vendor/rails/activesupport/lib/active_support/vendor/i18n-0.1.3/lib/i18n/backend/simple.rb

   1 require 'yaml'
   2
   3 module I18n
   4   module Backend
   5     class Simple
   6       INTERPOLATION_RESERVED_KEYS = %w(scope default)
   7       MATCH = /(\\\\)?\{\{([^\}]+)\}\}/
   8
   9       # Accepts a list of paths to translation files. Loads translations from
  10       # plain Ruby (*.rb) or YAML files (*.yml). See #load_rb and #load_yml
  11       # for details.
  12       def load_translations(*filenames)
  13         filenames.each { |filename| load_file(filename) }
  14       end
  15
  16       # Stores translations for the given locale in memory.
  17       # This uses a deep merge for the translations hash, so existing
  18       # translations will be overwritten by new ones only at the deepest
  19       # level of the hash.
  20       def store_translations(locale, data)
  21         merge_translations(locale, data)
  22       end
  23
  24       def translate(locale, key, options = {})
  25         raise InvalidLocale.new(locale) if locale.nil?
  26         return key.map { |k| translate(locale, k, options) } if key.is_a? Array
  27
  28         reserved = :scope, :default
  29         count, scope, default = options.values_at(:count, *reserved)
  30         options.delete(:default)
  31         values = options.reject { |name, value| reserved.include?(name) }
  32
  33         entry = lookup(locale, key, scope)
  34         if entry.nil?
  35           entry = default(locale, default, options)
  36           if entry.nil?
  37             raise(I18n::MissingTranslationData.new(locale, key, options))
  38           end
  39         end
  40         entry = pluralize(locale, entry, count)
  41         entry = interpolate(locale, entry, values)
  42         entry
  43       end
  44
  45       # Acts the same as +strftime+, but returns a localized version of the
  46       # formatted date string. Takes a key from the date/time formats
  47       # translations as a format argument (<em>e.g.</em>, <tt>:short</tt> in <tt>:'date.formats'</tt>).
  48       def localize(locale, object, format = :default)
  49         raise ArgumentError, "Object must be a Date, DateTime or Time object. #{object.inspect} given." unless object.respond_to?(:strftime)
  50
  51         type = object.respond_to?(:sec) ? 'time' : 'date'
  52         # TODO only translate these if format is a String?
  53         formats = translate(locale, :"#{type}.formats")
  54         format = formats[format.to_sym] if formats && formats[format.to_sym]
  55         # TODO raise exception unless format found?
  56         format = format.to_s.dup
  57
  58         # TODO only translate these if the format string is actually present
  59         # TODO check which format strings are present, then bulk translate then, then replace them
  60         format.gsub!(/%a/, translate(locale, :"date.abbr_day_names")[object.wday])
  61         format.gsub!(/%A/, translate(locale, :"date.day_names")[object.wday])
  62         format.gsub!(/%b/, translate(locale, :"date.abbr_month_names")[object.mon])
  63         format.gsub!(/%B/, translate(locale, :"date.month_names")[object.mon])
  64         format.gsub!(/%p/, translate(locale, :"time.#{object.hour < 12 ? :am : :pm}")) if object.respond_to? :hour
  65         object.strftime(format)
  66       end
  67
  68       def initialized?
  69         @initialized ||= false
  70       end
  71
  72       # Returns an array of locales for which translations are available
  73       def available_locales
  74         init_translations unless initialized?
  75         translations.keys
  76       end
  77
  78       def reload!
  79         @initialized = false
  80         @translations = nil
  81       end
  82
  83       protected
  84         def init_translations
  85           load_translations(*I18n.load_path.flatten)
  86           @initialized = true
  87         end
  88
  89         def translations
  90           @translations ||= {}
  91         end
  92
  93         # Looks up a translation from the translations hash. Returns nil if
  94         # eiher key is nil, or locale, scope or key do not exist as a key in the
  95         # nested translations hash. Splits keys or scopes containing dots
  96         # into multiple keys, i.e. <tt>currency.format</tt> is regarded the same as
  97         # <tt>%w(currency format)</tt>.
  98         def lookup(locale, key, scope = [])
  99           return unless key
 100           init_translations unless initialized?
 101           keys = I18n.send(:normalize_translation_keys, locale, key, scope)
 102           keys.inject(translations) do |result, k|
 103             if (x = result[k.to_sym]).nil?
