HTML::FormFu::Constraint::Required - Required Field Constraint
States that a value must be submitted. The empty string is not allowed.
Is a sub-class of, and inherits methods from HTML::FormFu::Constraint
Based on the original source code of HTML::Widget::Constraint::All,
by Sebastian Riedel,
This library is free software, you can redistribute it and/or modify it under the same terms as Perl itself.