numeric static method

String? Function(String?) numeric({
  1. String? message,
})

Validates only numbers

Implementation

static String? Function(String?) numeric({String? message}) {
  return (String? value) {
    if (value == null || value.trim().isEmpty) {
      return null;
    }

    if (!RegExp(r'^[0-9]+$').hasMatch(value)) {
      return message ?? _defaultMessages['numeric'];
    }

    return null;
  };
}