Extract block to helper function

app/controllers/admin/contact_versions_controller.rb

@@ -1,5 +1,7 @@
 module Admin
   class ContactVersionsController < BaseController
+    include ObjectVersionsHelper
+
     load_and_authorize_resource
 
     def index

app/helpers/object_versions_helper.rb

@@ -0,0 +1,10 @@
+module ObjectVersionsHelper
+  def attach_existing_fields(version, new_object)
+    version.object_changes.to_h.each do |k, v|
+      method_name = "#{k}=".to_sym
+      if new_object.respond_to?(method_name)
+        new_object.public_send(method_name, v.last)
+      end
+    end
+  end
+end

app/views/admin/domain_versions/archive.haml

@@ -56,10 +56,7 @@
           - @versions.each do |version|
             - if version
               - domain = Domain.new(version.object.to_h)
-              - version.object_changes.to_h.each do |k, v|
-                - method_name = "#{k}=".to_sym
-                - if domain.respond_to?(method_name)
-                  - domain.public_send("#{k}=", v.last)
+              - attach_existing_fields(version, domain)
 
               %tr
                 %td= link_to(domain.name, admin_domain_version_path(version.id))

app/views/admin/domain_versions/show.haml

@@ -1,8 +1,5 @@
 - domain = Domain.new(@version.object.to_h)
-- @version.object_changes.to_h.each do |k, v|
-  - method_name = "#{k}=".to_sym
-  - if domain.respond_to?(method_name)
-    - domain.public_send("#{k}=", v.last)
+- attach_existing_fields(@version, domain)
 
 - if @version
   - children = HashWithIndifferentAccess.new(@version.children)