Module Rack::Utils
In: lib/rack/utils.rb

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

Methods

Classes and Modules

Module Rack::Utils::Multipart
Class Rack::Utils::Context
Class Rack::Utils::HeaderHash

Constants

HTTP_STATUS_CODES = { 100 => 'Continue', 101 => 'Switching Protocols', 200 => 'OK', 201 => 'Created', 202 => 'Accepted', 203 => 'Non-Authoritative Information', 204 => 'No Content', 205 => 'Reset Content', 206 => 'Partial Content', 300 => 'Multiple Choices', 301 => 'Moved Permanently', 302 => 'Moved Temporarily', 303 => 'See Other', 304 => 'Not Modified', 305 => 'Use Proxy', 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 Time-out', 409 => 'Conflict', 410 => 'Gone', 411 => 'Length Required', 412 => 'Precondition Failed', 413 => 'Request Entity Too Large', 414 => 'Request-URI Too Large', 415 => 'Unsupported Media Type', 500 => 'Internal Server Error', 501 => 'Not Implemented', 502 => 'Bad Gateway', 503 => 'Service Unavailable', 504 => 'Gateway Time-out', 505 => 'HTTP Version not supported'   Every standard HTTP code mapped to the appropriate message. Stolen from Mongrel.

Public Instance methods

[Source]

    # File lib/rack/utils.rb, line 53
53:     def build_query(params)
54:       params.map { |k, v|
55:         if v.class == Array
56:           build_query(v.map { |x| [k, x] })
57:         else
58:           escape(k) + "=" + escape(v)
59:         end
60:       }.join("&")
61:     end

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).

[Source]

    # File lib/rack/utils.rb, line 11
11:     def escape(s)
12:       s.to_s.gsub(/([^ a-zA-Z0-9_.-]+)/n) {
13:         '%'+$1.unpack('H2'*$1.size).join('%').upcase
14:       }.tr(' ', '+')
15:     end

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

[Source]

    # File lib/rack/utils.rb, line 65
65:     def escape_html(string)
66:       string.to_s.gsub("&", "&").
67:         gsub("<", "&lt;").
68:         gsub(">", "&gt;").
69:         gsub("'", "&#39;").
70:         gsub('"', "&quot;")
71:     end

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 ’&;’).

[Source]

    # File lib/rack/utils.rb, line 32
32:     def parse_query(qs, d = '&;')
33:       params = {}
34:       
35:       (qs || '').split(/[#{d}] */n).each do |p|
36:         k, v = unescape(p).split('=', 2)
37:         
38:         if cur = params[k]
39:           if cur.class == Array
40:             params[k] << v
41:           else
42:             params[k] = [cur, v]
43:           end
44:         else
45:           params[k] = v
46:         end
47:       end
48:       
49:       return params
50:     end

[Source]

     # File lib/rack/utils.rb, line 74
 74:     def select_best_encoding(available_encodings, accept_encoding)
 75:       # http://www.w3.org/Protocols/rfc2616/rfc2616-sec14.html
 76: 
 77:       expanded_accept_encoding =
 78:         accept_encoding.map { |m, q|
 79:           if m == "*"
 80:             (available_encodings - accept_encoding.map { |m2, _| m2 }).map { |m2| [m2, q] }
 81:           else
 82:             [[m, q]]
 83:           end
 84:         }.inject([]) { |mem, list|
 85:           mem + list
 86:         }
 87: 
 88:       encoding_candidates = expanded_accept_encoding.sort_by { |_, q| -q }.map { |m, _| m }
 89: 
 90:       unless encoding_candidates.include?("identity")
 91:         encoding_candidates.push("identity")
 92:       end
 93: 
 94:       expanded_accept_encoding.find_all { |m, q|
 95:         q == 0.0
 96:       }.each { |m, _|
 97:         encoding_candidates.delete(m)
 98:       }
 99: 
100:       return (encoding_candidates & available_encodings)[0]
101:     end

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

[Source]

    # File lib/rack/utils.rb, line 19
19:     def unescape(s)
20:       s.tr('+', ' ').gsub(/((?:%[0-9a-fA-F]{2})+)/n){
21:         [$1.delete('%')].pack('H*')
22:       }
23:     end

[Validate]