length method
Checks the length of the value
makes sure it's between min
and max
range
Implementation
Validator length(
{int min = 0,
int max = int64Max,
String Function(String val, int min, int max)? errMsg}) {
validate((v) {
if (value == null || !value.toString().length.isBetween(min, max)) {
String err = max == int64Max
? 'Length must be greater than $min'
: 'Length must be between $min and $max';
return errMsg != null ? errMsg(value.toString(), min, max) : err;
}
return null;
});
return this;
}