Angular2 - how to call component function from outside the app

I am using a javascript Object that has a callback. Once the callback is fired I want to call a function inside an Angular2 component.

example HTML file.

    var run = new Hello('callbackfunction');

    function callbackfunction(){   
     // how to call the function **runThisFunctionFromOutside**
   }
   <script>
      System.config({
        transpiler: 'typescript', 
        typescriptOptions: { emitDecoratorMetadata: true }, 
        packages: {'js/app': {defaultExtension: 'ts'}} 
      });
      System.import('js/app/main')
            .then(null, console.error.bind(console));
    </script>

My App.component.ts

import {Component NgZone} from 'angular2/core';
import {GameButtonsComponent} from './buttons/game-buttons.component';
@Component({
  selector: 'my-app',
  template: ' blblb'
})
export class AppComponent {

constructor(private _ngZone: NgZone){}

ngOnInit(){
    calledFromOutside() {
        this._ngZone.run(() => {
          this.runThisFunctionFromOutside();
    });
  }
  }
runThisFunctionFromOutside(){
   console.log("run");
}

How can i call the function runThisFunctionFromOutside which is inside App.component.ts

I basically followed this answer, but I didn't want my "outside" code to know anything about NgZone. This is app.component.ts:

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

@Component({
  selector: 'my-app',
  templateUrl: 'app.component.html'
})
export class AppComponent implements OnInit, OnDestroy {
  constructor(private ngZone: NgZone) {}

  ngOnInit() {
    window.my = window.my || {};
    window.my.namespace = window.my.namespace || {};
    window.my.namespace.publicFunc = this.publicFunc.bind(this);
  }

  ngOnDestroy() {
    window.my.namespace.publicFunc = null;
  }

  publicFunc() {
    this.ngZone.run(() => this.privateFunc());
  }

  privateFunc() {
    // do private stuff
  }
}

I also had to add a definition for TypeScript to extend the window object. I put this in typings.d.ts:

interface Window { my: any; }

Calling the function from the console is now as simple as:

my.namespace.publicFunc()

See also How do expose angular 2 methods publicly?

When the component is constucted make it assign itself to a global variable. Then you can reference it from there and call methods. Don't forget to use zone.run(() => { ... }) so Angular gets notified about required change detection runs.

 function callbackfunction(){   
   // window['angularComponentRef'] might not yet be set here though
   window['angularComponent'].zone.run(() => {
     runThisFunctionFromOutside(); 
   });
 }

constructor(private _ngZone: NgZone){
  window['angularComponentRef'] = {component: this, zone: _ngZone};
}

ngOnDestroy() {
  window.angularComponent = null;
}

Plunker example1

In the browser console you have to switch from <topframe> to plunkerPreviewTarget.... because Plunker executes the code in an iFrame. Then run

window['angularComponentRef'].zone.run(() => {window['angularComponentRef'].component.callFromOutside('1');})

or

window.angularComponentRef.zone.run(() => {window.angularComponentRef.componentFn('2');})

An alternative approach

would be to dispatch events outside Angular and listen to them in Angular like explained in Angular 2 - communication of typescript functions with external js libraries

Plunker example2 (from the comments)

Below is a solution.

function callbackfunction(){   
   window.angularComponent.runThisFunctionFromOutside();
}
       <script>
          System.config({
            transpiler: 'typescript', 
            typescriptOptions: { emitDecoratorMetadata: true }, 
            packages: {'js/app': {defaultExtension: 'ts'}} 
          });
          System.import('js/app/main')
                .then(null, console.error.bind(console));
        </script>

My App.component.ts

import {Component NgZone} from 'angular2/core';
import {GameButtonsComponent} from './buttons/game-buttons.component';
@Component({
    selector: 'my-app',
       template: ' blblb'
})
export class AppComponent {

  constructor(private _ngZone: NgZone){
  window.angularComponent = {runThisFunctionFromOutside: this.runThisFunctionFromOutside, zone: _ngZone};
}


    runThisFunctionFromOutside(){
      console.log("run");
    }
}

An other approach without using global variables is to use pass a control object and bind its properties to the variables and methods to expose.

export class MyComponentToControlFromOutside implements OnChanges {

  @Input() // object to bind to internal methods
  control: {
    openDialog,
    closeDialog
  };

  ngOnChanges() {
    if (this.control) {
      // bind control methods to internal methods
      this.control.openDialog = this.internalOpenDialog.bind(this);
      this.control.closeDialog = this.internalCloseDialog;
    }
  }

  internalOpenDialog(): Observable<boolean> {
    // ...
  }

  internalCloseDialog(result: boolean) {
    // ...
  }
}

export class MyHostComponent {
   controlObject= {};
}

<my-component-to-control [control]="controlObject"></my-component-to-control>

<a (click)="controlObject.open()">Call open method</a>