How to highlight a column programmatically in AMCharts 4?

Question

In AMCharts version 3, there is a demo showing how to highlight a particular column.

Is this possible using AMCharts version 4? For example, in the Simple Column demo, highlight the UK column based on its value (ie, where country = 'UK').

I tried modifying the example at https://stackoverflow.com/a/54358490/906814 but I can't get a handle on the columns in order to assess their values and then apply the active state highlight (JSFiddle).

// copied from https://stackoverflow.com/a/54358490/906814 but not working yet
var activeState = series.columns.template.states.create("active");
activeState.properties.fill = am4core.color("#E94F37");

series.columns.each(function(column) {
  alert("column") // no alert is seen
  column.setState("active");
  column.isActive = true;
})

Answer 1

There are two approaches you can take.

1) Use an adapter on the column's fill and stroke and check the column value before modifying the color, e.g.

series.columns.template.adapter.add('fill', function(fill, target) {  
  if (target.dataItem && target.dataItem.categoryX == "UK") {
    return "#ff0000";
  }
  return fill;
});

series.columns.template.adapter.add('stroke', function(stroke, target) {  
  if (target.dataItem && target.dataItem.categoryX == "UK") {
    return "#ff0000";
  }
  return stroke;
})

Demo

2) Use a property field and set the stroke and fill from your data:

chart.data = [
  // ...
  {
    "country": "UK",
    "value": 1122,
    "color": "#ff0000"
  },
  // ...
];
// ...
series.columns.template.propertyFields.fill = "color";
series.columns.template.propertyFields.stroke = "color";

Demo