Angular2 passing function as component input is not working

Question

I\'ve a component that takes function as input. I\'ve passed this function from parent.

Though the function is called, the function is not able to access the depende

Answer 1

You need to .bind(this) if you pass methods around:

<custom-element [valFn]="customVal.bind(this)"></custom-element>

or

export class App {
  constructor(private service: CustomService) {
  }
  customVal(): string {
    return this.service.getVal();
  }
  customValFn = this.customVal.bind(this);
}

with

<custom-element [valFn]="customValFn"></custom-element>

Answer 2

You can pass a get/set property instead of a function in a similar way like that:

Somewhere in your view:

<input type="text" [(ngModel)]="yourprop">

In your component file:

@Component({
  selector: 'myapp',
  templateUrl: './myapp.component.html',
  styleUrls: ['./myapp.component.scss']
})
export class App {
  constructor() { }

  yourprop: any;

  get yourprop(): any {
    return this.scheduleEndDate;
  };

  //set accessor including call the onchange callback
  set yourprop(v: any) {
    // TODO do something else
    // You can do whatever you want just like you have passed a function

    if (v !== this.scheduleEndDate) {
      this.scheduleEndDate = v;
    }
  }

}

more info @ https://almerosteyn.com/2016/04/linkup-custom-control-to-ngcontrol-ngmodel