positiveNumber static method
Validate positive number
Implementation
static String? positiveNumber(String? value, {String? fieldName}) {
final numericError = numeric(value, fieldName: fieldName);
if (numericError != null) return numericError;
final numericValue = double.parse(value!);
if (numericValue <= 0) {
return '${fieldName ?? 'This field'} must be greater than 0';
}
return null;
}