Passing input and output through a parent component

Question

I am trying to pass some information from component A through parent component to component B.

I have a component A where I have outputs.

componentA.ts

@Output() status = new EventEmitter();
public getColor() {
   ...
   this.emit(color);
}

componentB.ts

@Input('status') status;

ngOnInit() {
  console.log(this.status) // Got EventEmitter false object
}

parent.html (Need to include component B in this HTML)

<componentA (status)="getStatus(s)"></componentA>
<componentB [status]="status"></componentB>

parent.ts

@Output() status=new EventEmitter();
public getStatus(s) {
    this.status.emit(s)
}

Currently I am getting "EventEmitter {_isScalar: false, observers: Array(0), closed: false, isStopped: false, hasError: false…" message, which I couldn't view the information passed from component A. I verify that s exists inside the getStatus function. If there's a better approach, please advice.

Answer 1

Your mistakes,

• this.emit in component A, which should be this.status.emit(..)
• In your component B you should be using ngOnChanges to listen the changes not ngOnInit

Follow the below code,

@Component({
  selector: 'my-app',
  template: `
    <div> 
      {{status}}
      <componentA (status)="getStatus($event)"></componentA>
    <componentB [status]="status"></componentB>
    </div>
  `,
})
export class App {
  name:string;
  status:string;
  getStatus(event){
    console.log(event)
    this.status = event
  }
  constructor() {

  }
}
@Component({
  selector: 'componentA',
  template: `
    <div>
     <button (click)="getColor()"> Click for red color</button>


    </div>
  `,
})
export class CompA {
  @Output() status = new EventEmitter<string>();
  public getColor() {
     this.status.emit('red');
}
}
@Component({
  selector: 'componentB',
  template: `
    <div>

    </div>
  `,
})
export class CompB {
  @Input('status') status;
  ngOnChanges() {
  console.log('CompB input arrived', this.status) // Got EventEmitter false object
}
}

LIVE DEMO