How does RoR's reloading content on refresh work?

Question

RoR allows you to, as long as the env is development, change parts of the your application code and then just refresh the browser--and everything is changed, without having to restart Mongrel.

How does this work, and where in the Rails codebase is this done?

(Or, alternatively, is there some easy way to do this with Rack+Mongrel?)

Thanks so much.

Answer 1

I can't answer the first part of your question, but Shotgun gives you this behavior in any Rack-based application.

Answer 2

You can check on config.cache_classes

In RAILS_ROOT/config/environments/development.rb, it is set as

config.cache_classes = false

while production.rb, it is set to true

I have no idea what particular code handles it but it should be somewhere in the actionpack/action_controller folder.