Templates in React Combo box component

2 Feb 202324 minutes to read

The ComboBox has been provided with several options to customize each list items, group title, header, and footer elements.

To get started with React ComboBox templates, you can check on this video:

Item template

The content of each list item within the ComboBox can be customized with the help of itemTemplate
property.

In the following sample, each list item is split into two columns to display relevant data’s.

[Class-component]

// import DataManager related classes
import { DataManager, ODataV4Adaptor, Query } from '@syncfusion/ej2-data';
import { ComboBoxComponent } from '@syncfusion/ej2-react-dropdowns';
import * as React from 'react';
import * as ReactDOM from 'react-dom';
export default class App extends React.Component {
    // bind the DataManager instance to dataSource property
    employeeData = new DataManager({
        adaptor: new ODataV4Adaptor,
        crossDomain: true,
        url: 'https://services.odata.org/V4/Northwind/Northwind.svc/'
    });
    // bind the Query instance to query property
    query = new Query().from('Employees').select(['FirstName', 'City', 'EmployeeID']).take(6);
    // maps the appropriate column to fields property
    fields = { text: 'FirstName', value: 'EmployeeID' };
    // sort the resulted items
    sortOrder = 'Ascending';
    // set the value to itemTemplate property
    itemTemplate(data) {
        return (<span className='item'><span className='name'>{data.FirstName}</span><span className='city'>{data.City}</span></span>);
    }
    render() {
        return (
        // specifies the tag for render the ComboBox component
        <ComboBoxComponent id="comboelement" query={this.query} itemTemplate={this.itemTemplate} dataSource={this.employeeData} fields={this.fields} sortOrder={this.sortOrder} placeholder="Select an employee"/>);
    }
}
ReactDOM.render(<App />, document.getElementById('sample'));
// import DataManager related classes
import { DataManager, ODataV4Adaptor, Query } from '@syncfusion/ej2-data';
import { SortOrder } from '@syncfusion/ej2-lists';
import { ComboBoxComponent } from '@syncfusion/ej2-react-dropdowns';
import * as React from 'react';
import * as ReactDOM from 'react-dom';

export default class App extends React.Component<{}, {}> {
    // bind the DataManager instance to dataSource property
    private employeeData: DataManager = new DataManager({
        adaptor: new ODataV4Adaptor,
        crossDomain: true,
        url: 'https://services.odata.org/V4/Northwind/Northwind.svc/'
    });
    // bind the Query instance to query property
    private query: Query = new Query().from('Employees').select(['FirstName', 'City', 'EmployeeID']).take(6);
    // maps the appropriate column to fields property
    private fields: object = { text: 'FirstName', value: 'EmployeeID' };
    // sort the resulted items
    private sortOrder: SortOrder = 'Ascending';
    // set the value to itemTemplate property
    public itemTemplate(data: any): JSX.Element {
      return (
       <span className='item' ><span className='name'>{data.FirstName}</span><span className='city'>{data.City}</span></span>
        );
    }
    public render() {
        return (
             // specifies the tag for render the ComboBox component
            <ComboBoxComponent id="comboelement" query={this.query} itemTemplate={this.itemTemplate} dataSource={this.employeeData} fields={this.fields} sortOrder={this.sortOrder} placeholder="Select an employee" />
        );
    }
}
ReactDOM.render(<App />, document.getElementById('sample'));

[Functional-component]

import { DataManager, ODataV4Adaptor, Query } from '@syncfusion/ej2-data';
import { ComboBoxComponent } from '@syncfusion/ej2-react-dropdowns';
import * as React from 'react';
import * as ReactDOM from 'react-dom';
function App() {
    // bind the DataManager instance to dataSource property
    const employeeData = new DataManager({
        adaptor: new ODataV4Adaptor,
        crossDomain: true,
        url: 'https://services.odata.org/V4/Northwind/Northwind.svc/'
    });
    // bind the Query instance to query property
    const query = new Query().from('Employees').select(['FirstName', 'City', 'EmployeeID']).take(6);
    // maps the appropriate column to fields property
    const fields = { text: 'FirstName', value: 'EmployeeID' };
    // sort the resulted items
    const sortOrder = 'Ascending';
    // set the value to itemTemplate property
    function itemTemplate(data) {
        return (<span className='item'><span className='name'>{data.FirstName}</span><span className='city'>{data.City}</span></span>);
    }
    return (
    // specifies the tag for render the ComboBox component
    <ComboBoxComponent id="comboelement" query={query} itemTemplate={itemTemplate} dataSource={employeeData} fields={fields} sortOrder={sortOrder} placeholder="Select an employee"/>);
}
ReactDOM.render(<App />, document.getElementById('sample'));
import { DataManager, ODataV4Adaptor, Query } from '@syncfusion/ej2-data';
import { SortOrder } from '@syncfusion/ej2-lists';
import { ComboBoxComponent } from '@syncfusion/ej2-react-dropdowns';
import * as React from 'react';
import * as ReactDOM from 'react-dom';

