Reactive Forms

Great Source: Angular Reactive Forms: Tips and Tricks by Netanel Basal

limit validation

export class AppComponent {
  control = new FormControl(null, {
    validators: Validators.minLength(4),
    updateOn: 'blur'
  });
}

run validator explicitly / optimize by debouncing

ngOnInit() {
  const name = this.group.get('name');

  name.valueChanges.pipe(
    debounceTime(300),
    untilDestroyed(this)
  ).subscribe(() => name.setErrors(Validators.minLength(2)(name)))
}

disable by default

new FormGroup({
  name: new FormControl({ disabled: true, value: null }),
  email: new FormControl()
})

// enable / disable explicitly w/o emitting valueChanged event
name.enable({ emitEvent: false });
name.disable({ emitEvent: false });