<?
/**
--
-- 表的结构 `daxue8_category`
--

CREATE TABLE `daxue8_category` (
`cid` smallint(6) NOT NULL auto_increment,
`pid` smallint(6) NOT NULL default '0',
`level` smallint(6) NOT NULL default '0',
`cname` char(64) NOT NULL default '',
`lft` smallint(6) NOT NULL default '0',
`rgt` smallint(6) NOT NULL default '0',
`uid` mediumint(8) NOT NULL default '0',
`username` char(32) NOT NULL default '',
`ctime` int(10) NOT NULL default '0',
`cstate` tinyint(1) NOT NULL default '0',
`gnum` mediumint(8) NOT NULL default '0',
`orderstyle` smallint(3) NOT NULL default '0',
PRIMARY KEY (`cid`)
) TYPE=MyISAM AUTO_INCREMENT=2 ;

--
-- 导出表中的数据 `daxue8_category`
--

INSERT INTO `daxue8_category` VALUES (1, 0, 1, 'root', 1, 2, 0, '管理员', 1163608814, 1, 0, 0);
*/
class category
{
var $module;

var $tbname;

function category()
{
$this->tbname=TB_PREX.'_category';
$this->module=new module($this->tbname);
}

/**
* 增加子节点
* @param array $node 待增加子节点的属性
* @param int $pid 父节点的ID
*/
function add($node,$pid){
//检查是否已经存在该节点
if($node_exist=$this->module->detail('where pid='.$pid.' and cname=\''.$node['cname'].'\'')){
//$this->error(__FUNCTION__.'():该节点'.$node['cname'].'已经存在！');
//print_r($node_exist);
return $node_exist['cid'];
}
//获取父节点信息
$pnode=$this->get_by_cid($pid);
//更新其他节点
$this->module->query('update `'.$this->tbname.'` set lft=lft+2 where lft>'.$pnode['rgt']);
$this->module->query('update `'.$this->tbname.'` set rgt=rgt+2 where rgt>='.$pnode['rgt']);
//插入新节点
$node['pid']=$pid;
$node['lft']=$pnode['rgt'];
$node['rgt']=$pnode['rgt']+1;
$node['level']=$pnode['level']+1;//层次加一
return $this->module->add($node);
}

/**
* 删除节点
* @param $cid 待删除的节点的ID
* @param $delete_childern 如果该节点存在子节点，是否强制删除。设置未true，则当存在子节点的时候，删除失败，返回false
*
*/
function delete($cid,$delete_childern=false)
{
//获取节点信息
$node=$this->get_by_cid($cid);
if(($this->child_num($node)>0)&&(!$delete_childern))$this->error(__FUNCTION__.'():该节点存在子节点！');
//删除该节点及其所有子节点
$this->module->delete('where lft between '.$node['lft'].' and '.$node['rgt']);
//修改相应的左右键值
$plus=$node['rgt']-$node['lft']+1;
$this->module->query('update `'.$this->tbname.'` set lft=lft-'.$plus.' where lft>'.$node['rgt']);
$this->module->query('update `'.$this->tbname.'` set rgt=rgt-'.$plus.' where rgt>'.$node['rgt']);
return true;
}

/**
* 更新一个节点
* @param array $set更新集
* @param int $cid 更新的节点的主键ID
*/
function update($set,$cid){
return $this->module->update($set,'where cid='.$cid);
}

/**
* 选取节点及其子节点
* @param int $cid节点的主键ID
* @param int $deep选取深度
*/
function select($cid,$deep=0)
{
//获取节点信息
$node=$this->get_by_cid($cid);
$where='where lft between '.$node['lft'].' and '.$node['rgt'];
if(!empty($deep))$where.=' and level<'.$node['level']+$deep;
if($deep==1){
$where.=' order by orderstyle desc';
}else{
$where.=' order by lft asc';
}
return $this->module->select($where);
}

/**
* 获取父节点路径
* @param int $cid 节点的ID
*/
function get_parent($cid)
{
$node=$this->get_by_cid($cid);
return $this->module->select('where lft<='.$node['lft'].' and rgt>='.$node['rgt'].' order by lft asc');
}
/**
* 选取子节点
* @param int $cid节点的主键ID
* @param int $deep选取深度
*/
function get_children($pid,$deep=0){
//获取节点信息
$pnode=$this->get_by_cid($pid);
$where='where lft>'.$pnode['lft'].' and rgt<'.$pnode['rgt'];
if(!empty($deep))$where.=' and level<='.($pnode['level']+$deep);
if($deep==1){
$where.=' order by orderstyle desc';
}else{
$where.=' order by lft asc';
}
return $this->module->select($where);
}

/**
* 获取第deep层子节点
* @param int $cid节点的主键ID
* @param int $deep选取深度
*/
function get_level_children($pid,$deep){
//获取节点信息
$pnode=$this->get_by_cid($pid);
$where='where lft>'.$pnode['lft'].' and rgt<'.$pnode['rgt'];
$where.=' and level='.($pnode['level']+$deep);
$where.=' order by orderstyle desc';
return $this->module->select($where);
}

/**
* 获取节点信息
* @param $cid 节点的主键ID
* @return array $node
*/
function get_by_cid($cid){
$node=$this->module->detail('where cid='.$cid);
if(!$node)$this->error(__FUNCTION__.'():获取节点'.$cid.'失败！');
return $node;
}
/**
* 获取子节点的数目
* @param array $node 节点信息
* @return num
*/
function child_num($node){
return ($node['rgt']-$node['lft']-1)/2;
}
/**
* 按照层次显示分类
* @param int $cid节点的主键ID
* @output
*/
function display($cid)
{
$nodes=$this->select($cid);
foreach($nodes as $node){
echo str_repeat(' ',$node['level']-1).$node['cname']."\n";
}
}
/*-------private-----------------------------------*/

function error($msg){
die('ERROR : file '.__FILE__.' function '.$msg);
}
}
?>