DevExtreme jQuery/JS - Customize Group Headers

By default, group headers display text of the key field in a bold font. You can define a custom template for the group headers if you need to. For Angular, AngularJS and Knockout apps, DevExtreme provides the dxTemplate markup component. The following code shows how to use dxTemplate to define a template for group headers.

Angular
HTML
TypeScript
<dx-select-box
    [dataSource]="selectBoxDataSource"
    [grouped]="true"
    groupTemplate="group"
    displayExpr="name"
    valueExpr="count">
    <div *dxTemplate="let data of 'group'">
        <p>{{data.key}} | Count: {{data.overallCount}}</p>
    </div>
</dx-select-box>
import { DxSelectBoxModule } from "devextreme-angular";
import DataSource from "devextreme/data/data_source";
// ...
export class AppComponent {
    fruitsVegetables = [{
        key: "Fruits",
        items: [
            { name: "Apples", count: 10 },
            { name: "Oranges", count: 12 },
            { name: "Lemons", count: 15 }
        ]
    }, {
        key: "Vegetables",
        items: [
            { name: "Potatoes", count: 5 },
            { name: "Tomatoes", count: 9 },
            { name: "Turnips", count: 8 }
        ]
    }];
    selectBoxDataSource = new DataSource({
        store: this.fruitsVegetables,
        map: function(groupedItem) {
            let overallCount = 0;
            groupedItem.items.forEach(function(item) {
                overallCount += item.count;
            })
            return Object.assign(groupedItem, { overallCount: overallCount });
        }
    });
}
@NgModule({
     imports: [
         // ...
         DxSelectBoxModule
     ],
     // ...
 })
Vue
App.vue
<template> 
    <DxSelectBox ...
        :data-source="selectBoxDataSource"
        :grouped="true"
        display-expr="name"
        value-expr="count"
        group-template="group"
    >
        <template #group="{ data }">
            <p>
                {{ data.key + ' | Count: ' + data.overallCount }}
            </p>
        </template>
    </DxSelectBox>
</template>

<script>
import 'devextreme/dist/css/dx.common.css';
import 'devextreme/dist/css/dx.light.css';

import { DxSelectBox } from 'devextreme-vue/select-box';
import DataSource from "devextreme/data/data_source";

export default {
    components: {
        DxSelectBox
    },
    data() {
        const fruitsVegetables = [{
            key: "Fruits",
            items: [
                { name: "Apples", count: 10 },
                { name: "Oranges", count: 12 },
                { name: "Lemons", count: 15 }
            ]
        }, {
            key: "Vegetables",
            items: [
                { name: "Potatoes", count: 5 },
                { name: "Tomatoes", count: 9 },
                { name: "Turnips", count: 8 }
            ]
        }];
        const selectBoxDataSource = new DataSource({
            store: fruitsVegetables,
            map: function(groupedItem) {
                let overallCount = 0;
                groupedItem.items.forEach(function(item) {
                    overallCount += item.count;
                })
                return Object.assign(groupedItem, { overallCount: overallCount });
            }
        });

        return {
            selectBoxDataSource
        }
    }
}
</script>
React
App.js
import React from 'react';
import 'devextreme/dist/css/dx.common.css';
import 'devextreme/dist/css/dx.light.css';

import SelectBox from 'devextreme-react/select-box';
import DataSource from "devextreme/data/data_source";

const fruitsVegetables = [{
    key: "Fruits",
    items: [
        { name: "Apples", count: 10 },
        { name: "Oranges", count: 12 },
        { name: "Lemons", count: 15 }
    ]
}, {
    key: "Vegetables",
    items: [
        { name: "Potatoes", count: 5 },
        { name: "Tomatoes", count: 9 },
        { name: "Turnips", count: 8 }
    ]
}];
const selectBoxDataSource = new DataSource({
    store: fruitsVegetables,
    map: function(groupedItem) {
        let overallCount = 0;
        groupedItem.items.forEach(function(item) {
            overallCount += item.count;
        })
        return Object.assign(groupedItem, { overallCount: overallCount });
    }
});

