To keep single pane open always in JavaScript Accordion control

08 May 2023 / 2 minutes to read

By default, all Accordion panels are collapsible. You can customize the Accordion to keep one panel as expanded state always. This is applicable for Single expand mode.

Source

Preview

index.ts

index.html

import {Accordion, ExpandEventArgs, AccordionClickArgs} from '@syncfusion/ej2-navigations';
import { enableRipple } from '@syncfusion/ej2-base';

enableRipple(true);
let clickEle: HTMLElement;
let accordion: Accordion = new Accordion({
    expandMode: 'Single',
    clicked: clicked,
    expanding: beforeExpand,
    items: [
      { header: 'ASP.NET', expanded:'true', content: 'Microsoft ASP.NET is a set of technologies in the Microsoft .NET Framework for building Web applications and XML Web services.' },
      { header: 'ASP.NET MVC', content: 'The Model-View-Controller (MVC) architectural pattern separates an application into three main components: the model, the view, and the controller.' },
      { header: 'JavaScript', content: 'JavaScript (JS) is an interpreted computer programming language. It was originally implemented as part of web browsers so that client-side scripts could interact with the user, control the browser, communicate asynchronously, and alter the document content that was displayed.' },
    ]
});
accordion.appendTo('#element');

function clicked (e: AccordionClickArgs): void {
  clickEle = (e.originalEvent.target as Element).closest('.e-acrdn-header');
}
function beforeExpand (e: ExpandEventArgs):void {
  let expandCount: number = this.element.querySelectorAll('.e-selected').length;
  let ele: HTMLElement= this.element.querySelectorAll('.e-selected')[0];
  if (ele) {
    ele = ele.firstChild as Element;
  }
  if (expandCount === 1 && ele === clickEle) {
    e.cancel = true;
  }
}

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

<head>
            
    <title>Essential JS 2 Accordion</title>
    <meta charset="utf-8" />
    <meta name="viewport" content="width=device-width, initial-scale=1.0" />
    <meta name="description" content="Typescript Toolbar Controls" />
    <meta name="author" content="Syncfusion" />
    <link href="index.css" rel="stylesheet" />
    <link href="//cdn.syncfusion.com/ej2/21.2.3/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'>
        <div id='element'></div>
        <br/><br/>
        <div id='result'></div>
    </div>
</body>

</html>