function App() {
    // bind the DataManager instance to dataSource property
    const employeeData: DataManager = new DataManager({
        adaptor: new ODataV4Adaptor,
        crossDomain: true,
        url: 'https://services.odata.org/V4/Northwind/Northwind.svc/'
    });
    // bind the Query instance to query property
    const query: Query = new Query().from('Employees').select(['FirstName', 'City', 'EmployeeID']).take(6);
    // maps the appropriate column to fields property
    const fields: object = { text: 'FirstName', value: 'EmployeeID' };
    // sort the resulted items
    const sortOrder: SortOrder = 'Ascending';
    // set the value to itemTemplate property
    function itemTemplate(data: any): JSX.Element {
        return (
            <span className='item' ><span className='name'>{data.FirstName}</span><span className='city'>{data.City}</span></span>
        );
    }
    return (
    // specifies the tag for render the ComboBox component
        <ComboBoxComponent id="comboelement" query={query} itemTemplate={itemTemplate} dataSource={employeeData} fields={fields} sortOrder={sortOrder} placeholder="Select an employee" />
    );
}
ReactDOM.render(<App />, document.getElementById('sample'));

Group template

The group header title under which appropriate sub-items are categorized can also be customize with the help of groupTemplate property. This template is common for both inline and floating group header template.

In the following sample, employees are grouped according to their city.

[Class-component]

// import DataManager related classes
import { DataManager, ODataV4Adaptor, Predicate, Query } from '@syncfusion/ej2-data';
import { ComboBoxComponent } from '@syncfusion/ej2-react-dropdowns';
import * as React from 'react';
import * as ReactDOM from 'react-dom';
export default class App extends React.Component {
    // bind the DataManager instance to dataSource property
    employeeData = new DataManager({
        adaptor: new ODataV4Adaptor,
        crossDomain: true,
        url: 'https://services.odata.org/V4/Northwind/Northwind.svc/'
    });
    // form  predicate to fetch the grouped data
    groupPredicate = new Predicate('City', 'equal', 'london').or('City', 'equal', 'seattle');
    // bind the Query instance to query property
    query = new Query().from('Employees').select(['FirstName', 'City', 'EmployeeID']).take(6).where(this.groupPredicate);
    // maps the appropriate column to fields property
    fields = { text: 'FirstName', value: 'EmployeeID', groupBy: 'City' };
    // sort the resulted items
    sortOrder = 'Ascending';
    // set the value to groupTemplate
    groupTemplate(data) {
        return (<strong>{data.City}</strong>);
    }
    render() {
        return (
        // specifies the tag for render the ComboBox component
        <ComboBoxComponent id="comboelement" query={this.query} groupTemplate={this.groupTemplate} dataSource={this.employeeData} fields={this.fields} sortOrder={this.sortOrder} placeholder="Select an employee"/>);
    }
}
ReactDOM.render(<App />, document.getElementById('sample'));
// import DataManager related classes
import { DataManager, ODataV4Adaptor, Predicate, Query } from '@syncfusion/ej2-data';
import { SortOrder } from '@syncfusion/ej2-lists';
import { ComboBoxComponent } from '@syncfusion/ej2-react-dropdowns';
import * as React from 'react';
import * as ReactDOM from 'react-dom';

export default class App extends React.Component<{}, {}> {
    // bind the DataManager instance to dataSource property
    private employeeData: DataManager = new DataManager({
        adaptor: new ODataV4Adaptor,
        crossDomain: true,
        url: 'https://services.odata.org/V4/Northwind/Northwind.svc/'
    });
    // form  predicate to fetch the grouped data
    private groupPredicate = new Predicate('City', 'equal', 'london').or('City', 'equal', 'seattle');
    // bind the Query instance to query property
    private query: Query = new Query().from('Employees').select(['FirstName', 'City', 'EmployeeID']).take(6).where(this.groupPredicate);
    // maps the appropriate column to fields property
    private fields: object = { text: 'FirstName', value: 'EmployeeID', groupBy: 'City' };
    // sort the resulted items
    private sortOrder: SortOrder = 'Ascending';
    // set the value to groupTemplate
    public groupTemplate(data: any): JSX.Element {
       return (
        <strong>{data.City}</strong>
        );
      }

