title: d3.js treemap new data doesn't render
body: <p>This is my first attempt at d3.js and I can't figure out how to redraw the treemap.  I am trying to load new data into the <a href="https://github.com/mbostock/d3/tree/master/examples/treemap" rel="nofollow">treemap example</a> using a json request.  I've added the following code to my treemap.js.  </p>
  
  <pre><code>d3.select(".search_field").on("click", function(){
      d3.json("/applications.json?search=Applejuice", function(json) {
          div.data([json]).selectAll("div")
              .data(treemap.nodes)
              .enter().append("div")
              .attr("class", "cell")
              .style("background", function(d) { return d.children ? color(d.name) : null; })
              .transition()
              .duration(1500)
              .call(cell);
     }); 
  });
  </code></pre>
  
  <p>I've inspected var div after the request completes and the data is loaded in the object correctly. </p>