rails 4 - require class in initializer or module that uses it - best practice

Question

I'm a fairly new RoR dev and ran into a question about best practices for require ing files from lib in Rails 4.

Background:

As it stands, files in my app's lib don't get autoloaded. I want to require a helper class called rate_limiter that lives in a subdirectory of lib. I've also created a throttle module that handles routes related to rate limiting, and uses this rate_limiter class.

The throttle module is already required at the top of my application controller.

Question: to make sure rate_limiter gets loaded at start of app, what's better:

1) include an initializer rate_limiter.rb that simply says require rate_limiter to load class.

2) add require rate_limiter to the top of a different module throttle, which uses rate_limiter and which already gets required at the top of application controller.

Wondering about best practices for clarity and maintainability going forward.

Thanks for any suggestions!

Answer 1

I believe this would be a more Rails way to include desired files and folders.

# config/application.rb
module YourAppName
  class Application < Rails::Application
    # Custom directories with classes and modules you want to be autoloadable.
    # config.autoload_paths += %W(#{config.root}/extras)
    config.autoload_paths += Dir[Rails.root.join('lib')]
  end
end

Answer 2

You probably could try the following scheme:

# config/application.rb:

# To make sure that your module namespace will be initialized without name collisions with files in your app directories
# require only root file and autoload other relative files in root file using features of ActiveSupport::Autoload
require_relative '../lib/my_module/my_module'

module AppName
  class Application < Rails::Application
    # Do not include all files in your lib. Require explicitly
    # .
    # ..
    # - lib/my_module/my_module.rb - root file
    # - lib/my_module/my_module - directory
    config.autoload_paths += Dir[Rails.root.join('lib', 'my_module')]
  end
end

Then in you module you can specify explicitly which files required and when

# lib/my_module/my_module.rb 
module MyModule
  extend ActiveSupport::Autoload

  autoload :Configuration
  autoload :SomeClass # at lib/my_module/my_module/some_class.rb
  autoload :AnotherClass

  eager_autoload do
    autoload :Errors # at lib/my_module/my_module/errors.rb
    autoload :BillError, 'my_module/errors'
  end
end

It is worth to read an official guide to understand generic process of Rails constant lookup