[SOLVED] How to know which category is clicked on a stacked bar chart in amcharts?

How to know which category is clicked on a stacked bar chart in amcharts?

I have a stacked bar chart and assigned a click listener on it to know which item was clicked.

series.columns.template.events.on("hit", function(ev) {
    console.log(ev.target);
}, this);

but in the corresponding target.dataItem json i am unable to find any field that has the category clicked. Only the year and the numerical value is available. How to get the actual legend categories?
Codepen implementation

Solution

You can access the series information through target.dataItem.component. This will contain the series information used to populate the legend, such as the name.

series.columns.template.events.on("hit", function(ev) {
    console.log(ev.target.dataItem.component.name);
}, this);

Demo below:

// Themes begin
am4core.useTheme(am4themes_animated);
// Themes end

// Create chart instance
var chart = am4core.create("chartdiv", am4charts.XYChart);

// Add data
chart.data = [{
  "year": "2016",
  "europe": 2.5,
  "namerica": 2.5,
  "asia": 2.1,
  "lamerica": 0.3,
  "meast": 0.2,
  "africa": 0.1
}, {
  "year": "2017",
  "europe": 2.6,
  "namerica": 2.7,
  "asia": 2.2,
  "lamerica": 0.3,
  "meast": 0.3,
  "africa": 0.1
}, {
  "year": "2018",
  "europe": 2.8,
  "namerica": 2.9,
  "asia": 2.4,
  "lamerica": 0.3,
  "meast": 0.3,
  "africa": 0.1
}];

chart.legend = new am4charts.Legend();
chart.legend.position = "right";

// Create axes
var categoryAxis = chart.yAxes.push(new am4charts.CategoryAxis());
categoryAxis.dataFields.category = "year";
categoryAxis.renderer.grid.template.opacity = 0;

var valueAxis = chart.xAxes.push(new am4charts.ValueAxis());
valueAxis.min = 0;
valueAxis.renderer.grid.template.opacity = 0;
valueAxis.renderer.ticks.template.strokeOpacity = 0.5;
valueAxis.renderer.ticks.template.stroke = am4core.color("#495C43");
valueAxis.renderer.ticks.template.length = 10;
valueAxis.renderer.line.strokeOpacity = 0.5;
valueAxis.renderer.baseGrid.disabled = true;
valueAxis.renderer.minGridDistance = 40;

// Create series
function createSeries(field, name) {
  var series = chart.series.push(new am4charts.ColumnSeries());
  series.dataFields.valueX = field;
  series.dataFields.categoryY = "year";
  series.stacked = true;
  series.name = name;
  
  var labelBullet = series.bullets.push(new am4charts.LabelBullet());
  labelBullet.locationX = 0.5;
  labelBullet.label.text = "{valueX}";
  labelBullet.label.fill = am4core.color("#fff");
  
   series.columns.template.events.on("hit", function(ev) {
        console.log(ev.target.dataItem.component.name);
    }, this);
}

createSeries("europe", "Europe");
createSeries("namerica", "North America");
createSeries("asia", "Asia");
createSeries("lamerica", "Latin America");
createSeries("meast", "Middle East");
createSeries("africa", "Africa");

#chartdiv {
  width: 100%;
  height: 500px;
}

<script src="https://www.amcharts.com/lib/4/core.js"></script>
<script src="https://www.amcharts.com/lib/4/charts.js"></script>
<script src="https://www.amcharts.com/lib/4/themes/animated.js"></script>
<div id="chartdiv"></div>