module VestalVersions # The ActiveRecord model representing versions. class Version < ActiveRecord::Base include Comparable # Associate polymorphically with the parent record. belongs_to :versioned, :polymorphic => true # ActiveRecord::Base#changes is an existing method, so before serializing the +changes+ column, # the existing +changes+ method is undefined. The overridden +changes+ method pertained to # dirty attributes, but will not affect the partial updates functionality as that's based on # an underlying +changed_attributes+ method, not +changes+ itself. undef_method :changes def changes self[:modifications] end serialize :modifications, Hash # In conjunction with the included Comparable module, allows comparison of version records # based on their corresponding version numbers, creation timestamps and IDs. def <=>(other) [number, created_at, id].map(&:to_i) <=> [other.number, other.created_at, other.id].map(&:to_i) end # Returns whether the version has a version number of 1. Useful when deciding whether to ignore # the version during reversion, as initial versions have no serialized changes attached. Helps # maintain backwards compatibility. def initial? number == 1 end end end