const renderGroup = (data) => {
    return (
        <p>
            {data.key + ' | Count: ' + data.overallCount}
        </p>
    );
}

class App extends React.Component {
    render() {
        return (
            <SelectBox ...
                dataSource={selectBoxDataSource}
                grouped="true"
                displayExpr="name"
                valueExpr="count"
                groupRender={renderGroup}
            />
        );
    }
}
export default App;
AngularJS
HTML
JavaScript
<div ng-controller="DemoController">
    <div dx-select-box="{
        dataSource: selectBoxDataSource,
        grouped: true,
        groupTemplate: 'group',
        displayExpr: 'name',
        valueExpr: 'count'
    }" dx-item-alias="itemObj">
        <div data-options="dxTemplate: { name: 'group' }">
            <p>{{itemObj.key}} | Count: {{itemObj.overallCount}}</p>
        </div>
    </div>
</div>
angular.module('DemoApp', ['dx'])
    .controller('DemoController', function ($scope) {
        var fruitsVegetables = [{
            key: "Fruits",
            items: [
                { name: "Apples", count: 10 },
                { name: "Oranges", count: 12 },
                { name: "Lemons", count: 15 }
            ]
        }, {
            key: "Vegetables",
            items: [
                { name: "Potatoes", count: 5 },
                { name: "Tomatoes", count: 9 },
                { name: "Turnips", count: 8 }
            ]
        }];
        $scope.selectBoxDataSource = new DevExpress.data.DataSource({
            store: fruitsVegetables,
            map: function(groupedItem) {
                var overallCount = 0;
                groupedItem.items.forEach(function(item) {
                    overallCount += item.count;
                })
                return $.extend(groupedItem, { overallCount: overallCount })
            }
        });
    });
NOTE
The dx-item-alias directive specifies the variable that is used to access the item object.
Knockout
HTML
JavaScript
<div data-bind="dxSelectBox: {
    dataSource: selectBoxDataSource,
    grouped: true,
    groupTemplate: 'group',
    displayExpr: 'name',
    valueExpr: 'count'
}">
    <div data-options="dxTemplate: { name: 'group' }">
        <p data-bind="text: key + ' | Count: ' + overallCount"></p>
    </div>
</div>
var fruitsVegetables = [{
    // ...
    // omitted for brevity
    // see the AngularJS code
}];

var viewModel = {
    selectBoxDataSource: new DevExpress.data.DataSource({
        store: fruitsVegetables,
        map: function(groupedItem) {
            var overallCount = 0;
            groupedItem.items.forEach(function(item) {
                overallCount += item.count;
            })
            return $.extend(groupedItem, { overallCount: overallCount })
        }
    })
};

ko.applyBindings(viewModel);

If you use jQuery alone, use DOM manipulation methods to combine the HTML markup for group headers. To apply this markup, use the groupTemplate callback function as shown in the following code.

JavaScript
var fruitsVegetables = [{
    // ...
    // omitted for brevity
    // see the AngularJS code
}];

$(function() {
    $("#selectBoxContainer").dxSelectBox({
        dataSource: new DevExpress.data.DataSource({
            store: fruitsVegetables,
            map: function(groupedItem) {
                var overallCount = 0;
                groupedItem.items.forEach(function(item) {
                    overallCount += item.count;
                });
                return $.extend(groupedItem, { overallCount: overallCount })
            }
        }),
        grouped: true,
        groupTemplate: function(groupData, _, groupElement) {
            groupElement.append(
                $("<p>").text(groupData.key + " | Count: " + groupData.overallCount)
            )
        },
        displayExpr: 'name',
        valueExpr: 'count'
    });
});

View Demo

In addition, you can use a 3rd-party template engine to perform the needed customizations. For more information, see the 3rd-Party Template Engines article.

See Also