A custom formatter function which returns the text to be displayed as indexLabel on dataPoints.
var  chart =  new  CanvasJS.Chart("container",
{
 .
 .
 data:[{
        indexLabelFormatter: function ( e ) {
               return "Custom IndexLabel"  + e.dataPoint.label;  
         }  
  }],
 .
 .
});
chart.render();
Below is the structure of object passed as parameter to the function
e: { // parameter sent to function
       chart,
       dataSeries,
       dataPoint,
       index,        // Available only in range charts
       total,        // Available only in stacked, pie and doughnut charts
       percent,      // Available only in stacked, pie and doughnut charts
 }
Comment
Hello,
Is it possible to use html? For example, I would like to make kg bold:
indexLabelFormatter: function(e){
return e.dataPoint.label + ” ” + e.dataPoint.y + ” ” + “kg” ;
}
What would I really like is to add padding to indexLabel. Here is my code:
type: “line”,
markerType: “square”,
markerColor: “#f49124”,
markerBorderColor: “#000”,
xValueType: “number”,
yValueType: “number”,
yValueFormatString: “#,###”,
indexLabel: “{c}”,
indexLabelBackgroundColor: “#f49124”,
indexLabelFontColor: “#fff”,
indexLabelFontSize: 18,
indexLabelLineThickness: 2,
indexLabelLineColor: “transparent”,
indexLabelPlacement: “outside”,
indexLabelFontWeight: “bold”,
IndexLabel has no padding and it is stacked to top left
Thanks for suggestions.