php tree类的使用（树形结构）

<?php

include "tree.class.php";

//模拟数据库
$data=array(
    array("id"=>1,"pid"=>0,"name"=>"一级栏目一"),
    array("id"=>2,"pid"=>0,"name"=>"一级栏目二"),
    array("id"=>3,"pid"=>1,"name"=>"二级栏目一"),
    array("id"=>4,"pid"=>3,"name"=>"三级栏目一"),
    array("id"=>5,"pid"=>4,"name"=>"四级栏目一"),
);

//转换数据
$tree_data=array();
foreach ($data as $key=>$value){
    $tree_data[$value["id"]]=array(
        "id"=>$value["id"],
        "parentid"=>$value["pid"],
        "name"=>$value["name"]
    );
}

/**
 * 输出树形结构
 */
$str="<tr>
    <td><input type="checkbox" name="list[$id]" value="$id"></td>
    <td>$id</td>
    <td>$spacer$name</td>
    <td><a href="add.php?id=$id">添加</a></td>
    <td><a href="del.php?id=$id">删除</a></td>
    <td><a href="update.php?id="$id">修改</a></td>
    </tr>";

$tree=new Tree();
$tree->init($tree_data);
echo "<table>";
echo $tree->get_tree(0, $str);
echo "</table>";


echo "<br/>";
echo "<br/>";
echo "<br/>";
echo "<br/>";

/**
 * 输出下拉列表
 */

$str="<option value=$id $selected>$spacer$name</option>";
$tree=new Tree();
$tree->init($tree_data);
echo "<select>";
echo $tree->get_tree(0, $str,2);
echo "</select>";

tree.class.php

<?php
/**
* 通用的树型类，可以生成任何树型结构
*/
class tree {
	/**
	* 生成树型结构所需要的2维数组
	* @var array
	*/
	public $arr = array();

	/**
	* 生成树型结构所需修饰符号，可以换成图片
	* @var array
	*/
	public $icon = array("│","├","└");
	public $nbsp = " ";

	/**
	* @access private
	*/
	public $ret = "";

	/**
	* 构造函数，初始化类
	* @param array 2维数组，例如：
	* array(
	*      1 => array("id"=>"1","parentid"=>0,"name"=>"一级栏目一"),
	*      2 => array("id"=>"2","parentid"=>0,"name"=>"一级栏目二"),
	*      3 => array("id"=>"3","parentid"=>1,"name"=>"二级栏目一"),
	*      4 => array("id"=>"4","parentid"=>1,"name"=>"二级栏目二"),
	*      5 => array("id"=>"5","parentid"=>2,"name"=>"二级栏目三"),
	*      6 => array("id"=>"6","parentid"=>3,"name"=>"三级栏目一"),
	*      7 => array("id"=>"7","parentid"=>3,"name"=>"三级栏目二")
	*      )
	*/
	public function init($arr=array()){
       $this->arr = $arr;
	   $this->ret = "";
	   return is_array($arr);
	}

    /**
	* 得到父级数组
	* @param int
	* @return array
	*/
	public function get_parent($myid){
		$newarr = array();
		if(!isset($this->arr[$myid])) return false;
		$pid = $this->arr[$myid]["parentid"];
		$pid = $this->arr[$pid]["parentid"];
		if(is_array($this->arr)){
			foreach($this->arr as $id => $a){
				if($a["parentid"] == $pid) $newarr[$id] = $a;
			}
		}
		return $newarr;
	}

    /**
	* 得到子级数组
	* @param int
	* @return array
	*/
	public function get_child($myid){
		$a = $newarr = array();
		if(is_array($this->arr)){
			foreach($this->arr as $id => $a){
				if($a["parentid"] == $myid) $newarr[$id] = $a;
			}
		}
		return $newarr ? $newarr : false;
	}

    /**
	* 得到当前位置数组
	* @param int
	* @return array
	*/
	public function get_pos($myid,&$newarr){
		$a = array();
		if(!isset($this->arr[$myid])) return false;
        $newarr[] = $this->arr[$myid];
		$pid = $this->arr[$myid]["parentid"];
		if(isset($this->arr[$pid])){
		    $this->get_pos($pid,$newarr);
		}
		if(is_array($newarr)){
			krsort($newarr);
			foreach($newarr as $v){
				$a[$v["id"]] = $v;
			}
		}
		return $a;
	}

    /**
	* 得到树型结构
	* @param int ID，表示获得这个ID下的所有子级
	* @param string 生成树型结构的基本代码，例如："<option value=$id $selected>$spacer$name</option>"
	* @param int 被选中的ID，比如在做树型下拉框的时候需要用到
	* @return string
	*/
	public function get_tree($myid, $str, $sid = 0, $adds = "", $str_group = ""){
		$number=1;
		$child = $this->get_child($myid);
		if(is_array($child)){
		    $total = count($child);
			foreach($child as $id=>$value){
				$j=$k="";
				if($number==$total){
					$j .= $this->icon[2];
				}else{
					$j .= $this->icon[1];
					$k = $adds ? $this->icon[0] : "";
				}
				$spacer = $adds ? $adds.$j : "";
				$selected = $id==$sid ? "selected" : "";
				@extract($value);
				$parentid == 0 && $str_group ? eval("$nstr = "$str_group";") : eval("$nstr = "$str";");
				$this->ret .= $nstr;
				$nbsp = $this->nbsp;
				$this->get_tree($id, $str, $sid, $adds.$k.$nbsp,$str_group);
				$number++;
			}
		}
		return $this->ret;
	}
    /**
	* 同上一方法类似,但允许多选
	*/
	public function get_tree_multi($myid, $str, $sid = 0, $adds = ""){
		$number=1;
		$child = $this->get_child($myid);
		if(is_array($child)){
		    $total = count($child);
			foreach($child as $id=>$a){
				$j=$k="";
				if($number==$total){
					$j .= $this->icon[2];
				}else{
					$j .= $this->icon[1];
					$k = $adds ? $this->icon[0] : "";
				}
				$spacer = $adds ? $adds.$j : "";
				
