base.rb

require 'thread'
require 'time'
require 'uri'
require 'rack'
require 'rack/builder'

module Sinatra
  VERSION = '0.9.0.5'

  # The request object. See Rack::Request for more info:
  # http://rack.rubyforge.org/doc/classes/Rack/Request.html
  class Request < Rack::Request
    def user_agent
      @env['HTTP_USER_AGENT']
    end

    def accept
      @env['HTTP_ACCEPT'].to_s.split(',').map { |a| a.strip }
    end

    # Override Rack 0.9.x's #params implementation (see #72 in lighthouse)
    def params
      self.GET.update(self.POST)
    rescue EOFError => boom
      self.GET
    end
  end

  # The response object. See Rack::Response and Rack::ResponseHelpers for
  # more info:
  # http://rack.rubyforge.org/doc/classes/Rack/Response.html
  # http://rack.rubyforge.org/doc/classes/Rack/Response/Helpers.html
  class Response < Rack::Response
    def initialize
      @status, @body = 200, []
      @header = Rack::Utils::HeaderHash.new({'Content-Type' => 'text/html'})
    end

    def write(str)
      @body << str.to_s
      str
    end

    def finish
      @body = block if block_given?
      if [204, 304].include?(status.to_i)
        header.delete "Content-Type"
        [status.to_i, header.to_hash, []]
      else
        body = @body || []
        body = [body] if body.respond_to? :to_str
        if header["Content-Length"].nil? && body.respond_to?(:to_ary)
          header["Content-Length"] = body.to_ary.
            inject(0) { |len, part| len + part.bytesize }.to_s
        end
        [status.to_i, header.to_hash, body]
      end
    end
  end

  class NotFound < NameError #:nodoc:
    def code ; 404 ; end
  end

  # Methods available to routes, before filters, and views.
  module Helpers
    # Set or retrieve the response status code.
    def status(value=nil)
      response.status = value if value
      response.status
    end

    # Set or retrieve the response body. When a block is given,
    # evaluation is deferred until the body is read with #each.
    def body(value=nil, &block)
      if block_given?
        def block.each ; yield call ; end
        response.body = block
      else
        response.body = value
      end
    end

    # Halt processing and redirect to the URI provided.
    def redirect(uri, *args)
      status 302
      response['Location'] = uri
      halt(*args)
    end

    # Halt processing and return the error status provided.
    def error(code, body=nil)
      code, body    = 500, code.to_str if code.respond_to? :to_str
      response.body = body unless body.nil?
      halt code
    end

    # Halt processing and return a 404 Not Found.
    def not_found(body=nil)
      error 404, body
    end

    # Access the underlying Rack session.
    def session
      env['rack.session'] ||= {}
    end

    # Look up a media type by file extension in Rack's mime registry.
    def media_type(type)
      Base.media_type(type)
    end

    # Set the Content-Type of the response body given a media type or file
    # extension.
    def content_type(type, params={})
      media_type = self.media_type(type)
      fail "Unknown media type: %p" % type if media_type.nil?
      if params.any?
        params = params.collect { |kv| "%s=%s" % kv }.join(', ')
        response['Content-Type'] = [media_type, params].join(";")
      else
        response['Content-Type'] = media_type
      end
    end

    # Set the Content-Disposition to "attachment" with the specified filename,
    # instructing the user agents to prompt to save.
    def attachment(filename=nil)
      response['Content-Disposition'] = 'attachment'
      if filename
        params = '; filename="%s"' % File.basename(filename)
        response['Content-Disposition'] << params
      end
    end

    # Use the contents of the file at +path+ as the response body.
    def send_file(path, opts={})
      stat = File.stat(path)
      last_modified stat.mtime

      content_type media_type(opts[:type]) ||
        media_type(File.extname(path)) ||
        response['Content-Type'] ||
        'application/octet-stream'

      response['Content-Length'] ||= (opts[:length] || stat.size).to_s

      if opts[:disposition] == 'attachment' || opts[:filename]
        attachment opts[:filename] || path
      elsif opts[:disposition] == 'inline'
        response['Content-Disposition'] = 'inline'
      end

      halt StaticFile.open(path, 'rb')
    rescue Errno::ENOENT
      not_found
    end

    class StaticFile < ::File #:nodoc:
      alias_method :to_path, :path
      def each
        rewind
        while buf = read(8192)
          yield buf
        end
      end
    end