    public render() {
        return (
             // specifies the tag for render the ComboBox component
            <ComboBoxComponent id="comboelement" query={this.query} groupTemplate={this.groupTemplate} dataSource={this.employeeData} fields={this.fields} sortOrder={this.sortOrder} placeholder="Select an employee" />
        );
    }
}
ReactDOM.render(<App />, document.getElementById('sample'));

[Functional-component]

import { DataManager, ODataV4Adaptor, Predicate, Query } from '@syncfusion/ej2-data';
import { ComboBoxComponent } from '@syncfusion/ej2-react-dropdowns';
import * as React from 'react';
import * as ReactDOM from 'react-dom';
function App() {
    // bind the DataManager instance to dataSource property
    const employeeData = new DataManager({
        adaptor: new ODataV4Adaptor,
        crossDomain: true,
        url: 'https://services.odata.org/V4/Northwind/Northwind.svc/'
    });
    // form  predicate to fetch the grouped data
    const groupPredicate = new Predicate('City', 'equal', 'london').or('City', 'equal', 'seattle');
    // bind the Query instance to query property
    const query = new Query().from('Employees').select(['FirstName', 'City', 'EmployeeID']).take(6).where(groupPredicate);
    // maps the appropriate column to fields property
    const fields = { text: 'FirstName', value: 'EmployeeID', groupBy: 'City' };
    // sort the resulted items
    const sortOrder = 'Ascending';
    // set the value to groupTemplate
    function groupTemplate(data) {
        return (<strong>{data.City}</strong>);
    }
    return (
    // specifies the tag for render the ComboBox component
    <ComboBoxComponent id="comboelement" query={query} groupTemplate={groupTemplate} dataSource={employeeData} fields={fields} sortOrder={sortOrder} placeholder="Select an employee"/>);
}
ReactDOM.render(<App />, document.getElementById('sample'));
import { DataManager, ODataV4Adaptor, Predicate, Query } from '@syncfusion/ej2-data';
import { SortOrder } from '@syncfusion/ej2-lists';
import { ComboBoxComponent } from '@syncfusion/ej2-react-dropdowns';
import * as React from 'react';
import * as ReactDOM from 'react-dom';

function App() {
    // bind the DataManager instance to dataSource property
    const employeeData: DataManager = new DataManager({
        adaptor: new ODataV4Adaptor,
        crossDomain: true,
        url: 'https://services.odata.org/V4/Northwind/Northwind.svc/'
    });
    // form  predicate to fetch the grouped data
    const groupPredicate = new Predicate('City', 'equal', 'london').or('City', 'equal', 'seattle');
    // bind the Query instance to query property
    const query: Query = new Query().from('Employees').select(['FirstName', 'City', 'EmployeeID']).take(6).where(groupPredicate);
    // maps the appropriate column to fields property
    const fields: object = { text: 'FirstName', value: 'EmployeeID', groupBy: 'City' };
    // sort the resulted items
    const sortOrder: SortOrder = 'Ascending';
    // set the value to groupTemplate
    function groupTemplate(data: any): JSX.Element {
        return (
            <strong>{data.City}</strong>
        );
    }

    return (
    // specifies the tag for render the ComboBox component
        <ComboBoxComponent id="comboelement" query={query} groupTemplate={groupTemplate} dataSource={employeeData} fields={fields} sortOrder={sortOrder} placeholder="Select an employee" />
    );
}
ReactDOM.render(<App />, document.getElementById('sample'));

Header template

The header element is shown statically at the top of the popup list items within the ComboBox, and any custom element can be placed as a header element using the
headerTemplate property.

In the following sample, the list items and its headers are designed and displayed as two columns similar to multiple columns of the grid.

