validator method
A function that must return a validation error if the provided
value
is invalid and null
otherwise.
Implementation
@override
EmailValidationError? validator(String value) {
if (value.isEmpty) {
return EmailValidationError.empty;
} else {
if (emailRegExp != null) {
if (!emailRegExp!.hasMatch(value)) {
return EmailValidationError.invalid;
}
} else if (!_defaultEmailRegExp.hasMatch(value)) {
return EmailValidationError.invalid;
}
}
return null;
}