Getting started with EJ2 TypeScript Dropdown Tree control
5 Feb 202511 minutes to read
This section explains you about how to create a simple Dropdown Tree control and configure its available functionalities in TypeScript using the Essential JS 2 quickstart.
Dependencies
The following list of dependencies are required to use the Dropdown Tree control 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 development environment
Open the command prompt from the required directory, and run the following command to clone the Syncfusion JavaScript (Essential JS 2) quickstart project from GitHub.
git clone https://github.com/SyncfusionExamples/ej2-quickstart-webpack- ej2-quickstart
After cloning the application in the ej2-quickstart
folder, run the following command line to navigate to the ej2-quickstart
folder.
cd ej2-quickstart
Add Syncfusion JavaScript packages
Syncfusion JavaScript (Essential JS 2) packages are available on the npmjs.com public registry. You can install all Syncfusion JavaScript (Essential JS 2) controls in a single @syncfusion/ej2 package or individual packages for each control.
The quickstart application is preconfigured with the dependent @syncfusion/ej2 package in the ~/package.json
file. Use the following command to install the dependent npm packages from the command prompt.
npm install
Import the Syncfusion CSS styles
Combined CSS files are available in the Essential JS 2 package root folder. This can be referenced in the ~/src/styles/styles.css
file of your application using the following code.
@import '../../node_modules/@syncfusion/ej2-base/styles/material.css';
@import '../../node_modules/@syncfusion/ej2-navigations/styles/material.css';
@import '../../node_modules/@syncfusion/ej2-inputs/styles/material.css';
@import '../../node_modules/@syncfusion/ej2-buttons/styles/material.css';
@import '../../node_modules/@syncfusion/ej2-dropdowns/styles/material.css';
To refer individual control CSS, please refer to the Individual control theme files section. If you want to refer the combined control styles, please make use of our
CRG
(Custom Resource Generator) in your application.
Initialize the Dropdown Tree
Add the HTML input element that needs to be initialized as a Dropdown Tree in index.html
.
[src/index.html]
<!DOCTYPE html>
<html lang="en">
<head>
<title>Essential JS 2 Dropdown Tree control</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 rel="shortcut icon" href="resources/favicon.ico" />
<link href="https://maxcdn.bootstrapcdn.com/bootstrap/3.3.7/css/bootstrap.min.css" rel="stylesheet" />
</head>
<body>
<div id='container' style="margin:0 auto; width:300px;">
<!--element which is going to render the Dropdown Tree-->
<input type="text" tabindex="1" id='ddTreeElement' />
</div>
</body>
</html>
Now, import the Dropdown Tree control to your app.ts
and initialize it to the element #ddTreeElement
as shown below.
[src/app/app.ts]
import { DropDownTree } from '@syncfusion/ej2-dropdowns';
// initialize Dropdown Tree control
let DropDownTreeObject: DropDownTree = new DropDownTree();
// render initialized Dropdown Tree
DropDownTreeObject.appendTo('#ddTreeElement');
Binding data source
The Dropdown Tree control can load the data either from local data sources or remote data services. This can be done using the dataSource
property that is a member of the fields
property. The dataSource property supports array of JavaScript objects and DataManager. Here, an array of JSON values is passed to the Dropdown Tree control.
import { DropDownTree } from '@syncfusion/ej2-dropdowns';
//define the array of JSON
let data: { [key: string]: Object }[] = [
{
nodeId: '01', nodeText: 'Music',
nodeChild: [
{ nodeId: '01-01', nodeText: 'Gouttes.mp3' }
]
},
{
nodeId: '02', nodeText: 'Videos', expanded: true,
nodeChild: [
{ nodeId: '02-01', nodeText: 'Naturals.mp4' },
{ nodeId: '02-02', nodeText: 'Wild.mpeg' },
]
},
{
nodeId: '03', nodeText: 'Documents',
nodeChild: [
{ nodeId: '03-01', nodeText: 'Environment Pollution.docx' },
{ nodeId: '03-02', nodeText: 'Global Water, Sanitation, & Hygiene.docx' },
{ nodeId: '03-03', nodeText: 'Global Warming.ppt' },
{ nodeId: '03-04', nodeText: 'Social Network.pdf' },
{ nodeId: '03-05', nodeText: 'Youth Empowerment.pdf' },
]
},
];
// initialize Dropdown Tree control
let DropDownTreeObject: DropDownTree = new DropDownTree({
//binding data source through fields property
fields: { dataSource: data, value: 'nodeId', text: 'nodeText', child: 'nodeChild' }
});
// render initialized Dropdown Tree
DropDownTreeObject.appendTo('#ddTreeElement');
Run the application
After completing the configuration required to render a basic Dropdown Tree, run the following command to display the output in your default browser.
npm run start
The following example explains the output in your browser.
import { DropDownTree } from '@syncfusion/ej2-dropdowns';
//define the array of JSON
let data: { [key: string]: Object }[] = [
{
nodeId: '01', nodeText: 'Music',
nodeChild: [
{ nodeId: '01-01', nodeText: 'Gouttes.mp3' }
]
},
{
nodeId: '02', nodeText: 'Videos', expanded: true,
nodeChild: [
{ nodeId: '02-01', nodeText: 'Naturals.mp4' },
{ nodeId: '02-02', nodeText: 'Wild.mpeg' },
]
},
{
nodeId: '03', nodeText: 'Documents',
nodeChild: [
{ nodeId: '03-01', nodeText: 'Environment Pollution.docx' },
{ nodeId: '03-02', nodeText: 'Global Water, Sanitation, & Hygiene.docx' },
{ nodeId: '03-03', nodeText: 'Global Warming.ppt' },
{ nodeId: '03-04', nodeText: 'Social Network.pdf' },
{ nodeId: '03-05', nodeText: 'Youth Empowerment.pdf' },
]
},
];
// initialize Dropdown Tree control
let DropDownTreeObject: DropDownTree = new DropDownTree({
//binding data source through fields property
fields: { dataSource: data, value: 'nodeId', text: 'nodeText', child: 'nodeChild' },
// set placeholder to Dropdown Tree input element
placeholder: "Select a Item"
});
// render initialized Dropdown Tree
DropDownTreeObject.appendTo('#ddltreeelement');
<!DOCTYPE html>
<html lang="en">
<head>
<title>Essential JS 2 Dropdown Tree</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/ej2/28.2.3/ej2-base/styles/material.css" rel="stylesheet" />
<link href="https://cdn.syncfusion.com/ej2/28.2.3/ej2-inputs/styles/material.css" rel="stylesheet" />
<link href="https://cdn.syncfusion.com/ej2/28.2.3/ej2-buttons/styles/material.css" rel="stylesheet" />
<link href="https://cdn.syncfusion.com/ej2/28.2.3/ej2-lists/styles/material.css" rel="stylesheet" />
<link href="https://cdn.syncfusion.com/ej2/28.2.3/ej2-navigations/styles/material.css" rel="stylesheet" />
<link href="https://cdn.syncfusion.com/ej2/28.2.3/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>
<script src="https://cdn.syncfusion.com/ej2/syncfusion-helper.js" type ="text/javascript"></script>
</head>
<body>
<div id='loader'>LOADING....</div>
<div id='container' style="margin:0 auto; width:250px;">
<input type="text" tabindex="1" id='ddltreeelement' />
</div>
</body>
</html>
#container {
visibility: hidden;
}
#loader {
color: #008cff;
height: 40px;
width: 30%;
position: absolute;
top: 45%;
left: 45%;
}