I have a post on stackoverflow which outlines the problem I am having:
ruby on rails - What is the replacement for ActionController::Base.relative_url_root? - Stack Overflow
In short, I ported a rails 2.x to rails3 and started getting a
deprecation warning for using
ActionController::Base.relative_url_root. I switched to using
config.action_controller.relative_url_root and while any calls to
external resources (like css/jss/images) does have the url root
appended, none of my routes do.
Is config.action_controller.relative_url_root the right replacements
for ActionController::Base.relative_url_root?