belongs_to :old_way, :foreign_key => [:way_id, :version]
- validates_presence_of :old_way
- validates_length_of :k, :maximum => 255, :allow_blank => true
- validates_uniqueness_of :k, :scope => [:way_id, :version]
- validates_length_of :v, :maximum => 255, :allow_blank => true
+ validates :old_way, :presence => true, :associated => true
+ validates :k, :v, :allow_blank => true, :length => { :maximum => 255 }
+ validates :k, :uniqueness => { :scope => [:way_id, :version] }
end