This is a sort of follow-up post to ZeroMQ, iOS and Python from a year ago. I again wrote a test app and server. Of the earlier components, iOS stayed, but ZeroMQ I replaced with WebSockets and the server is this time written in Clojure.

Idea of the exercise is the same as last time: two-way communication between an iOS client and server over a persistent connection. WebSockets is a more mainstream technology than ZeroMQ with a wide variety of servers available, even if it is a young spec and not quite everything has stabilized yet.

On the iOS side there's two options, short of writing the protocol implementation yourself: some kind of horrible Javascript-UIWebView bridge and Square's SocketRocket. I went for SocketRocket. It's available from CocoaPods and at least in this brief test worked fine.

Last time I was planning on doing the server in Clojure but ran out of patience. This time the technology stack was easier. I pretty much followed Jay Fields' example with just a few changes here and there and had a server running in no time.

The system doesn't do anything fancy, or do it particularly beautifully: the app waits for a button tap, sends a number wrapped in JSON to the server, the server increments it and sends it back.

The code is on BitBucket as always. Enjoy.