Hide indexLabel if corresponding y value is negative - CanvasJS JavaScript Charts

Hide indexLabel if corresponding y value is negative - CanvasJS JavaScript Charts

by canvasjs

HTML

<script src="https://canvasjs.com/assets/script/canvasjs.min.js"></script>
<div id="chartContainer" style="height: 360px; width: 100%;"></div>

JavaScript

var chart= new CanvasJS.Chart("chartContainer", {
    title:{
        text: "Hide indexLabel if corresponding y value is Negative"
    },
    data: [   
    {
        type: "line", 
        dataPoints: [        
            { x: 10, y: 1, indexLabel: "dataPoint1" },            
            { x: 20, y: 2, indexLabel: "dataPoint2" },
            { x: 30, y: 0, indexLabel: "dataPoint3" },
            { x: 40, y: -5, indexLabel: "dataPoint4" },
            { x: 50, y: 10, indexLabel: "dataPoint5" },
            { x: 60, y: -8, indexLabel: "dataPoint6" }
        ]
    }
    ]
});

function hideIndexLabel() {
      var length = chart.options.data[0].dataPoints.length;
      for( i = 0; i < length; i++ ) {
        if( chart.options.data[0].dataPoints[i].y < 0 ) {
            chart.options.data[0].dataPoints[i].indexLabel = "";
        }
        else
          chart.options.data[0].dataPoints[i].indexLabel = chart.options.data[0].dataPoints[i].indexLabel;
      }      
}

hideIndexLabel();
chart.render();