    # Set the last modified time of the resource (HTTP 'Last-Modified' header)
    # and halt if conditional GET matches. The +time+ argument is a Time,
    # DateTime, or other object that responds to +to_time+.
    #
    # When the current request includes an 'If-Modified-Since' header that
    # matches the time specified, execution is immediately halted with a
    # '304 Not Modified' response.
    def last_modified(time)
      time = time.to_time if time.respond_to?(:to_time)
      time = time.httpdate if time.respond_to?(:httpdate)
      response['Last-Modified'] = time
      halt 304 if time == request.env['HTTP_IF_MODIFIED_SINCE']
      time
    end

    # Set the response entity tag (HTTP 'ETag' header) and halt if conditional
    # GET matches. The +value+ argument is an identifier that uniquely
    # identifies the current version of the resource. The +strength+ argument
    # indicates whether the etag should be used as a :strong (default) or :weak
    # cache validator.
    #
    # When the current request includes an 'If-None-Match' header with a
    # matching etag, execution is immediately halted. If the request method is
    # GET or HEAD, a '304 Not Modified' response is sent.
    def etag(value, kind=:strong)
      raise TypeError, ":strong or :weak expected" if ![:strong,:weak].include?(kind)
      value = '"%s"' % value
      value = 'W/' + value if kind == :weak
      response['ETag'] = value

      # Conditional GET check
      if etags = env['HTTP_IF_NONE_MATCH']
        etags = etags.split(/\s*,\s*/)
        halt 304 if etags.include?(value) || etags.include?('*')
      end
    end

    ## Sugar for redirect (example:  redirect back)
    def back ; request.referer ; end

  end

  # Template rendering methods. Each method takes a the name of a template
  # to render as a Symbol and returns a String with the rendered output.
  module Templates
    def erb(template, options={})
      require 'erb' unless defined? ::ERB
      render :erb, template, options
    end

    def haml(template, options={})
      require 'haml' unless defined? ::Haml
      options[:options] ||= self.class.haml if self.class.respond_to? :haml
      render :haml, template, options
    end

    def sass(template, options={}, &block)
      require 'sass' unless defined? ::Sass
      options[:layout] = false
      render :sass, template, options
    end

    def builder(template=nil, options={}, &block)
      require 'builder' unless defined? ::Builder
      options, template = template, nil if template.is_a?(Hash)
      template = lambda { block } if template.nil?
      render :builder, template, options
    end

  private
    def render(engine, template, options={}) #:nodoc:
      data   = lookup_template(engine, template, options)
      output = __send__("render_#{engine}", template, data, options)
      layout, data = lookup_layout(engine, options)
      if layout
        __send__("render_#{engine}", layout, data, options) { output }
      else
        output
      end
    end

    def lookup_template(engine, template, options={})
      case template
      when Symbol
        if cached = self.class.templates[template]
          lookup_template(engine, cached, options)
        else
          ::File.read(template_path(engine, template, options))
        end
      when Proc
        template.call
      when String
        template
      else
        raise ArgumentError
      end
    end

    def lookup_layout(engine, options)
      return if options[:layout] == false
      options.delete(:layout) if options[:layout] == true
      template = options[:layout] || :layout
      data     = lookup_template(engine, template, options)
      [template, data]
    rescue Errno::ENOENT
      nil
    end

    def template_path(engine, template, options={})
      views_dir =
        options[:views_directory] || self.options.views || "./views"
      "#{views_dir}/#{template}.#{engine}"
    end

    def render_erb(template, data, options, &block)
      original_out_buf = @_out_buf
      data = data.call if data.kind_of? Proc

      instance = ::ERB.new(data, nil, nil, '@_out_buf')
      locals = options[:locals] || {}
      locals_assigns = locals.to_a.collect { |k,v| "#{k} = locals[:#{k}]" }

      src = "#{locals_assigns.join("\n")}\n#{instance.src}"
      eval src, binding, '(__ERB__)', locals_assigns.length + 1
      @_out_buf, result = original_out_buf, @_out_buf
      result
    end

    def render_haml(template, data, options, &block)
      engine = ::Haml::Engine.new(data, options[:options] || {})
      engine.render(self, options[:locals] || {}, &block)
    end

    def render_sass(template, data, options, &block)
      engine = ::Sass::Engine.new(data, options[:sass] || {})
      engine.render
    end

    def render_builder(template, data, options, &block)
      xml = ::Builder::XmlMarkup.new(:indent => 2)
      if data.respond_to?(:to_str)
        eval data.to_str, binding, '<BUILDER>', 1
      elsif data.kind_of?(Proc)
        data.call(xml)
      end
      xml.target!
    end
  end

