lib/paper_trail/version.rb in airblade-paper_trail-1.0.1 vs lib/paper_trail/version.rb in airblade-paper_trail-1.1.0

@@ -2,19 +2,58 @@
   belongs_to :item, :polymorphic => true
   validates_presence_of :event
 
   def reify
     unless object.nil?
-      # Using +item_type.constantize+ rather than +item.class+
-      # allows us to retrieve destroyed objects.
-      model = item_type.constantize.new
-      YAML::load(object).each do |k, v|
+      # Attributes
+
+      attrs = YAML::load object
+
+      # Normally a polymorphic belongs_to relationship allows us
+      # to get the object we belong to by calling, in this case,
+      # +item+.  However this returns nil if +item+ has been
+      # destroyed, and we need to be able to retrieve destroyed
+      # objects.
+      #
+      # In this situation we constantize the +item_type+ to get hold of
+      # the class...except when the stored object's attributes
+      # include a +type+ key.  If this is the case, the object
+      # we belong to is using single table inheritance and the
+      # +item_type+ will be the base class, not the actual subclass.
+      # If +type+ is present but empty, the class is the base class.
+
+      if item
+        model = item
+      else
+        class_name = attrs['type'].blank? ? item_type : attrs['type']
+        klass = class_name.constantize
+        model = klass.new
+      end
+
+      attrs.each do |k, v|
         begin
           model.send "#{k}=", v
         rescue NoMethodError
           RAILS_DEFAULT_LOGGER.warn "Attribute #{k} does not exist on #{item_type} (Version id: #{id})."
         end
       end
+
       model
     end
   end
+
+  def next
+    Version.first :conditions => ["id > ? AND item_type = ? AND item_id = ?", id, item_type, item_id],
+                  :order => 'id ASC'
+  end
+
+  def previous
+    Version.first :conditions => ["id < ? AND item_type = ? AND item_id = ?", id, item_type, item_id],
+                  :order => 'id DESC'
+  end
+
+  def index
+    Version.all(:conditions => ["item_type = ? AND item_id = ?", item_type, item_id],
+                :order => 'id ASC').index(self)
+  end
+  
 end