‹input id="name" class="form-control"
      formControlName="name" required ›

‹div *ngIf="name.invalid && (name.dirty || name.touched)"
    class="alert alert-danger"›

  ‹div *ngIf="name.errors.required"›
    Name is required.
  ‹/div›
  ‹div *ngIf="name.errors.minlength"›
    Name must be at least 4 characters long.
  ‹/div›
  ‹div *ngIf="name.errors.forbiddenName"›
    Name cannot be Bob.
  ‹/div›
‹/div›