Angular 2 typescript call javascript function

Question

Is there a proper way to call a JavaScript function from a component in Angular 2 (TypeScript)?

Here is my component:

import { ElementRef, AfterViewInit } from '@angular/core'; export class AppComponent implements AfterViewInit { constructor(private _elementRef: ElementRef) { } ngAfterViewInit() { /** * Works but i have this error : * src/app.component.ts(68,9): error TS2304: Cannot find name 'MYTHEME'. * src/app.component.ts(69,9): error TS2304: Cannot find name 'MYTHEME'. */ MYTHEME.documentOnLoad.init(); MYTHEME.documentOnReady.init(); /** * Works without error, but doesn't seem like a right way to do it */ var s = document.createElement("script"); s.text = "MYTHEME.documentOnLoad.init(); MYTHEME.documentOnReady.init();"; this._elementRef.nativeElement.appendChild(s); } } 

Calling the JavaScript function directly leads to a compilation error, but the syntax in the "compiled" JavaScript file (app.component.js) is correct:

 AppComponent.prototype.ngAfterViewInit = function () { MYTHEME.documentOnLoad.init(); MYTHEME.documentOnReady.init(); }; 

The 2nd method (appendChild) works without errors, but I don’t think (changing the DOM from typescript / angular) is the right way to do this.

I found this: Using the Javascript function from Typescript I tried to declare an interface:

 interface MYTHEME { documentOnLoad: Function; documentOnReady: Function; } 

But TypeScript does not seem to recognize it (there is no error in the declaration of the interface).

thanks

Edit:

Following the answer of Juan Mendes, this is what I ended up with:

 import { AfterViewInit } from '@angular/core'; interface MYTHEME { documentOnLoad: INIT; documentOnReady: INIT; } interface INIT { init: Function; } declare var MYTHEME: MYTHEME; export class AppComponent implements AfterViewInit { constructor() { } ngAfterViewInit() { MYTHEME.documentOnLoad.init(); MYTHEME.documentOnReady.init(); } } 

Answer 1

You must tell TypeScript about external (JavaScript) declarations using declare . See https://www.typescriptlang.org/docs/handbook/writing-declaration-files.html

 interface MyTheme { documentOnLoad: Function; documentOnReady: Function; } declare var MYTHEME: MyTheme; 

Or anonymously

 declare var MYTHEME: {documentOnLoad: Function, documentOnReady: Function};