Blazor router NotFound updates (#30329)

Author: guardrex

aspnetcore/blazor/components/control-head-content.md

@@ -113,8 +113,20 @@ When the [`::after` pseudo-selector](https://developer.mozilla.org/docs/Web/CSS/
 
 ## Not found page title
 
+:::moniker range=">= aspnetcore-8.0"
+
+*This section only applies to Blazor WebAssembly apps.*
+
+In Blazor apps created from Blazor WebAssembly project template, the `NotFound` component template in the `App` component (`App.razor`) sets the page title to `Not found`.
+
+:::moniker-end
+
+:::moniker range="< aspnetcore-8.0"
+
 In Blazor apps created from Blazor project templates, the `NotFound` component template in the `App` component (`App.razor`) sets the page title to `Not found`.
 
+:::moniker-end
+
 `App.razor`:
 
 ```razor

aspnetcore/blazor/components/layouts.md

@@ -245,6 +245,13 @@ Specifying the layout as a default layout in the `Router` component is a useful
 
 To set a layout for arbitrary Razor template content, specify the layout with a <xref:Microsoft.AspNetCore.Components.LayoutView> component. You can use a <xref:Microsoft.AspNetCore.Components.LayoutView> in any Razor component. The following example sets a layout component named `ErrorLayout` for the `MainLayout` component's <xref:Microsoft.AspNetCore.Components.Routing.Router.NotFound> template (`<NotFound>...</NotFound>`).
 
+:::moniker range=">= aspnetcore-8.0"
+
+> [!NOTE]
+> The following example is specifically for a Blazor WebAssembly app because Blazor Web Apps don't use the <xref:Microsoft.AspNetCore.Components.Routing.Router.NotFound> template (`<NotFound>...</NotFound>`). However, the template is supported for backward compatibility to avoid a breaking change in the framework. Blazor Web Apps typically process bad URL requests by either displaying the browser's built-in 404 UI or returning a custom 404 page from the ASP.NET Core server via ASP.NET Core middleware (for example, [`UseStatusCodePagesWithRedirects`](xref:fundamentals/error-handling#usestatuscodepageswithredirects) / [API documentation](xref:Microsoft.AspNetCore.Builder.StatusCodePagesExtensions.UseStatusCodePagesWithRedirects%2A)).
+
+:::moniker-end
+
 `App.razor`:
 
 ```razor

aspnetcore/blazor/fundamentals/routing.md

@@ -112,8 +112,11 @@ When the <xref:Microsoft.AspNetCore.Components.Routing.Router> component navigat
 
 ## Provide custom content when content isn't found
 
-<!-- UPDATE 8.0 NotFound isn't part of the BWA template ...
-     confirm if it's a no-op with SSR/BWA -->
+:::moniker range=">= aspnetcore-8.0"
+
+*This section only applies to Blazor WebAssembly apps.* Blazor Web Apps don't use the <xref:Microsoft.AspNetCore.Components.Routing.Router.NotFound> template (`<NotFound>...</NotFound>`), but the template is supported for backward compatibility to avoid a breaking change in the framework. Blazor Web Apps typically process bad URL requests by either displaying the browser's built-in 404 UI or returning a custom 404 page from the ASP.NET Core server via ASP.NET Core middleware (for example, [`UseStatusCodePagesWithRedirects`](xref:fundamentals/error-handling#usestatuscodepageswithredirects) / [API documentation](xref:Microsoft.AspNetCore.Builder.StatusCodePagesExtensions.UseStatusCodePagesWithRedirects%2A)).
+
+:::moniker-end
 
 The <xref:Microsoft.AspNetCore.Components.Routing.Router> component allows the app to specify custom content if content isn't found for the requested route.
 

aspnetcore/blazor/security/index.md

@@ -279,9 +279,6 @@ If `user.Identity.IsAuthenticated` is `true`, claims can be enumerated and membe
 
 Set up the `Task<`<xref:Microsoft.AspNetCore.Components.Authorization.AuthenticationState>`>` [cascading parameter](xref:blazor/components/cascading-values-and-parameters) using the <xref:Microsoft.AspNetCore.Components.Authorization.AuthorizeRouteView> and <xref:Microsoft.AspNetCore.Components.Authorization.CascadingAuthenticationState> components.
 
