build-countries-json.rb

require 'countries'
require 'json'

ISO3166.configure do |config|
    config.locales = [:en, :cs, :de, :es, :fr, :ja, :nl, :sk]
end

# {
#   AF: {
#     name: {
#       en: "Afghanistan"
#       fr: "Afghanistan"
#     }
#     subdivisions: {
#       BAL: {
#         name: {
#           en: "Balkh"
#           fr: "Balkh"
#         }
#       }
#     }
#   }
# }
# 

country_codes = ISO3166::Data.codes
countries_data = Hash[country_codes.collect { |country_code|
    country = ISO3166::Country.new(country_code)
    subdivision_codes = country.subdivisions.keys
    subdivisions_data = Hash[subdivision_codes.collect { |subdivision_code|
        subdivision_data = {
            :name => country.subdivisions[subdivision_code].translations
        }
        [subdivision_code, subdivision_data]
    }]
    country_data = {
        :name => country.translations,
        :subdivisions => subdivisions_data
    }
    [country_code, country_data]
}]

print JSON.generate countries_data