gistfile1.rb

# put this in RAILS_ROOT/lib

module AccessToken
  
  class << self
    def current=(token)
      Thread.current[:token] = token
    end
    
    def current
      Thread.current[:token] ||= ""
    end
  end
  
end

# put this in RAILS_ROOT/lib/routing_filter

require 'i18n'
require 'routing_filter/base'

module RoutingFilter
  class Token < Base

    def around_recognize(path, env, &block)
      token = extract_token!(path)                    # remove the token from the beginning of the path
      returning yield do |params|                     # invoke the given block (calls more filters and finally routing)
        params[:token] = token if token               # set recognized token to the resulting params hash
      end
    end

    def around_generate(*args, &block)
      token = args.extract_options!.delete(:token)    # extract the passed :token option
      token = AccessToken.current if token.nil?       # default to I18n.token when token is nil (could also be false)

      returning yield do |result|
        if token
          url = result.is_a?(Array) ? result.first : result
          prepend_token!(url, token)
        end
      end
    end

    protected

      def extract_token!(path)
        path.sub! /([a-z\d]+\-[a-z\d]+\-[a-z\d]+\-[a-z\d]+\-[a-z\d]+)\//, ''
        $1
      end

      def prepend_token!(url, token)
        url.sub!(%r(^(http.?://[^/]*)?(.*))) { "#{$1}/#{token}#{$2}" }
      end
  end
end

# put this in your application_controller

before_filter :set_token

protected

  def set_token
    AccessToken.current = params[:token].to_sym if params[:token]
  end
  
# add this to your routes.rb

map.filter :token