1 files changed, 38 insertions, 5 deletions

diff --git a/activerecord/lib/active_record/associations/builder/association.rb b/activerecord/lib/active_record/associations/builder/association.rb
index 96fca97440..9a6896dd55 100644
--- a/activerecord/lib/active_record/associations/builder/association.rb
+++ b/activerecord/lib/active_record/associations/builder/association.rb
@@ -1,7 +1,7 @@
 module ActiveRecord::Associations::Builder
   class Association #:nodoc:
     class_attribute :valid_options
-    self.valid_options = [:class_name, :foreign_key, :select, :conditions, :include, :extend, :readonly, :validate]
+    self.valid_options = [:class_name, :foreign_key, :select, :conditions, :include, :extend, :readonly, :validate, :references]
 
     # Set by subclasses
     class_attribute :macro
@@ -16,6 +16,10 @@ module ActiveRecord::Associations::Builder
       @model, @name, @options = model, name, options
     end
 
+    def mixin
+      @model.generated_feature_methods
+    end
+
     def build
       validate_options
       reflection = model.create_reflection(self.class.macro, name, options, model)
@@ -36,18 +40,47 @@ module ActiveRecord::Associations::Builder
 
       def define_readers
         name = self.name
-
-        model.redefine_method(name) do |*params|
+        mixin.redefine_method(name) do |*params|
           association(name).reader(*params)
         end
       end
 
       def define_writers
         name = self.name
-
-        model.redefine_method("#{name}=") do |value|
+        mixin.redefine_method("#{name}=") do |value|
           association(name).writer(value)
         end
       end
+
+      def dependent_restrict_raises?
+        ActiveRecord::Base.dependent_restrict_raises == true
+      end
+
+      def dependent_restrict_deprecation_warning
+        if dependent_restrict_raises?
+          msg = "In the next release, `:dependent => :restrict` will not raise a `DeleteRestrictionError`. "\
+                "Instead, it will add an error on the model. To fix this warning, make sure your code " \
+                "isn't relying on a `DeleteRestrictionError` and then add " \
+                "`config.active_record.dependent_restrict_raises = false` to your application config."
+          ActiveSupport::Deprecation.warn msg
+        end
+      end
+
+      def define_restrict_dependency_method
+        name = self.name
+        mixin.redefine_method(dependency_method_name) do
+          has_one_macro = association(name).reflection.macro == :has_one
+          if has_one_macro ? !send(name).nil? : send(name).exists?
+            if dependent_restrict_raises?
+              raise ActiveRecord::DeleteRestrictionError.new(name)
+            else
+              key  = has_one_macro ? "one" : "many"
+              errors.add(:base, :"restrict_dependent_destroy.#{key}",
+                         :record => self.class.human_attribute_name(name).downcase)
+              return false
+            end
+          end
+        end
+      end
   end
 end