validateField static method
Implementation
static String? validateField(String? value, {String? field, int? length}) {
if (value == null || value.isEmpty) {
if (field != null) {
if (length != null) {
return "$field must be $length characters long";
}
return "Please input your $field";
} else {
if (length != null) {
return "This field required $length characters long";
}
return "Please input required field";
}
}
return null;
}