Data Binding in EJ2 TypeScript MultiSelect Dropdown

04 Sep 202613 minutes to read

The MultiSelect loads the data either from local data sources or remote data services using the dataSource property. It supports the data type of array or DataManager.

The MultiSelect also supports different kinds of data services such as OData, OData V4, and Web API, and data formats such as XML, JSON, and JSONP with the help of DataManager adaptors.

Fields Type Description
text string Specifies the display text of each list item.
value number or string Specifies the hidden data value mapped to each list item that should contain a unique value.
groupBy string Specifies the category under which the list item has to be grouped.
iconCss string Specifies the icon class of each list item.

When binding complex data to the MultiSelect, fields should be mapped correctly. Otherwise, the selected item remains undefined.

Binding local data

Local data can be represented in the following two ways.

1. Array of string

The MultiSelect supports loading an array of primitive data such as strings and numbers. Here, both the value and text fields behave the same way.

import { MultiSelect } from '@syncfusion/ej2-dropdowns';

// define the array of data
let sportsData: string[] = ['Badminton', 'Cricket', 'Football', 'Golf', 'Tennis'];

// initialize MultiSelect component
let msObject: MultiSelect = new MultiSelect({
    //set the data to dataSource property
    dataSource: sportsData,
    // set placeholder to multiSelect input element
    placeholder: "Select games"
});

// render initialized multiSelect
msObject.appendTo('#select');
<!DOCTYPE html>
<html lang="en">

<head>
    <title>Essential JS 2 MultiSelect</title>
    <meta charset="utf-8" />
    <meta name="viewport" content="width=device-width, initial-scale=1.0" />
    <meta name="description" content="Typescript UI Controls" />
    <meta name="author" content="Syncfusion" />
    <link href="styles.css" rel="stylesheet" />
    <link href="https://cdn.syncfusion.com/ej2/34.2.2/ej2-base/styles/material.css" rel="stylesheet" />
    <link href="https://cdn.syncfusion.com/ej2/34.2.2/ej2-inputs/styles/material.css" rel="stylesheet" />
    <link href="https://cdn.syncfusion.com/ej2/34.2.2/ej2-dropdowns/styles/material.css" rel="stylesheet" />
    <link href="https://cdn.syncfusion.com/ej2/34.2.2/ej2-buttons/styles/material.css" rel="stylesheet" />
    <script src="https://cdnjs.cloudflare.com/ajax/libs/systemjs/0.19.38/system.js"></script>
    <script src="systemjs.config.js"></script>
</head>

<body>
    <div id='loader'>LOADING....</div>
    <div id='container' style="margin:0 auto; width:250px;">
        <input type="text" tabindex="1" id='select' />
    </div>
</body>

</html>

2. Array of objects

The MultiSelect can generate its list items through an array of complex data. For this, the appropriate columns should be mapped to the fields property.

In the following example, the id and sports columns from the data have been mapped to the value and text fields, respectively.

import { MultiSelect } from '@syncfusion/ej2-dropdowns';

//define the array of complex data
let sportsData: { [key: string]: Object }[] = [
    { id: 'game1', sports: 'Badminton' },
    { id: 'game2', sports: 'Football' },
    { id: 'game3', sports: 'Tennis' }
];

//initiate the MultiSelect
let msObject: MultiSelect = new MultiSelect({
    // bind the sports Data to datasource property
    dataSource: sportsData,
    // maps the appropriate column to fields property
    fields: { text: 'sports', value: 'id' },
    //set the placeholder to MultiSelect input
    placeholder:"Select games"
});
//render the component
msObject.appendTo('#select');
<!DOCTYPE html>
<html lang="en">

<head>
    <title>Essential JS 2 MultiSelect</title>
    <meta charset="utf-8" />
    <meta name="viewport" content="width=device-width, initial-scale=1.0" />
    <meta name="description" content="Typescript UI Controls" />
    <meta name="author" content="Syncfusion" />
    <link href="styles.css" rel="stylesheet" />
    <link href="https://cdn.syncfusion.com/ej2/34.2.2/ej2-base/styles/material.css" rel="stylesheet" />
    <link href="https://cdn.syncfusion.com/ej2/34.2.2/ej2-inputs/styles/material.css" rel="stylesheet" />
    <link href="https://cdn.syncfusion.com/ej2/34.2.2/ej2-dropdowns/styles/material.css" rel="stylesheet" />
    <link href="https://cdn.syncfusion.com/ej2/34.2.2/ej2-buttons/styles/material.css" rel="stylesheet" />
    <script src="https://cdnjs.cloudflare.com/ajax/libs/systemjs/0.19.38/system.js"></script>
    <script src="systemjs.config.js"></script>
</head>

<body>
    <div id='loader'>LOADING....</div>
    <div id='container' style="margin:0 auto; width:250px;">
        <br>
        <!--element which is going to render the MultiSelect-->
        <input type="text" tabindex="1" id='select' />
    </div>
</body>

</html>

3. Array of complex objects

The MultiSelect can generate its list items through an array of complex data. For this, the appropriate columns should be mapped to the fields property.

