Locale does not switch while iterating in Rails - ruby-on-rails-3

Question

I have extended RefineryCMS blog/admin/posts controller with Export action, which export post to xml and save it to file. I need export all translated versions of post. When I click export it saves all files, but all files have same locale.
Is it anything wrong with my code:
def generate_xml_by_locales
translated_locales.each do |l|
::I18n.locale = l
file = File.new("blog_#{l}.xml", "wb")
xml = Builder::XmlMarkup.new :target => file
xml.instruct!
xml.blog do
xml.title post.title
xml.description "Sixteenth installment of development diary"
xml.language l.to_s
xml.author "Dan"
xml.date post.created_at
xml.category "diary"
xml.text post.body
end
file.close
end
end
Thanks for help.

Answer 1

I did one modification, which work just fine. Instead of changing locale via I18n.locale I use translations.where(locale: lang).first . Don't know if it is the best solution, but it just works.
Refactored code:
def generate_xml_by_locales
translated_locales.each do |lang|
generate_xml(translations.where(locale: lang).first, lang)
end
end
def generate_xml post, lang
file = File.new("blog_#{lang}.xml", "wb")
xml = Builder::XmlMarkup.new :target => file
xml.instruct!
xml.blog do
xml.title post.title
xml.description "Sixteenth installment of development diary"
xml.language lang.to_s
xml.author "Dan"
xml.date post.created_at
xml.category "diary"
xml.text post.body
end
file.close
end