Provide Association Extensions access to the instance that the association is being accessed from. Closes #4433 [josh@hasmanythrough.com]

git-svn-id: http://svn-commit.rubyonrails.org/rails/trunk@4372 5ecf4fe2-1ee6-0310-87b1-e25e094e27de

2 files changed, 20 insertions, 1 deletions

diff --git a/activerecord/lib/active_record/associations.rb b/activerecord/lib/active_record/associations.rb
index ad28407e57..e1a0289039 100755
--- a/activerecord/lib/active_record/associations.rb
+++ b/activerecord/lib/active_record/associations.rb
@@ -232,6 +232,13 @@ module ActiveRecord
     #     has_many :people, :extend => [FindOrCreateByNameExtension, FindRecentExtension]
     #   end
     #
+    # Some extensions can only be made to work with knowledge of the association proxy's internals.
+    # Extensions can access relevant state using accessors on the association proxy:
+    # 
+    # * +proxy_owner+ - Returns the object the association is part of.
+    # * +proxy_reflection+ - Returns the reflection object that describes the association.
+    # * +proxy_target+ - Returns the associated object for belongs_to and has_one, or the collection of associated objects for has_many and has_and_belongs_to_many.
+    #
     # === Association Join Models
     # 
     # Has Many associations can be configured with the :through option to use an explicit join model to retrieve the data.  This
diff --git a/activerecord/lib/active_record/associations/association_proxy.rb b/activerecord/lib/active_record/associations/association_proxy.rb
index adf7ad6ac6..ce0e154644 100644
--- a/activerecord/lib/active_record/associations/association_proxy.rb
+++ b/activerecord/lib/active_record/associations/association_proxy.rb
@@ -4,7 +4,7 @@ module ActiveRecord
       attr_reader :reflection
       alias_method :proxy_respond_to?, :respond_to?
       alias_method :proxy_extend, :extend
-      instance_methods.each { |m| undef_method m unless m =~ /(^__|^nil\?|^proxy_respond_to\?|^proxy_extend|^send)/ }
+      instance_methods.each { |m| undef_method m unless m =~ /(^__|^nil\?$|^send$|proxy_)/ }
 
       def initialize(owner, reflection)
         @owner, @reflection = owner, reflection
@@ -12,6 +12,18 @@ module ActiveRecord
         reset
       end
       
+      def proxy_owner
+        @owner
+      end
+      
+      def proxy_reflection
+        @reflection
+      end
+      
+      def proxy_target
+        @target
+      end
+      
       def respond_to?(symbol, include_priv = false)
         proxy_respond_to?(symbol, include_priv) || (load_target && @target.respond_to?(symbol, include_priv))
       end