Question

I want to add a validation in my model where I have 2 fields:

t.boolean :first
t.boolean :second

I want to ensure that when

first field is false

then

second field is always false

Is that possible?

Answer 1

You can do something like this in Rails3:

class MyValidator < ActiveModel::EachValidator
  def validate_each(object, attribute, value)
    unless {your condition here}
      object.errors[attribute] << (options[:message] || "your error here") 
    end
  end
end

Edit: Forgot to mention that this example is from Railscasts: http://railscasts.com/episodes/211-validations-in-rails-3 in case you need more detailed information on this topic