require_dependency 'person' class Person attr_accessible :lattes_url validate :lattes_url_validate? def lattes_url_validate? valid_url_start = 'http://lattes.cnpq.br/' unless self.lattes_url =~ /http:\/\/lattes.cnpq.br\/\d+/ errors[:base] << "Sorry, the lattes url is not valid." end end end