module ActionView::Helpers::TranslationHelper

def missing_translation(key, options)
  keys = I18n.normalize_keys(options[:locale] || I18n.locale, key, options[:scope])
  title = +"translation missing: #{keys.join(".")}"
  options.each do |name, value|
    unless name == :scope
      title << ", " << name.to_s << ": " << ERB::Util.html_escape(value)
    end
  end
  if ActionView::Base.debug_missing_translation
    content_tag("span", keys.last.to_s.titleize, class: "translation_missing", title: title)
  else
    title
  end
end