Module: Rack::Utils

Included in:
Chunked, ContentLength
Defined in:
lib/rack/utils.rb

Overview

Rack::Utils contains a grab-bag of useful methods for writing web applications adopted from all kinds of Ruby libraries.

Defined Under Namespace

Modules: Multipart Classes: Context, HeaderHash

Constant Summary collapse

DEFAULT_SEP = 
/[&;] */n
HTTP_STATUS_CODES =

Every standard HTTP code mapped to the appropriate message. Generated with:

curl -s http://www.iana.org/assignments/http-status-codes | \
  ruby -ane 'm = /^(\d{3}) +(\S[^\[(]+)/.match($_) and
             puts "      #{m[1]}  => \x27#{m[2].strip}x27,"'

{
  100  => 'Continue',
  101  => 'Switching Protocols',
  102  => 'Processing',
  200  => 'OK',
  201  => 'Created',
  202  => 'Accepted',
  203  => 'Non-Authoritative Information',
  204  => 'No Content',
  205  => 'Reset Content',
  206  => 'Partial Content',
  207  => 'Multi-Status',
  226  => 'IM Used',
  300  => 'Multiple Choices',
  301  => 'Moved Permanently',
  302  => 'Found',
  303  => 'See Other',
  304  => 'Not Modified',
  305  => 'Use Proxy',
  306  => 'Reserved',
  307  => 'Temporary Redirect',
  400  => 'Bad Request',
  401  => 'Unauthorized',
  402  => 'Payment Required',
  403  => 'Forbidden',
  404  => 'Not Found',
  405  => 'Method Not Allowed',
  406  => 'Not Acceptable',
  407  => 'Proxy Authentication Required',
  408  => 'Request Timeout',
  409  => 'Conflict',
  410  => 'Gone',
  411  => 'Length Required',
  412  => 'Precondition Failed',
  413  => 'Request Entity Too Large',
  414  => 'Request-URI Too Long',
  415  => 'Unsupported Media Type',
  416  => 'Requested Range Not Satisfiable',
  417  => 'Expectation Failed',
  422  => 'Unprocessable Entity',
  423  => 'Locked',
  424  => 'Failed Dependency',
  426  => 'Upgrade Required',
  500  => 'Internal Server Error',
  501  => 'Not Implemented',
  502  => 'Bad Gateway',
  503  => 'Service Unavailable',
  504  => 'Gateway Timeout',
  505  => 'HTTP Version Not Supported',
  506  => 'Variant Also Negotiates',
  507  => 'Insufficient Storage',
  510  => 'Not Extended',
}
STATUS_WITH_NO_ENTITY_BODY =

Responses with HTTP status codes that should not have an entity body

Set.new((100..199).to_a << 204 << 304)
SYMBOL_TO_STATUS_CODE = 
HTTP_STATUS_CODES.inject({}) { |hash, (code, message)|
  hash[message.downcase.gsub(/\s|-/, '_').to_sym] = code
  hash
}

Class Method Summary collapse

Class Method Details

.build_nested_query(value, prefix = nil) ⇒ Object 



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# File 'lib/rack/utils.rb', line 111

def build_nested_query(value, prefix = nil)
  case value
  when Array
    value.map { |v|
      build_nested_query(v, "#{prefix}[]")
    }.join("&")
  when Hash
    value.map { |k, v|
      build_nested_query(v, prefix ? "#{prefix}[#{escape(k)}]" : escape(k))
    }.join("&")
  when String
    raise ArgumentError, "value must be a Hash" if prefix.nil?
    "#{prefix}=#{escape(value)}"
  else
    prefix
  end
end

.build_query(params) ⇒ Object 



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# File 'lib/rack/utils.rb', line 100

def build_query(params)
  params.map { |k, v|
    if v.class == Array
      build_query(v.map { |x| [k, x] })
    else
      "#{escape(k)}=#{escape(v)}"
    end
  }.join("&")
end

.bytesize(string) ⇒ Object 



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# File 'lib/rack/utils.rb', line 221

def bytesize(string)
  string.bytesize
end

.delete_cookie_header!(header, key, value = {}) ⇒ Object 



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# File 'lib/rack/utils.rb', line 201

def delete_cookie_header!(header, key, value = {})
  unless Array === header["Set-Cookie"]
    header["Set-Cookie"] = [header["Set-Cookie"]].compact
  end

  header["Set-Cookie"].reject! { |cookie|
    cookie =~ /\A#{escape(key)}=/
  }

  set_cookie_header!(header, key,
             {:value => '', :path => nil, :domain => nil,
               :expires => Time.at(0) }.merge(value))

  nil
end

.escape(s) ⇒ Object

Performs URI escaping so that you can construct proper query strings faster. Use this rather than the cgi.rb version since it’s faster. (Stolen from Camping).



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# File 'lib/rack/utils.rb', line 14

def escape(s)
  s.to_s.gsub(/([^ a-zA-Z0-9_.-]+)/n) {
    '%'+$1.unpack('H2'*bytesize($1)).join('%').upcase
  }.tr(' ', '+')
end

.escape_html(string) ⇒ Object

Escape ampersands, brackets and quotes to their HTML/XML entities.



