use Catalyst 'FormValidator'; $c->form( optional => ['rest'] ); print $c->form->valid('rest');
Note that not only is this plugin disrecommended (as it takes over the global "$c->form" method, rather than being applyable in only part of your application), but Data::FormValidator itself is not recommended for use.
Merge values with FormValidator.
$c->form( required => ['yada'] );
Returns a Data::FormValidator::Results object.
The actual parameters sent to $c->form are the same as the profile in Data::FormValidator's check function.