title: ZingChart how to modify node upon click/select
body: <p>I am using ZingChart for a standard bar graph.  I have the selected state for individual bars working as I would like but for one thing.  Is there a way to show the value box (set to visible:false globally) to show just for the selected node when it is clicked/selected?  I was able to make the value box for every node show in a click event I added to call an outside function using the modifyplot method but I don't see a similar method for nodes such as modifynode.  If this is not an option, is there any way to insert a "fake" value box the markup of which would be created on the fly during the click event and have that element show above the selected node?  Below is my render code for the chart in question.  Thanks for your time!</p>
  
  <pre><code>zingchart.render({
          id: "vsSelfChartDiv",
          width: '100%',
          height: '100%',
          output: 'svg',
          data: myChartVsSelf,
          events:{
              node_click:function(p){
                  zingchart.exec('vsSelfChartDiv', 'modifyplot', {
                      graphid : 0,
                      plotindex : p.plotindex,
                      nodeindex : p.nodeindex,
                      data : {
                          "value-box":{
                              "visible":true
                          }
                      }
                  });
                  var indexThis = p.nodeindex;
                  var indexDateVal = $('#vsSelfChartDiv-graph-id0-scale_x-item_'+indexThis).find('tspan').html();
                  updateTop(indexDateVal);
              }
          }
      });
  </code></pre>