lib/paper_trail/version.rb in paper_trail-1.6.4 vs lib/paper_trail/version.rb in paper_trail-1.6.5

@@ -1,9 +1,29 @@
 class Version < ActiveRecord::Base
   belongs_to :item, :polymorphic => true
   validates_presence_of :event
 
+  named_scope :with_item_keys, lambda { |item_type, item_id| {
+    :conditions => { :item_type => item_type, :item_id => item_id }
+  } }
+
+  named_scope :subsequent, lambda { |version| {
+    :conditions => ["id > ?", version.is_a?(ActiveRecord::Base) ? version.id : version],
+    :order      => "id ASC",
+  } }
+
+  named_scope :preceding, lambda { |version| {
+    :conditions => ["id < ?", version.is_a?(ActiveRecord::Base) ? version.id : version],
+    :order      => "id DESC",
+  } }
+
+  named_scope :after, lambda { |timestamp| {
+    :conditions => ['created_at > ?', timestamp],
+    # TODO: is this :order necessary, considering its presence on the has_many :versions association?
+    :order      => 'created_at ASC, id ASC'
+  } }
+
   # Restore the item from this version.
   #
   # This will automatically restore all :has_one associations as they were "at the time",
   # if they are also being versioned by PaperTrail.  NOTE: this isn't always guaranteed
   # to work so you can either change the lookback period (from the default 3 seconds) or
@@ -67,22 +87,23 @@
   # This is an alias for `whodunnit`.
   def terminator
     whodunnit
   end
 
+  def sibling_versions
+    Version.with_item_keys(item_type, item_id)
+  end
+
   def next
-    Version.first :conditions => ["id > ? AND item_type = ? AND item_id = ?", id, item_type, item_id],
-                  :order => 'id ASC'
+    sibling_versions.subsequent(self).first
   end
 
   def previous
-    Version.first :conditions => ["id < ? AND item_type = ? AND item_id = ?", id, item_type, item_id],
-                  :order => 'id DESC'
+    sibling_versions.preceding(self).first
   end
 
   def index
-    Version.all(:conditions => ["item_type = ? AND item_id = ?", item_type, item_id],
-                :order => 'id ASC').index(self)
+    sibling_versions.all(:select => :id, :order => "id ASC").map(&:id).index(self.id)
   end
 
   private
 
   # Restore the `model`'s has_one associations as they were when this version was