multiple language application

hi,
I've been asked to design a multiple language application for an
architectural firm and I need advice with which is the best approach
to it with Rails.
Basically all the tables have some common fields that doesn't need to
be translated and some others that need translation.
At first it seems the application will be quite changing since not all
the targets are clearly defined so, ease of change will make a good
point.

best regards,
indi

Just right now I’m solving definitely this kind of task.

I choose an approach where each content having to be translated, is String or Text.

Then I created two STI+polymorphic tables (models): MetaText and MetaString. Each of them has columns “value” and “locale” to specify language.

class MetaString < ActiveRecord::Base

attr_accessible :value, :locale

belongs_to :resource, :polymorphic => true

end

class MetaText < ActiveRecord::Base

attr_accessible :value, :locale

belongs_to :resource, :polymorphic => true

end

For each model I’ve created STI models for whatever string/text content to be translated. STI is needed to specify model behavior, such as validation or etc…

Example:

class ArticleTitle < MetaString

validates_lenght_of :value, :maximum => 200

end

class ArticleContent < MetaText

validates_lenght_of :value, :minimum => 200

end

class Article < ActiveRecord::Base

has_many :titles, :class_name => “ArticleTitle”, :as => :resource, :dependent => :delete_all

has_many :contents, :class_name => “ArticleTitle”, :as => :resource, :dependent => :delete_all

def title(locale=nil)

items = titles.to_a

items.find {|i| i.locale == locale || I18n.locale} || items.first

end

def content(locale=nil)

items = contents.to_a

items.find {|i| i.locale == locale || I18n.locale} || items.first

end

end

I18n.locale - application-level locale accessor.

I choose an approach (subdomain = locale):

http://railscasts.com/episodes/221-subdomains-in-rails-3