How to customize error messages for validates numericality sub-options?

Question

How can I customize the error messages for sub options when validating numericality on a field in an ActiveRecord model?

Example:

validates :month, :numericality => {
  :greater_than_or_equal_to => 1,
  :less_than_or_equal_to    => 12
}

In this case if the 'month' attribute is more than 12, I want to provide custom error message instead of the default "must be less than or equal to 12". How to achieve this?

Answer 1

If you don't want to use a custom validator, you could use the en.yml file instead. Assuming "post" was your model name, this provides examples for age-specific messages, post-specific messages, and generic (all models) messages.

en:
  activerecord:
    errors:
      models:
        post:
          attributes:
            age:
              less_than_or_equal_to: "Age-specific error" # Applies only to post.age
          less_than_or_equal_to: "Post-specific error" # Applies to all other fields for a post
      messages:
        less_than_or_equal_to: "Generic error" # Applies to all other models