require 'version' module LaserLemon module VestalVersions def self.included(base) base.extend ClassMethods end module ClassMethods def versioned has_many :versions, :as => :versioned, :order => 'versions.number ASC', :dependent => :destroy do def between(from_value, to_value) from, to = number_at(from_value), number_at(to_value) return [] if from.nil? || to.nil? condition = (from == to) ? to : Range.new(*[from, to].sort) all( :conditions => {:number => condition}, :order => "versions.number #{(from > to) ? 'DESC' : 'ASC'}" ) end def at(value) case value when Version then value when Numeric then find_by_number(value.floor) when Symbol then respond_to?(value) ? send(value) : nil when Date, Time then last(:conditions => ['versions.created_at <= ?', value.to_time]) end end def number_at(value) case value when Version then value.number when Numeric then value.floor when Symbol, Date, Time then at(value).try(:number) end end end after_save :create_version, :if => :needs_version? include InstanceMethods alias_method_chain :reload, :versions end end module InstanceMethods private def needs_version? !changed.empty? end def reset_version(new_version = nil) @last_version = nil if new_version.nil? @version = new_version end def create_version if versions.empty? versions.create(:changes => attributes, :number => 1) else versions.create(:changes => changes, :number => (last_version + 1)) end reset_version end public def version @version ||= last_version end def last_version @last_version ||= versions.maximum(:number) end def reverted? version != last_version end def reload_with_versions(*args) reset_version reload_without_versions(*args) end def revert_to(value) to_value = versions.number_at(value) return version if to_value == version chain = versions.between(version, to_value) return version if chain.empty? new_version = chain.last.number backward = chain.first > chain.last backward ? chain.pop : chain.shift timestamps = %w(created_at created_on updated_at updated_on) chain.each do |version| version.changes.except(*timestamps).each do |attribute, change| new_value = backward ? change.first : change.last write_attribute(attribute, new_value) end end reset_version(new_version) end def revert_to!(value) revert_to(value) reset_version if saved = save saved end def latest_changes return {} if version.nil? || version == 1 versions.at(version).changes end end end end ActiveRecord::Base.send(:include, LaserLemon::VestalVersions)