NotFoundPage

NotFoundPage renders a whole page not found page: a title, a sentence, a link home, an optional search box and a list of suggested pages. It asks search engines not to index the page. Use it as the router's not found page.

Package Osirion.Blazor.Cms.Web, namespace Osirion.Blazor.Cms.Web.Components. Source on GitHub.

There is no live demo on this page. NotFoundPage sets the page title and adds a noindex robots tag to the head, so rendering it inside this page would ask search engines to drop the documentation page. Open any address that does not exist on this site, such as /no-such-page, to see it.

Usage

On .NET 10, give the router a not found page and use NotFoundPage there. The router answers with status 404. This is the page the example site routes to, with suggestions and a search box:

@page "/not-found"
@using Osirion.Blazor.Cms.Web.Components
@using Osirion.Blazor.Components

<NotFoundPage Message="The page you are looking for does not exist or has moved."
              Suggestions="suggestions"
              ShowSearch />

@code {
    private static readonly IReadOnlyList<ContentNotFoundSuggestion> suggestions =
    [
        new() { Text = "Documentation", Url = "/docs", Description = "Every component, with examples." },
        new() { Text = "Blog", Url = "/blog", Description = "Guides, release notes and patterns." }
    ];
}

<Router AppAssembly="typeof(Program).Assembly" NotFoundPage="typeof(Pages.NotFound)">
    <Found Context="routeData">
        <RouteView RouteData="routeData" DefaultLayout="typeof(Layout.MainLayout)" />
    </Found>
</Router>

On .NET 9, put the component in the router's NotFound template instead; under static server-side rendering it then sets the status to 404 itself.

ShowSearch adds a search box that submits to SearchUrl (/search by default), so turn it on only when the site has a search page there. ChildContent adds your own markup under the box, for example a contact link.

Parameters

Behavior

• Rendering. The page renders on the server and needs no script.
• Head. The page sets the document title to Title and writes <meta name="robots" content="noindex" />.
• Status. On .NET 10 the page does not set the status; the router's NotFoundPage does. Setting it from the page there would send an empty response. On .NET 9 the page sets status 404 on the request while the response has not started, so use it inside the router's NotFound template there.
• Content. The page renders OsirionContentNotFound with the error code 404, your Title (the page's h1) and Message, a primary button to HomeUrl labeled HomeText, the suggestions when there is at least one, and the search box when ShowSearch is on.
• Security. All text is encoded. The addresses in HomeUrl, SearchUrl and the suggestions are written as given, so build them from values you control.
• Attributes. Class, Style and unmatched attributes go to the root element, and so does Theme as data-theme (data-bs-theme under Bootstrap) when it is Light or Dark.

Styling

The root element has the class osirion-not-found-page, which pads the page. The content is an OsirionContentNotFound, which has its own classes (osirion-content-not-found and its parts); see its page for them.

Related

• CMS pages: the group overview
• OsirionContentNotFound: the component the page is built on
• SearchBox: the search box