php实现的树形结构数据存取类实例，树形实例

复制代码 代码如下:

<?php
/**
* Tanphp framework
*
*
* @category Tanphp
* @package Data_structure
* @version $Id: Tree.php 25024 2012-11-26 22:22:22 tanbo $
*/

/**
* 树形结构数据存取类
*
* 用于对树形结构数据进行快速的存取
*
* @param array $arr 参数必须为标准的二维数组，包含索引字段（id）与表示树形结构的字段(path),如example中所示
*
* @example
* $arr = array(
* array( 'id' => 1, 'name' => 'php', 'path' => '1' ),
* array( 'id' => 3, 'name' => 'php1', 'path' => '1-3' ),
* array( 'id' => 2, 'name' => 'mysql', 'path' => '2' ),
* array( 'id' => 6, 'name' => 'mysql1', 'path' => '2-6' ),
* array( 'id' => 7, 'name' => 'mysql2', 'path' => '2-7' ),
* array( 'id' => 5, 'name' => 'php11', 'path' => '1-3-5' ),
* array( 'id' => 4, 'name' => 'php2', 'path' => '1-4' ),
* );
* $cate = new Tree($arr);
*
* $data = $cate->getChild(2);
*
* print_r($data->toArray());
*
*
*/
class Tree
{
public $_info; //节点信息
public $_child = array(); //子节点
private $_parent; //父节点
private $_data; //当前操作的临时数据
private static $_indexs = array(); //所有节点的索引
private static $_index_key = ‘id’; //索引键
private static $_tree_key = ‘path’; //树形结构表达键
private static $_tree_delimiter = ‘-‘; //属性结构表达分割符

/**
* 构造函数
*
* @param array $arr
* @param boole $force_sort 如果为真，将会强制对$arr 进行排序
* @return void
*/
public function __construct(array $arr = array(), $force_sort=true)
{
if ($force_sort === true) {
$arr=$this->_array_sort($arr, self::$_tree_key);
}
if (!emptyempty($arr)) {
$this->_init($arr);
}
}

/**
* 初始存储树形数据
*
* @param array $arr
* @return void
*/
private function _init(array $arr)
{
foreach ($arr as $item) {
$path = $item[self::$_tree_key];
$paths = explode(self::$_tree_delimiter, $path);
$count_paths = count($paths);
$parent_id = isset($paths[$count_paths-2]) ? $paths[$count_paths-2] : NULL;

if ( $count_paths>1 //如果有父级
&& array_key_exists($parent_id, self::$_indexs) //父级已经被存入索引
&& self::$_indexs[$parent_id] instanceof Tree //父级为Tree对象
) {
self::$_indexs[$parent_id]->addChild($item);
} elseif ($count_paths == 1) {
$this->addChild($item);
} else {
throw new Exception(“path数据错误”.var_export($item, true));
}
}

//print_r(self::$_indexs);
}

/**
* 添加子节点
*
* @param array $item
* @return void
*/
public function addChild(array $item, $parent = NULL)
{
$child = new Tree();
$child->_info = $item;
$child->_parent = $parent == NULL ? $this : $parent;
$child->_parent->_child[] = $child;

$this->_addIndex($item, $child->_getSelf());
}

/**
* 添加节点到索引
*
* @param array $item
* @param mix $value
* @return void
*/
private function _addIndex(array $item, $value)
{
if (array_key_exists(self::$_index_key, $item) && is_int($item[self::$_index_key])) {
self::$_indexs[$item[self::$_index_key]] = $value;
} else {
throw new Exception(“id字段不存在或者不为字符串”);
}
}

/**
* 获取对自己的引用
*
* @return Tree object quote
*/
private function _getSelf()
{
return $this;
}

/**
* 获取指定id的节点的子节点
*
* @param int $id
* @return Tree object
*/
public function getChild($id)
{
$data = self::$_indexs[$id]->_child;
$this->_data = $data;
return $this;
}

/**
* 获取指定id的节点的父节点
*
* @param int $id
* @return Tree object
*/
public function getParent($id)
{
$data = self::$_indexs[$id]->_parent;
$this->_data = $data;
return $this;
}

/**
* 获取指定id的节点的同级节点
*
* @param int $id
* @return Tree object
*/
public function getBrother($id)
{
$data = self::$_indexs[$id]->_parent->_child;
$this->_data = $data;
return $this;
}

/**
* 将Tree对象转化为数组
*
* @param object $object
* @return array
*/
public function toArray($obj = NULL)
{
$obj = ($obj === NULL) ? $this->_data : $obj;
$arr = array();
$_arr = is_object($obj) ? $this->_getBaseInfo($obj) : $obj;

if (is_array($_arr)) {
foreach ($_arr as $key => $val){

$val = (is_array($val) || is_object($val)) ? $this->toArray($val) : $val;
$arr[$key] = $val;
}
} else {
throw new Exception(“_arr不是数组”);
}

return $arr;
}

/**
* 过滤_parent等字段，以免造成无限循环
*
* @param object $obj
* @return void
*/
private function _getBaseInfo($obj)
{
$vars = get_object_vars($obj);
$baseInfo[‘_info’] = $vars[‘_info’];
$baseInfo[‘_child’] = $vars[‘_child’];
return $baseInfo;
}

/**
* 二维数组排序
*
* 根据指定的键名对二维数组进行升序或者降序排列
*
* @param array $arr 二维数组
* @param string $keys
* @param string $type 必须为 asc或desc
* @throws 当参数非法时抛出异常
* @return 返回排序好的数组
*/
private function _array_sort(array $arr, $keys, $type = ‘asc’) {
if (!is_string($keys)) {
throw new Exception(“非法参数keys:参数keys的类型必须为字符串”);
}

$keysvalue = $new_array = array();
foreach ($arr as $k=>$v) {
if (!is_array($v) || !isset($v[$keys])) {
throw new Exception(“参数arr不是二维数组或arr子元素中不存在键'{$keys}'”);
}
$keysvalue[$k] = $v[$keys];
}

switch ($type) {
case ‘asc’:
asort($keysvalue);
break;
case ‘desc’:
arsort($keysvalue);
break;
default:
throw new Exception(“非法参数type ：参数type的值必须为 ‘asc’ 或 ‘desc'”);
}

reset($keysvalue);
foreach ($keysvalue as $k=>$v) {
$new_array[$k] = $arr[$k];
}
return $new_array;
}
}
?>