  # Base class for all Sinatra applications and middleware.
  class Base
    include Rack::Utils
    include Helpers
    include Templates

    attr_accessor :app

    def initialize(app=nil)
      @app = app
      yield self if block_given?
    end

    # Rack call interface.
    def call(env)
      dup.call!(env)
    end

    attr_accessor :env, :request, :response, :params

    def call!(env)
      @env      = env
      @request  = Request.new(env)
      @response = Response.new
      @params   = nil

      invoke { dispatch! }
      invoke { error_block!(response.status) }

      # never respond with a body on HEAD requests
      @response.body = [] if @env['REQUEST_METHOD'] == 'HEAD'

      @response.finish
    end

    # Access options defined with Base.set.
    def options
      self.class
    end

    # Exit the current block and halt the response.
    def halt(*response)
      response = response.first if response.length == 1
      throw :halt, response
    end

    # Pass control to the next matching route.
    def pass
      throw :pass
    end

    # Forward the request to the downstream app -- middleware only.
    def forward
      fail "downstream app not set" unless @app.respond_to? :call
      status, headers, body = @app.call(@request.env)
      @response.status = status
      @response.body = body
      headers.each { |k, v| @response[k] = v }
      nil
    end

  private
    # Run before filters and then locate and run a matching route.
    def route!
      @params = nested_params(@request.params)

      # before filters
      self.class.filters.each { |block| instance_eval(&block) }

      # routes
      if routes = self.class.routes[@request.request_method]
        original_params = @params
        path            = unescape(@request.path_info)

        routes.each do |pattern, keys, conditions, block|
          if match = pattern.match(path)
            values = match.captures.to_a
            params =
              if keys.any?
                keys.zip(values).inject({}) do |hash,(k,v)|
                  if k == 'splat'
                    (hash[k] ||= []) << v
                  else
                    hash[k] = v
                  end
                  hash
                end
              elsif values.any?
                {'captures' => values}
              else
                {}
              end
            @params = original_params.merge(params)
            @block_params = values

            catch(:pass) do
              conditions.each { |cond|
                throw :pass if instance_eval(&cond) == false }
              throw :halt, instance_eval(&block)
            end
          end
        end
      end

      # No matching route found or all routes passed -- forward downstream
      # when running as middleware; 404 when running as normal app.
      if @app
        forward
      else
        raise NotFound
      end
    end

    def nested_params(params)
      return indifferent_hash.merge(params) if !params.keys.join.include?('[')
      params.inject indifferent_hash do |res, (key,val)|
        if key.include?('[')
          head = key.split(/[\]\[]+/)
          last = head.pop
          head.inject(res){ |hash,k| hash[k] ||= indifferent_hash }[last] = val
        else
          res[key] = val
        end
        res
      end
    end

    def indifferent_hash
      Hash.new {|hash,key| hash[key.to_s] if Symbol === key }
    end

    # Run the block with 'throw :halt' support and apply result to the response.
    def invoke(&block)
      res = catch(:halt) { instance_eval(&block) }
      return if res.nil?

      case
      when res.respond_to?(:to_str)
        @response.body = [res]
      when res.respond_to?(:to_ary)
        res = res.to_ary
        if Fixnum === res.first
          if res.length == 3
            @response.status, headers, body = res
            @response.body = body if body
            headers.each { |k, v| @response.headers[k] = v } if headers
          elsif res.length == 2
            @response.status = res.first
            @response.body   = res.last
          else
            raise TypeError, "#{res.inspect} not supported"
          end
        else
          @response.body = res
        end
      when res.respond_to?(:each)
        @response.body = res
      when (100...599) === res
        @response.status = res
      end

      res
    end

    # Dispatch a request with error handling.
    def dispatch!
      route!
    rescue NotFound => boom
      handle_not_found!(boom)
    rescue ::Exception => boom
      handle_exception!(boom)
    end

    def handle_not_found!(boom)
      @env['sinatra.error'] = boom
      @response.status      = 404
      @response.body        = ['<h1>Not Found</h1>']
      error_block! boom.class, NotFound
    end

    def handle_exception!(boom)
      @env['sinatra.error'] = boom

      dump_errors!(boom) if options.dump_errors?
      raise boom         if options.raise_errors?

