title: How to label Highcharts tooltip from json data?
body: <p>i am passing data as JSON to highcharts this JSON comes from a java method so i cant change this...so please dont suggest to change JSON format...
  my code for highchart is below...</p>
  
  <pre><code>var json = [{
      "value": 12,
      "name": "platform1",
      "key": "event4"
  }, {
      "value": 10,
      "name": "platform1",
      "key": "event1"
  }, {
      "value": 14,
      "name": "platform1",
      "key": "event3"
  }, {
      "value": 9,
      "name": "platform1",
      "key": "event2"
  }, {
      "value": 13,
      "name": "platform3",
      "key": "event4"
  }, {
      "value": 13,
      "name": "platform3",
      "key": "event1"
  }];
  var processed_json = new Array();
  $.map(json, function (obj, i) {
      processed_json.push([obj.key, parseInt(obj.value), obj.name]);
  });
  
  $('#container').highcharts({
      chart: {
          type: 'column'
      },
      xAxis: {
          type: "category"
      },
      tooltip: {
          formatter: function () {
              return 'Branch: &lt;b&gt;' + this.series.name +
                  '&lt;/b&gt;&lt;br/&gt;Platform: ' + this.point.y;
          }
      },
      series: [{
          name: 'Data',
          data: processed_json
      }]
  });
  </code></pre>
  
  <p>i am trying to put platform name on the tooltip as i hover over...but i can not find any way to do that...plus is there any way i can create legends as number of platforms...right now i only have one legend named "Data".</p>
  
  <p>jfiddle can be found here : <a href="http://jsfiddle.net/QTJb7/" rel="nofollow">http://jsfiddle.net/QTJb7/</a></p>