little persistence refactoring to improve readability

lib/aasm/aasm.rb

@@ -3,7 +3,7 @@ module AASM
   def self.included(base) #:nodoc:
     base.extend AASM::ClassMethods
     AASM::StateMachine[base] ||= AASM::StateMachine.new('')
-    AASM::Persistence.set_persistence(base)
+    AASM::Persistence.load_persistence(base)
     super
   end
 

lib/aasm/persistence.rb

@@ -1,20 +1,28 @@
 module AASM
   module Persistence
-    # Checks to see this class or any of it's superclasses inherit from
-    # ActiveRecord::Base and if so includes ActiveRecordPersistence
-    def self.set_persistence(base)
-      # Use a fancier auto-loading thingy, perhaps.  When there are more persistence engines.
-      hierarchy = base.ancestors.map {|klass| klass.to_s}
+    class << self
 
-      require File.join(File.dirname(__FILE__), 'persistence', 'base')
-      require File.join(File.dirname(__FILE__), 'persistence', 'read_state')
-      if hierarchy.include?("ActiveRecord::Base")
-        require File.join(File.dirname(__FILE__), 'persistence', 'active_record_persistence')
-        base.send(:include, AASM::Persistence::ActiveRecordPersistence)
-      elsif hierarchy.include?("Mongoid::Document")
-        require File.join(File.dirname(__FILE__), 'persistence', 'mongoid_persistence')
-        base.send(:include, AASM::Persistence::MongoidPersistence)
+      def load_persistence(base)
+        # Use a fancier auto-loading thingy, perhaps.  When there are more persistence engines.
+        hierarchy = base.ancestors.map {|klass| klass.to_s}
+
+        if hierarchy.include?("ActiveRecord::Base")
+          require_files_for('active_record_persistence')
+          base.send(:include, AASM::Persistence::ActiveRecordPersistence)
+        elsif hierarchy.include?("Mongoid::Document")
+          require_files_for('mongoid_persistence')
+          base.send(:include, AASM::Persistence::MongoidPersistence)
+        end
       end
-    end
+
+    private
+
+      def require_files_for(persistence)
+        require File.join(File.dirname(__FILE__), 'persistence', 'base')
+        require File.join(File.dirname(__FILE__), 'persistence', 'read_state')
+        require File.join(File.dirname(__FILE__), 'persistence', persistence)
+      end
+
+    end # class << self
   end
 end # AASM