How to set "activate" class to bootstrap navbar in Angular 2 while using page anchor navigation? - html

Question

I am creating a single page website using Angular 2 and Bootstrap 4.
I created a navbar component that is always on top of the page and I am using page anchor navigation (#id). Please note that I haven't created a routing module (so far it hasn't been necessary to do this).
The navbar code is below:
<nav class="navbar navbar-default fixed-top navbar-inverse navbar-toggleable-md">
<div class="container">
<div class="navbar-header">
<button class="navbar-toggler navbar-toggler-right btn btn-outline-secondary" (click)="isCollapsed = !isCollapsed" [attr.aria-expanded]="!isCollapsed" aria-controls="collapseExample">
<i class="fa fa-bars" aria-hidden="true"></i>
</button>
<a class="navbar-brand" href="index.html">Garatéa</a>
</div>
<div id="collapseExample" class="navbar-collapse collapse" [ngbCollapse]="isCollapsed">
<ul class="nav navbar-nav ml-auto">
<li class="nav-item"><a class="nav-link" href="#home">Início</a></li>
<li class="nav-item"><a class="nav-link" href="#about">Sobre</a></li>
<li class="nav-item"><a class="nav-link" href="#team">Quem Somos</a></li>
<li class="nav-item"><a class="nav-link" href="#contact">Contato</a></li>
</ul>
</div>
</div>
</nav>
Each link corresponds to a section of the single page website, for example, the home component template is:
<div id="home" class="text-center home-background">
<div class="overlay">
<div class="content">
<h1>Bem vindo à <strong><span class="title-text">Garatéa</span></strong></h1>
<p class="lead">Somos uma inciativa que <strong>aumenta a taxa de sobrevivência</strong> em emergências médicas.</p>
</div>
</div>
</div>
My question is: how can I highlight the link in the navbar that corresponds to the section of the website that I am currently browsing? For example, if I am looking at the team about section, I expect to have an active CSS class on the navbar: <li class="nav-item active"><a class="nav-link" href="#about">Sobre</a></li>.

Answer 1

You can use the srcElement on click of that <a> tag as below
<a class="nav-link" (click)="clickedLink($event)">Início</a>
<a class="nav-link" (click)="clickedLink($event)">Início</a>
<a class="nav-link" (click)="clickedLink($event)">Início</a>
Method will be as
clickedLink(e){
let element = e.srcElement;
console.log(e)
for(let i =0; i <element.parentElement.children.length ; i++){
if(element.parentElement.children[i].classList.contains('active')){
element.parentElement.children[i].classList.remove('active')
}
}
element.classList.add('active');
}
LIVE DEMO