LyNullableStringIsAlpha constructor
LyNullableStringIsAlpha(
- String message
Validation that requires a string to contain only letters (a-zA-Z).
If the value contains anything other than letters, the message
is returned.
Example:
final validator = LyNullableStringIsAlpha('Invalid alpha');
final result = validation('abc123');
print(result); // Invalid alpha
Implementation
LyNullableStringIsAlpha(super.message);