Calculate and display percent value of each column/bar

This demo uses graph's option labelFunction to set a custom function that would calculate each column's percent value and display it as a label over the column.

Please note that labelText needs to also be set to any text in order for labelFunction to be invoked at all.

We're also using color and labelPosition to both set color and position of those labels respectively.

"graphs": [ {
  "valueField": "visits",
  "colorField": "color",
  "type": "column",
  "lineAlpha": 0.1,
  "fillAlphas": 1,
  "labelText": " ",
  "labelPosition": "inside",
  "color": "#fff",
  "labelFunction": function( item ) {
    /**
     * Calculate total of values across all
     * columns in the graph
     */
    var total = 0;
    for ( var i = 0; i < chart.dataProvider.length; i++ ) {
      total += chart.dataProvider[ i ][ item.graph.valueField ];
    }

    /**
     * Calculate percet value of this label
     */
    var percent = Math.round( ( item.values.value / total ) * 1000 ) / 10;
    return percent + "%";
  }
} ]