      @response.status = 500
      error_block! boom.class, Exception
    end

    # Find an custom error block for the key(s) specified.
    def error_block!(*keys)
      errmap = self.class.errors
      keys.each do |key|
        if block = errmap[key]
          res = instance_eval(&block)
          return res
        end
      end
      nil
    end

    def dump_errors!(boom)
      backtrace = clean_backtrace(boom.backtrace)
      msg = ["#{boom.class} - #{boom.message}:",
        *backtrace].join("\n ")
      @env['rack.errors'].write(msg)
    end

    def clean_backtrace(trace)
      return trace unless options.clean_trace?

      trace.reject { |line|
        line =~ /lib\/sinatra.*\.rb/ ||
          (defined?(Gem) && line.include?(Gem.dir))
      }.map! { |line| line.gsub(/^\.\//, '') }
    end

    @routes     = {}
    @filters    = []
    @conditions = []
    @templates  = {}
    @middleware = []
    @callsite   = nil
    @errors     = {}

    class << self
      attr_accessor :routes, :filters, :conditions, :templates,
        :middleware, :errors

    public
      def set(option, value=self)
        if value.kind_of?(Proc)
          metadef(option, &value)
          metadef("#{option}?") { !!__send__(option) }
          metadef("#{option}=") { |val| set(option, Proc.new{val}) }
        elsif value == self && option.respond_to?(:to_hash)
          option.to_hash.each { |k,v| set(k, v) }
        elsif respond_to?("#{option}=")
          __send__ "#{option}=", value
        else
          set option, Proc.new{value}
        end
        self
      end

      def enable(*opts)
        opts.each { |key| set(key, true) }
      end

      def disable(*opts)
        opts.each { |key| set(key, false) }
      end

      def error(codes=Exception, &block)
        if codes.respond_to? :each
          codes.each { |err| error(err, &block) }
        else
          @errors[codes] = block
        end
      end

      def not_found(&block)
        error 404, &block
      end

      def template(name, &block)
        templates[name] = block
      end

      def layout(name=:layout, &block)
        template name, &block
      end

      def use_in_file_templates!
        ignore = [/lib\/sinatra.*\.rb/, /\(.*\)/, /rubygems\/custom_require\.rb/]
        file = caller.
          map  { |line| line.sub(/:\d+.*$/, '') }.
          find { |line| ignore.all? { |pattern| line !~ pattern } }
        if data = ::IO.read(file).split('__END__')[1]
          data.gsub!(/\r\n/, "\n")
          template = nil
          data.each_line do |line|
            if line =~ /^@@\s*(.*)/
              template = templates[$1.to_sym] = ''
            elsif template
              template << line
            end
          end
        end
      end

      # Look up a media type by file extension in Rack's mime registry.
      def media_type(type)
        return type if type.nil? || type.to_s.include?('/')
        type = ".#{type}" unless type.to_s[0] == ?.
        Rack::Mime.mime_type(type, nil)
      end

      def before(&block)
        @filters << block
      end

      def condition(&block)
        @conditions << block
      end

   private
      def host_name(pattern)
        condition { pattern === request.host }
      end

      def user_agent(pattern)
        condition {
          if request.user_agent =~ pattern
            @params[:agent] = $~[1..-1]
            true
          else
            false
          end
        }
      end

      def accept_mime_types(types)
        types = [types] unless types.kind_of? Array
        types.map!{|t| media_type(t)}

        condition {
          matching_types = (request.accept & types)
          unless matching_types.empty?
            response.headers['Content-Type'] = matching_types.first
            true
          else
            false
          end
        }
      end

    public
      def get(path, opts={}, &block)
        conditions = @conditions.dup
        route('GET', path, opts, &block)

        @conditions = conditions
        route('HEAD', path, opts, &block)
      end

      def put(path, opts={}, &bk); route 'PUT', path, opts, &bk; end
      def post(path, opts={}, &bk); route 'POST', path, opts, &bk; end
      def delete(path, opts={}, &bk); route 'DELETE', path, opts, &bk; end
      def head(path, opts={}, &bk); route 'HEAD', path, opts, &bk; end

    private
      def route(verb, path, opts={}, &block)
        host_name  opts[:host]  if opts.key?(:host)
        user_agent opts[:agent] if opts.key?(:agent)
        accept_mime_types opts[:provides] if opts.key?(:provides)

        pattern, keys = compile(path)
        conditions, @conditions = @conditions, []

        define_method "#{verb} #{path}", &block
        unbound_method = instance_method("#{verb} #{path}")
        block =
          if block.arity != 0
            lambda { unbound_method.bind(self).call(*@block_params) }
          else
            lambda { unbound_method.bind(self).call }
          end

