rails/rails — pull request #12457 by miry (2013-10-07 14:58:24+00:00)
Title: Ability to use the custom format for error messages

Ability to provide custom error full message format depends on Model name, not just global:

Example:

```yaml
#config/locales/en.yml
en:
activerecord:
errors:
models:
user:
format: "%{message}"

attributes:
name:
blank: Please provide the name!

```

```ruby
#app/models/user.rb
class User < AR::Base

# add_column :users, :name, :string
validates :name, presence: true

end

user = User.new
user.validate!
user.errors.full_messages_for(:name) # => ['Please provide the name!']
```