Handle Tooltip Events

When a tooltip becomes shown or hidden, the PieChart fires the tooltipShown or tooltipHidden event that you can handle with a function. If the handling function is not going to be changed during the lifetime of the widget, assign it to the onTooltipShown or onTooltipHidden option respectively, when you configure the widget.

jQuery
JavaScript
$(function() {
    $("#pieChartContainer").dxPieChart({
        // ...
        onTooltipShown: function (e) {
            var point = e.target;
            // Handler of the "tooltipShown" event
        },
        onTooltipHidden: function (e) {
            var point = e.target;
            // Handler of the "tooltipHidden" event
        }
    });
});
Angular
HTML
TypeScript
<dx-pie-chart ...
    (onTooltipShown)="onTooltipShown($event)"
    (onTooltipHidden)="onTooltipHidden($event)">
</dx-pie-chart>
export class AppComponent {
    onTooltipShown (e) {
        let point = e.target;
        // Handler of the "tooltipShown" event
    },
    onTooltipHidden (e) {
        let point = e.target;
        // Handler of the "tooltipHidden" event
    }
}

If you are going to change the event handlers at runtime or if you need to attach several handlers to a single event, subscribe to this event using the on(eventName, eventHandler) method. This approach is more typical of jQuery.

JavaScript
var tooltipShownHandler1 = function (e) {
    var point = e.target;
    // First handler of the "tooltipShown" event
};

var tooltipShownHandler2 = function (e) {
    var point = e.target;
    // Second handler of the "tooltipShown" event
};

$("#pieChartContainer").dxPieChart("instance")
    .on("tooltipShown", tooltipShownHandler1)
    .on("tooltipShown", tooltipShownHandler2);
See Also