javascript - iframe inside angular2 component, Property 'contentWindow' does not exist on type 'HTMLElement' -

i have iframe inside angular2 component, , trying change content of iframe accessing contentwindow.
iframe should contain simple button.

my code:

    import { component } '@angular/core';     @component({       moduleid: module.id,       selector: 'component-iframe',       template: '<iframe id="iframe"></iframe>'     })     export class componentiframe  {       constructor() {         let iframe = document.getelementbyid('iframe');          let content = '<button id="button" class="button" >my button </button>';         let doc =  iframe.contentdocument || iframe.contentwindow;         doc.open();         doc.write(content);       doc.close();     }    } 

if comment constructor's code , start app, compiles , runs correctly. uncomment , runs (the button present in iframe).

if decomment code start app (npm start) have compilation bugs message:

property 'contentwindow' not exist on type 'htmlelement'

.

i tried alternative of putting costructor's code ngoninit(), ngaftercontentinit(), ngafterviewinit() error persists.

the template doesn't exist in dom yet when constructor executed

use instead

import { component, viewchild, elementref } '@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();   } }