validate method

  1. @override
String? validate(
  1. String? value
)
override

Validates the value and returns an error string if it fails, or null if it passes.

Implementation

@override
String? validate(String? value) {
  if (value == null || value.isEmpty) return null;
  if (!RegExp(
          r'^[0-9a-fA-F]{8}-[0-9a-fA-F]{4}-[0-9a-fA-F]{4}-[0-9a-fA-F]{4}-[0-9a-fA-F]{12}$')
      .hasMatch(value)) {
    return message;
  }
  return null;
}