sinatra

request.path_info
request.url
env["HTTP_REFERER"]

Sinatra#register
extension.registered(self) if extension.respond_to?(:registered)  

Views / Templates
Templates are assumed to be located directly under the ./views directory. To use a different views directory:

  set :views, File.dirname(__FILE__) + '/templates'
One important thing to remember is that you always have to reference templates with symbols, even if they’re in a subdirectory (in this case, use :'subdir/template'). You must use a symbol because otherwise rendering methods will render any strings passed to them directly.


Accessing Variables in Templates
Templates are evaluated within the same context as route handlers. Instance variables set in route handlers are directly accessible by templates:

  get '/:id' do
    @foo = Foo.find(params[:id])
    haml '%h1= @foo.name'
  end
Or, specify an explicit Hash of local variables:

  get '/:id' do
    foo = Foo.find(params[:id])
    haml '%h1= bar.name', :locals => { :bar => foo }
  end
This is typically used when rendering templates as partials from within other templates.

731     # Returns pass block.
732     def process_route(pattern, keys, conditions)
733       @original_params ||= @params
734       route = @request.route
735       route = '/' if route.empty? and not settings.empty_path_info?
736       if match = pattern.match(route)
737         values = match.captures.to_a
738         params =
739           if keys.any?
740             keys.zip(values).inject({}) do |hash,(k,v)|
741               if k == 'splat'
742                 (hash[k] ||= []) << v
743               else
744                 hash[k] = v
745               end
746               hash
747             end
748           elsif values.any?
749             {'captures' => values}
750           else
751             {}
752           end
753         @params = @original_params.merge(params)
754         @block_params = values
755         catch(:pass) do
756           conditions.each { |cond|
757             throw :pass if instance_eval(&cond) == false }
758           yield
759         end
760       end
761     ensure
762       @params = @original_params
763     end