How to use the I18n fallback features in Rails 3

Question

I am getting an "translation missing" error message from Rails 3:

activerecord:
  notices:
    messages:
      success: 
        create: "Something was created"
    models:
      user:
        success:
          create: "Thanks for registration"

I18n.t("activerecord.notices.models.user.success.create")
# => "Thanks for registration"


I18n.t("activerecord.notices.models.book.success.create") 
# => "translation missing: de, activerecord, notices, models, book, success, create"

I don't know why the book model doesn't get the fallback massage. I have set config.i18n.fallbacks = true.

Solution 1

When a :default option is given, its value will be returned if the translation is missing:

I18n.t :missing, :default => 'Not here'
# => 'Not here'

More info here

Solution 2

I set in config/application.rb usually

    config.i18n.fallbacks = [:de, :fr, :en]

So you can declare the order of the fallback.

But keep attention in some environments/*.rb the configuration is overwritten.

Solution 3

[Answer is for Rails 2]

Have you enabled fallbacks for your backend? Assuming it's Simple(based on yml in example):

Put this in an initializer:

require "i18n/backend/fallbacks" 
I18n::Backend::Simple.send(:include, I18n::Backend::Fallbacks)

https://github.com/svenfuchs/i18n/wiki/Fallbacks

Solution 4

In rails 3+, this is set in the config/environments files :

  # Enable locale fallbacks for I18n (makes lookups for any locale fall back to
  # the I18n.default_locale when a translation can not be found)
  config.i18n.fallbacks = true

Solution 5

I believe the best way to handle a missing string, is to display a default locale, rather than an error message.

Add this line in application.rb to fallback to the english locale.

config.i18n.fallbacks = [:en]

In case you want to specify locale-specific fallbacks, you can use the following:

config.i18n.fallbacks = {:de => [:de,:en], :en => [:en,:de]}

Also, note that you can enable and disable fallbacks based on your environment. So while on development it might make sense to have an error displayed, you can instead enable fallbacks in your environments/production.rb with the following:

config.i18n.fallbacks = true

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