# File lib/active_record/validations.rb, line 464 def validates_presence_of(*attr_names) configuration = { :message => ActiveRecord::Errors.default_error_messages[:blank], :on => :save } configuration.update(attr_names.extract_options!) # can't use validates_each here, because it cannot cope with nonexistent attributes, # while errors.add_on_empty can send(validation_method(configuration[:on]), configuration) do |record| record.errors.add_on_blank(attr_names, configuration[:message]) end end