i18n Pluralization

Solution 1:

Try this:

en.yml :

en:
  misc:
    kids:
      zero: no kids
      one: 1 kid
      other: %{count} kids

In a view:

You have <%= t('misc.kids', :count => 4) %>

Updated answer for languages with multiple pluralization (tested with Rails 3.0.7):

File config/initializers/pluralization.rb:

require "i18n/backend/pluralization" 
I18n::Backend::Simple.send(:include, I18n::Backend::Pluralization)

File config/locales/plurals.rb:

{:ru => 
  { :i18n => 
    { :plural => 
      { :keys => [:one, :few, :other],
        :rule => lambda { |n| 
          if n == 1
            :one
          else
            if [2, 3, 4].include?(n % 10) && 
               ![12, 13, 14].include?(n % 100) && 
               ![22, 23, 24].include?(n % 100)

              :few 
            else
              :other 
            end
          end
        } 
      } 
    } 
  } 
}

#More rules in this file: https://github.com/svenfuchs/i18n/blob/master/test/test_data/locales/plurals.rb
#(copy the file into `config/locales`)

File config/locales/en.yml:

en:
  kids:
    zero: en_zero
    one: en_one
    other: en_other

File config/locales/ru.yml:

ru:
  kids:
    zero: ru_zero
    one: ru_one
    few: ru_few
    other: ru_other

Test:

$ rails c
>> I18n.translate :kids, :count => 1
=> "en_one"
>> I18n.translate :kids, :count => 3
=> "en_other"
>> I18n.locale = :ru
=> :ru
>> I18n.translate :kids, :count => 1
=> "ru_one"
>> I18n.translate :kids, :count => 3
=> "ru_few"  #works! yay! 
>> I18n.translate :kids, :count => 5
=> "ru_other"  #works! yay! 

Solution 2:

I hope Russian-speaking Ruby on Rails programmers could find this. Just want to share my own very precise Russian pluralization formula. It based on Unicode Specs. Here is contents of config/locales/plurals.rb file only, everything else should be done as same as in answer above.

{:ru => 
  { :i18n => 
    { :plural => 
      { :keys => [:zero, :one, :few, :many],
        :rule => lambda { |n| 
          if n == 0
            :zero
          elsif
            ( ( n % 10 ) == 1 ) && ( ( n % 100 != 11 ) )
            # 1, 21, 31, 41, 51, 61...
            :one
          elsif
            ( [2, 3, 4].include?(n % 10) \
            && ![12, 13, 14].include?(n % 100) )
            # 2-4, 22-24, 32-34...
            :few
          elsif ( (n % 10) == 0 || \
            ![5, 6, 7, 8, 9].include?(n % 10) || \
            ![11, 12, 13, 14].include?(n % 100) )
            # 0, 5-20, 25-30, 35-40...
            :many
          end
        } 
      } 
    } 
  } 
}

Native speakers may enjoy cases such as 111 and 121. And here the test results:

• zero: 0 запросов/куриц/яблок
• one: 1 запрос/курица/яблоко
• few: 3 запроса/курицы/яблока
• many: 5 запросов/куриц/яблок
• one: 101 запрос/курица/яблоко
• few: 102 запроса/курицы/яблока
• many: 105 запросов/куриц/яблок
• many: 111 запросов/куриц/яблок
• many: 119 запросов/куриц/яблок
• one: 121 запрос/курица/яблоко
• few: 122 запроса/курицы/яблока
• many: 125 запросов/куриц/яблок

Thanks for initial answer!