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)

Class Method Summary collapse

Class Method Details

.build_nested_query(value, prefix = nil) ⇒ Object 



112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
 
# File 'lib/rack/utils.rb', line 112

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 



101
102
103
104
105
106
107
108
109
 
# File 'lib/rack/utils.rb', line 101

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 



222
223
224
 
# File 'lib/rack/utils.rb', line 222

def bytesize(string)
  string.bytesize
end

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



202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
 
# File 'lib/rack/utils.rb', line 202

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).



14
15
16
17
18
 
# 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.



132
133
134
135
136
137
138
 
# File 'lib/rack/utils.rb', line 132

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 



69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
 
# File 'lib/rack/utils.rb', line 69

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 



57
58
59
60
61
62
63
64
65
66
 
# File 'lib/rack/utils.rb', line 57

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 ‘&;’).



36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
 
# 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 



141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
 
# File 'lib/rack/utils.rb', line 141

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 



171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
 
# File 'lib/rack/utils.rb', line 171

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

.unescape(s) ⇒ Object

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



22
23
24
25
26
 
# File 'lib/rack/utils.rb', line 22

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