php 无限分类 下拉列表

php代码

<?php
error_reporting(E_ALL ^ E_NOTICE);

class Tree
{
 
    /**
     +------------------------------------------------
     * 生成树型结构所需要的2维数组
     +------------------------------------------------
     * @author yangyunzhou@foxmail.com
     +------------------------------------------------
     * @var Array
     */
    var $arr = array();
 
    /**
     +------------------------------------------------
     * 生成树型结构所需修饰符号，可以换成图片
     +------------------------------------------------
     * @author yangyunzhou@foxmail.com
     +------------------------------------------------
     * @var Array
     */
    var $icon = array(&#39; │&#39;,&#39; ├&#39;,&#39; └&#39;);
 
    /**
    * @access private
    */
    var $ret = &#39;&#39;;
 
    /**
    * 构造函数，初始化类
    * @param array 2维数组，例如：
    * array(
    *      1 => array(&#39;id&#39;=>&#39;1&#39;,&#39;parentid&#39;=>0,&#39;name&#39;=>&#39;一级栏目一&#39;),
    *      2 => array(&#39;id&#39;=>&#39;2&#39;,&#39;parentid&#39;=>0,&#39;name&#39;=>&#39;一级栏目二&#39;),
    *      3 => array(&#39;id&#39;=>&#39;3&#39;,&#39;parentid&#39;=>1,&#39;name&#39;=>&#39;二级栏目一&#39;),
    *      4 => array(&#39;id&#39;=>&#39;4&#39;,&#39;parentid&#39;=>1,&#39;name&#39;=>&#39;二级栏目二&#39;),
    *      5 => array(&#39;id&#39;=>&#39;5&#39;,&#39;parentid&#39;=>2,&#39;name&#39;=>&#39;二级栏目三&#39;),
    *      6 => array(&#39;id&#39;=>&#39;6&#39;,&#39;parentid&#39;=>3,&#39;name&#39;=>&#39;三级栏目一&#39;),
    *      7 => array(&#39;id&#39;=>&#39;7&#39;,&#39;parentid&#39;=>3,&#39;name&#39;=>&#39;三级栏目二&#39;)
    *      )
    */
    function tree($arr=array())
    {
       $this->arr = $arr;
       $this->ret = &#39;&#39;;
       return is_array($arr);
    }
 
    /**
    * 得到父级数组
    * @param int
    * @return array
    */
    function get_parent($myid)
    {
        $newarr = array();
        if(!isset($this->arr[$myid])) return false;
        $pid = $this->arr[$myid][&#39;parentid&#39;];
        $pid = $this->arr[$pid][&#39;parentid&#39;];
        if(is_array($this->arr))
        {
            foreach($this->arr as $id => $a)
            {
                if($a[&#39;parentid&#39;] == $pid) $newarr[$id] = $a;
            }
        }
        return $newarr;
    }
 
    /**
    * 得到子级数组
    * @param int
    * @return array
    */
    function get_child($myid)
    {
        $a = $newarr = array();
        if(is_array($this->arr))
        {
            foreach($this->arr as $id => $a)
            {
                if($a[&#39;parentid&#39;] == $myid) $newarr[$id] = $a;
            }
        }
        return $newarr ? $newarr : false;
    }
 
    /**
    * 得到当前位置数组
    * @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][&#39;parentid&#39;];
        if(isset($this->arr[$pid]))
        {
            $this->get_pos($pid,$newarr);
        }
        if(is_array($newarr))
        {
            krsort($newarr);
            foreach($newarr as $v)
            {
                $a[$v[&#39;id&#39;]] = $v;
            }
        }
        return $a;
    }
 
    /**
     * -------------------------------------
     *  得到树型结构
     * -------------------------------------
     * @author yangyunzhou@foxmail.com
     * @param $myid 表示获得这个ID下的所有子级
     * @param $str 生成树形结构基本代码, 例如: "<option value=\$id \$select>\$spacer\$name</option>"
     * @param $sid 被选中的ID, 比如在做树形下拉框的时候需要用到
     * @param $adds
     * @param $str_group
     */
    function get_tree($myid, $str, $sid = 0, $adds = &#39;&#39;, $str_group = &#39;&#39;)
    {
        $number=1;
        $child = $this->get_child($myid);
        if(is_array($child)) {
            $total = count($child);
            foreach($child as $id=>$a) {
                $j=$k=&#39;&#39;;
                if($number==$total) {
                    $j .= $this->icon[2];
                } else {
                    $j .= $this->icon[1];
                    $k = $adds ? $this->icon[0] : &#39;&#39;;
                }
                $spacer = $adds ? $adds.$j : &#39;&#39;;
                $selected = $id==$sid ? &#39;selected&#39; : &#39;&#39;;
                @extract($a);
                $parentid == 0 && $str_group ? eval("\$nstr = \"$str_group\";") : eval("\$nstr = \"$str\";");
                $this->ret .= $nstr;
                $this->get_tree($id, $str, $sid, $adds.$k.&#39; &#39;,$str_group);
                $number++;
            }
        }
        return $this->ret;
    }
 
