redis, pub/sub, rails 3, phusion passenger

I have another application publishing messages to redis server. Within my rails application, when a user clicks a button, I want a popup to display that shows live updates. I want the controller to publish notifications to redis, and I want my javascript to subscribe to those events and respond when it finds a suitable channel. What I do not know how to do is actually keep a control open like that: to continuously publish messages when it finds them on redis. Is this possible to do in rails 3/phusion passenger?