isLowerCase method Null safety
- {String message = "Validator.isLowerCase"}
Returns a Validator that accepts a value where all letters are lower-case.
TODO: Check whether there is a better way to validate this.
Implementation
Validator isLowerCase({
String message = "Validator.isLowerCase",
}) {
return add(
(value) => value == value?.toLowerCase() ? null : message,
);
}