Getting started with JavaScript DropDownList control

17 Mar 2023 / 4 minutes to read

This section explains how to create a simple DropDownList component and configure its available functionalities in TypeScript using the Essential JS 2 quickstart seed repository.

Dependencies

The following list of dependencies are required to use the DropDownList component in your application.

|-- @syncfusion/ej2-dropdowns
    |-- @syncfusion/ej2-base
    |-- @syncfusion/ej2-data
    |-- @syncfusion/ej2-inputs
    |-- @syncfusion/ej2-lists
    |-- @syncfusion/ej2-navigations
    |-- @syncfusion/ej2-popups
        |-- @syncfusion/ej2-buttons

Set up of the development environment

To get started with the DropDownList component, you have to clone the Essential JS 2 quickstart project and install the npm packages by using the following commands.

git clone https://github.com/syncfusion/ej2-quickstart.git quickstart
cd quickstart
npm install

The project is preconfigured with common settings (src/styles/styles.css, system.config.js ) to start all the Essential JS 2 components.

Initialize the DropDownList

The DropDownList can be initialized through three different tags as described in the Initialize Tags.

Add the HTML input element that needs to be initialized as a DropDownList in index.html.

[src/index.html]

<!DOCTYPE html>
<html lang="en">

<head>
    <title>Essential JS 2 DropDownList component</title>
    <meta charset="utf-8" />
    <meta name="viewport" content="width=device-width, initial-scale=1.0, user-scalable=no" />
    <meta name="description" content="Essential JS 2" />
    <meta name="author" content="Syncfusion" />
    <link href="https://maxcdn.bootstrapcdn.com/bootstrap/3.3.7/css/bootstrap.min.css" rel="stylesheet" />

    <!--style reference from app-->
    <link href="/styles/styles.css" rel="stylesheet" />

    <!--system js reference and configuration-->
    <script src="node_modules/systemjs/dist/system.src.js" type="text/javascript"></script>
    <script src="system.config.js" type="text/javascript"></script>
</head>

<body>
    <div id='container' style="margin:0 auto; width:300px;">
        <!--element which is going to render the DropDownList-->
        <input type="text" tabindex="1" id='ddlelement' />
    </div>

</body>

</html>

Now, import the DropDownList component to your app.ts and initialize it to the element #ddlelement as shown below.

[src/app/app.ts]

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

// initialize DropDownList component
let dropDownListObject: DropDownList = new DropDownList();

// render initialized DropDownList
dropDownListObject.appendTo('#ddlelement');

Binding data source

After initialization, populate the DropDownList with data using the dataSource property. Here, an array of string values is passed to the DropDownList component.

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

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

// initialize DropDownList component
let dropDownListObject: DropDownList = new DropDownList({
    //set the data to dataSource property
    dataSource: sportsData
});

// render initialized DropDownList
dropDownListObject.appendTo('#ddlelement');

Run the application

After completing the configuration required to render a basic DropDownList, run the following command to display the output in your default browser.

npm run start

The following example illustrates the output in your browser.

Source

Preview

app.ts

index.html

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

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

// initialize DropDownList component
let dropDownListObject: DropDownList = new DropDownList({
    //set the data to dataSource property
    dataSource: sportsData,
    // set placeholder to DropDownList input element
    placeholder: "Select a game"
});

// render initialized DropDownList
dropDownListObject.appendTo('#ddlelement');

<!DOCTYPE html>
<html lang="en">

<head>
            
    <title>Essential JS 2 DropDownList</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="//cdn.syncfusion.com/ej2/20.4.48/ej2-base/styles/material.css" rel="stylesheet" />
    <link href="//cdn.syncfusion.com/ej2/20.4.48/ej2-inputs/styles/material.css" rel="stylesheet" />
    <link href="//cdn.syncfusion.com/ej2/20.4.48/ej2-dropdowns/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='ddlelement' />
    </div>
</body>

</html>

By default, the width of the popup list automatically adjusts according to the DropDownList input element’s width, and the height of the popup list has ‘300px’.

The height and width of the popup list can also be customized using the popupHeight and popupWidth properties respectively.

In the following sample, popup list’s width and height are configured.