function validate_custom($path, $filtered, $args) { echo "path: {$path}\n"; echo "value: "; var_export($filtered); echo "\n"; echo "args: "; var_export($args); echo "\n"; $valid_if_true = $filtered === $args; \AIIX\Form::msgIfFalse($valid_if_true, $path, 123, 'custom key'); }