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# File 'lib/rack/utils.rb', line 131

def escape_html(string)
  string.to_s.gsub("&", "&amp;").
    gsub("<", "&lt;").
    gsub(">", "&gt;").
    gsub("'", "&#39;").
    gsub('"', "&quot;")
end

.normalize_params(params, name, v = nil) ⇒ Object 



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# File 'lib/rack/utils.rb', line 68

def normalize_params(params, name, v = nil)
  name =~ %r(\A[\[\]]*([^\[\]]+)\]*)
  k = $1 || ''
  after = $' || ''

  return if k.empty?

  if after == ""
    params[k] = v
  elsif after == "[]"
    params[k] ||= []
    raise TypeError, "expected Array (got #{params[k].class.name}) for param `#{k}'" unless params[k].is_a?(Array)
    params[k] << v
  elsif after =~ %r(^\[\]\[([^\[\]]+)\]$) || after =~ %r(^\[\](.+)$)
    child_key = $1
    params[k] ||= []
    raise TypeError, "expected Array (got #{params[k].class.name}) for param `#{k}'" unless params[k].is_a?(Array)
    if params[k].last.is_a?(Hash) && !params[k].last.key?(child_key)
      normalize_params(params[k].last, child_key, v)
    else
      params[k] << normalize_params({}, child_key, v)
    end
  else
    params[k] ||= {}
    raise TypeError, "expected Hash (got #{params[k].class.name}) for param `#{k}'" unless params[k].is_a?(Hash)
    params[k] = normalize_params(params[k], after, v)
  end

  return params
end

.parse_nested_query(qs, d = nil) ⇒ Object 



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# File 'lib/rack/utils.rb', line 56

def parse_nested_query(qs, d = nil)
  params = {}

  (qs || '').split(d ? /[#{d}] */n : DEFAULT_SEP).each do |p|
    k, v = unescape(p).split('=', 2)
    normalize_params(params, k, v)
  end

  return params
end

.parse_query(qs, d = nil) ⇒ Object

Stolen from Mongrel, with some small modifications: Parses a query string by breaking it up at the ‘&’ and ‘;’ characters. You can also use this to parse cookies by changing the characters used in the second parameter (which defaults to ‘&;’).



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# File 'lib/rack/utils.rb', line 36

def parse_query(qs, d = nil)
  params = {}

  (qs || '').split(d ? /[#{d}] */n : DEFAULT_SEP).each do |p|
    k, v = p.split('=', 2).map { |x| unescape(x) }
    if cur = params[k]
      if cur.class == Array
        params[k] << v
      else
        params[k] = [cur, v]
      end
    else
      params[k] = v
    end
  end

  return params
end

.select_best_encoding(available_encodings, accept_encoding) ⇒ Object 



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# File 'lib/rack/utils.rb', line 140

def select_best_encoding(available_encodings, accept_encoding)
  # http://www.w3.org/Protocols/rfc2616/rfc2616-sec14.html

  expanded_accept_encoding =
    accept_encoding.map { |m, q|
      if m == "*"
        (available_encodings - accept_encoding.map { |m2, _| m2 }).map { |m2| [m2, q] }
      else
        [[m, q]]
      end
    }.inject([]) { |mem, list|
      mem + list
    }

  encoding_candidates = expanded_accept_encoding.sort_by { |_, q| -q }.map { |m, _| m }

  unless encoding_candidates.include?("identity")
    encoding_candidates.push("identity")
  end

  expanded_accept_encoding.find_all { |m, q|
    q == 0.0
  }.each { |m, _|
    encoding_candidates.delete(m)
  }

  return (encoding_candidates & available_encodings)[0]
end

.set_cookie_header!(header, key, value) ⇒ Object 



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# File 'lib/rack/utils.rb', line 170

def set_cookie_header!(header, key, value)
  case value
  when Hash
    domain  = "; domain="  + value[:domain] if value[:domain]
    path    = "; path="    + value[:path]   if value[:path]
    # According to RFC 2109, we need dashes here.
    # N.B.: cgi.rb uses spaces...
    expires = "; expires=" + value[:expires].clone.gmtime.
      strftime("%a, %d-%b-%Y %H:%M:%S GMT") if value[:expires]
    secure = "; secure"  if value[:secure]
    httponly = "; HttpOnly" if value[:httponly]
    value = value[:value]
  end
  value = [value] unless Array === value
  cookie = escape(key) + "=" +
    value.map { |v| escape v }.join("&") +
    "#{domain}#{path}#{expires}#{secure}#{httponly}"

  case header["Set-Cookie"]
  when Array
    header["Set-Cookie"] << cookie
  when String
    header["Set-Cookie"] = [header["Set-Cookie"], cookie]
  when nil
    header["Set-Cookie"] = cookie
  end

  nil
end

.status_code(status) ⇒ Object 



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# File 'lib/rack/utils.rb', line 396

def status_code(status)
  if status.is_a?(Symbol)
    SYMBOL_TO_STATUS_CODE[status] || 500
  else
    status.to_i
  end
end

.unescape(s) ⇒ Object

Unescapes a URI escaped string. (Stolen from Camping).



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# File 'lib/rack/utils.rb', line 22

def unescape(s)
  s.tr('+', ' ').gsub(/((?:%[0-9a-fA-F]{2})+)/n){
    [$1.delete('%')].pack('H*')
  }
end