Merge branch 'master' into nested_has_many_through

Conflicts:
	activerecord/CHANGELOG
	activerecord/lib/active_record/association_preload.rb
	activerecord/lib/active_record/associations.rb
	activerecord/lib/active_record/associations/class_methods/join_dependency.rb
	activerecord/lib/active_record/associations/class_methods/join_dependency/join_association.rb
	activerecord/lib/active_record/associations/has_many_association.rb
	activerecord/lib/active_record/associations/has_many_through_association.rb
	activerecord/lib/active_record/associations/has_one_association.rb
	activerecord/lib/active_record/associations/has_one_through_association.rb
	activerecord/lib/active_record/associations/through_association_scope.rb
	activerecord/lib/active_record/reflection.rb
	activerecord/test/cases/associations/has_many_through_associations_test.rb
	activerecord/test/cases/associations/has_one_through_associations_test.rb
	activerecord/test/cases/reflection_test.rb
	activerecord/test/cases/relations_test.rb
	activerecord/test/fixtures/memberships.yml
	activerecord/test/models/categorization.rb
	activerecord/test/models/category.rb
	activerecord/test/models/member.rb
	activerecord/test/models/reference.rb
	activerecord/test/models/tagging.rb

1 files changed, 53 insertions, 0 deletions

diff --git a/activerecord/lib/active_record/associations/builder/association.rb b/activerecord/lib/active_record/associations/builder/association.rb
new file mode 100644
index 0000000000..96fca97440
--- /dev/null
+++ b/activerecord/lib/active_record/associations/builder/association.rb
@@ -0,0 +1,53 @@
+module ActiveRecord::Associations::Builder
+  class Association #:nodoc:
+    class_attribute :valid_options
+    self.valid_options = [:class_name, :foreign_key, :select, :conditions, :include, :extend, :readonly, :validate]
+
+    # Set by subclasses
+    class_attribute :macro
+
+    attr_reader :model, :name, :options, :reflection
+
+    def self.build(model, name, options)
+      new(model, name, options).build
+    end
+
+    def initialize(model, name, options)
+      @model, @name, @options = model, name, options
+    end
+
+    def build
+      validate_options
+      reflection = model.create_reflection(self.class.macro, name, options, model)
+      define_accessors
+      reflection
+    end
+
+    private
+
+      def validate_options
+        options.assert_valid_keys(self.class.valid_options)
+      end
+
+      def define_accessors
+        define_readers
+        define_writers
+      end
+
+      def define_readers
+        name = self.name
+
+        model.redefine_method(name) do |*params|
+          association(name).reader(*params)
+        end
+      end
+
+      def define_writers
+        name = self.name
+
+        model.redefine_method("#{name}=") do |value|
+          association(name).writer(value)
+        end
+      end
+  end
+end