I have two formControl inside a formGroup inside of a formArray like this:

<form [formGroup]="fg" (ngSubmit)="SaveInput()">
  <ul formArrayName="comments">
    <div *ngFor="let cm of fg.get('comments')['controls']">
      <input readonly formControlName="xts">
      <input type="text" formControlName="xtxt">
    </div>
  </ul>
</form>

When data from xtxt is saved in DB and returns a timestamp, I'd like to have this timestamp value displayed on xts. I'm able to set the value in two places and confirmed are good. But it's not reflected in display

SaveInput()
{
  ...
  this.mySvc.saveInput(param)
  .subscribe
  (
    good =>
    {
      let x =<FormGroup>this.fg.get(selectionString);
      x.value.xts = good.timestamp;  // <-- place 1
      x.controls.xts.value = good.timestamp; // <-- place 2
    }
  );
}

CodePudding user response：

you shouldn't set value directly but use methods. I believe patchValue suits your case the best. Cheers!