Added Base#clear_association_cache to empty all the cached associations

#347 [Tobias Luetke]

git-svn-id: http://svn-commit.rubyonrails.org/rails/trunk@252 5ecf4fe2-1ee6-0310-87b1-e25e094e27de

activerecord/CHANGELOG

@@ -1,5 +1,7 @@
 *SVN*
 
+* Added Base#clear_association_cache to empty all the cached associations #347 [Tobias Luetke]
+
 * Added more informative exceptions in establish_connection #356 [bitsweat]
 
 * Fixed that options[:counter_sql] was overwritten with interpolated sql rather than original sql #355 [bitsweat]

activerecord/lib/active_record/associations.rb

@@ -34,6 +34,13 @@ def self.append_features(base)
       base.extend(ClassMethods)
     end
 
+    # Clears out the association cache 
+    def clear_association_cache #:nodoc:
+      self.class.reflect_on_all_associations.to_a.each do |assoc|
+        instance_variable_set "@#{assoc.name}", nil
+      end
+    end
+
     # Associations are a set of macro-like class methods for tying objects together through foreign keys. They express relationships like 
     # "Project has one Project Manager" or "Project belongs to a Portfolio". Each macro adds a number of methods to the class which are 
     # specialized according to the collection or association symbol and the options hash. It works much the same was as Ruby's own attr*