Working with d3js I found myself in need of a tooltip to explicate data as it is explored in a chart. The best way to use d3 with Reagent (react.js) is to use reagent to handle the DOM manipulations and d3 to handle more elaborate visualizaion calculations. We don’t follow the d3 model of adding an event to every dom element to trigger a tooltip item to be created, which duplication would behave poorly with React state maintenance.