# File lib/facets/uri.rb, line 109
  def cgi_escape(string)
    string.gsub(/([^ a-zA-Z0-9_.-]+)/n) do
      '%' + $1.unpack('H2' * $1.size).join('%').upcase
    end.tr(' ', '+')
  end

# File lib/facets/uri.rb, line 125
  def cgi_parse(query)
    params = Hash.new([].freeze)

    query.split(/[&;]/n).each do |pairs|
      key, value = pairs.split('=',2).collect{|v| cgi_unescape(v) }
      if params.has_key?(key)
        params[key].push(value)
      else
        params[key] = [value]
      end
    end

    params
  end

# File lib/facets/uri.rb, line 117
  def cgi_unescape(string)
    string.tr('+', ' ').gsub(/((?:%[0-9a-fA-F]{2})+)/n) do
      [$1.delete('%')].pack('H*')
    end
  end

# File lib/facets/uri.rb, line 169
  def chomp_query_string(uri)
    return nil unless uri
    query_string = self.get_query_string(uri)
    return uri.dup.chomp("?#{query_string}")
  end

# File lib/facets/uri.rb, line 33
  def decode(uri)
    # gmosx: hmm is this needed?
    # guard against invalid filenames for example pictures with
    # spaces uploaded by users
    escaped_uri = uri.gsub(/ /, "+")

    if md = URI::REGEXP::REL_URI.match(escaped_uri)

      path = "#{md[5]}#{md[6]}"
      type = File.extname(path)
      query_string = md[7]

#      real_path = "#{$root_dir}/#{path}"

      parameters = URI.query_to_hash(query_string)
      path.gsub!(/\+/, " ")

      return [path, type, parameters, query_string]

    end # match

    # this is usefull for uncovering bugs!
    raise ArgumentError.new("the parameter '#{uri}' is not a valid uri")
  end

# File lib/facets/uri.rb, line 149
  def get_query_string(uri)
    return nil unless uri
    # gmosx: INVESTIGATE ruby's URI seems to differently handle
    # abs and rel uris.
    if md = URI::REGEXP::ABS_URI.match(uri)
      return md[8]
    elsif md = URI::REGEXP::REL_URI.match(uri)
      return md[7]
    end
    return nil
  end

# File lib/facets/uri.rb, line 94
  def hash_to_query(parameters)
    return '' unless parameters
    pairs = []
    parameters.each do |param, value|
      pairs << "#{param}=#{cgi_escape(value.to_s)}"
    end
    #return pairs.join('&')
    return pairs.join(";")
  end

# File lib/facets/uri.rb, line 70
  def query_to_hash(query_string)
    return {} unless query_string

    query_parameters = cgi_parse(query_string)

    query_parameters.each { |key, val|
      # replace the array with an object
      query_parameters[key] = val[0] if 1 == val.length
    }

    # set default value to nil! cgi sets this to []
    query_parameters.default = nil

    return query_parameters
  end

# File lib/facets/uri.rb, line 188
  def update_query_string(uri, parameters)
    query_string = self.get_query_string(uri)
    rest = uri.dup.gsub(/\?#{query_string}/, "")

    hash = self.query_string_to_hash(query_string)
    hash.update(parameters)
    query_string = self.hash_to_query_string(hash)

    unless query_string.blank?
      return "#{rest}?#{query_string}"
    else
      return rest
    end
  end

# File lib/facets/uri.rb, line 208
  def update_request_uri(request, parameters)
    hash = request.parameters.dup()
    hash.update(parameters)

    # use this in hash_to_querystring.
    query_string = hash.collect { |k, v|
      "#{k}=#{v}"
    }.join(";")

    #return "#{request.translated_uri}?#{query_string}"
    return "#{request.path}?#{query_string}"
  end