MongoDB-based Backend::Store implementation for I18n gem
2010 / 12 / 28Currently I’m working on a web project on top of rails 3 and mongodb.
Recently we faced the necessity of changing I18n backend from simple to something more dynamic (in fact, we wanted to allow the non-geeks from our team to participate in the internationalization process via web interface).
I googled for “mongodb i18n”, “mongo_mapper i18n”, “mongodb i18n backend”, etc. and found nothing, so I wrote my own implementation of mongodb backend for I18n, called mongo-i18n (in fact, «wrote» is too strong a word — all that I needed to do was to implement three methods of the store interface:)
You can grab the sources here or you can install the gem via command line:
gem install mongo-i18n
Usage:
I recommend to start with Chain backend while mongodb collection is empty, and move to entirely mongodb-based backend when you populate your database with all I18n messages.
Begin with:
collection = Mongo::Connection.new['my_app_related_db'].collection('i18n')
I18n.backend = I18n::Backend::Chain.new(I18n::Backend::KeyValue.new(MongoI18n::Store.new(collection)), I18n.backend)
And finish with:
collection = Mongo::Connection.new['my_app_related_db'].collection('i18n')
I18n.backend = I18n::Backend::KeyValue.new(MongoI18n::Store.new(collection)
If you are already using a mongodb ORM in your project (and I suppose you are, why else would you be reading this article? :), I recommend using the existing database connection.
collection = MongoMapper.database.collection('i18n')
I18n.backend = I18n::Backend::KeyValue.new(MongoI18n::Store.new(collection))
Free Christmas gift, the rake file to import en.yml into mongodb:
# usage:
# bundle exec rake locale:file RAILS_ENV=production
# if you want to export a different locale (not en.yml), provide locale option, as follows:
# bundle exec rake locale:file RAILS_ENV=production locale=ru
require 'mongo-i18n'
def write_to_database(sc, path, value)
key = path.join('.')
sc[key] = value.to_json
end
# traverse through hash
def traverse(sc, obj, path)
case obj
when Hash
obj.each do |k,v|
traverse(sc, v, path + [k])
end
when Array
obj.each {|v| traverse(sc, v) }
else # end values
write_to_database(sc, path, obj)
end
end
namespace :locale do
desc <<-eos
Exports $app/config/locale/$locale.yml contents to mongodb database.
If locale is not specified, default (en) locale file will be exported.
eos
task :file do
locale = ENV['locale'] || "en"
environment = ENV['RAILS_ENV'] || "development"
# I keep mongodb connection descriptor in config/mongodb.yml
config = YAML::load(File.read(Rails.root.join('config/mongodb.yml')))
collection = Mongo::Connection.new[config["development"]["database"]].collection('i18n')
store = MongoI18n::Store.new(collection)
dump = YAML::load(File.open(Rails.root.join("config","locales", "#{locale}.yml")))
traverse(store, dump, [])
end
end
Any feedback would be welcome.