validator static method

String? validator({
  1. String? value,
  2. required Pattern pattern,
  3. String? errorMessage,
})

validator for all text and string values

Implementation

static String? validator({String? value, required Pattern pattern, String? errorMessage}) {
  final notEmpty = value?.trim().isNotEmpty;
  if (notEmpty != null) {
    return hasMatch(value: value?.trim(), pattern: pattern)
        ? null
        : notEmpty
            ? (errorMessage ?? '')
            : "Cannot be empty";
  } else {
    return errorMessage ?? '';
  }
}