Rails reloading classes and 'has been removed from the module tree but is still active!' ArgumentError

instrumentation, ruby-on-rails, ruby-on-rails-4.1

Solution

The first approach looks cleaner -

Adding path where may 'FooBar::ControllerRuntimeis defined toconfig.autoload_one_paths`

Reasons -

1) If you really wanna do some monkey patches in file like lib/extensions.rb, you may manually require it:

in config/initializers/require.rb:

require "#{Rails.root}/lib/extensions"

2) Follows proper naming conventions as you will have to list down the class and module .

I wouldn't suggest auto-loading for production application though , but if it's the last option than you can certainly try it out .

Good read here on the same - http://www.williambharding.com/blog/technology/rails-3-autoload-modules-and-classes-in-production/

Problem

I wrote custom instrumentation in my Rails application. I enable it in `config/initializers/instrumentation.rb`file like this: ``` ActiveSupport.on_load(:action_controller) do include FooBar::ControllerRuntime end ``` But this leads me to errors `A copy of FooBar::ControllerRuntime has been removed from the module tree but is still active!`. I figure it out that I can resolve it in two ways: - Adding path where may 'FooBar::ControllerRuntime`is defined to`config.autoload_one_paths` - Defining `:to_prepare` callback in `ActionController::Railtie` Second solution looks like this: ``` config.to_prepare do ActionController.include FooBar::ControllerRuntime end ``` This long introduction leads to question: which way is better? With first I am disabling reloading of classes which lay in the same path as my `FooBar::ControllerRuntime`. With second I don't feel it is good to messup with `ActionController::Railtie`. Right know `ActionController::Railtie` doesn't have defined `to_prepare` but what happend if in next release it will have?

Original source