
-        // case we don't actually track the named event handlers.
-        //
-        // We don't enforce the global uniqueness of the event handler name inside the base renderer either. That's
-        // handled by the EndpointRenderer that takes care of ensuring that only one component defined the expected
-        // named event handler before dispatching the named event.
-        //
         // At this stage, we only ensure that the named event handler is unique per component instance, as that,
         // combined with the check that the EndpointRenderer does, is enough to ensure the uniqueness and the stability
         // of the named event handler over time **globally**.
         //
-        // Note that we only enforce this condition at the time we are going to dispatch a named event to a specific
-        // named event handler. In any other case, even though is an error, we don't care, as:
+        // Tracking and uniqueness are enforced when we are trying to dispatch an event to a named event handler, since in
+        // any other case we don't actually track the named event handlers. We do this because:
         // 1) We don't want to break the user's app if we don't have to.
         // 2) We don't have to pay the cost of continously tracking all events all the time to throw.
         // That's why raising the error is delayed until we are forced to make a decission.

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

@@ -419,13 +419,10 @@ public virtual Task DispatchEventAsync(ulong eventHandlerId, EventFieldInfo? fie
             if (quiesce)
             {
                 _pendingTasks ??= new();
-                task = callback.InvokeAsync(eventArgs);
-                AddToPendingTasksWithErrorHandling(task, receiverComponentState);
-            }
-            else
-            {
-                task = callback.InvokeAsync(eventArgs);
             }
+
+            task = callback.InvokeAsync(eventArgs);
+            AddToPendingTasksWithErrorHandling(task, receiverComponentState);
         }
         catch (Exception e)
         {

src/Components/Components/src/RouteView.cs

@@ -77,15 +77,6 @@ protected virtual void Render(RenderTreeBuilder builder)
 
     private void RenderPageWithParameters(RenderTreeBuilder builder)
     {
-        var pathStart = NavigationManager.BaseUri.Length - 1;
-        var bindingId = NavigationManager.Uri.Substring(
-            pathStart,
-            NavigationManager.Uri.AsSpan().IndexOfAny("?#") switch
-            {
-                -1 => NavigationManager.Uri.Length - pathStart,
-                var index => index - pathStart
-            });
-
         builder.OpenComponent<CascadingModelBinder>(0);
         builder.AddComponentParameter(1, nameof(CascadingModelBinder.ChildContent), (RenderFragment<ModelBindingContext>)RenderPageWithContext);
         builder.CloseComponent();

src/Components/Endpoints/src/RazorComponentEndpointInvoker.cs

@@ -59,6 +59,11 @@ private async Task RenderComponentCore()
             hostParameters,
             waitForQuiescence: isPost);
 
+        if (isPost && !_renderer.HasCapturedEvent())
+        {
+            _context.Response.StatusCode = StatusCodes.Status404NotFound;
+        }
+
         var quiesceTask = isPost ? _renderer.DispatchCapturedEvent() : htmlContent.QuiescenceTask;
 
         if (isPost)

src/Components/Endpoints/src/Rendering/EndpointHtmlRenderer.cs

@@ -119,6 +119,8 @@ protected override void TrackNamedEventId(ulong eventHandlerId, int componentId,
         }
     }
 
+    internal bool HasCapturedEvent() => _capturedNamedEvent != default;
+
     internal Task DispatchCapturedEvent()
     {
         if (_capturedNamedEvent == default)

src/Components/test/E2ETest/ServerRenderingTests/FormHandlingTest.cs

@@ -49,6 +49,18 @@ public void CanDispatchToNamedForm()
         DispatchToFormCore(dispatchToForm);
     }
 
+    [Fact]
+    public void CanDispatchToNamedFormNoParentBindingContext()
+    {
+        var dispatchToForm = new DispatchToForm(this)
+        {
+            Url = "forms/named-form-no-form-context",
+            FormCssSelector = "form[name=named-form-handler]",
+            ExpectedActionValue = "forms/named-form-no-form-context?handler=named-form-handler",
+        };
+        DispatchToFormCore(dispatchToForm);
+    }
+
     [Fact]
     public void CanDispatchToNamedFormInNestedContext()
     {

src/Components/test/testassets/Components.TestServer/RazorComponents/Pages/Forms/FormOutsideBindingContextNoOps.razor

@@ -2,7 +2,7 @@
 @using Microsoft.AspNetCore.Components.Forms
 @layout NoFormContextLayout
 
-<h2>Default form</h2>
+<h2>Form outside a cascading binding context no-ops</h2>
 
 <EditForm EditContext="_editContext" method="POST" OnValidSubmit="() => _submitted = true" >
     <input id="send" type="submit" value="Send" />

src/Components/test/testassets/Components.TestServer/RazorComponents/Pages/Forms/ModifyHttpContextForm.razor

@@ -8,7 +8,7 @@
 @using Microsoft.AspNetCore.Components.Forms
 @using Microsoft.AspNetCore.Mvc;
 
-<h2>Default form</h2>
+<h2>Event handler sets cookie during form POST</h2>
 
 <EditForm EditContext="_editContext" method="POST" OnValidSubmit="HandleSubmit">
     <input id="send" type="submit" value="Send" />

src/Components/test/testassets/Components.TestServer/RazorComponents/Pages/Forms/NamedFormContextNoFormContextLayout.razor

@@ -0,0 +1,19 @@
+@page "/forms/named-form-no-form-context"
+@layout NoFormContextLayout
+@using Microsoft.AspNetCore.Components.Forms
+
+<h2>Named form</h2>
+
+<EditForm FormHandlerName="named-form-handler" EditContext="_editContext" method="POST" OnValidSubmit="() => _submitted = true" >
+    <input id="send" type="submit" value="Send" />
+</EditForm>
+
+@if (_submitted)
+{
+    <p id="pass">Form submitted!</p>
+}
+
+@code{
+    bool _submitted = false;
+    EditContext _editContext = new EditContext(new object());
+}

src/Components/test/testassets/Components.TestServer/RazorComponents/Pages/Forms/NonStreamingRenderingForm.razor

@@ -5,7 +5,7 @@
 @using Microsoft.AspNetCore.Components.Forms
 @using Microsoft.AspNetCore.Mvc;
 
-<h2>Default form</h2>
+<h2>Non streaming async form</h2>
 
 <EditForm EditContext="_editContext" method="POST" OnValidSubmit="HandleSubmit">
     <input id="send" type="submit" value="Send" />

src/Components/test/testassets/Components.TestServer/RazorComponents/Pages/Forms/StreamingRenderingForm.razor

@@ -6,7 +6,7 @@
 @using Microsoft.AspNetCore.Components.Forms
 @using Microsoft.AspNetCore.Mvc;
 
-<h2>Default form</h2>
+<h2>Streaming rendering async form</h2>
 
 <EditForm EditContext="_editContext" method="POST" OnValidSubmit="HandleSubmit">
     <input id="send" type="submit" value="Send" />

src/Components/test/testassets/Components.TestServer/RazorComponents/Pages/Forms/SwitchingDispatchedComponentsDoesNotBind.razor

@@ -2,7 +2,7 @@
 @using Components.TestServer.RazorComponents
 @using Microsoft.AspNetCore.Components.Authorization
 
-<h2>Form disappears before dispatching</h2>
+<h2>Form component instance changes before dispatching</h2>
 
 @if (!_ready)
 {