RecordActive中default_errors_messages的改变

正在看railsspace_building_a_social_networking_website_with_ruby_on_rails一书，Rails_Space的测试代码，在测试时发现用下列验证输入信息过长的错误。在Rails2.2.2中发生错误。
error_messages = ActiveRecord::Errors.default_error_messages
sprintf(error_messages[:too_long], length)
经查看代码，在rails-2.0前，可以把default_error_messages中%d替换成数字。
在Rails2.2.2中，default_error_messages定义发生了变化,不能把{{counter}}提换成数字。可以在script/console 中，通过输入ActiveRecord::Errors.default_error_messages查看详细内容。
2.0以前，在validations.rb中
   @@default_error_messages = {
      :inclusion => "is not included in the list",
      :exclusion => "is reserved",
      :invalid => "is invalid",
      :confirmation => "doesn't match confirmation",
      :accepted  => "must be accepted",
      :empty => "can't be empty",
      :blank => "can't be blank",
      :too_long => "is too long (maximum is %d characters)",
      :too_short => "is too short (minimum is %d characters)",
      :wrong_length => "is the wrong length (should be %d characters)",
      :taken => "has already been taken",
      :not_a_number => "is not a number",
      :greater_than => "must be greater than %d",
      :greater_than_or_equal_to => "must be greater than or equal to %d",
      :equal_to => "must be equal to %d",
      :less_than => "must be less than %d",
      :less_than_or_equal_to => "must be less than or equal to %d",
     dd => "must be odd",
      :even => "must be even"
    }
2.2.2，在validations.rb中
   def default_error_messages 
    ActiveSupport::Deprecation.warn("ActiveRecord::Errors.default_error_messages
      has been deprecated. Please use
      I18n.translate('activerecord.errors.messages').")
      I18n.translate 'activerecord.errors.messages'
    end

google后看到解决方法，顺手贴下，因为自己之前也有疑问，而楼主并没有说解决方法..

correct_error_message = I18n.translate
"activerecord.errors.messages.too_long", :count=>max_length

因为rails2.2.2之后，error message要集中处理(多语言的问题)，所以通过I18n.translate这个method来代入参数就好了，不需要自己手动修改error message.