inject programming code into iphone app

I saw in this article you can run some javascript in a UIWebView: http://iphoneincubator.com/blog/windows-views/how-to-inject-javascript-functions-into-a-uiwebview

It would be great if I could inject some business logic into my app based on a few parameters I have or be able to customize it on the fly via the web by downloading updated code that would become part of the app.

has anyone done this开发者_StackOverflow社区 or is this even a possibility?

I would advise you to avoid doing it. Any app that downloads code will get rejected on the App Store.

From the App Store Review Guidelines:

2.7 Apps that download code in any way or form will be rejected