I'm working with https://github.com/robfig/revel
which uses the Play framework, a Java web framework.  I've never used any sort of webframework, so it's pretty new in all ways for me.  It's pretty early in revel's life too, but I'm benefiting from the Play Framework's documentation as well as the demo apps in revel.

Here's a data structure that I'm building right now for populating a side nav bar.

This prints:

{3 [{Category1 [link one link two]}]}

The Side nav bar is from Twitter Bootstrap's Fluid Layout example, here's the relevant section: