url_for

# File actionpack/lib/action_dispatch/http/url.rb, line 23
        def url_for(options = {})
          unless options[:host].present? || options[:only_path].present?
            raise ArgumentError, 'Missing host to link to! Please provide the :host parameter, set default_url_options[:host], or set :only_path to true'
          end

          rewritten_url = ""

          unless options[:only_path]
            unless options[:protocol] == false
              rewritten_url << (options[:protocol] || "http")
              rewritten_url << ":" unless rewritten_url.match(%{:|//})
            end
            rewritten_url << "//" unless rewritten_url.match("//")
            rewritten_url << rewrite_authentication(options)
            rewritten_url << host_or_subdomain_and_domain(options)
            rewritten_url << ":#{options.delete(:port)}" if options[:port]
          end

          path = options.delete(:path) || ''

          params = options[:params] || {}
          params.reject! {|k,v| v.to_param.nil? }

          rewritten_url << (options[:trailing_slash] ? path.sub(/\?|\z/) { "/" + $& } : path)
          rewritten_url << "?#{params.to_query}" unless params.empty?
          rewritten_url << "##{Rack::Mount::Utils.escape_uri(options[:anchor].to_param.to_s)}" if options[:anchor]
          rewritten_url
        end