title: EXTJS 4.2.2 Line Chart with value displayed at the datapoints
body: <p>I am using extjs 4.2.2 Chart. My requirement is to display a line chart also want to display the values in the node. In some of the posts I saw that can be done using Series label. Somehow it is not displaying the values in the node or the datapoints. Following is the chart code.</p>
  
  <pre><code>items : [ {
      xtype : 'chart',
      // renderTo : Ext.getBody(),
      width : 1600,
      animate : true,
      height : 400,
      shadow : true,
      // theme: 'Category2',
      store : 'SWeatherPoint',
      axes : [ {
          title : 'Temperature',
          type : 'Numeric',
          position : 'left',
          fields : [ 'temperature' ],
          minimum : 0,
          maximum : 100,
          minorTickSteps : 1,
          // grid: true
          grid : {
              odd : {
                  opacity : 1,
                  fill : '#ddd',
                  stroke : '#bbb',
                  'stroke-width' : 0.5
              }
          }
      }, {
          title : 'Day of the Month',
          type : 'Time',
          position : 'bottom',
          fields : [ 'date' ],
          dateFormat : 'M d',
          constrain : true,
          fromDate : new Date('1/1/07'),
          toDate : new Date('1/30/07'),
          grid : true
      } ],
      series : [ {
          type : 'line',
          xField : 'date',
          yField : 'temperature',
          highlight : {
              size : 7,
              radius : 7
          },
          axis : 'left',
          smooth : true,
          fill : true,
          label : {
  //              display : 'under', // or 'rotate'
               field : 'temperature',
              renderer : function(label, storeItem, item, i, display,         animate, index) {
                  console.log(this);
                  console.log(item.get('temperature')+''+item+'' + i+''+display+ ''+index);
                  return String(item.get('temperature'));
              }
  
  
          },
          tips : {
              trackMouse : true,
              width : 200,
              height : 28,
              renderer : function(storeItem, item) {
                  this.setTitle(storeItem.get('temperature') + ': '
                          + storeItem.get('date') + ' views');
              }
          },
          style : {
              fill : '#18428E',
              stroke : '#18428E',
              'stroke-width' : 3,
              'stroke-dasharray' : 10
          // You need to add this!
          },
          markerConfig : {
              type : 'circle',
              size : 4,
              radius : 4,
              'stroke-width' : 0,
              fill : '#18428E',
              stroke : '#18428E'
          }
      } ]
  </code></pre>
  
  <p>It will be helpful if someone could point the issue.</p>
  
  <p>Thanks,
  Amit</p>