A small effort in making a plugin which helps you detect the users preferred language, as sent by the HTTP header.

• Splits the http-header into languages specified by the user
• Returns empty array if header is illformed.
• Corrects case to xx-XX
• Sorted by priority given, as much as possible.
• Gives you the most important language
• Gives compatible languages See also: http://www.w3.org/Protocols/rfc2616/rfc2616-sec14.html

class SomeController < ApplicationController def some_action

  request.user_preferred_languages
  # => [ 'nl-NL', 'nl-BE', 'nl', 'en-US', 'en' ]
  
  available = %w{en en-US nl-BE}
  request.preferred_language_from(available)
  # => 'nl-BE'
  
  request.user_preferred_languages
  # => [ 'en-GB']
  available = %w{en-US}
  request.compatible_language_from(available)
  # => 'en-US'
end

end

Install the gem http_accept_language, require it in your Rails 3 app.

• 2010-12-28: Gem release
• 2010-01-05: Gem release
• 2009-03-12: Rails 2.3 compatible

Copyright (c) 2008-2010 Iain Hecker, released under the MIT license