    /**
    * 同上一方法类似,但允许多选
    */
    function get_tree_multi($myid, $str, $sid = 0, $adds = &#39;&#39;)
    {
        $number=1;
        $child = $this->get_child($myid);
        if(is_array($child))
        {
            $total = count($child);
            foreach($child as $id=>$a)
            {
                $j=$k=&#39;&#39;;
                if($number==$total)
                {
                    $j .= $this->icon[2];
                }
                else
                {
                    $j .= $this->icon[1];
                    $k = $adds ? $this->icon[0] : &#39;&#39;;
                }
                $spacer = $adds ? $adds.$j : &#39;&#39;;
 
                $selected = $this->have($sid,$id) ? &#39;selected&#39; : &#39;&#39;;
                @extract($a);
                eval("\$nstr = \"$str\";");
                $this->ret .= $nstr;
                $this->get_tree_multi($id, $str, $sid, $adds.$k.&#39; &#39;);
                $number++;
            }
        }
        return $this->ret;
    }
 
    function have($list,$item){
        return(strpos(&#39;,,&#39;.$list.&#39;,&#39;,&#39;,&#39;.$item.&#39;,&#39;));
    }
 
    /**
     +------------------------------------------------
     * 格式化数组
     +------------------------------------------------
     * @author yangyunzhou@foxmail.com
     +------------------------------------------------
     */
    function getArray($myid=0, $sid=0, $adds=&#39;&#39;)
    {
        $number=1;
        $child = $this->get_child($myid);
        if(is_array($child)) {
            $total = count($child);
            foreach($child as $id=>$a) {
                $j=$k=&#39;&#39;;
                if($number==$total) {
                    $j .= $this->icon[2];
                } else {
                    $j .= $this->icon[1];
                    $k = $adds ? $this->icon[0] : &#39;&#39;;
                }
                $spacer = $adds ? $adds.$j : &#39;&#39;;
                @extract($a);
                $a[&#39;name&#39;] = $spacer.&#39; &#39;.$a[&#39;name&#39;];
                $this->ret[$a[&#39;id&#39;]] = $a;
                $fd = $adds.$k.&#39; &#39;;
                $this->getArray($id, $sid, $fd);
                $number++;
            }
        }
 
        return $this->ret;
    }
}



$data=array( 
          1 => array(&#39;id&#39;=>&#39;1&#39;,&#39;parentid&#39;=>0,&#39;name&#39;=>&#39;一级栏目一&#39;), 
          2 => array(&#39;id&#39;=>&#39;2&#39;,&#39;parentid&#39;=>0,&#39;name&#39;=>&#39;一级栏目二&#39;), 
          3 => array(&#39;id&#39;=>&#39;3&#39;,&#39;parentid&#39;=>1,&#39;name&#39;=>&#39;二级栏目一&#39;), 
          4 => array(&#39;id&#39;=>&#39;4&#39;,&#39;parentid&#39;=>1,&#39;name&#39;=>&#39;二级栏目二&#39;), 
          5 => array(&#39;id&#39;=>&#39;5&#39;,&#39;parentid&#39;=>2,&#39;name&#39;=>&#39;二级栏目三&#39;), 
          6 => array(&#39;id&#39;=>&#39;6&#39;,&#39;parentid&#39;=>3,&#39;name&#39;=>&#39;三级栏目一&#39;), 
          7 => array(&#39;id&#39;=>&#39;7&#39;,&#39;parentid&#39;=>3,&#39;name&#39;=>&#39;&#39;), 
		  8 => array(&#39;id&#39;=>&#39;8&#39;,&#39;parentid&#39;=>3,&#39;name&#39;=>&#39;三级栏目三&#39;),
		  9 => array(&#39;id&#39;=>&#39;9&#39;,&#39;parentid&#39;=>7,&#39;name&#39;=>&#39;四级分类三&#39;),
          ); 
$tree = new Tree;           
$tree->tree($data);        
  
// 如果使用数组, 请使用 getArray方法 
//$tree->getArray(); 
// 下拉菜单选项使用 get_tree方法 
$html=&#39;<select name="tree">&#39;; 
$str = "<option value=\$id \$select>\$spacer\$name</option>"; 
$html .= $tree->get_tree(0,$str,-1).&#39;</select>&#39;; 
echo $html; 
?>