Rack Middleware · SiteMaps — marcosgz

SiteMaps::Middleware serves generated sitemap files directly from the app. Useful when you’ve generated to public/sitemaps/ (filesystem adapter) and want proper Content-Type, gzip handling, and XSL stylesheet routing without editing your web-server config.

Basic usage

# config/application.rb (Rails)
config.middleware.use SiteMaps::Middleware, adapter: -> { SiteMaps.current_adapter }

Or inline in config.ru:

require 'site_maps'

use SiteMaps::Middleware, adapter: SiteMaps.current_adapter
run MyApp

Options

use SiteMaps::Middleware,
  adapter:        SiteMaps.current_adapter,
  public_prefix:  nil,
  storage_prefix: nil,
  x_robots_tag:   'noindex, follow',
  cache_control:  'public, max-age=3600'

Option	Purpose
`adapter`	Adapter instance (or a callable returning one — useful if the adapter is reconfigured at boot).
`public_prefix`	Strip from request path before lookup — e.g. `/sitemap` if your app mounts them under a sub-path.
`storage_prefix`	Prepend to the lookup key — e.g. `tenants/acme` for multi-tenant layouts.
`x_robots_tag`	`X-Robots-Tag` header added to served files.
`cache_control`	`Cache-Control` header.

Behavior

The middleware intercepts requests for *.xml and *.xml.gz files:

Matches → serve from the adapter with Content-Type: application/xml, plus X-Robots-Tag and Cache-Control.
Gzipped sources → auto-decompress on serve so XSL stylesheets render in the browser. Clients asking for .xml.gz still get the compressed bytes.
Doesn’t match → env passes through to @app.call.

XSL stylesheets

The middleware also serves the built-in XSL stylesheets — pretty sitemap rendering for human visitors — at their referenced paths. Configure their URLs via:

configure do |config|
  config.xsl_stylesheet_url       = '/_sitemap-stylesheet.xsl'
  config.xsl_index_stylesheet_url = '/_sitemap-index-stylesheet.xsl'
end

Multi-tenant routing

For per-tenant sitemaps stored under subpaths:

use SiteMaps::Middleware,
  adapter:        per_request_adapter,
  storage_prefix: ->(request) { "tenants/#{request.host.split('.').first}" }

If the adapter itself already scopes paths by tenant, no prefix is needed — just point it at the right one for each request.

robots.txt integration

Emit a Sitemap: directive for the generated file:

# config.ru or a controller
SiteMaps::RobotsTxt.sitemap_directive('https://example.com/sitemap.xml')
# => "Sitemap: https://example.com/sitemap.xml"

SiteMaps::RobotsTxt.render(
  sitemap_url:      'https://example.com/sitemap.xml',
  extra_directives: ['Disallow: /admin']
)
# => "Sitemap: https://example.com/sitemap.xml\nDisallow: /admin"