Create collapsible tabs in Angular Tab component
28 Sep 202311 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
createdevent. - Bind the
selectedevent 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 { Component, ViewChild } from '@angular/core';
import { SelectEventArgs, TabComponent } from '@syncfusion/ej2-angular-navigations';
import { enableRipple, isNullOrUndefined } from '@syncfusion/ej2-base';
enableRipple(true);
/**
* Collapsible Tab
*/
@Component({
selector: 'app-container',
template: `<ejs-tab id="element" class="e-background" (created)="tabCreated()" (selected)="tabSelected($event)" #element>
<e-tabitems>
<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.
</ng-template>
</e-tabitem>
<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.
</ng-template>
</e-tabitem>
<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.
</ng-template>
</e-tabitem>
</e-tabitems>
</ejs-tab>`
})
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) => {
this.updateCollapseClass(0);
};
(toolbarItem[1] as HTMLElement).onclick = (e: Event) => {
this.updateCollapseClass(1);
};
(toolbarItem[2] as HTMLElement).onclick = (e: Event) => {
this.updateCollapseClass(2);
};
// 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;
(this.tabInstance.element.children[1].children[0].classList.add('collapse'));
this.actLine.classList.add('collapse');
}
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++) {
cnttrgs[i].classList.remove('collapse');
}
if (this.actLine !== undefined) {
this.actLine.classList.remove('collapse');
}
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 => el.id === `e-content-element_${index}`)[0] as HTMLElement;
if (!isNullOrUndefined(cntEle) && cntEle.classList.contains('collapse')) {
cntEle.classList.remove('collapse');
(this.actLine as HTMLElement).classList.remove('collapse');
} else if (!isNullOrUndefined(cntEle)) {
cntEle.classList.add('collapse');
(this.actLine as HTMLElement).classList.add('collapse');
}
}
}import { NgModule } from '@angular/core';
import { BrowserModule } from '@angular/platform-browser';
import { FormsModule } from '@angular/forms';
import { AppComponent } from './app.component';
import { TabModule } from '@syncfusion/ej2-angular-navigations';
/**
* Module
*/
@NgModule({
imports: [
BrowserModule, FormsModule, TabModule
],
declarations: [AppComponent],
bootstrap: [AppComponent]
})
export class AppModule { }import { platformBrowserDynamic } from '@angular/platform-browser-dynamic';
import { enableProdMode } from '@angular/core';
import { AppModule } from './app.module';
import 'zone.js';
enableProdMode();
platformBrowserDynamic().bootstrapModule(AppModule);