php無限分類且支持輸出樹狀圖的詳細介紹

復制代碼 代碼如下:
<?php
/**
* 通用的樹型類，可以生成任何樹型結構
*/
class tree
{
    /**
    * 生成樹型結構所需要的2維數組
    * @var array
    */
    var $arr = array();

    /**
    * 生成樹型結構所需修飾符號，可以換成圖片
    * @var array
    */
    var $icon = array('│','├','└');

    /**
    * @access private
    */
    var $ret = '';

    /**
    * 構造函數，初始化類
    * @param array 2維數組，例如：
    * array(
    *      1 => array('id'=>'1','parentid'=>0,'name'=>'一級欄目一'),
    *      2 => array('id'=>'2','parentid'=>0,'name'=>'一級欄目二'),
    *      3 => array('id'=>'3','parentid'=>1,'name'=>'二級欄目一'),
    *      4 => array('id'=>'4','parentid'=>1,'name'=>'二級欄目二'),
    *      5 => array('id'=>'5','parentid'=>2,'name'=>'二級欄目三'),
    *      6 => array('id'=>'6','parentid'=>3,'name'=>'三級欄目一'),
    *      7 => array('id'=>'7','parentid'=>3,'name'=>'三級欄目二')
    *      )
    */
    function tree($arr=array())
    {
       $this->arr = $arr;
       $this->ret = '';
       return is_array($arr);
    }

    /**
    * 得到父級數組
    * @param int
    * @return array
    */
    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;
    }

    /**
    * 得到子級數組
    * @param int
    * @return array
    */
    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;
    }

    /**
    * 得到當前位置數組
    * @param int
    * @return array
    */
    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;
    }

 
    /**
     * -------------------------------------
     *  得到樹型結構
     * -------------------------------------
     * @author  Midnight(楊雲洲),  [email protected]
     * @param $myid 表示獲得這個ID下的所有子級
     * @param $str 生成樹形結構基本代碼, 例如: "<option value=\$id \$select>\$spacer\$name</option>"
     * @param $sid 被選中的ID, 比如在做樹形下拉框的時候需要用到
     * @param $adds
     * @param $str_group
     * @return unknown_type
     */
    function get_tree($myid, $str, $sid = 0, $adds = '', $str_group = '')
    {
        $number=1;
        $child = $this->get_child($myid);
        if(is_array($child))
        {
            $total = count($child);
            foreach($child as $id=>$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 = $id==$sid ? 'selected' : '';
                @extract($a);
                $parentid == 0 && $str_group ? eval("\$nstr = \"$str_group\";") : eval("\$nstr = \"$str\";");
                $this->ret .= $nstr;
                $this->get_tree($id, $str, $sid, $adds.$k.' ',$str_group);
                $number++;
            }
        }
        return $this->ret;
    }
    /**
    * 同上一方法類似,但允許多選
    */
    function get_tree_multi($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' : '';
                //echo $sid.'=>'.$id.' : '.$selected.' . <br/>';
                @extract($a);
                eval("\$nstr = \"$str\";");
                $this->ret .= $nstr;
                $this->get_tree_multi($id, $str, $sid, $adds.$k.' ');
                $number++;
            }
        }
        return $this->ret;
    }

    function have($list,$item){
        return(strpos(',,'.$list.',',','.$item.','));
    }
}
?>