ruby - I18n : how can I guard against empty interpolation arguments?

Question

给定以下 i18n key :

greeting: "Hi %{name}! Feeling %{adjective}?"

如果我打电话 I18n.t!("greeting", adjective: "strigine") ，我得到一个异常(exception): I18n::MissingInterpolationArgument .这很好。

但是，如果我根本不传递任何参数，我只会得到原始字符串。

I18n.t!("greeting") # => "Hi %{name}! Feeling %{adjective}?"

我想确保这不会发生。 如果没有给出参数，是否有此方法调用的版本 ，还是我必须自己编码？

Answer 1

I18n 是故意这样做的

原因是documented in the tests如下:

If no interpolation parameter is not given, I18n should not alter the string. This behavior is due to three reasons:

• Checking interpolation keys in all strings hits performance, badly;
• This allows us to retrieve untouched values through I18n. For example I could have a middleware that returns I18n lookup results in JSON to be processed through Javascript. Leaving the keys untouched allows the interpolation to happen at the javascript level;
• Security concerns: if I allow users to translate a web site, they can insert %{} in messages causing the I18n lookup to fail in every request.

如何解决它

如果你想在这种情况下出现异常，你可以定义一个这样的方法:

  # Needed because I18n will happily return the raw template string if given
  # no interpolation arguments
  # https://github.com/svenfuchs/i18n/blob/v0.7.0/lib/i18n/tests/interpolation.rb#L6-L21
  def i18n_strict_t!(key, options = {})
    localized = I18n.t!(key, options)
    if missing = localized.match(I18n::INTERPOLATION_PATTERN)
      fail I18n::MissingInterpolationArgument.new(
        missing.captures.first, options, localized
      )
    end
    localized
  end

用法:

i18n_strict_t!("greeting")
# => I18n::MissingInterpolationArgument: missing
# interpolation argument "name" in
# "Hi %{name}! Feeling %{adjective}?" ({} given)
i18n_strict_t!("greeting", name: "Carla", adjective: "taciturn")
# => "Hi Carla! Feeling taciturn?"

或者对于更慢但更简单的实现:

def i18n_strict_t!(key, options = {})
  options[:force_interpolation] = true if options.empty?
  I18n.t!(key, options)
end