Question

I’m adding a validator inside the User.rb model to validate the birthdate given is over 18 years old before create the devise user.

This is the validation I have.

# user.rb
validates :birthdate, :before => lambda { 18.years.ago }, :before_message => "must be at least 18 years old"

Inside the User schema

# User schema
t.date     "birthdate"

Problem is that I’m getting the following error when trying to save the object.

ArgumentError in Devise::RegistrationsController#create

Unknown validator: 'BeforeValidator'

Answer 1

Unknown validator: 'BeforeValidator' means you’ve overestimated the magic 🙂

Try this:

validate do |user|
  if user.birthdate > 18.years.ago
    errors.add(:birthdate, "must be at least 18 years old")
  end
end