'0' Number not pass required option.

[akhamuliak]

For example if I want to make gender or some other field field as select box and have 0 value for male and 1 for female.

Because of bug I can't set gender field as required, because male selection doesn't pass required validation.

https://github.com/in2code-de/femanager/blob/develop/Classes/Domain/Validator/AbstractValidator.php#L58
It's because empty($var) function return false if $var = 0 or $var = '0'

So I think something like this will solve the issue

protected function validateRequired($value)
    {
        if (!is_object($value)) {
            if (is_numeric($value)) {
                return true;
            }
            return !empty($value);

        } elseif (count($value)) {
            return true;
        }
        return false;
    }

[sbusemann]

this will be in the next release.