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angular - Angular2 scroll to element that has *ngIf

I am writing a form in Angular 2 where the user submits the form, it is validated and if there are any errors with the inputs, I want to scroll the user's browser to the first element with the class "error"

The problem is, all of my errors use *ngIf like so:

<input type="text" [(ngModel)]="model.first_name">
<div class="error" *ngIf="errors.first_name">
    {{errors.first_name}}
</div>

In my submit function

submit(){
   this.errors = this.validate();
   if(this.errors.any()){
      var errorDivs = document.getElementsByClassName("error");
      if(errorDivs.length > 0){
         errorDivs[0].scrollIntoView();
      }
   }
}

I realize this is because *ngIf removes the div from the DOM completely and the Angular check for changes hasn't been given a chance to run yet. Is there a clever and clean way to do this?

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1 Reply

0 votes
by (71.8m points)

Not sure I fully understand your question.

Using a directive like below would make the element scroll into view when errors.first_name becomes truthy:

<div class="error" *ngIf="errors.first_name" scrollTo>
    {{errors.first_name}}
</div>
@Directive({ selector: '[scrollTo]'})
class ScrollToDirective implements AfterViewInit {
  constructor(private elRef:ElementRef) {}
  ngAfterViewInit() {
    this.elRef.nativeElement.scrollIntoView();
  }
}

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