private function _tag($tags_str)
{
$tagArr = preg_split("/\\s+/", $tags_str, -1, PREG_SPLIT_NO_EMPTY);
$tags = array(array(), array());
foreach ($tagArr as $tag) {
if (preg_match('/-(.+)/', $tag, $arr)) {
array_push($tags[1], $arr[1]);
} else {
array_push($tags[0], $tag);
}
}
return $tags;
}