class AWS::Record::PresenceValidator

def message
  options[:message] || 'may not be blank'
end

def validate_attribute record, attribute_name, value
  blank = case
  when value.nil?                 then true
  when value.is_a?(String)        then value !~ /\S/
  when value == false             then false # defeat false.blank? == true
  when value.respond_to?(:empty?) then value.empty?
  when value.respond_to?(:blank?) then value.blank?
  else false
  end
  record.errors.add(attribute_name, message) if blank
end