[Class-component]

// import DataManager related classes
import { DataManager, ODataV4Adaptor, Query } from '@syncfusion/ej2-data';
import { ComboBoxComponent } from '@syncfusion/ej2-react-dropdowns';
import * as React from 'react';
import * as ReactDOM from 'react-dom';
export default class App extends React.Component {
    // bind the DataManager instance to dataSource property
    employeeData = new DataManager({
        adaptor: new ODataV4Adaptor,
        crossDomain: true,
        url: 'https://services.odata.org/V4/Northwind/Northwind.svc/'
    });
    // bind the Query instance to query property
    query = new Query().from('Employees').select(['FirstName', 'City', 'EmployeeID']).take(6);
    // maps the appropriate column to fields property
    fields = { text: 'FirstName', value: 'EmployeeID' };
    // sort the resulted items
    sortOrder = 'Ascending';
    // set the value to header template
    headerTemplate(data) {
        return (<span className='head'><span className='name'>Name</span><span className='city'>City</span></span>);
    }
    // set the value to item template
    itemTemplate(data) {
        return (<span className='item'><span className='name'>{data.FirstName}</span><span className='city'>{data.City}</span></span>);
    }
    render() {
        return (
        // specifies the tag for render the ComboBox component
        <ComboBoxComponent id="comboelement" query={this.query} headerTemplate={this.headerTemplate} dataSource={this.employeeData} sortOrder={this.sortOrder} itemTemplate={this.itemTemplate} fields={this.fields} placeholder="Select an employee"/>);
    }
}
ReactDOM.render(<App />, document.getElementById('sample'));
// import DataManager related classes
import { DataManager, ODataV4Adaptor, Query } from '@syncfusion/ej2-data';
import { SortOrder } from '@syncfusion/ej2-lists';
import { ComboBoxComponent } from '@syncfusion/ej2-react-dropdowns';
import * as React from 'react';
import * as ReactDOM from 'react-dom';

export default class App extends React.Component<{}, {}> {
    // bind the DataManager instance to dataSource property
    private employeeData: DataManager = new DataManager({
        adaptor: new ODataV4Adaptor,
        crossDomain: true,
        url: 'https://services.odata.org/V4/Northwind/Northwind.svc/'
    });
    // bind the Query instance to query property
    private query: Query = new Query().from('Employees').select(['FirstName', 'City', 'EmployeeID']).take(6);
    // maps the appropriate column to fields property
    private fields: object = { text: 'FirstName', value: 'EmployeeID' };
    // sort the resulted items
    private sortOrder: SortOrder = 'Ascending';
    // set the value to header template
    public headerTemplate(data: any): JSX.Element {
      return (
       <span className='head'><span className='name'>Name</span><span className='city'>City</span></span>
        );
      }
    // set the value to item template
    public itemTemplate(data: any): JSX.Element {
      return (
       <span className='item' ><span className='name'>{data.FirstName}</span><span className='city'>{data.City}</span></span>
        );
      }
    public render() {
        return (
             // specifies the tag for render the ComboBox component
            <ComboBoxComponent id="comboelement" query={this.query} headerTemplate={this.headerTemplate} dataSource={this.employeeData} sortOrder={this.sortOrder} itemTemplate={this.itemTemplate}  fields={this.fields} placeholder="Select an employee" />
        );
    }
}
ReactDOM.render(<App />, document.getElementById('sample'));

[Functional-component]

// import DataManager related classes
import { DataManager, ODataV4Adaptor, Query } from '@syncfusion/ej2-data';
import { ComboBoxComponent } from '@syncfusion/ej2-react-dropdowns';
import * as React from 'react';
import * as ReactDOM from 'react-dom';
function App() {
    // bind the DataManager instance to dataSource property
    const employeeData = new DataManager({
        adaptor: new ODataV4Adaptor,
        crossDomain: true,
        url: 'https://services.odata.org/V4/Northwind/Northwind.svc/'
    });
    // bind the Query instance to query property
    const query = new Query().from('Employees').select(['FirstName', 'City', 'EmployeeID']).take(6);
    // maps the appropriate column to fields property
    const fields = { text: 'FirstName', value: 'EmployeeID' };
    // sort the resulted items
    const sortOrder = 'Ascending';
    // set the value to header template
    function headerTemplate(data) {
        return (<span className='head'><span className='name'>Name</span><span className='city'>City</span></span>);
    }
    // set the value to item template
    function itemTemplate(data) {
        return (<span className='item'><span className='name'>{data.FirstName}</span><span className='city'>{data.City}</span></span>);
    }
    return (
    // specifies the tag for render the ComboBox component
    <ComboBoxComponent id="comboelement" query={query} headerTemplate={headerTemplate} dataSource={employeeData} sortOrder={sortOrder} itemTemplate={itemTemplate} fields={fields} placeholder="Select an employee"/>);
}
ReactDOM.render(<App />, document.getElementById('sample'));
// import DataManager related classes
import { DataManager, ODataV4Adaptor, Query } from '@syncfusion/ej2-data';
import { SortOrder } from '@syncfusion/ej2-lists';
import { ComboBoxComponent } from '@syncfusion/ej2-react-dropdowns';
import * as React from 'react';
import * as ReactDOM from 'react-dom';

