DuckCorp » CyborgHood

require 'locale'

module CyborgHood

# RFC2616 Accept-Language field

# (used in RFC2798 'preferredLanguage' attribute type)

class AcceptLanguage

LANG_RANGE_Q_PATTERN="([a-z]{1,8}(-[a-z]{1,8})*(;q=)|\*)"

ACCEPT_LANG_PATTERN="#{LANG_RANGE_Q_PATTERN}( *, *#{LANG_RANGE_Q_PATTERN})*"

attr_reader :sorted_lang_list

private :new

def initialize(sorted_lang_list)

@sorted_lang_list = sorted_lang_list

end

def self.parse(accept_language_list)

return nil unless accept_language_list =~ Regexp.new(ACCEPT_LANG_PATTERN, Regexp::EXTENDED | Regexp::IGNORECASE)

list = accept_language_list.split(',').collect do |lang_range_q|

lang_range, quality = lang_range_q.split(';')

quality ||= 1

[Locale::Object.new(lang_range), quality]

end

sorted_list = list.sort do |l1, l2|

r = l1[1] <=> l2[1]

# if quality is equal, then prefer the most specific language tag

if r == 0

l1[0].to_iso3066.size <=> l2[0].to_iso3066.size

else

r

end

end

new(sorted_list)

end

def reduce(available_language_list)

# return a new object with ordered matching language tags

end

end

end