app/models/claim.rb
class Claim < ActiveRecord::Base
has_one :item
belongs_to :claim_type
attr_accessible :claim_type_id, :note
validates_presence_of :claim_type_id
before_validation :check_attributes
def check_attributes
if self.id
self.destroy if self.claim_type_id.blank? && self.note.blank?
end
end
end