DevExtreme Angular - Bi-Directional Bar Chart

In a bi-directional bar chart, two sets of bars "grow" from the axis in the center in two opposite directions. This chart can be used to compare two values side by side. This article describes the main steps to implement a bi-directional bar chart using the Chart widget.

View Demo

Prepare Data

To prepare data for the bi-directional bar chart, convert one of the two sets of bars' values from positive to negative. You can change the sign in each value manually or use the DevExtreme DataSource's map function:

jQuery
JavaScript
var population = [
    { age: "0-4", male: 3.1, female: 2.9 },
    { age: "5-9", male: 3.1, female: 3.0 },
    // ...
];

$(function() {
    $("#chartContainer").dxChart({
        dataSource: {
            store: {
                type: "array",
                data: population
            },
            map: function (dataItem) {
                return {
                    age: dataItem.age,
                    male: dataItem.male,
                    female: -dataItem.female // Changing the values' sign
                }
            }
        }
    });
});
Angular
TypeScript
HTML
import { DxChartModule } from "devextreme-angular";
import DataSource from "devextreme/data/data_source";
import ArrayStore from "devextreme/data/array_store";
// ...
export class AppComponent {
    dataSource: DataSource;
    population = [
        { age: "0-4", male: 3.1, female: 2.9 },
        { age: "5-9", male: 3.1, female: 3.0 },
        // ...
    ];
    constructor() {
        this.dataSource = new DataSource({
            store: new ArrayStore({
                data: this.population
            }),
            map: (dataItem) => {
                return {
                    age: dataItem.age,
                    male: dataItem.male,
                    female: -dataItem.female // Changing the values' sign
                }
            }
        });
    }
}
@NgModule({
    imports: [
        // ...
        DxChartModule
    ],
    // ...
})
<dx-chart
    [dataSource]="dataSource">
</dx-chart>

Configure the Series

You need two Stacked Bar series for the bi-directional bar chart. The following code declares and binds them to the data source from the previous topic:

jQuery
JavaScript
$(function() {
    $("#chartContainer").dxChart({
        // ...
        commonSeriesSettings: {
            type: "stackedbar",
            argumentField: "age"
        },
        series: [{
            valueField: "male",
            name: "Male"
        }, {
            valueField: "female",
            name: "Female"
        }]
    });
});
Angular
HTML
<dx-chart ... >
    <dxo-common-series-settings
        type="stackedbar"
        argumentField="age">
    </dxo-common-series-settings>
    <dxi-series valueField="male" name="Male"></dxi-series>
    <dxi-series valueField="female" name="Female"></dxi-series>
</dx-chart>
See Also

Rotate the Chart

Bars in the Stacked Bar series are vertical by default. Change them to horizontal by setting the rotated option to true.

jQuery
JavaScript
$(function() {
    $("#chartContainer").dxChart({
        // ...
        rotated: true
    });
});
Angular
HTML
<dx-chart ...
    [rotated]="true">
</dx-chart>
See Also

Customize the Appearance

UI elements like tooltips and axis labels display incorrect data when you convert the chart's values from positive to negative. You can fix this by customizing these elements' text:

jQuery
JavaScript
$(function() {
    $("#chartContainer").dxChart({
        // ...
        tooltip: {
            enabled: true,
            customizeTooltip: function (pointInfo) {
                return {
                    text: Math.abs(pointInfo.originalValue)
                };
            }
        },
        valueAxis: {
            label: {
                customizeText: function (axisValue) {
                    return Math.abs(axisValue.value) + '%';
                }
            }
        }
    });
});
Angular
HTML
TypeScript
<dx-chart ... >
    <dxo-tooltip
        [enabled]="true"
        [customizeTooltip]="customizeTooltip">
    </dxo-tooltip>
    <dxi-value-axis>
        <dxo-label [customizeText]="customizeLabel"></dxo-label>
    </dxi-value-axis>
</dx-chart>
import { DxChartModule } from "devextreme-angular";
// ...
export class AppComponent {
    // ...
    customizeTooltip (pointInfo) {
        return {
            text: Math.abs(pointInfo.originalValue)
        };
    }
    customizeLabel (axisValue) {
        return Math.abs(axisValue.value) + '%';
    }
}
@NgModule({
    imports: [
        // ...
        DxChartModule
    ],
    // ...
})

You can also adjust the bar's width. See Specify the Bar Width for details.

This article outlined the steps to implement a bi-directional bar chart and provided code examples for each step. Refer to the Bi-Directional Bar Chart demo for the full code.

View Demo