Yii 嵌套设置到下拉菜单

I'm using Yii nested set behavior, which helps me to keep my categories nested as seen here (nevermind title rows, they are in russian):

我想做的就是拥有 Bootstrap 嵌套菜单，应该是这样的：

    $criteria = new CDbCriteria;
    $criteria->order = 'root, lft';
    $categories = Category::model()->findAll($criteria);
    foreach($categories as $i => $category) {
      $items[$i]['label'] = $category->title;
      $items[$i]['url'] = $category->url;
      $items[$i]['active'] = false;
      $items[$i]['items'] = array(
        array('label'=>'123', 'url'=>'#'),
        array('label'=>'123', 'url'=>'#'),
        array('label'=>'123', 'url'=>'#', 'items'=>array(
            array('label'=>'1234', 'url'=>'#'),
            array('label'=>'1234', 'url'=>'#'),
            array('label'=>'1234', 'url'=>'#', 'items'=>array(
                array('label'=>'1234', 'url'=>'#'),
                array('label'=>'1234', 'url'=>'#'),
                array('label'=>'1234', 'url'=>'#'),
            )),
        )),
    ); 
}
$this->widget('bootstrap.widgets.TbMenu', array(
    'type'=>'pills',
    'stacked'=>false, // whether this is a stacked menu
    'items'=>$items
)); 

我不明白如何完成这件事，顺便说一句我读过这个话题 http://semlabs.co.uk/journal/converting-nested-set-model-data-in-to-multi-dimensional-arrays-in-php只是不知道如何实际应用这个函数来解决我的问题。感谢任何帮助。

这是我用来格式化为json对象的函数，你可以修改它来生成php数组。

protected function formatJstree(){
        $categories = $this->descendants()->findAll();
        $level=0;
        $parent = 0;
        $data = array();
        foreach( $categories as $n => $category )
        {
            $node = array(
                'data'=> "{$category->title}",
                'attr'=>array('id'=>"category_id_{$category->category_id}")
            );
            if($category->level == $level){
                $data[$parent]["children"][] = $node;
            }
            else if($level != 0 && $category->level > $level){
                if(!isset($data[$n]["children"])){
                    $data[$n]["children"] = array();
                }
                $data[$parent]["children"][] = $node;
            }
            else
            {
                $data[] = $node;
                $parent = $n;
            }
            $level=$category->level;

        }
        return $data;

    }