Feeds and Sitemap

MapOsirionFeeds maps three endpoints built from the published content of your content providers: an XML sitemap at /sitemap.xml, an RSS 2.0 feed at /feed.xml and an Atom 1.0 feed at /atom.xml. Search engines read the sitemap; feed readers subscribe to either feed. These are endpoints, not components, so this page has no demo and no parameter table.

Package Osirion.Blazor.Cms.Web, namespace Osirion.Blazor.Cms.Web.Feeds. Source on GitHub. Available from 4.0.

Usage

Call it in Program.cs after the content services are registered:

using Osirion.Blazor.Cms.Web.Feeds;

app.MapOsirionFeeds(feeds =>
{
    feeds.SiteUrl = "https://example.com";
    feeds.FeedDirectory = "blog";
    feeds.AdditionalSitemapUrls = ["/", "/blog"];
});

With no arguments, app.MapOsirionFeeds() maps all three endpoints over all content and builds URLs from the request.

Configuration

OsirionFeedOptions has these properties:

The options are checked when MapOsirionFeeds runs: a SiteUrl that is not an absolute http or https URL throws ArgumentException, and a FeedItemCount below 1 throws ArgumentOutOfRangeException, so a bad value stops the application at startup instead of producing broken feeds.

What goes into each document

• Sitemap. Each URL has a lastmod from the item's last_modified front matter, then, with the file system provider and FileSystemOptions.UseFileWriteTimeAsLastModified turned on (it is off by default), the file's write time, then the item's creation date: its date front matter, or for a file the file's creation time. Set last_modified when dates must survive a fresh checkout or a new deployment. Items whose seo_properties.robots contains noindex are left out, and duplicate URLs are written once. The sitemap covers all content; FeedDirectory and FeedLocale do not apply to it.
• RSS. Each item has its title, link, a permalink guid, pubDate from the creation date (date) and the description front matter. The channel carries an atom:link rel="self" pointing to /feed.xml.
• Atom. Each entry has an id (its URL), title, link, published (the creation date), updated (the last-modified date, or the creation date), the author when set, and the description as its summary. The feed's own updated is the newest entry's, or the current time for an empty feed. The feed-level author is the feed title, which satisfies Atom's rule that every entry has an author.
• Feeds carry descriptions, not full article bodies. Unpublished items (published: false) never appear, and a feed lists items by creation date even when a provider ignores the sort order.
• Characters that XML cannot represent are dropped from titles and descriptions rather than failing the request.

Security and caching

Set SiteUrl, or Osirion:Seo:SiteUrl from the release after 4.1.0, in production. Without either, URLs follow whatever Host header a request sends, so a forged header could put another host into a response that a cache or crawler stores. Responses are marked public, so browsers and shared caches may keep serving a document for up to CacheDuration after the content changes.

Pointing crawlers and readers at them

Add the sitemap to your robots.txt:

Sitemap: https://example.com/sitemap.xml

Let browsers and feed readers discover the feeds from the page head, for example in App.razor:

<link rel="alternate" type="application/rss+xml" title="Example blog" href="/feed.xml" />
<link rel="alternate" type="application/atom+xml" title="Example blog" href="/atom.xml" />

Related

• SeoMetadataRenderer: head metadata; its SiteName and SiteDescription options also title the feeds
• ContentList: the list pages whose links the feeds share
• CMS Web core components