function App() {
    // bind the DataManager instance to dataSource property
    const employeeData: DataManager = new DataManager({
        adaptor: new ODataV4Adaptor,
        crossDomain: true,
        url: 'https://services.odata.org/V4/Northwind/Northwind.svc/'
    });
    // bind the Query instance to query property
    const query: Query = new Query().from('Employees').select(['FirstName', 'City', 'EmployeeID']).take(6);
    // maps the appropriate column to fields property
    const fields: object = { text: 'FirstName', value: 'EmployeeID' };
    // sort the resulted items
    const sortOrder: SortOrder = 'Ascending';
    // set the value to header template
    function headerTemplate(data: any): JSX.Element {
      return (
       <span className='head'><span className='name'>Name</span><span className='city'>City</span></span>
        );
      }
    // set the value to item template
    function itemTemplate(data: any): JSX.Element {
        return (
            <span className='item' ><span className='name'>{data.FirstName}</span><span className='city'>{data.City}</span></span>
        );
    }
    return (
    // specifies the tag for render the ComboBox component
        <ComboBoxComponent id="comboelement" query={query} headerTemplate={headerTemplate} dataSource={employeeData} sortOrder={sortOrder} itemTemplate={itemTemplate}  fields={fields} placeholder="Select an employee" />
    );
}
ReactDOM.render(<App />, document.getElementById('sample'));

The ComboBox has options to show a footer element at the bottom of the list items in the popup list. Here, you can place any custom element as a footer element using the footerTemplate property.

In the following sample, footer element displays the total number of list items present in the ComboBox.

[Class-component]

import { ComboBoxComponent } from '@syncfusion/ej2-react-dropdowns';
import * as React from 'react';
import * as ReactDOM from 'react-dom';
export default class App extends React.Component {
    // define the array of data
    sportsData = ["BasketBall", "Cricket", "Football", "Golf"];
    // set the value to footer template
    footerTemplate(data) {
        return (<span className='foot'/>);
    }
    render() {
        return (
        // specifies the tag for render the ComboBox component
        <ComboBoxComponent id="comboelement" footerTemplate={this.footerTemplate} dataSource={this.sportsData} placeholder="Select a game"/>);
    }
}
ReactDOM.render(<App />, document.getElementById('sample'));
import { ComboBoxComponent } from '@syncfusion/ej2-react-dropdowns';
import * as React from 'react';
import * as ReactDOM from 'react-dom';

export default class App extends React.Component<{}, {}> {
    // define the array of data
    private sportsData: string[] = ["BasketBall", "Cricket", "Football", "Golf"];

    // set the value to footer template
     public footerTemplate(data: any): JSX.Element {
      return (
       <span className='foot'/>
        );
      }
    public render() {
        return (
              // specifies the tag for render the ComboBox component
            <ComboBoxComponent id="comboelement" footerTemplate={this.footerTemplate} dataSource={this.sportsData} placeholder="Select a game" />
        );
    }
}
ReactDOM.render(<App />, document.getElementById('sample'));

[Functional-component]

import { ComboBoxComponent } from '@syncfusion/ej2-react-dropdowns';
import * as React from 'react';
import * as ReactDOM from 'react-dom';
function App() {
    // define the array of data
    const sportsData = ["BasketBall", "Cricket", "Football", "Golf"];
    // set the value to footer template
    function footerTemplate(data) {
        return (<span className='foot'/>);
    }
    return (
    // specifies the tag for render the ComboBox component
    <ComboBoxComponent id="comboelement" footerTemplate={footerTemplate} dataSource={sportsData} placeholder="Select a game"/>);
}
ReactDOM.render(<App />, document.getElementById('sample'));
import { ComboBoxComponent } from '@syncfusion/ej2-react-dropdowns';
import * as React from 'react';
import * as ReactDOM from 'react-dom';

function App() {
    // define the array of data
    const sportsData: string[] = ["BasketBall", "Cricket", "Football", "Golf"];

    // set the value to footer template
    function footerTemplate(data: any): JSX.Element {
        return (
            <span className='foot'/>
        );
    }
    return (
    // specifies the tag for render the ComboBox component
        <ComboBoxComponent id="comboelement" footerTemplate={footerTemplate} dataSource={sportsData} placeholder="Select a game" />
    );
}
ReactDOM.render(<App />, document.getElementById('sample'));

No records template

The ComboBox is provided with support to custom design the popup list content when no data is found and no matches found on search with the help of
noRecordsTemplate property.