        (routes[verb] ||= []).
          push([pattern, keys, conditions, block]).last
      end

      def compile(path)
        keys = []
        if path.respond_to? :to_str
          special_chars = %w{. + ( )}
          pattern =
            path.gsub(/((:\w+)|[\*#{special_chars.join}])/) do |match|
              case match
              when "*"
                keys << 'splat'
                "(.*?)"
              when *special_chars
                Regexp.escape(match)
              else
                keys << $2[1..-1]
                "([^/?&#]+)"
              end
            end
          [/^#{pattern}$/, keys]
        elsif path.respond_to? :match
          [path, keys]
        else
          raise TypeError, path
        end
      end

    public
      def helpers(*extensions, &block)
        class_eval(&block) if block_given?
        include *extensions
      end

      def register(*extensions, &block)
        extensions << Module.new(&block) if block
        extend *extensions
      end

      def development? ; environment == :development ; end
      def test? ; environment == :test ; end
      def production? ; environment == :production ; end

      def configure(*envs, &block)
        return if reloading?
        yield if envs.empty? || envs.include?(environment.to_sym)
      end

      def use(middleware, *args, &block)
        reset_middleware
        @middleware << [middleware, args, block]
      end

      def run!(options={})
        set options
        handler      = detect_rack_handler
        handler_name = handler.name.gsub(/.*::/, '')
        puts "== Sinatra/#{Sinatra::VERSION} has taken the stage " +
          "on #{port} for #{environment} with backup from #{handler_name}" unless handler_name =~/cgi/i
        handler.run self, :Host => host, :Port => port do |server|
          trap(:INT) do
            ## Use thins' hard #stop! if available, otherwise just #stop
            server.respond_to?(:stop!) ? server.stop! : server.stop
            puts "\n== Sinatra has ended his set (crowd applauds)" unless handler_name =~/cgi/i
          end
        end
      rescue Errno::EADDRINUSE => e
        puts "== Someone is already performing on port #{port}!"
      end

      def call(env)
        synchronize do
          reload! if reload?
          construct_middleware if @callsite.nil?
          @callsite.call(env)
        end
      end

      def reload!
        @reloading = true
        superclass.send :reset!, self
        $LOADED_FEATURES.delete("sinatra.rb")
        ::Kernel.load app_file
        @reloading = false
      end

    private
      def detect_rack_handler
        servers = Array(self.server)
        servers.each do |server_name|
          begin
            return Rack::Handler.get(server_name)
          rescue LoadError
          rescue NameError
          end
        end
        fail "Server handler (#{servers.join(',')}) not found."
      end

      def construct_middleware(builder=Rack::Builder.new)
        builder.use Rack::Session::Cookie if sessions?
        builder.use Rack::CommonLogger if logging?
        builder.use Rack::MethodOverride if methodoverride?
        @middleware.each { |c, args, bk| builder.use(c, *args, &bk) }
        builder.run new
        @callsite = builder.to_app
      end

      def reset_middleware
        @callsite = nil
      end

      def reset!(subclass = self)
        subclass.routes     = dupe_routes
        subclass.templates  = templates.dup
        subclass.conditions = []
        subclass.filters    = filters.dup
        subclass.errors     = errors.dup
        subclass.middleware = middleware.dup
        subclass.send :reset_middleware
      end

      def inherited(subclass)
        reset!(subclass)
        super
      end

      def reloading?
        @reloading ||= false
      end

      @@mutex = Mutex.new
      def synchronize(&block)
        if lock?
          @@mutex.synchronize(&block)
        else
          yield
        end
      end

      def dupe_routes
        routes.inject({}) do |hash,(request_method,routes)|
          hash[request_method] = routes.dup
          hash
        end
      end

      def metadef(message, &block)
        (class << self; self; end).
          send :define_method, message, &block
      end
    end

    set :raise_errors, true
    set :dump_errors, false
    set :clean_trace, true
    set :sessions, false
    set :logging, false
    set :methodoverride, false
    set :static, false
    set :environment, (ENV['RACK_ENV'] || :development).to_sym

    set :run, false
    set :server, %w[thin mongrel webrick]
    set :host, '0.0.0.0'
    set :port, 4567

    set :app_file, nil
    set :root, Proc.new { app_file && File.expand_path(File.dirname(app_file)) }
    set :views, Proc.new { root && File.join(root, 'views') }
    set :public, Proc.new { root && File.join(root, 'public') }
    set :reload, Proc.new { app_file? && app_file !~ /\.ru$/i && development? }
    set :lock, Proc.new { reload? }