-<!-- UPDATE 8.0 Need to confirm this next bit in the BWA world
-     e.g., did Found survive the NotFound removal?  -->
-
 When you create a Blazor app from one of the Blazor project templates with authentication enabled, the app includes the <xref:Microsoft.AspNetCore.Components.Authorization.AuthorizeRouteView> and <xref:Microsoft.AspNetCore.Components.Authorization.CascadingAuthenticationState> components shown in the following example. A client-side Blazor app includes the required service registrations as well. Additional information is presented in the [Customize unauthorized content with the Router component](#customize-unauthorized-content-with-the-router-component) section.
 
 ```razor
@@ -292,7 +289,6 @@ When you create a Blazor app from one of the Blazor project templates with authe
                 DefaultLayout="@typeof(MainLayout)" />
             ...
         </Found>
-        ...
     </Router>
 </CascadingAuthenticationState>
 ```
@@ -502,9 +498,6 @@ Not authorized.
 
 To authorize users for resources, pass the request's route data to the <xref:Microsoft.AspNetCore.Components.Authorization.AuthorizeRouteView.Resource> parameter of <xref:Microsoft.AspNetCore.Components.Authorization.AuthorizeRouteView>.
 
-<!-- UPDATE 8.0 Confirm the following remark in the BWA world
-     i.e., did Found content survive the NotFound drop? -->
-
 In the <xref:Microsoft.AspNetCore.Components.Routing.Router.Found?displayProperty=nameWithType> content for a requested route:
 
 ```razor
@@ -605,9 +598,6 @@ In the following `EditUser` component, the resource at `/users/{id}/edit` has a
 
 The <xref:Microsoft.AspNetCore.Components.Routing.Router> component, in conjunction with the <xref:Microsoft.AspNetCore.Components.Authorization.AuthorizeRouteView> component, allows the app to specify custom content if:
 
-<!-- UPDATE 8.0 React to NotFound changes in the BWA world
-     the following removed NotFound content and tags -->
-
 * The user fails an [`[Authorize]`](xref:Microsoft.AspNetCore.Authorization.AuthorizeAttribute) condition applied to the component. The markup of the [`<NotAuthorized>`](xref:Microsoft.AspNetCore.Components.Authorization.AuthorizeRouteView.NotAuthorized?displayProperty=nameWithType) element is displayed. The [`[Authorize]`](xref:Microsoft.AspNetCore.Authorization.AuthorizeAttribute) attribute is covered in the [`[Authorize]` attribute](#authorize-attribute) section.
 * Asynchronous authorization is in progress, which usually means that the process of authenticating the user is in progress. The markup of the [`<Authorizing>`](xref:Microsoft.AspNetCore.Components.Authorization.AuthorizeRouteView.Authorizing?displayProperty=nameWithType) element is displayed.
 
@@ -624,13 +614,22 @@ The <xref:Microsoft.AspNetCore.Components.Routing.Router> component, in conjunct
                 </Authorizing>
             </AuthorizeRouteView>
         </Found>
-        ...
     </Router>
 </CascadingAuthenticationState>
 ```
 
+:::moniker range=">= aspnetcore-8.0"
+
+The content of `<NotAuthorized>` and `<Authorizing>` tags can include arbitrary items, such as other interactive components.
+
+:::moniker-end
+
+:::moniker range="< aspnetcore-8.0"
+
 The content of `<NotFound>`, `<NotAuthorized>`, and `<Authorizing>` tags can include arbitrary items, such as other interactive components.
 
+:::moniker-end
+
 If the `<NotAuthorized>` tag isn't specified, the <xref:Microsoft.AspNetCore.Components.Authorization.AuthorizeRouteView> uses the following fallback message:
 
 ```html

aspnetcore/blazor/security/server/index.md

@@ -197,9 +197,6 @@ services.AddScoped<AuthenticationStateProvider,
 
 Confirm or add an <xref:Microsoft.AspNetCore.Components.Authorization.AuthorizeRouteView> and <xref:Microsoft.AspNetCore.Components.Authorization.CascadingAuthenticationState> for the Blazor router:
 
-<!-- UPDATE 8.0 Check for dropping NotFound
-     Did Found survive? -->
-
 ```razor
 <CascadingAuthenticationState>
     <Router ...>
@@ -208,7 +205,6 @@ Confirm or add an <xref:Microsoft.AspNetCore.Components.Authorization.AuthorizeR
                 DefaultLayout="@typeof(MainLayout)" />
             ...
         </Found>
-        ...
     </Router>
 </CascadingAuthenticationState>
 ```