Search results

Getting started with JavaScript Dropdown Tree control

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 of the development environment

To get started with the Dropdown Tree control, 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 pre-configured with the common settings (src/styles/styles.css, system.config.js ) to start all the Essential JS 2 controls.

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 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 Dropdown Tree-->
        <input type="text" tabindex="1" id='ddltreeelement' />
    </div>

</body>

</html>

Now, import the Dropdown Tree control to your app.ts and initialize it to the element #ddltreeelement 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('#ddltreeelement');

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('#ddltreeelement');

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.

Source
Preview
app.ts
index.html
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 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/ej2-base/styles/material.css" rel="stylesheet" />
    <link href="//cdn.syncfusion.com/ej2/ej2-inputs/styles/material.css" rel="stylesheet" />
    <link href="//cdn.syncfusion.com/ej2/ej2-buttons/styles/material.css" rel="stylesheet" />
    <link href="//cdn.syncfusion.com/ej2/ej2-lists/styles/material.css" rel="stylesheet" />
    <link href="//cdn.syncfusion.com/ej2/ej2-navigations/styles/material.css" rel="stylesheet" />
    <link href="//cdn.syncfusion.com/ej2/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='ddltreeelement' />
    </div>
</body>

</html>