    # static files route
    get(/.*[^\/]$/) do
      pass unless options.static? && options.public?
      path = options.public + unescape(request.path_info)
      pass unless File.file?(path)
      send_file path, :disposition => nil
    end

    error ::Exception do
      response.status = 500
      content_type 'text/html'
      '<h1>Internal Server Error</h1>'
    end

    configure :development do
      get '/__sinatra__/:image.png' do
        filename = File.dirname(__FILE__) + "/images/#{params[:image]}.png"
        content_type :png
        send_file filename
      end

      error NotFound do
        (<<-HTML).gsub(/^ {8}/, '')
        <!DOCTYPE html>
        <html>
        <head>
          <style type="text/css">
          body { text-align:center;font-family:helvetica,arial;font-size:22px;
            color:#888;margin:20px}
          #c {margin:0 auto;width:500px;text-align:left}
          </style>
        </head>
        <body>
          <h2>Sinatra doesn't know this ditty.</h2>
          <img src='/__sinatra__/404.png'>
          <div id="c">
            Try this:
            <pre>#{request.request_method.downcase} '#{request.path_info}' do\n  "Hello World"\nend</pre>
          </div>
        </body>
        </html>
        HTML
      end

      error do
        next unless err = request.env['sinatra.error']
        heading = err.class.name + ' - ' + err.message.to_s
        (<<-HTML).gsub(/^ {8}/, '')
        <!DOCTYPE html>
        <html>
        <head>
          <style type="text/css">
            body {font-family:verdana;color:#333}
            #c {margin-left:20px}
            h1 {color:#1D6B8D;margin:0;margin-top:-30px}
            h2 {color:#1D6B8D;font-size:18px}
            pre {border-left:2px solid #ddd;padding-left:10px;color:#000}
            img {margin-top:10px}
          </style>
        </head>
        <body>
          <div id="c">
            <img src="/__sinatra__/500.png">
            <h1>#{escape_html(heading)}</h1>
            <pre>#{escape_html(clean_backtrace(err.backtrace) * "\n")}</pre>
            <h2>Params</h2>
            <pre>#{escape_html(params.inspect)}</pre>
          </div>
        </body>
        </html>
        HTML
      end
    end
  end

  # Base class for classic style (top-level) applications.
  class Default < Base
    set :raise_errors, Proc.new { test? }
    set :dump_errors, true
    set :sessions, false
    set :logging, Proc.new { ! test? }
    set :methodoverride, true
    set :static, true
    set :run, Proc.new { ! test? }

    def self.register(*extensions, &block) #:nodoc:
      added_methods = extensions.map {|m| m.public_instance_methods }.flatten
      Delegator.delegate *added_methods
      super(*extensions, &block)
    end
  end

  # The top-level Application. All DSL methods executed on main are delegated
  # to this class.
  class Application < Default
  end

  module Delegator #:nodoc:
    def self.delegate(*methods)
      methods.each do |method_name|
        eval <<-RUBY, binding, '(__DELEGATE__)', 1
          def #{method_name}(*args, &b)
            ::Sinatra::Application.#{method_name}(*args, &b)
          end
          private :#{method_name}
        RUBY
      end
    end

    delegate :get, :put, :post, :delete, :head, :template, :layout, :before,
             :error, :not_found, :configures, :configure, :set, :set_option,
             :set_options, :enable, :disable, :use, :development?, :test?,
             :production?, :use_in_file_templates!, :helpers
  end

  def self.new(base=Base, options={}, &block)
    base = Class.new(base)
    base.send :class_eval, &block if block_given?
    base
  end

  # Extend the top-level DSL with the modules provided.
  def self.register(*extensions, &block)
    Default.register(*extensions, &block)
  end

  # Include the helper modules provided in Sinatra's request context.
  def self.helpers(*extensions, &block)
    Default.helpers(*extensions, &block)
  end
end

class String #:nodoc:
  # Define String#each under 1.9 for Rack compatibility. This should be
  # removed once Rack is fully 1.9 compatible.
  alias_method :each, :each_line  unless ''.respond_to? :each

  # Define String#bytesize as an alias to String#length for Ruby 1.8.6 and
  # earlier.
  alias_method :bytesize, :length unless ''.respond_to? :bytesize
end