如何在Ruby on Rails中获取翻译文件的反向查找含义

Question

I'm a user of RoR.

From the official documentation, I understand how to define translation file about activerecord.

Sample is about User mode.

en:
  activerecord:
    models:
      user: Dude
    attributes:
      user:
        login: "Handle"

and get attribute meaning like this. "login" -> "Handle"

User.human_attribute_name("login")

Now, I want to know the model attribute name. "Handle" -> "login"

How do I get this?

Answer 1

I did not see a method in I18n that has such functionality, but you can do some really nasty stuff if you want:

kv = I18n::Backend::KeyValue.new({})
flat = kv.flatten_translations(:en, I18n.config.backend.send(:translations), false, nil)
flat.find {|key, value| value == "Handle"}

This should output en.activerecord.attributes.user.login

Answer 2

Elaborating on @phoet 's nice little hack (thanks!)

module ReverseTranslationLookup
  extend self

  def lookup(locale, copy)
    locale_messages(locale)[copy]
  end

  private

  def locale_messages(locale)
    messages[locale] ||= build_backend(locale)
  end

  def messages
    @messages ||= {}
  end

  def build_backend(locale)
    backend      = I18n::Backend::KeyValue.new({})
    translations = I18n.config.backend.send(:translations)
    backend.flatten_translations(locale, translations, false, nil)
      .select { |key, val| val.is_a?(String) }
      .invert
  end
end