In the following sample, popup list content displays the notification of no data available.

[Class-component]

import { ComboBoxComponent } from '@syncfusion/ej2-react-dropdowns';
import * as React from 'react';
import * as ReactDOM from 'react-dom';
export default class App extends React.Component {
    // define the array of data
    data = [];
    // set the value to noRecords template
    noRecordsTemplate(data) {
        return (<span className='norecord'> NO DATA AVAILABLE</span>);
    }
    render() {
        return (
        // specifies the tag for render the ComboBox component
        <ComboBoxComponent id="comboelement" noRecordsTemplate={this.noRecordsTemplate = this.noRecordsTemplate.bind(this)} dataSource={this.data} placeholder="Select an item"/>);
    }
}
ReactDOM.render(<App />, document.getElementById('sample'));
import { ComboBoxComponent } from '@syncfusion/ej2-react-dropdowns';
import * as React from 'react';
import * as ReactDOM from 'react-dom';

export default class App extends React.Component<{}, {}> {
    // define the array of data
    private data: string[] = [];

    // set the value to noRecords template
     public noRecordsTemplate(data: any): JSX.Element {
      return (
       <span className='norecord'> NO DATA AVAILABLE</span>
        );
      }
    public render() {
        return (
            // specifies the tag for render the ComboBox component
            <ComboBoxComponent id="comboelement" noRecordsTemplate={this.noRecordsTemplate = this.noRecordsTemplate.bind(this)} dataSource={this.data} placeholder="Select an item" />
        );
    }
}
ReactDOM.render(<App />, document.getElementById('sample'));

[Functional-component]

import { ComboBoxComponent } from '@syncfusion/ej2-react-dropdowns';
import * as React from 'react';
import * as ReactDOM from 'react-dom';
function App() {
    // define the array of data
    const data = [];
    // set the value to noRecords template
    function noRecordsTemplate(data) {
        return (<span className='norecord'> NO DATA AVAILABLE</span>);
    }
    return (
    // specifies the tag for render the ComboBox component
    <ComboBoxComponent id="comboelement" noRecordsTemplate={noRecordsTemplate = noRecordsTemplate.bind(this)} dataSource={data} placeholder="Select an item"/>);
}
ReactDOM.render(<App />, document.getElementById('sample'));
import { ComboBoxComponent } from '@syncfusion/ej2-react-dropdowns';
import * as React from 'react';
import * as ReactDOM from 'react-dom';

function App() {
    // define the array of data
    const data: string[] = [];

    // set the value to noRecords template
    function noRecordsTemplate(data: any): JSX.Element {
        return (
            <span className='norecord'> NO DATA AVAILABLE</span>
        );
    }

    return (
    // specifies the tag for render the ComboBox component
        <ComboBoxComponent id="comboelement" noRecordsTemplate={noRecordsTemplate = noRecordsTemplate.bind(this)} dataSource={data} placeholder="Select an item" />
    );

}
ReactDOM.render(<App />, document.getElementById('sample'));

Action failure template

There is also an option to custom design the popup list content when the data fetch request fails at the remote server. This can be achieved using the
actionFailureTemplate property.

In the following sample, when the data fetch request fails, the ComboBox displays the notification.

