Rails Engine Decorators¶ ↑

Extend Rails Engine’s business logic (models, controllers, helpers, etc.) easily from your application or other engine.

This solution was first implemented in the Forem engine, see github.com/radar/forem/pull/260

• Kunal Chaudhari, github.com/kunalchaudhari

• Ryan Bigg, github.com/radar

• Philip Arndt, github.com/parndt

• Antonio Tapiador, github.com/atd

(From Forem’s patch):

Standard practice for including such changes in your application or extension is to create a file within the relevant app/models or app/controllers directory with the original class name with _decorator appended.

### Adding a custom method to the Post model:

# app/decorators/models/forem/post_decorator.rb

Forem::Post.class_eval do
  def some_method
    ...
  end
end

### Adding a custom method to the PostsController:

# app/decorators/controllers/forem/posts_controller_decorator.rb

Forem::PostsController.class_eval do
  def some_action
    ...
  end
end

The exact same format can be used to redefine an existing method.