Javascript scroll to specific element by ID

Question

I have a menu bar with 4 tabs and when I press on every tab it should scroll down to the corresponding category (a specific id), on the same page. This is the code for the menu:

  template: `
        <div class="action-container">
          <div class="btn-group quick-navigation custom-group" role="group">
            <a *ngFor="let section of sections" [scrollTo]="section.id" (click)="active = section.id"
               class="btn btn-secondary" [class.active]="section.id == active">{{section.name}}</a>
          </div>
        </div>
      `,

And this one is the scroll directive:

 @Directive({
      selector: '[scrollTo]'
    })
    export class ScrollToDirective {
      @Input() scrollTo: string;
      @HostListener('click', ['$event']) onClick(e) {
        console.log(this.scrollTo);
        console.log($(`#${this.scrollTo}`).offset().top - 150);
        $('html, body').animate({
          scrollTop: $(`#${this.scrollTo}`).offset().top - 150
        }, 500);
      }
    }

The problem is that the offset().top-150 of a specific element changes after switching tabs multiple times and the first time it will redirect to the correct element, but after that, the page will jump randomly to different elements.

I have attached a print screen of the console.

console screenshot

Any suggestions? Thank you!

Answer 1

You don't have to compute any value to do what you want, and don't have to use JavaScript at all. At least, as you don't want a smooth scrolling.

You can easily scroll to any element with it id setting the href attribute :

<a href="#my_id" id="my_link">Click me to scroll down</a>

...

<section id="my_id">...</section>

Ok, according to your comment, there is a conflict with the angular's Router when doing this, so with a little bit of JavaScript you can solve the problem :

document.getElementById("my_link").addEventListener("click",(e)=>{
    e.preventDefault();
    document.querySelector(e.currentTarget.href).scrollIntoView();
});