In the following example, the Code.Id and Country.Name columns from the data have been mapped to the value and text fields, respectively.

import { MultiSelect } from '@syncfusion/ej2-dropdowns';

//define the array of complex data
let countriesData: { [key: string]: Object }[] = [
        { Country: { Name: 'Australia' }, Code: { Id: 'AU' }},
        { Country: { Name: 'Bermuda' },Code: { Id: 'BM' }},
        { Country:{ Name: 'Canada'}, Code:{ Id: 'CA'} },
        { Country:{Name: 'Cameroon'}, Code:{ Id: 'CM'} },
        { Country:{Name: 'Denmark'}, Code:{ Id: 'DK' }},
        { Country:{Name: 'France'}, Code: { Id:'FR'} }
];

//initiate the MultiSelect
let msObject: MultiSelect = new MultiSelect({
    // bind the sports Data to datasource property
    dataSource: countriesData,
    // maps the appropriate column to fields property
    fields: { text: 'Country.Name', value: 'Code.Id' },
    //set the placeholder to MultiSelect input
    placeholder:"Select a country"
});
//render the component
msObject.appendTo('#select');
<!DOCTYPE html>
<html lang="en">

<head>
    <title>Essential JS 2 MultiSelect</title>
    <meta charset="utf-8" />
    <meta name="viewport" content="width=device-width, initial-scale=1.0" />
    <meta name="description" content="Typescript UI Controls" />
    <meta name="author" content="Syncfusion" />
    <link href="styles.css" rel="stylesheet" />
    <link href="https://cdn.syncfusion.com/ej2/34.2.2/ej2-base/styles/material.css" rel="stylesheet" />
    <link href="https://cdn.syncfusion.com/ej2/34.2.2/ej2-inputs/styles/material.css" rel="stylesheet" />
    <link href="https://cdn.syncfusion.com/ej2/34.2.2/ej2-dropdowns/styles/material.css" rel="stylesheet" />
    <link href="https://cdn.syncfusion.com/ej2/34.2.2/ej2-buttons/styles/material.css" rel="stylesheet" />
    <script src="https://cdnjs.cloudflare.com/ajax/libs/systemjs/0.19.38/system.js"></script>
    <script src="systemjs.config.js"></script>
</head>

<body>
    <div id='loader'>LOADING....</div>
    <div id='container' style="margin:0 auto; width:250px;">
        <br>
        <!--element which is going to render the MultiSelect-->
        <input type="text" tabindex="1" id='select' />
    </div>
</body>

</html>

Binding remote data

The MultiSelect supports retrieval of data from remote data services with the help of the DataManager component. The Query property is used to fetch data from the database and bind it to the MultiSelect.

The following sample displays the first 6 contacts from the Customers table of the Northwind data service.

import { MultiSelect } from '@syncfusion/ej2-dropdowns';
//import DataManager related classes
import { Query, DataManager, ODataV4Adaptor } from '@syncfusion/ej2-data';

//initiates the component
let customers: MultiSelect = new MultiSelect({
    //bind the DataManager instance to dataSource property
    dataSource: new DataManager({
            url: 'https://services.odata.org/V4/Northwind/Northwind.svc/',
            adaptor: new ODataV4Adaptor,
            crossDomain: true
        }),
    //bind the Query instance to query property
    query: new Query().from('Customers').select(['ContactName', 'CustomerID']).take(6),
    //map the appropriate columns to fields property
    fields: { text: 'ContactName', value: 'CustomerID' },
    //set the placeholder to MultiSelect input
    placeholder:"Select customers",
    //sort the resulted items
    sortOrder: 'Ascending'
});

//render the component
customers.appendTo('#select');
<!DOCTYPE html>
<html lang="en">

<head>
    <title>Essential JS 2 MultiSelect</title>
    <meta charset="utf-8" />
    <meta name="viewport" content="width=device-width, initial-scale=1.0" />
    <meta name="description" content="Typescript UI Controls" />
    <meta name="author" content="Syncfusion" />
    <link href="styles.css" rel="stylesheet" />
    <link href="https://cdn.syncfusion.com/ej2/34.2.2/ej2-base/styles/material.css" rel="stylesheet" />
    <link href="https://cdn.syncfusion.com/ej2/34.2.2/ej2-inputs/styles/material.css" rel="stylesheet" />
    <link href="https://cdn.syncfusion.com/ej2/34.2.2/ej2-dropdowns/styles/material.css" rel="stylesheet" />
    <link href="https://cdn.syncfusion.com/ej2/34.2.2/ej2-buttons/styles/material.css" rel="stylesheet" />
    <script src="https://cdnjs.cloudflare.com/ajax/libs/systemjs/0.19.38/system.js"></script>
    <script src="systemjs.config.js"></script>
</head>

<body>
    <div id='loader'>LOADING....</div>
    <div id='container' style="margin:0 auto; width:250px;">
        <br>
        <!--element which is going to render the MultiSelect-->
        <input type="text" tabindex="1" id='select' />
    </div>
</body>

</html>

See Also