				$selected = $this->have($sid,$id) ? "selected" : "";
				@extract($a);
				eval("$nstr = "$str";");
				$this->ret .= $nstr;
				$this->get_tree_multi($id, $str, $sid, $adds.$k." ");
				$number++;
			}
		}
		return $this->ret;
	}
	 /**
	* @param integer $myid 要查询的ID
	* @param string $str   第一种HTML代码方式
	* @param string $str2  第二种HTML代码方式
	* @param integer $sid  默认选中
	* @param integer $adds 前缀
	*/
	public function get_tree_category($myid, $str, $str2, $sid = 0, $adds = ""){
		$number=1;
		$child = $this->get_child($myid);
		if(is_array($child)){
		    $total = count($child);
			foreach($child as $id=>$a){
				$j=$k="";
				if($number==$total){
					$j .= $this->icon[2];
				}else{
					$j .= $this->icon[1];
					$k = $adds ? $this->icon[0] : "";
				}
				$spacer = $adds ? $adds.$j : "";
				
				$selected = $this->have($sid,$id) ? "selected" : "";
				@extract($a);
				if (empty($html_disabled)) {
					eval("$nstr = "$str";");
				} else {
					eval("$nstr = "$str2";");
				}
				$this->ret .= $nstr;
				$this->get_tree_category($id, $str, $str2, $sid, $adds.$k." ");
				$number++;
			}
		}
		return $this->ret;
	}
	
	/**
	 * 同上一类方法，jquery treeview 风格，可伸缩样式（需要treeview插件支持）
	 * @param $myid 表示获得这个ID下的所有子级
	 * @param $effected_id 需要生成treeview目录数的id
	 * @param $str 末级样式
	 * @param $str2 目录级别样式
	 * @param $showlevel 直接显示层级数，其余为异步显示，0为全部限制
	 * @param $style 目录样式 默认 filetree 可增加其他样式如"filetree treeview-famfamfam"
	 * @param $currentlevel 计算当前层级，递归使用 适用改函数时不需要用该参数
	 * @param $recursion 递归使用 外部调用时为FALSE
	 */
    function get_treeview($myid,$effected_id="example",$str="<span class="file">$name</span>", $str2="<span class="folder">$name</span>" ,$showlevel = 0 ,$style="filetree " , $currentlevel = 1,$recursion=FALSE) {
        $child = $this->get_child($myid);
        if(!defined("EFFECTED_INIT")){
           $effected = " id="".$effected_id.""";
           define("EFFECTED_INIT", 1);
        } else {
           $effected = "";
        }
		$placeholder = 	"<ul><li><span class="placeholder"></span></li></ul>";
        if(!$recursion) $this->str .="<ul".$effected."  class="".$style."">";
        foreach($child as $id=>$a) {

        	@extract($a);
			if($showlevel > 0 && $showlevel == $currentlevel && $this->get_child($id)) $folder = "hasChildren"; //如设置显示层级模式@2011.07.01
        	$floder_status = isset($folder) ? " class="".$folder.""" : "";		
            $this->str .= $recursion ? "<ul><li".$floder_status." id="".$id."">" : "<li".$floder_status." id="".$id."">";
            $recursion = FALSE;
            if($this->get_child($id)){
            	eval("$nstr = "$str2";");
            	$this->str .= $nstr;
                if($showlevel == 0 || ($showlevel > 0 && $showlevel > $currentlevel)) {
					$this->get_treeview($id, $effected_id, $str, $str2, $showlevel, $style, $currentlevel+1, TRUE);
				} elseif($showlevel > 0 && $showlevel == $currentlevel) {
					$this->str .= $placeholder;
				}
            } else {
                eval("$nstr = "$str";");
                $this->str .= $nstr;
            }
            $this->str .=$recursion ? "</li></ul>": "</li>";
        }
        if(!$recursion)  $this->str .="</ul>";
        return $this->str;
    }
	
	/**
	 * 获取子栏目json
	 * Enter description here ...
	 * @param unknown_type $myid
	 */
	public function creat_sub_json($myid, $str="") {
		$sub_cats = $this->get_child($myid);
		$n = 0;
		if(is_array($sub_cats)) foreach($sub_cats as $c) {			
			$data[$n]["id"] = iconv(CHARSET,"utf-8",$c["catid"]);
			if($this->get_child($c["catid"])) {
				$data[$n]["liclass"] = "hasChildren";
				$data[$n]["children"] = array(array("text"=>" ","classes"=>"placeholder"));
				$data[$n]["classes"] = "folder";
				$data[$n]["text"] = iconv(CHARSET,"utf-8",$c["catname"]);
			} else {				
				if($str) {
					@extract(array_iconv($c,CHARSET,"utf-8"));
					eval("$data[$n]["text"] = "$str";");
				} else {
					$data[$n]["text"] = iconv(CHARSET,"utf-8",$c["catname"]);
				}
			}
			$n++;
		}
		return json_encode($data);		
	}
	private function have($list,$item){
		return(strpos(",,".$list.",",",".$item.","));
	}
}
?>