PHP 分类树的构建 使用与Extjs Tree的构建

<?php

/**

 +----------------------------------------------------------

 *  分类树

 +----------------------------------------------------------

 */

function list_to_tree($list, $pk='id',$pid = 'pid',$child = '_child',$root=0)

{

    // 创建Tree

    $tree = array();

    if(is_array($list)) {

        // 创建基于主键的数组引用

        $refer = array();

        foreach ($list as $key => $data) {

            $refer[$data[$pk]] =& $list[$key];

        }

        foreach ($list as $key => $data) {

            // 判断是否存在parent

            $parentId = $data[$pid];

            if ($root == $parentId) {

                $tree[] =& $list[$key];

            }else{

                if (isset($refer[$parentId])) {

                    $parent =& $refer[$parentId];

                    $parent[$child][] =& $list[$key];

                }

            }

        }

    }

    return $tree;

}

?>