activerecord - Is there a way to get a collection of all the Models in your Rails app?

Question

Is there a way that you can get a collection of all of the Models in your Rails app?

Basically, can I do the likes of: -

Models.each do |model|
  puts model.class.name
end

Answer 1

The whole answer for Rails 3, 4 and 5 is:

If cache_classes is off (by default it's off in development, but on in production):

Rails.application.eager_load!

Then:

ActiveRecord::Base.descendants

This makes sure all models in your application, regardless of where they are, are loaded, and any gems you are using which provide models are also loaded.

This should also work on classes that inherit from ActiveRecord::Base, like ApplicationRecord in Rails 5, and return only that subtree of descendants:

ApplicationRecord.descendants

If you'd like to know more about how this is done, check out ActiveSupport::DescendantsTracker.