Getting started in EJ2 TypeScript Treeview control

16 Jun 202310 minutes to read

This section explains the steps required to create a simple JavaScript TreeView component, and configure its available functionalities in TypeScript using the Essential JS 2 quickstart seed repository. This seed repository is preconfigured with all the Essential JS 2 packages.

Dependencies

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

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

Setup for local development

Clone the Essential JS 2 quickstart application project from GitHub, and install the necessary npm packages using the following command line scripts.

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

Configuring system JS

The Syncfusion TreeView packages should be mapped in the system.config.js configuration file.

System.config({
    paths: {
        'npm:': './node_modules/',
        'syncfusion:': 'npm:@syncfusion/'
    },
    map: {
        app: 'app',

        //Syncfusion packages mapping
        "@syncfusion/ej2-base": "syncfusion:ej2-base/dist/ej2-base.umd.min.js",
        "@syncfusion/ej2-data": "syncfusion:ej2-data/dist/ej2-data.umd.min.js",
        "@syncfusion/ej2-lists": "syncfusion:ej2-lists/dist/ej2-lists.umd.min.js",
        "@syncfusion/ej2-inputs": "syncfusion:ej2-inputs/dist/ej2-inputs.umd.min.js",
        "@syncfusion/ej2-buttons": "syncfusion:ej2-buttons/dist/ej2-buttons.umd.min.js",
        "@syncfusion/ej2-splitbuttons": "syncfusion:ej2-splitbuttons/dist/ej2-splitbuttons.umd.min.js",
        "@syncfusion/ej2-popups": "syncfusion:ej2-popups/dist/ej2-popups.umd.min.js",
        "@syncfusion/ej2-navigations": "syncfusion:ej2-navigations/dist/ej2-navigations.umd.min.js",
    },
    packages: {
        'app': { main: 'app', defaultExtension: 'js' }
    }
});

System.import('app');

Adding CSS reference

Combined CSS files are available in the Essential JS 2 package root folder. This can be referenced in your [src/styles/styles.css] 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';

To refer individual component CSS, please refer to the Individual Component theme files section. If you want to refer the combined component styles, please make use of our CRG (Custom Resource Generator) in your application.

Adding TreeView component

Now, you can start adding Essential JS 2 TreeView component to the application. To get started, add the TreeView component to app.ts and index.html files using the following code. Then, add the HTML <div> element for TreeView component to your index.html.

[src/index.html]

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

<head>
    <title>Essential JS 2 for TreeView</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 TreeView" />
    <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" />

    <!--style reference from node_modules/@syncfusion/ej2/-->
    <link href="/styles/styles.css" rel="stylesheet" />

    <script src="node_modules/systemjs/dist/system.src.js" type="text/javascript"></script>
    <script src="system.config.js" type="text/javascript"></script>

</head>

<body>
    <!--Element which will render as TreeView-->
    <div id="tree"></div>
</body>

</html>

Place the following TreeView code in app.ts.

[src/app/app.ts]

import { enableRipple } from '@syncfusion/ej2-base';
enableRipple(true);
import { TreeView } from '@syncfusion/ej2-navigations'

//Initialize TreeView component
let treeViewInstance: TreeView = new TreeView();

//Render initialized TreeView
treeViewInstance.appendTo("#tree");

Binding data source

TreeView can load 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 TreeView component.

[src/app/app.ts]

import { enableRipple } from '@syncfusion/ej2-base';
enableRipple(true);
import { TreeView } from '@syncfusion/ej2-navigations';

//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 TreeView component
let treeViewInstance: TreeView = new TreeView({
    fields: { dataSource: data, id: 'nodeId', text: 'nodeText', child: 'nodeChild' }
});

//Render initialized TreeView
treeViewInstance.appendTo("#tree");

Run the application

You have to use the npm start command to run the application in the browser.

npm start
import { enableRipple } from '@syncfusion/ej2-base';
enableRipple(true);
import { TreeView } from '@syncfusion/ej2-navigations';

//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 TreeView component
let treeViewInstance: TreeView = new TreeView({
    fields: { dataSource: data, id: 'nodeId', text: 'nodeText', child: 'nodeChild' }
});

//Render initialized TreeView
treeViewInstance.appendTo("#tree");
<!DOCTYPE html>
<html lang="en">

<head>
    <title>Essential JS 2 for TreeView </title>
    <meta charset="utf-8" />
    <meta name="viewport" content="width=device-width, initial-scale=1.0" />
    <meta name="description" content="Essential JS 2 for TreeView UI Control" />
    <meta name="author" content="Syncfusion" />
    <link href="index.css" rel="stylesheet" />
    <link href="https://cdn.syncfusion.com/ej2/23.1.36/ej2-base/styles/material.css" rel="stylesheet" />
    <link href="https://cdn.syncfusion.com/ej2/23.1.36/ej2-navigations/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'>
        <div id='treeparent'>
            <div id="tree"></div>
        </div>
    </div>
</body>

</html>

You can also explore our JavaScript TreeView example to knows how to present and manipulate data.