Serves generated sitemaps and the built-in XSL stylesheets.

plug SiteMaps.Plug,
  sitemaps: &MyAppWeb.Sitemaps.for_conn/1,
  aliases: %{"/sitemap.xml" => "/sitemaps/sitemap.xml.gz"}

Works in an endpoint, a pipeline or behind a router forward. Requests that are not sitemap files of the resolved module pass through untouched, so the plug can sit in front of the rest of the app.

Options

• :sitemaps - {module, context}, or a function receiving the conn and returning {module, context} or nil (pass through). Use a remote capture (&Mod.fun/1) when the plug is initialized at compile time. Required.
• :aliases - map of request path to the path to serve, e.g. %{"/sitemap.xml" => "/sitemap.xml.gz"}. An .xml path aliased to an .xml.gz file is served uncompressed.
• :x_robots_tag - x-robots-tag header (default "noindex, follow", nil to omit)
• :cache_control - cache-control header. For sitemaps it defaults to the configured cache_control, and the header is left out when both are nil. Stylesheets use this option when given, otherwise "public, max-age=3600".
• :stylesheet_paths - {urlset_path, index_path} serving the built-in stylesheets (default {"/_sitemap-stylesheet.xsl", "/_sitemap-index-stylesheet.xsl"}, nil to disable). Point xsl_stylesheet_url/xsl_index_stylesheet_url at them.

The request path must be inside the directory of the configured sitemap URL; the file key is the percent-decoded path relative to it. Keys failing SiteMaps.Adapter.validate_key/1 are rejected. Only .xml and .xml.gz files are served. A .xml request for a missing file falls back to its .xml.gz version, decompressed, when the sitemaps are gzipped.

Requests with an if-modified-since header at or after the file last_modified (compared in whole seconds) get a 304 Not Modified. HEAD requests get the GET headers without decompressing the file; content-length is omitted when the file would be decompressed.