private function implode(array $config)
{
$palette = '';
foreach ($config as $legend => $group) {
if (count($group['fields']) < 1) {
continue;
}
if ('' !== $palette) {
$palette .= ';';
}
if (!is_int($legend)) {
$palette .= sprintf('{%s%s},', $legend, $group['hide'] ? ':hide' : '');
}
$palette .= implode(',', $group['fields']);
}
return $palette;
}