Take a look at Concerns
Create a folder in your models directory called concerns. Add a module there:
module MyConcernModule
extend ActiveSupport::Concern
included do
after_save :do_something
end
def do_something
...
end
end
Next, include that in the models you wish to run the after_save in:
class MyModel < ActiveRecord::Base
include MyConcernModule
end
Depending on what you’re doing, this might get you close without observers.