iframe inside angular2 component, Property ‘contentWindow’ does not exist on type ‘HTMLElement’

The template doesn’t exist in the DOM yet when the constructor is executed

Use instead

import { Component, ViewChild, ElementRef } from '@angular/core';
@Component({
  moduleId: module.id,
  selector: 'component-iframe',
  template: '<iframe #iframe></iframe>'
})
export class ComponentIframe  {
  @ViewChild('iframe') iframe: ElementRef;

  ngAfterViewInit() {
    let content="<button id="button" class="button" >My button </button>";
    let doc =  this.iframe.nativeElement.contentDocument || this.iframe.nativeElement.contentWindow;
    doc.open();
    doc.write(content);
    doc.close();
  }
}