Create collapsible tabs in Angular Tab component

27 Apr 202411 minutes to read

You can achieve collapse and expand functionality in Tab by adding/removing a custom CSS class in the click event handler for each tab.

  • Define a CSS class to set the style property display as none. Here ‘collapse’ class is added to the content element for hiding it using created event.
  • Bind the selected event for Tab to collapse the initially selected Tab item
    and bind custom click handler for the Tab headers.
  • In the event handler, add and remove ‘collapse’ class to hide and show the corresponding Tab content.
import { NgModule } from '@angular/core'
import { BrowserModule } from '@angular/platform-browser'
import { FormsModule } from '@angular/forms'
import { TabModule } from '@syncfusion/ej2-angular-navigations'

import { Component, ViewChild } from '@angular/core';
import { SelectEventArgs, TabComponent } from '@syncfusion/ej2-angular-navigations';
import { enableRipple, isNullOrUndefined } from '@syncfusion/ej2-base';


 * Collapsible Tab

imports: [
         FormsModule, TabModule

standalone: true,
    selector: 'app-container',
    template: `<ejs-tab id="element" class="e-background" (created)="tabCreated()" (selected)="tabSelected($event)" #element>
                    <e-tabitem [header]='headerText[0]'>
                        <ng-template #content>
                            Twitter is an online social networking service that enables users to send and read short 140-character messages called "tweets".
                            Registered users can read and post tweets, but those who are unregistered can only read them. Users access Twitter
                            through the website interface, SMS or mobile device app Twitter Inc. is based in San Francisco and has more than 25
                            offices around the world. Twitter was created in March 2006 by Jack Dorsey, Evan Williams, Biz Stone, and Noah Glass
                            and launched in July 2006. The service rapidly gained worldwide popularity, with more than 100 million users posting
                            340 million tweets a day in 2012.The service also handled 1.6 billion search queries per day.
                    <e-tabitem [header]='headerText[1]'>
                        <ng-template #content>
                            Facebook is an online social networking service headquartered in Menlo Park, California. Its website was launched on February
                            4, 2004, by Mark Zuckerberg with his Harvard College roommates and fellow students Eduardo Saverin, Andrew McCollum,
                            Dustin Moskovitz and Chris Hughes.The founders had initially limited the website\'\s membership to Harvard students,
                            but later expanded it to colleges in the Boston area, the Ivy League, and Stanford University. It gradually added support
                            for students at various other universities and later to high-school students.
                    <e-tabitem [header]='headerText[2]'>
                        <ng-template #content>
                            WhatsApp Messenger is a proprietary cross-platform instant messaging client for smartphones that operates under a subscription
                            business model. It uses the Internet to send text messages, images, video, user location and audio media messages to
                            other users using standard cellular mobile numbers. As of February 2016, WhatsApp had a user base of up to one billion,[10]
                            making it the most globally popular messaging application. WhatsApp Inc., based in Mountain View, California, was acquired
                            by Facebook Inc. on February 19, 2014, for approximately US$19.3 billion.

export class AppComponent {

  @ViewChild('element') tabInstance!: TabComponent;

  public trgIndex?: number;
  public actLine?: HTMLElement;

  public headerText: Object[] = [
    { text: 'Twitter' },
    { text: 'Facebook' },
    { text: 'WhatsApp' }

  public tabCreated(): void {
    // Custom click event binding for each tab item to make collapse/expand
    const childrenArray = Array.from((this.tabInstance).element.children[0].children[0].children);
    const toolbarItem: Element[] = childrenArray.filter(el => el.classList.contains('e-toolbar-item'));
    (toolbarItem[0] as HTMLElement).onclick = (e: Event) => {

    (toolbarItem[1] as HTMLElement).onclick = (e: Event) => {

    (toolbarItem[2] as HTMLElement).onclick = (e: Event) => {

    // After tab created first tab content and active line are hidden by adding custom class to make it collapse state
    this.actLine = document.querySelector('.e-indicator') as HTMLElement;

  public tabSelected(e: SelectEventArgs): void {
    // If next tab item selected custom class is removed from content and active line element
    const childrenArray = Array.from(this.tabInstance.element.children[1].children);
    const cnttrgs = childrenArray.filter(el => el.classList.contains('e-item'));
    for (let i: number = 0; i < cnttrgs.length; i++) {
    if (this.actLine !== undefined) {
    this.trgIndex = e.selectedIndex;

  public updateCollapseClass(index: number): void {
    // Custom classes are added/removed from tab content and active line element, when the same tab item again clicked
    const childrenArray = Array.from(this.tabInstance.element.children[1].children);
    const cntEle: HTMLElement = childrenArray.filter(el => === `e-content-element_${index}`)[0] as HTMLElement;
    if (!isNullOrUndefined(cntEle) && cntEle.classList.contains('collapse')) {
      (this.actLine as HTMLElement).classList.remove('collapse');
    } else if (!isNullOrUndefined(cntEle)) {
      (this.actLine as HTMLElement).classList.add('collapse');
import { bootstrapApplication } from '@angular/platform-browser';
import { AppComponent } from './app.component';
import 'zone.js';
bootstrapApplication(AppComponent).catch((err) => console.error(err));