After child has been initialised, operation from parent component on child DOM causes ExpressionChangedAfterItHasBeenCheckedError

问题

I'd like to make some operation from parent component on child component after child component has been initialised.

Parent:

export class ParentComponent implements AfterViewInit {
  @ViewChild('child') childComponent: ChildComponent;

  ngAfterViewInit() {
    this.childComponent.domMethod('boo');
  }
}

<p>parent</p>

<app-child #child></app-child>

Child:

export class ChildComponent implements OnInit {
  constructor(private readonly cdr: ChangeDetectorRef,) {

  }
  public term = '';
  public items;
  ngOnInit() {
    this.items = [
      { name: 'foo' },
      { name: 'bar' },
      { name: 'baz' },
      { name: 'boo' },
      { name: 'zoo' },
    ];
  }

  domMethod(value: string) {
    // const input = document.getElementById('childInput') as HTMLInputElement;
    // input.value = value;
    this.term = value;
    this.cdr.markForCheck(); // <-- enabling this line cause ExpressionChangedAfterItHasBeenCheckedError
  }
}

<p>child</p>

<input type="text" id="childInput" [(ngModel)]="term">

<ul>
    <li *ngFor="let item of items | search: term">{{item.name}}</li>
</ul>

Link to StackBlitz for reproduction

Edit:

If I add setTimeout to the parent component, it works. Can I achieve it without setTimeout?

  ngAfterViewInit() {
    setTimeout(() => {
      this.childComponent.domMethod('boo');
    })
  }

回答1:

you have use detectionChanges for this:

constructor(private _cd: ChangeDetectorRef){}

ngAfterViewInit() {
      this.childComponent.domMethod('boo');
      this._cd.detectChanges();

  }

来源：https://stackoverflow.com/questions/54072065/after-child-has-been-initialised-operation-from-parent-component-on-child-dom-c