Posted about 8 years ago. Visible to the public. Repeats.
Customizing Rails error messages for models and attributes
Rails has generic error messages you can define in your locale
.yml files. You may override those application-wide error messages using model or attribute scope like this:
en: activerecord: errors: messages: invalid: is invalid # used for any invalid attribute in the application models: car: invalid: does not work # used for invalid car attributes attributes: driver: invalid: not allowed to drive # used if the car's driver attribute is invalid