title: d3 + Backbone: updating elements for which data has changed
body: <p>I'm using d3 with Backbone.js models. When the model attributes change, an event is fired and the model is marked with a hasChanged() flag and it returns a changedAttributes() hash. I understand how to use d3's enter() and exit() to handle models that have either been created or removed. What I am having trouble figuring out is how I can modify the respective DOM elements based on model attributes changing. I can use the Backbone helpers to figure out what to modify, but what is the next step with d3?</p>