 104               return nil
 105             else
 106               x
 107             end
 108           end
 109         end
 110
 111         # Evaluates a default translation.
 112         # If the given default is a String it is used literally. If it is a Symbol
 113         # it will be translated with the given options. If it is an Array the first
 114         # translation yielded will be returned.
 115         #
 116         # <em>I.e.</em>, <tt>default(locale, [:foo, 'default'])</tt> will return +default+ if
 117         # <tt>translate(locale, :foo)</tt> does not yield a result.
 118         def default(locale, default, options = {})
 119           case default
 120             when String then default
 121             when Symbol then translate locale, default, options
 122             when Array  then default.each do |obj|
 123               result = default(locale, obj, options.dup) and return result
 124             end and nil
 125           end
 126         rescue MissingTranslationData
 127           nil
 128         end
 129
 130         # Picks a translation from an array according to English pluralization
 131         # rules. It will pick the first translation if count is not equal to 1
 132         # and the second translation if it is equal to 1. Other backends can
 133         # implement more flexible or complex pluralization rules.
 134         def pluralize(locale, entry, count)
 135           return entry unless entry.is_a?(Hash) and count
 136           # raise InvalidPluralizationData.new(entry, count) unless entry.is_a?(Hash)
 137           key = :zero if count == 0 && entry.has_key?(:zero)
 138           key ||= count == 1 ? :one : :other
 139           raise InvalidPluralizationData.new(entry, count) unless entry.has_key?(key)
 140           entry[key]
 141         end
 142
 143         # Interpolates values into a given string.
 144         #
 145         #   interpolate "file {{file}} opened by \\{{user}}", :file => 'test.txt', :user => 'Mr. X'
 146         #   # => "file test.txt opened by {{user}}"
 147         #
 148         # Note that you have to double escape the <tt>\\</tt> when you want to escape
 149         # the <tt>{{...}}</tt> key in a string (once for the string and once for the
 150         # interpolation).
 151         def interpolate(locale, string, values = {})
 152           return string unless string.is_a?(String)
 153
 154           string.gsub(MATCH) do
 155             escaped, pattern, key = $1, $2, $2.to_sym
 156
 157             if escaped
 158               pattern
 159             elsif INTERPOLATION_RESERVED_KEYS.include?(pattern)
 160               raise ReservedInterpolationKey.new(pattern, string)
 161             elsif !values.include?(key)
 162               raise MissingInterpolationArgument.new(pattern, string)
 163             else
 164               values[key].to_s
 165             end
 166           end
 167         end
 168
 169         # Loads a single translations file by delegating to #load_rb or
 170         # #load_yml depending on the file extension and directly merges the
 171         # data to the existing translations. Raises I18n::UnknownFileType
 172         # for all other file extensions.
 173         def load_file(filename)
 174           type = File.extname(filename).tr('.', '').downcase
 175           raise UnknownFileType.new(type, filename) unless respond_to?(:"load_#{type}")
 176           data = send :"load_#{type}", filename # TODO raise a meaningful exception if this does not yield a Hash
 177           data.each { |locale, d| merge_translations(locale, d) }
 178         end
 179
 180         # Loads a plain Ruby translations file. eval'ing the file must yield
 181         # a Hash containing translation data with locales as toplevel keys.
 182         def load_rb(filename)
 183           eval(IO.read(filename), binding, filename)
 184         end
 185
 186         # Loads a YAML translations file. The data must have locales as
 187         # toplevel keys.
 188         def load_yml(filename)
 189           YAML::load(IO.read(filename))
 190         end
 191
 192         # Deep merges the given translations hash with the existing translations
 193         # for the given locale
 194         def merge_translations(locale, data)
 195           locale = locale.to_sym
 196           translations[locale] ||= {}
 197           data = deep_symbolize_keys(data)
 198
 199           # deep_merge by Stefan Rusterholz, see http://www.ruby-forum.com/topic/142809
 200           merger = proc { |key, v1, v2| Hash === v1 && Hash === v2 ? v1.merge(v2, &merger) : v2 }
 201           translations[locale].merge!(data, &merger)
 202         end
 203
 204         # Return a new hash with all keys and nested keys converted to symbols.
 205         def deep_symbolize_keys(hash)
 206           hash.inject({}) { |result, (key, value)|
 207             value = deep_symbolize_keys(value) if value.is_a? Hash
 208             result[(key.to_sym rescue key) || key] = value
 209             result
 210           }
 211         end
 212     end
 213   end
 214 end