Rails 7.1 adds --parent option to the controllers

Rails generators are provided by the framework and can be invoked using the rails generate command or its shorthand rails g. When using a generator, you provide some options and arguments to specify what you want to generate, and Rails will create the necessary files and configurations for you.

Rails' common generators are Models, Scaffold, Mailer, Job, Channel, Migration, View, Resource and Controllers. Generators significantly speed up the development process, especially when creating standard components of a Rails application.

The Rails controller generator can be used as below:

rails generate controller ControllerName [action action] [options]

Where ControllerName is the name of the controller you want to create, [action action] represents the optional list of actions you want to include in the controller. --skip-routes, --no-assets, --no-controller-specs, and --template-engine are a few options that can be passed to the rails generate controller command.

Before Rails 7.1

Before Rails 7.1, the controller's generator had no support to specify the parent class. You must manually update the controller file and mention the parent controller.

> rails generate controller admin/users
  create  app/controllers/admin/users_controller.rb
  invoke  slim
  create    app/views/admin/users
  invoke  rspec
  create    spec/requests/admin/users_spec.rb
  .....

# app/controllers/admin/users_controller.rb
class Admin::UsersController < ApplicationController
end

# if your application has AdminController, you need to edit
# the file and change it to your parent controller. For eg.

class Admin::UsersController < AdminController
end

In Rails 7.1

Rails 7.1 adds the --parent options to controller generator that helps the developer pass the parent controller name.

You must pass --parent=CONTROLLER_NAME to the rails generate controller command as below:

> rails generate controller admin/users --parent=admin_controller
  create  app/controllers/admin/users_controller.rb
  invoke  slim
  create    app/views/admin/users
  invoke  rspec
  create    spec/requests/admin/users_spec.rb
  .....

# app/controllers/admin/users_controller.rb
class Admin::UsersController < AdminController
end

The command generates Admin::UsersController with the AdminController as the parent class. To know more about this feature, please refer to this Rails PR.