title: jqPlot: print pointLabels from json file
body: <p>I'd like to render a chart from a <code>JSON</code> file with <code>jqPlot</code>.
  With the help of some examples I came to the following code that work fine:</p>
  
  <pre><code>$(document).ready(function(){  
  var ajaxDataRenderer = function(url, plot) {
      var ret = null;
      $.ajax({
          // have to use synchronous here, else returns before data is fetched
          async: false,
          url: url,
          dataType:'json',
          success: function(data) {
              ret = data;
          }
      });
      return ret;
  };
  
  var jsonurl = "./json_3.json";
  
  plo12 = $.jqplot('chart2', jsonurl,{
      dataRenderer: ajaxDataRenderer,
      title: 'User Activity Chart (AJAX JSON Data Renderer)',
      legend: {show:true},
      seriesDefaults: {
          showMarker:true,
          pointLabels: { show:true } 
      },
      axes: {
          xaxis: {
              renderer:$.jqplot.DateAxisRenderer,
              tickOptions: {
                  formatString:'%a %d %b %H:%M'
              }
          },
          yaxis: {
              tickOptions: {
                  show: false
              },
          }
      }
  });
  });
  </code></pre>
  
  <p>And the <code>JSON</code> file looks like this:</p>
  
  <pre><code>[
      [
          ["2012-02-07 10:00", 10, "start"],
          ["2012-02-07 23:43" ,10, "end"]
      ],
      [
          ["2012-02-07 01:45", 20, "start"],
          ["2012-02-07 08:18", 20, "end"]
      ]
   ]
  </code></pre>
  
  <p>This way I can draw as many series as I want.
  The only problem now is that the labels (start/end) are not printed on the chart and I can't understand why.
  I thought that this line of code was enough:</p>
  
  <pre><code>pointLabels: { show:true } 
  </code></pre>
  
  <p>Any advice?</p>