form validation (ng-required, $error) en Angular moderno

<form name="f" ng-submit="f.$valid && vm.save()" novalidate>
  <input name="email" type="email" ng-model="vm.email" required>
  <span ng-show="f.email.$touched && f.email.$error.required">Required</span>
</form>

form = new FormGroup({
  email: new FormControl('', {
    nonNullable: true,
    validators: [Validators.required, Validators.email],
  }),
});

<form [formGroup]="form" (ngSubmit)="save()">
  <input formControlName="email" type="email" />
  @if (form.controls.email.touched && form.controls.email.hasError('required')) {
    <span>Required</span>
  }
</form>