I18n: How to load default :en locales instead of "translation missing" errors?

Translation missing...

Default language set in Rails app is English (hence :en locales). We can change the language in file config/application.rb:

config.i18n.default_locale = :en

Changing the language we have to translate all previous strings. Otherwise, we will see translation missing: bla bla bla...

How to avoid it and replace ugly errors with default :en strings?

Solution

Create a new file i18n_missing_translations.rb and place there the following code:

i18n_simple_backend = I18n::Backend::Simple.new
old_handler = I18n.exception_handler
I18n.exception_handler = lambda do |exception, locale, key, options|
  case exception
  when I18n::MissingTranslation
    i18n_simple_backend.translate(:en, key, options || {})
  else
    old_handler.call(exception, locale, key, options)
  end
end

Put your file in config/initializers folder and restart Rails server.

Source of the code