vendor/plugins/globalize2/lib/globalize/locale/language_tag.rb

   1 # for specifications see http://en.wikipedia.org/wiki/IETF_language_tag
   2 #
   3 # SimpleParser does not implement advanced usages such as grandfathered tags
   4
   5 module Globalize
   6   module Locale
   7     module Rfc4646
   8       SUBTAGS = [:language, :script, :region, :variant, :extension, :privateuse, :grandfathered]
   9       FORMATS = {:language => :downcase, :script => :capitalize, :region => :upcase, :variant => :downcase}
  10     end
  11
  12     class LanguageTag < Struct.new(*Rfc4646::SUBTAGS)
  13       class << self
  14         def parser
  15           @@parser ||= SimpleParser
  16         end
  17
  18         def parser=(parser)
  19           @@parser = parser
  20         end
  21
  22         def tag(tag)
  23           matches = parser.match(tag)
  24           new *matches if matches
  25         end
  26       end
  27
  28       Rfc4646::FORMATS.each do |name, format|
  29         define_method(name) { self[name].send(format) unless self[name].nil? }
  30       end
  31
  32       def to_sym
  33         to_s.to_sym
  34       end
  35
  36       def to_s
  37         @tag ||= to_a.compact.join("-")
  38       end
  39
  40       def to_a
  41         members.collect {|attr| self.send(attr) }
  42       end
  43
  44       def parent
  45         segs = to_a.compact
  46         segs.length < 2 ? nil : LanguageTag.tag(segs[0..(segs.length-2)].join('-'))
  47       end
  48
  49       def parents(include_self = true)
  50         result, parent = [], self.dup
  51         result << parent if include_self
  52         while parent = parent.parent
  53           result << parent
  54         end
  55         result
  56       end
  57
  58       module SimpleParser
  59         PATTERN = %r{\A(?:
  60           ([a-z]{2,3}(?:(?:-[a-z]{3}){0,3})?|[a-z]{4}|[a-z]{5,8}) # language
  61           (?:-([a-z]{4}))?                                        # script
  62           (?:-([a-z]{2}|\d{3}))?                                  # region
  63           (?:-([0-9a-z]{5,8}|\d[0-9a-z]{3}))*                     # variant
  64           (?:-([0-9a-wyz](?:-[0-9a-z]{2,8})+))*                   # extension
  65           (?:-(x(?:-[0-9a-z]{1,8})+))?|                           # privateuse subtag
  66           (x(?:-[0-9a-z]{1,8})+)|                                 # privateuse tag
  67           /* ([a-z]{1,3}(?:-[0-9a-z]{2,8}){1,2}) */               # grandfathered
  68           )\z}xi
  69
  70         class << self
  71           def match(tag)
  72             c = PATTERN.match(tag.to_s).captures
  73             c[0..4] << (c[5].nil? ? c[6] : c[5])  << c[7] # TODO c[7] is grandfathered, throw a NotImplemented exception here?
  74           rescue
  75             false
  76           end
  77         end
  78       end
  79     end
  80   end
  81 end