Selection

API

The selection capability is not provided out of the box, but it can be implemented using the pointClick event. The following code gives an example of a scenario when clicking on a point selects it, and clicking on it again clears the selection. Call a point's isSelected() method to check whether it is selected.

jQuery
JavaScript
$(function() {
    $("#pieChartContainer").dxPieChart({
        // ...
        onPointClick: function (e) {
            var point = e.target;
            if (point.isSelected()) {
                point.clearSelection();
            } else {
                point.select();
            }
        }
    });
});
Angular
HTML
TypeScript
<dx-pie-chart
    (onPointClick)="onPointClick($event)">
</dx-pie-chart>
import { DxPieChartModule } from 'devextreme-angular';
// ...
export class AppComponent {
    onPointClick (e) {
        let point = e.target;
        if (point.isSelected()) {
            point.clearSelection();
        } else {
            point.select();
        }
    };
}
@NgModule({
    imports: [
        // ...
        DxPieChartModule
    ],
    // ...
})

In the previous code example, a specific point's selection was cleared. Call a series' clearSelection() method if you need to clear all the selected points in that series.

jQuery
JavaScript
$(function() {
    $("#pieChartContainer").dxPieChart({
        // ...
        onPointClick: function (e) {
            var series = e.target.series;
            if (series.isSelected()) {
                series.clearSelection();
            } else {
                series.select();
            }
        }
    });
});
Angular
HTML
TypeScript
<dx-pie-chart
    (onPointClick)="onPointClick($event)">
</dx-pie-chart>
import { DxPieChartModule } from 'devextreme-angular';
// ...
export class AppComponent {
    onPointClick (e) {
        let series = e.target.series;
        if (series.isSelected()) {
            series.clearSelection();
        } else {
            series.select();
        }
    };
}
@NgModule({
    imports: [
        // ...
        DxPieChartModule
    ],
    // ...
})

In a multi-series PieChart, you can clear the entire selection at once by calling the PieChart instance's clearSelection() method.

jQuery
JavaScript
$("#pieChartContainer").dxPieChart("clearSelection");
Angular
TypeScript
import { ..., ViewChild } from '@angular/core';
import { DxPieChartModule, DxPieChartComponent } from 'devextreme-angular';
// ...
export class AppComponent {
    @ViewChild(DxPieChartComponent) pieChart: DxPieChartComponent;
    clearSelection() {
        this.pieChart.instance.clearSelection();
    }
}
@NgModule({
    imports: [
        // ...
        DxPieChartModule
    ],
    // ...
})
See Also

User Interaction

When a user selects a series point, its style changes to the one specified by the series.selectionStyle object.

jQuery
JavaScript
$(function() {
    $("#pieChartContainer").dxPieChart({
        // ...
        series: {
            selectionStyle: {
                // ...
            }
        }
    });
});
Angular
HTML
TypeScript
<dx-pie-chart>
    <dxi-series>
        <dxo-selection-style>
            <!-- ...-->
        </dxo-selection-style>
    </dxi-series>
</dx-pie-chart>
import { DxPieChartModule } from 'devextreme-angular';
// ...
export class AppComponent {
    // ...
}
@NgModule({
    imports: [
        // ...
        DxPieChartModule
    ],
    // ...
})

You can disable the selection capability by settings the series.selectionMode option to "none".

jQuery
JavaScript
$(function() {
    $("#pieChartContainer").dxPieChart({
        series: {
            selectionMode: "none"
        }
    });
});
Angular
HTML
TypeScript
<dx-pie-chart>
    <dxi-series
        selectionMode="none">
    </dxi-series>
</dx-pie-chart>
import { DxPieChartModule } from 'devextreme-angular';
// ...
export class AppComponent {
    // ...
}
@NgModule({
    imports: [
        // ...
        DxPieChartModule
    ],
    // ...
})

Only a single point can be in the selected state at a time by default. If you need to allow multiple points to be in this state, assign "multiple" to the pointSelectionMode option.

jQuery
JavaScript
$(function() {
    $("#pieChartContainer").dxPieChart({
        // ...
        pointSelectionMode: 'multiple' // or 'single'
    });
});
Angular
HTML
TypeScript
<dx-pie-chart 
    pointSelectionMode="multiple"> <!-- or 'single' -->
</dx-pie-chart>
import { DxPieChartModule } from 'devextreme-angular';
// ...
export class AppComponent {
    // ...
}
@NgModule({
    imports: [
        // ...
        DxPieChartModule
    ],
    // ...
})

View Demo

Events

When a user selects a series point, the PieChart fires the pointSelectionChanged event that you can handle with a function. Assign this function to the onPointSelectionChanged option when you configure the widget if it is going to remain unchanged during the widget's lifetime. Call the point's isSelected() method to check whether it was selected or the selection was cleared.

jQuery
JavaScript
$(function() {
    $("#pieChartContainer").dxPieChart({
        // ...
        onPointSelectionChanged: function (e) {
            var point = e.target;
            if (point.isSelected()) {
                // Commands to execute when the point is selected
            } else {
                // Commands to execute when the selection is cleared
            }
        }
    });
});
Angular
HTML
TypeScript
<dx-pie-chart
    (onPointSelectionChanged)="onPointSelectionChanged($event)">
</dx-pie-chart>
import { DxPieChartModule } from 'devextreme-angular';
// ...
export class AppComponent {
    onPointSelectionChanged (e) {
        let point = e.target;
        if (point.isSelected()) {
            // Commands to execute when the point is selected
        } else {
            // Commands to execute when the selection is cleared
        }
    };
}
@NgModule({
    imports: [
        // ...
        DxPieChartModule
    ],
    // ...
})

Subscribe to the pointSelectionChanged event using the on(eventName, eventHandler) method if you are going to change the event handler at runtime or if you need to attach several handlers to the event. This approach is more typical of jQuery.

JavaScript
var pointSelectionChangedHandler1 = function (e) {
    var point = e.target;
    // First handler of the "pointSelectionChanged" event
};

var pointSelectionChangedHandler2 = function (e) {
    var point = e.target;
    // Second handler of the "pointSelectionChanged" event
};

$("#pieChartContainer").dxPieChart("instance")
    .on("pointSelectionChanged", pointSelectionChangedHandler1)
    .on("pointSelectionChanged", pointSelectionChangedHandler2);
See Also