一段完美的无限级分类递归

//获取树
public function tree()
{
    $pid = $this->request->get('pid/d', 0);
    $step = $this->request->get('step/d', 0);
    $cutIds = $this->request->get('cut_ids/s', '');

    $cutIds = explode(',', $cutIds);
    $tree = ModelCate::getTree($pid, $step, $cutIds);
    $this->result(200, $tree);
}

 

/**
 * 获取分类树
 * @param integer $pid 不传默认为0，即从根开始，传了值则从该类目开始往下获取。
 * @param integer $step 递归层级，传入0或大于实际层级的数字则一直找到末级
 * @param array $cutIds 从返回的树结构中砍掉指定id的分支，可传入多个id
 * @return array
 */
public static function getTree($pid, $step, $cutIds = [])
{
    $row = [];
    $step--;
    $childs = self::where([['pid', '=', $pid], ['id', 'not in', $cutIds]])->field('id,pid,title')->select();
    foreach ($childs as $key => $value) {
        if($step){
            $value['children'] = self::getTree($value['id'], $step, $cutIds);
        }
        $row[] = $value;
    }
    return $row;
}

 

进一步减化，只用8行：

public static function getTree($pid, $step, $cutIds = [])
{
    $row = [];
    $step--;
    $childs = self::where([['pid', '=', $pid], ['id', 'not in', $cutIds]])->field('id,pid,title')->select();
    foreach ($childs as $key => $value) {
        $value['children'] = $step ? self::getTree($value['id'], $step, $cutIds) : [];
        $row[] = $value;
    }
    return $row;
}

 

进一步减化，只用6行：

public static function getTree($pid, $step, $cutIds = [])
{
    $step--;
    $rows = self::where([['pid', '=', $pid], ['id', 'not in', $cutIds]])->field('id,pid,title')->select();
    foreach ($rows as $key => $value) {
        $rows[$key]['children'] = $step ? self::getTree($value['id'], $step, $cutIds) : [];
    }
    return $rows;
}