React List - Customize Group Headers

By default, group headers contain the text of the key field in a bold font. You can define a custom template for group headers if you need to. For 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-list
    [dataSource]="listDataSource"
    [grouped]="true"
    groupTemplate="group"
    itemTemplate="item">
    <div *dxTemplate="let itemObj of 'item'">
        <p style="margin:0px">{{itemObj.name}} | {{itemObj.count}}</p>
    </div>
    <div *dxTemplate="let groupObj of 'group'">
        <p>{{groupObj.key}} | {{groupObj.overallCount}}</p>
    </div>
</dx-list>
import { DxListModule } 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 }
        ]
    }];
    listDataSource = new DataSource({
        store: fruitsVegetables,
        map: function(groupedItem) {
            let overallCount = 0;
            groupedItem.items.forEach(function(item) {
                overallCount += item.count;
            })
            return Object.assign(groupedItem, { overallCount: overallCount });
        }
    });
}
@NgModule({
    imports: [
        // ...
        DxListModule
    ],
    // ...
})
AngularJS
HTML
JavaScript
<div ng-controller="DemoController">
    <div dx-list="{
        dataSource: listDataSource,
        grouped: true,
        groupTemplate: 'group',
        itemTemplate: 'item'
    }" dx-item-alias="itemObj">
        <div data-options="dxTemplate: { name: 'group' }">
            <p>{{ itemObj.key }} | {{ itemObj.overallCount }}</p>
        </div>
        <div data-options="dxTemplate: { name: 'item' }">
            <p style="margin:0">{{ itemObj.name }} | {{ itemObj.count }}</p>
        </div>
    </div>
</div>
angular.module('DemoApp', ['dx'])
    .controller('DemoController', function ($scope) {
        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 }
            ]
        }];
        $scope.listDataSource = new DevExpress.data.DataSource({
            store: fruitsVegetables,
            map: function(groupedItem) {
                let 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="dxList: {
    dataSource: listDataSource,
    grouped: true,
    groupTemplate: 'group',
    itemTemplate: 'item'
}">
    <div data-options="dxTemplate: { name: 'group' }">
        <p data-bind="text: key + ' | ' + overallCount"></p>
    </div>
    <div data-options="dxTemplate: { name: 'item' }">
        <p data-bind="text: name + ' | ' + count" style="margin:0"></p>
    </div>
</div>
const fruitsVegetables = [{
    // ...
    // omitted for brevity
    // see the AngularJS code
}];

const viewModel = {
    listDataSource: new DevExpress.data.DataSource({
        store: fruitsVegetables,
        map: function(groupedItem) {
            let 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
const fruitsVegetables = [{
    // ...
    // omitted for brevity
    // see the AngularJS code
}];

$(function() {
    $("#listContainer").dxList({
        dataSource: new DevExpress.data.DataSource({
            store: fruitsVegetables,
            map: function(groupedItem) {
                let 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 + " | " + groupData.overallCount)
            )
        },
        itemTemplate: function(data, _, element) {
            element.append(
                $("<p>").text(data.name + " | " + data.count).css("margin", 0)
            )
        }
    });
});

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