递归的方法

//控制器
public function recursion($data,$path=0,$flag=1){
    static $arr=array();
    foreach($data as $key=>$val){
        if($val['parent_id']==$path){
            $val['flag']=$flag;
            $arr[]=$val;
            $this->recursion($data,$val['type_id'],$flag+1);
        }
    }
    return $arr;
}
//前台展示
<select name="type" class="input w50" data-validate="required:请选择分类">
    <?php foreach($type as $key=>$val){?>
        <option value="<?php echo $val['type_id']?>"><?php echo str_repeat('&nbsp;&nbsp;&nbsp;',$val['flag'])?>
            <?php echo $val['type_name']?></option>
    <?php }?>
</select>
//下拉框展示
重点是这个str_repeat