pattern static method

ValidationRule pattern(
  1. String pattern, {
  2. required String message,
})

Validation rule to check if a string matches a regex pattern.

Returns message if it does not match.

Implementation

static ValidationRule pattern(String pattern, {required String message}) {
  return ValidationRule(
    (value) => RegExp(pattern).hasMatch(value ?? '') ? null : '',
    message,
  );
}