PHP unlimited classification code supports array formatting and direct menu output_PHP tutorial

/**
+------------------------------------------------ --
* Universal tree class
+----------------------------------- -------------
* @author yangyunzhou@foxmail.com
+---------------------- --------------------------
* @date November 23, 2010 10:09:31
+--- ---------------------------------------------
*/
class Tree
{

/**
+------------------------------------------------ --
* 2-dimensional array required to generate tree structure
+--------------------------------- ------------------
* @author yangyunzhou@foxmail.com
+----------------- -------------------------------
* @var Array
*/
var $arr = array();

/**
+------------------------------------------------ --
* The modification symbols required to generate a tree structure can be replaced by pictures
+-------------------------- --------------------------
* @author yangyunzhou@foxmail.com
+------------- ----------------------------------
* @var Array
*/
var $icon = array('│','├',' └');

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

/**
* Constructor, initialize class
* @param array 2-dimensional array, for example:
* array(
* 1 => array('id'=>'1','parentid '=>0,'name'=>'First-level column one'),
* 2 => array('id'=>'2','parentid'=>0,'name '=>'First-level column two'),
* 3 => array('id'=>'3','parentid'=>1,'name'=>'Second-level column one'),
* 4 => array('id'=>'4','parentid'=>1,'name'=>'Second-level column two'),
* 5 => array('id'=>'5','parentid'=>2,'name'=>'Second-level column three'),
* 6 => array('id '=>'6','parentid'=>3,'name'=>'Third-level column one'),
* 7 => array('id'=>'7', 'parentid'=>3,'name'=>'Third-level column two')
* )
*/
function tree($arr=array())
{
$this->arr = $arr;
$this->ret = '';
return is_array($arr);
}

/**
* get parent array
* @param int
* @return array
*/
function get_parent($myid)
{
$newarr = array();
if(!isset($this->arr[$myid])) return false;
$pid = $this->arr[$myid]['pid'];
$pid = $this->arr[$pid]['pid'];
if(is_array($this->arr))
{
foreach($this->arr as $id => $a)
{
if($a['pid'] == $pid) $newarr[$id] = $a;
}
}
return $newarr;
}

/**
* Get child array
* @param int
* @return array
*/
function get_child($myid)
{
$a = $newarr = array();
if(is_array($this->arr))
{
foreach($this->arr as $id => $a)
{
if($a['pid'] == $myid) $newarr[$id] = $a;
}
}
return $newarr ? $newarr : false;
}

/**
* Get the current position array
* @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]['pid'];
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;
}

/**
* -------------------------------------
* Get tree structure
* -------------------------------------
* @author yangyunzhou@foxmail. com
* @param $myid means to get all the children under this ID
* @param $str generates the basic code of the tree structure, for example: "$spacer$name< ;/option>"
* @param $sid The selected ID, such as when making a tree drop-down box.
* @param $adds
* @param $str_group
*/
function get_tree($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;
}

/**
* Similar to the previous method, but allows multiple selections
*/
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;
}

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

/**
+------------------------------------------------ --
* Format array
+---------------------------------------- ----------
* @author yangyunzhou@foxmail.com
+--------------------- --------------------------
*/
function getArray($myid=0, $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 : '';
@extract($a);
$a['title'] = $spacer.' '.$a['title'];
$this->ret[$a['id']] = $a;
$fd = $adds.$k.' ';
$this->getArray($id, $sid, $fd);
$number++;
}
}

return $this->ret;
}
}
?>