Question

How to load & get collection of all active-record models used inside rails app.
It should give classes from gems, plugins as well as subclasses having active-record base in parent hierarchy.

ActiveRecord::Base.descendants.collect(&:name)

gives me list but its only after all classes gets loaded.
Is there any way to load all classes inside rails app manually ?

Answer 1

The problem with Ruby is that “all classes” is a somewhat difficult thing to ascertain. Some of them may be generated dynamically and conditionally.

Sometimes you can just load what’s present in app/models:

Dir.glob(File.expand_path("app/models/*.rb", Rails.root)).each do |model_file|
  require model_file
end

If there’s other locations that may contain models you’ll need to include those, too.

You might have dependencies, though, and that can preclude model A from loading before model B. This is why the autoloader is used by default and things just aren’t loaded in.

The only reliable way to get them all loaded is to somehow exercise them all at least once.