Merge pull request #22567 from gsamokovarov/introduce-application-record

Introduce ApplicationRecord, an Active Record layer supertype

2 files changed, 23 insertions, 1 deletions

diff --git a/activerecord/CHANGELOG.md b/activerecord/CHANGELOG.md
index 87420a0746..f1921dded8 100644
--- a/activerecord/CHANGELOG.md
+++ b/activerecord/CHANGELOG.md
@@ -1,3 +1,18 @@
+*   Introduce ApplicationRecord, an Active Record layer super type.
+
+    An `ApplicationRecord` let's engines have models, isolated from the main
+    application. Plugin authors can use it to distribute extensions as modules
+    to be included into `ApplicationRecord`, instead of monkey patches. It can
+    also serve as a place for applications to customize the default
+    `ActiveRecord::Base` model behaviour.
+
+    Newly generated applications have `app/models/application_record.rb`
+    present by default. Generators are smart enough to recognize that
+    newly generated models have to inherit from `ApplicationRecord` only if
+    it's present.
+
+    *Genadi Samokovarov*
+
 *   Version the API presented to migration classes, so we can change parameter
     defaults without breaking existing migrations, or forcing them to be
     rewritten through a deprecation cycle.
diff --git a/activerecord/lib/rails/generators/active_record/model/model_generator.rb b/activerecord/lib/rails/generators/active_record/model/model_generator.rb
index 395951ac9d..e4c9539362 100644
--- a/activerecord/lib/rails/generators/active_record/model/model_generator.rb
+++ b/activerecord/lib/rails/generators/active_record/model/model_generator.rb
@@ -43,9 +43,16 @@ module ActiveRecord
 
         # Used by the migration template to determine the parent name of the model
         def parent_class_name
-          options[:parent] || "ActiveRecord::Base"
+          options[:parent] || determine_default_parent_class
         end
 
+        def determine_default_parent_class
+          if File.exist?('app/models/application_record.rb')
+            "ApplicationRecord"
+          else
+            "ActiveRecord::Base"
+          end
+        end
     end
   end
 end