Angular 6 Reactive Forms : How to set focus on first invalid input

Question

Under my Angular 6 app , i\'m using Reactive Forms .

My purpose is when submitting , i want to set focus on first invalid input when

Answer 1

We can set focus on first invalid input simply by just write this code in the submit() of the form.

   if(this.form.invalid)
    {  
      // Got focus to the error field
    let invalidFields = [].slice.call(document.getElementsByClassName('ng-invalid'));
    invalidFields[1].focus();  

    }