[Class-component]

// import DataManager related classes
import { DataManager, ODataV4Adaptor, Query } from '@syncfusion/ej2-data';
import { ComboBoxComponent } from '@syncfusion/ej2-react-dropdowns';
import * as React from 'react';
import * as ReactDOM from 'react-dom';
export default class App extends React.Component {
    // bind the DataManager instance to dataSource property
    customerData = new DataManager({
        adaptor: new ODataV4Adaptor,
        crossDomain: true,
        url: 'http://services.odata.org/V4/Northwind/Northwind.svcs/'
    });
    // bind the Query instance to query property
    query = new Query().from('Customers').select(['ContactName', 'CustomerID']).take(6);
    // maps the appropriate column to fields property
    fields = { text: 'ContactName', value: 'CustomerID' };
    // set the value to action failure template
    template(data) {
        return (<span className='action-failure'> Data fetch get fails</span>);
    }
    render() {
        return (
        // specifies the tag for render the ComboBox component
        <ComboBoxComponent id="comboelement" actionFailureTemplate={this.template = this.template.bind(this)} query={this.query} dataSource={this.customerData} fields={this.fields} placeholder="Select a customer"/>);
    }
}
ReactDOM.render(<App />, document.getElementById('sample'));
// import DataManager related classes
import { DataManager, ODataV4Adaptor, Query } from '@syncfusion/ej2-data';
import { ComboBoxComponent } from '@syncfusion/ej2-react-dropdowns';
import * as React from 'react';
import * as ReactDOM from 'react-dom';

export default class App extends React.Component<{}, {}> {
    // bind the DataManager instance to dataSource property
    private customerData: DataManager = new DataManager({
        adaptor: new ODataV4Adaptor,
        crossDomain: true,
        url: 'http://services.odata.org/V4/Northwind/Northwind.svcs/'
    });
    // bind the Query instance to query property
    private query: Query = new Query().from('Customers').select(['ContactName', 'CustomerID']).take(6);
    // maps the appropriate column to fields property
    private fields: object = { text: 'ContactName', value: 'CustomerID' };
    // set the value to action failure template
    public template(data: any): JSX.Element {
      return (
       <span className='action-failure'> Data fetch get fails</span>
        );
      }
    public render() {
        return (
            // specifies the tag for render the ComboBox component
            <ComboBoxComponent id="comboelement" actionFailureTemplate={this.template = this.template.bind(this)} query={this.query} dataSource={this.customerData} fields={this.fields} placeholder="Select a customer" />
        );
    }
}
ReactDOM.render(<App />, document.getElementById('sample'));

[Functional-component]

// import DataManager related classes
import { DataManager, ODataV4Adaptor, Query } from '@syncfusion/ej2-data';
import { ComboBoxComponent } from '@syncfusion/ej2-react-dropdowns';
import * as React from 'react';
import * as ReactDOM from 'react-dom';
function App() {
    // bind the DataManager instance to dataSource property
    const customerData = new DataManager({
        adaptor: new ODataV4Adaptor,
        crossDomain: true,
        url: 'http://services.odata.org/V4/Northwind/Northwind.svcs/'
    });
    // bind the Query instance to query property
    const query = new Query().from('Customers').select(['ContactName', 'CustomerID']).take(6);
    // maps the appropriate column to fields property
    const fields = { text: 'ContactName', value: 'CustomerID' };
    // set the value to action failure template
    function template(data) {
        return (<span className='action-failure'> Data fetch get fails</span>);
    }
    return (
    // specifies the tag for render the ComboBox component
    <ComboBoxComponent id="comboelement" actionFailureTemplate={template = template.bind(this)} query={query} dataSource={customerData} fields={fields} placeholder="Select a customer"/>);
}
ReactDOM.render(<App />, document.getElementById('sample'));
// import DataManager related classes
import { DataManager, ODataV4Adaptor, Query } from '@syncfusion/ej2-data';
import { ComboBoxComponent } from '@syncfusion/ej2-react-dropdowns';
import * as React from 'react';
import * as ReactDOM from 'react-dom';

function App() {
    // bind the DataManager instance to dataSource property
    const customerData: DataManager = new DataManager({
        adaptor: new ODataV4Adaptor,
        crossDomain: true,
        url: 'http://services.odata.org/V4/Northwind/Northwind.svcs/'
    });
    // bind the Query instance to query property
    const query: Query = new Query().from('Customers').select(['ContactName', 'CustomerID']).take(6);
    // maps the appropriate column to fields property
    const fields: object = { text: 'ContactName', value: 'CustomerID' };
    // set the value to action failure template
    function template(data: any): JSX.Element {
        return (
            <span className='action-failure'> Data fetch get fails</span>
        );
    }
    return (
    // specifies the tag for render the ComboBox component
        <ComboBoxComponent id="comboelement" actionFailureTemplate={template = template.bind(this)} query={query} dataSource={customerData} fields={fields} placeholder="Select a customer" />
    );
}
ReactDOM.render(<App />, document.getElementById('sample'));

See Also