PHP 递归读取无限级分类

/**
     * 【获取第一级分类】
     *  20170829
     *
     * @return array
     */
    public function getCateList(){
        $this->catelog = [];
        //获取第一级分类
        $rst = $this->find()->where(['is_root'=>0, 'status' => 10])->asArray()->all();

        if($rst){
            foreach ($rst as $row){
                $this->catelog[] = [
                    'id' => $row['id_cate'],
                    'catename' => $row['catename'],
                    'catename_en' => $row['catename_en'],
                    'cover' => $row['cover'],
                    'depath' => 0,
                    'is_root' => $row['is_root'],
                ];
                //获取子分类
                $this->getChild($row['id_cate'], 1);

            }
        }

        return $this->catelog;
    }


    /**
     * 【递归获取所有子分类】
     *  20170829
     *
     * @param $id
     * @param $depth
     */
    function getChild($id,$depth ){
        //global $catalog;

        $rst = $this->find()->where(['is_root' => $id, 'status' => 10])->asArray()->all();
        if (count($rst) > 0) {
            foreach ($rst as $row){
                $this->catelog[] = [
                    'id' => $row['id_cate'],
                    'catename' => $row['catename'],
                    'catename_en' => $row['catename_en'],
                    'cover' => $row['cover'],
                    'depath' => $depth,
                    'is_root' => $row['is_root'],
                ];
                $this->getChild($row['id_cate'], 2);
            }
        }

    }