Modularized Helpers, allows enable/disable of self-closing XHTML

tags (<link .../>) by
enable :xhtml
in your Application file

lib/sinatra/static_assets.rb

@@ -3,6 +3,7 @@ require 'sinatra/url_for'
 
 module Sinatra
   module StaticAssets
+    module Helpers
       # In HTML <link> and <img> tags have no end tag.
       # In XHTML, on the contrary, these tags must be properly closed.
       #
@@ -35,13 +36,13 @@ module Sinatra
 
       private
 
-    def tag(name, options = {})
-      start_tag = "<#{name}#{tag_options(options) if options}"
+      def tag(name, local_options = {})
+        start_tag = "<#{name}#{tag_options(local_options) if local_options}"
         if block_given?
           content = yield
           "#{start_tag}>#{content}</#{name}>"
         else
-        "#{start_tag}/>"
+          "#{start_tag}#{"/" if options.xhtml}>"
         end
       end
 
@@ -72,5 +73,11 @@ module Sinatra
 
     end
 
-  helpers StaticAssets
+    def self.registered(app)
+      app.helpers StaticAssets::Helpers
+      app.disable :xhtml
+    end
+  end
+
+  register StaticAssets
 end