Added support for associating unsaved objects #402 [Tim Bates]

Added replace to associations, so you can do project.manager.replace(new_manager) or project.milestones.replace(new_milestones) #402 [Tim Bates]
Added build and create methods to has_one and belongs_to associations, so you can now do project.manager.build(attributes) #402 [Tim Bates]
Fixed that Base#== wouldn't work for multiple references to the same unsaved object #402 [Tim Bates]
Added that if a before_* callback returns false, all the later callbacks and the associated action are cancelled. If an after_* callback returns false, all the later callbacks are cancelled. Callbacks are generally run in the order they are defined, with the exception of callbacks defined as methods on the model, which are called last. #402 [Tim Bates]

git-svn-id: http://svn-commit.rubyonrails.org/rails/trunk@417 5ecf4fe2-1ee6-0310-87b1-e25e094e27de

1 files changed, 49 insertions, 0 deletions

diff --git a/activerecord/lib/active_record/associations/association_proxy.rb b/activerecord/lib/active_record/associations/association_proxy.rb
new file mode 100644
index 0000000000..dcba207e20
--- /dev/null
+++ b/activerecord/lib/active_record/associations/association_proxy.rb
@@ -0,0 +1,49 @@
+module ActiveRecord
+  module Associations
+    class AssociationProxy #:nodoc:
+      alias_method :proxy_respond_to?, :respond_to?
+      instance_methods.each { |m| undef_method m unless m =~ /(^__|^nil\?|^proxy_respond_to\?|^send)/ }
+
+      def initialize(owner, association_name, association_class_name, association_class_primary_key_name, options)
+        @owner = owner
+        @options = options
+        @association_name = association_name
+        @association_class = eval(association_class_name)
+        @association_class_primary_key_name = association_class_primary_key_name
+
+        reset
+      end
+      
+      def method_missing(symbol, *args, &block)
+        load_target
+        @target.send(symbol, *args, &block)
+      end
+
+      def respond_to?(symbol, include_priv = false)
+        load_target
+        proxy_respond_to?(symbol, include_priv) || @target.respond_to?(symbol, include_priv)
+      end
+
+      def loaded?
+        @loaded
+      end
+
+      private
+        def load_target
+          unless @owner.new_record?
+            begin
+              @target = find_target if not loaded?
+            rescue ActiveRecord::RecordNotFound
+              reset
+            end
+          end
+          @loaded = true
+          @target
+        end
+
+        def raise_on_type_mismatch(record)
+          raise ActiveRecord::AssociationTypeMismatch, "#{@association_class} expected, got #{record.class}" unless record.is_a?(@association_class)
+        end
+    end
+  end
+end