How to translate active record model validations

Question

When I submit a form with an error in it, it returns an error message. How can I translate these error messages with i18n? I already have translation for all the other texts in my views, so I know how l18n works in Rails. I now get this:

2 errors prohibited this user from being saved:

Email translation missing: nl.activerecord.errors.models.user.attributes.email.blank
Email translation missing: nl.activerecord.errors.models.user.attributes.email.blank

I want to translate both the title and the errors.

Answer 1

The translation for the title would be:

nl:
  activerecord:
    errors:
      template:
        header:
          one:   "1 error prohibited this %{model} from being saved"
          other: "%{count} errors prohibited this %{model} from being saved"
        body:    "There were problems with the following fields:"

For translating the error messages, Rails will use the following order of translations:

activerecord.errors.models.user.attributes.name.blank
activerecord.errors.models.user.blank
activerecord.errors.messages.blank
errors.attributes.name.blank
errors.messages.blank

So you could add:

nl:
  activerecord:
    errors:
      models:
        user:
          attributes:
            email:
              blank: "foo blank in nl bar baz"

It's documented in the Rails Internationalization (I18n) API Guide, which might give you some more insight.

Answer 2

Just use the Dutch translations file that you can find here. It contains translations for most (if not all) ActiveRecord validation messages.

Copy the file to config/locales/ in your project.

Alternate method

If you want to benefit from updated translations, add the following to your Gemfile instead of copying the translation files by hand:

gem 'rails-i18n'

Answer 3

The rails I18n guide covers this pretty well.

You can put the following in config/locales/nl.yml to translate the attributes:

nl:
  activerecord:
    models:
      user: "User"
    attributes:
      email: "Email"

For the error messages, ActiveRecord will look them up in the following namespaces:

activerecord.errors.models.[model_name].attributes.[attribute_name]
activerecord.errors.models.[model_name]
activerecord.errors.messages
errors.attributes.[attribute_name]
errors.messages

model, attribute and value are interpolated and available in your translations, for example:

nl:
  errors:
    messages:
      blank: "Please fill the %{model}'s %{attribute}"