validate method
Validation that works in concert with the number accessor.
Implementation
@override
Map<String, dynamic>? validate(AbstractControl abstractControl) {
assert(abstractControl is Control, 'Can only be used with a Control');
final control = abstractControl as Control;
// Handled by accessor validator or value set by forms system
if (control.value == null && !isBlank(control.rawValue)) {
return {checkIntegerErrorKey: numberIsNotIntegerMsg()};
}
return null;
}