Angular2 add class to body tag

I would love to comment. But due to missing reputation I write an answer.
Well I know two possibilities to solve this issue.

1. Inject the Global Document. Well it might not be the best practice as I don’t know if nativescript etc supports that. But it is at least better than use pure JS.

constructor(@Inject(DOCUMENT) private document: Document) {}

ngOnInit(){
   this.document.body.classList.add('test');
}

Well and perhaps even better. You could inject the renderer or renderer 2 (on NG4) and add the class with the renderer.

export class myModalComponent implements OnDestroy {

  constructor(private renderer: Renderer) {
    this.renderer.setElementClass(document.body, 'modal-open', true);
  }

  ngOnDestroy(): void {
    this.renderer.setElementClass(document.body, 'modal-open', false);
  }
}

EDIT FOR ANGULAR4:

import { Component, OnDestroy, Renderer2 } from '@angular/core';

export class myModalComponent implements OnDestroy {

  constructor(private renderer: Renderer2) {
    this.renderer.addClass(document.body, 'modal-open');
  }

  ngOnDestroy(): void {
    this.renderer.removeClass(document.body, 'modal-open');
  }
}