Backport of lazy evaluation of has_many ..., :dependent => :___

[#2627 state:committed]

Signed-off-by: Jeremy Kemper <jeremy@bitsweat.net>

activerecord/lib/active_record/associations.rb

@@ -1415,14 +1415,6 @@ def find_with_associations(options = {})
         # finder conditions.
         def configure_dependency_for_has_many(reflection, extra_conditions = nil)
           if reflection.options.include?(:dependent)
-            # Add polymorphic type if the :as option is present
-            dependent_conditions = []
-            dependent_conditions << "#{reflection.primary_key_name} = \#{record.#{reflection.name}.send(:owner_quoted_id)}"
-            dependent_conditions << "#{reflection.options[:as]}_type = '#{base_class.name}'" if reflection.options[:as]
-            dependent_conditions << sanitize_sql(reflection.options[:conditions], reflection.quoted_table_name) if reflection.options[:conditions]
-            dependent_conditions << extra_conditions if extra_conditions
-            dependent_conditions = dependent_conditions.collect {|where| "(#{where})" }.join(" AND ")
-            dependent_conditions = dependent_conditions.gsub('@', '\@')
             case reflection.options[:dependent]
               when :destroy
                 method_name = "has_many_dependent_destroy_for_#{reflection.name}".to_sym
@@ -1431,24 +1423,22 @@ def configure_dependency_for_has_many(reflection, extra_conditions = nil)
                 end
                 before_destroy method_name
               when :delete_all
-                module_eval %Q{
-                  before_destroy do |record|                  # before_destroy do |record|
-                    delete_all_has_many_dependencies(record,  #   delete_all_has_many_dependencies(record,
-                      "#{reflection.name}",                   #     "posts",
-                      #{reflection.class_name},               #     Post,
-                      %@#{dependent_conditions}@)             #     %@...@) # this is a string literal like %(...)
-                  end                                         # end
-                }
+                before_destroy do |record|
+                  record.class.send(:delete_all_has_many_dependencies,
+                  record,
+                  reflection.name,
+                  reflection.klass,
+                  reflection.dependent_conditions(record, record.class, extra_conditions))
+                end
               when :nullify
-                module_eval %Q{
-                  before_destroy do |record|                  # before_destroy do |record|
-                    nullify_has_many_dependencies(record,     #   nullify_has_many_dependencies(record,
-                      "#{reflection.name}",                   #     "posts",
-                      #{reflection.class_name},               #     Post,
-                      "#{reflection.primary_key_name}",       #     "user_id",
-                      %@#{dependent_conditions}@)             #     %@...@) # this is a string literal like %(...)
-                  end                                         # end
-                }
+                before_destroy do |record|
+                  record.class.send(:nullify_has_many_dependencies,
+                  record,
+                  reflection.name,
+                  reflection.klass,
+                  reflection.primary_key_name,
+                  reflection.dependent_conditions(record, record.class, extra_conditions))
+                end
               else
                 raise ArgumentError, "The :dependent option expects either :destroy, :delete_all, or :nullify (#{reflection.options[:dependent].inspect})"
             end

activerecord/lib/active_record/reflection.rb

@@ -277,6 +277,17 @@ def validate?
         !options[:validate].nil? ? options[:validate] : (options[:autosave] == true || macro == :has_many)
       end
 
+      def dependent_conditions(record, base_class, extra_conditions)
+        dependent_conditions = []
+        dependent_conditions << "#{primary_key_name} = #{record.send(name).send(:owner_quoted_id)}"
+        dependent_conditions << "#{options[:as]}_type = '#{base_class.name}'" if options[:as]
+        dependent_conditions << klass.send(:sanitize_sql, options[:conditions]) if options[:conditions]
+        dependent_conditions = dependent_conditions.collect {|where| "(#{where})" }.join(" AND ")
+        dependent_conditions << extra_conditions if extra_conditions
+        dependent_conditions = dependent_conditions.gsub('@', '\@')
+        dependent_conditions
+      end
+
       private
         def derive_class_name
           class_name = name.to_s.camelize

activerecord/test/cases/associations/has_many_associations_test.rb

@@ -1138,5 +1138,23 @@ def test_normal_method_call_in_association_proxy
   def test_instance_eval_in_association_proxy
     assert_equal 'Welcome to the weblog', Comment.all.map { |comment| comment.post }.sort_by(&:id).first.instance_eval{title}
   end
+
+  def test_defining_has_many_association_with_delete_all_dependency_lazily_evaluates_target_class
+    ActiveRecord::Reflection::AssociationReflection.any_instance.expects(:class_name).never
+    class_eval <<-EOF
+      class DeleteAllModel < ActiveRecord::Base
+        has_many :nonentities, :dependent => :delete_all
+      end
+    EOF
+  end
+
+  def test_defining_has_many_association_with_nullify_dependency_lazily_evaluates_target_class
+    ActiveRecord::Reflection::AssociationReflection.any_instance.expects(:class_name).never
+    class_eval <<-EOF
+      class NullifyModel < ActiveRecord::Base
+        has_many :nonentities, :dependent => :nullify
+      end
+    EOF
+  end
 end