lib/mongoid/versioning.rb in mongoid-2.0.0.beta.15 vs lib/mongoid/versioning.rb in mongoid-2.0.0.beta.16

@@ -3,22 +3,32 @@
   # Include this module to get automatic versioning of root level documents.
   # This will add a version field to the +Document+ and a has_many association
   # with all the versions contained in it.
   module Versioning
     extend ActiveSupport::Concern
+
     included do
       field :version, :type => Integer, :default => 1
       embeds_many :versions, :class_name => self.name
       set_callback :save, :before, :revise
     end
 
+    module ClassMethods #:nodoc:
+      attr_accessor :version_max
+      def max_versions(number)
+        self.version_max = number.to_i
+      end
+    end
+
     # Create a new version of the +Document+. This will load the previous
     # document from the database and set it as the next version before saving
-    # the current document. It then increments the version number.
+    # the current document. It then increments the version number. If a #max_versions
+    # limit is set in the model and it's exceeded, the oldest version gets discarded.
     def revise
       last_version = self.class.first(:conditions => { :_id => id, :version => version })
       if last_version
         self.versions << last_version.clone
+        self.versions.shift if self.class.version_max.present? && self.versions.length > self.class.version_max
         self.version = version + 1
         @modifications["versions"] = [ nil, @attributes["versions"] ] if @modifications
       end
     end
   end