php+xml留言板实例教程二-PHP源码

这是一个xml 解析类

class Message_XML extends DOMDocument
{
const file_name = "e:/myphp/xmldom/xml/message.xml";
private $root; //根节点
private $PageNo; //当前页
private $allNum; //记录总数
private $PageSize; //页大小
private $allPages; //总页数
public function __construct()
{
parent::__construct();
if(!file_exists(self::file_name))
{
$xmlStr = "";
$this -> loadXML($xmlStr);
$this -> save(self::file_name);
}else{
$this -> load(self::file_name);
}
$this -> root = $this -> documentElement;
$this -> get_pagemsg();
}
//得到页信息
private function get_pagemsg()
{
$this -> PageSize = 3; //页大小
$allNode = $this -> getElementsByTagName("record");
$this -> allNum = $allNode -> length; //记录总数
$this -> allPages = ceil($this -> allNum / $this -> PageSize); //总页数
$this -> PageNo = $_GET["PageNo"];
if($this -> PageNo <1 || !is_numeric($this -> PageNo))
{
$this -> PageNo = 1;
}else if($this -> PageNo > $this -> allPages){
$this -> PageNo = $this -> allPages;
}
$this -> PageNo = (int)$this -> PageNo;
}
//显示留言
public function show_message()
{
$start_num = ($this -> PageNo - 1) * $this -> PageSize; //记录开始数
$end_num = $start_num + $this -> PageSize - 1; //记录结束数
$allNode = $this -> getElementsByTagName("record");
$i = 0;
foreach($allNode as $v)
{
if($i >= $start_num && $i <= $end_num)
{
$autoid = $v -> getElementsByTagName("autoid") -> item(0) -> nodeValue;
$subject = $v -> getElementsByTagName("subject") -> item(0) -> nodeValue;
$cOntent= $v -> getElementsByTagName("content") -> item(0) -> nodeValue;
$str = "

留言标题：$subject

留言内容：

        $content

";
$str .= "

编辑 删除

";
print $str;
}
$i++;
}
$this -> get_pageCode();
}
//得到当前页码
public function get_pageCode()
{
$str = "

当前页：".$this -> PageNo." / ".$this -> allPages."   首页 上一页 下一页 末页";
$str .= "   ";
print $str;
}
//添加留言页面
public function post_message()
{
print "

";
print "

标题：

";
print "

内容：

";
print "

";
}
//添加留言
public function add_message($Subject,$Content)
{
$autoid = microtime(); //留言ID
$autoid = substr(strrchr(str_replace(" ","",$autoid),"."),1);
$node_top = $this -> root ->appendChild($this -> createElement("record"));
$node_top -> appendChild($this -> createElement("autoid",$autoid));
$node_top -> appendChild($this -> createElement("subject",$Subject));
$node_top -> appendChild($this -> createElement("content",$Content));
$this -> save(self::file_name);
echo "";
}
//清空留言
public function clear_message()
{
$fp = @ fopen(self::file_name,"w+");
if($fp)
{
$str = "";
fwrite($fp,$str);
fclose($fp);
echo "";
}else{
echo "";
}
}
//设置节点路径和操作对象ID
private function set_nodePath($AutoID)
{
$xpath = new DOMXPath($this);
$node_top = $xpath -> query("//record[autoid=$AutoID]");
return $node_top;
}
//删除留言
public function delete_message($AutoID)
{
$node_top = $this -> set_nodePath($AutoID);
$this -> root -> removeChild($node_top -> item(0));
$this -> save(self::file_name);
echo "";
}
//编辑留言页面
public function edit_message($AutoID)
{
$node_top = $this -> set_nodePath($AutoID);
//取值方法1
//$subject = $node_top -> item(0) -> getElementsByTagName("subject") -> item(0) -> nodeValue;
//$cOntent= $node_top -> item(0) -> getElementsByTagName('content') -> item(0) ->nodeValue;
//取值方法2
foreach($node_top -> item(0) -> childNodes as $v)
{
$value[] = $v -> textContent; //注意：这里的$value必须这样写成一个数组，否则要出错
}
print "

";
print "

标题：

";
print "

内容：$value[2]

";
print "

";
}
//编辑留言
public function save_message($AutoID,$Subject,$Content)
{
$node_top = $this -> set_nodePath($AutoID);
$replace_info[0] = $AutoID;
$replace_info[1] = $Subject;
$replace_info[2] = $Content;
$i = 0;
foreach($node_top -> item(0) -> childNodes as $v)
{
$new_cOntent= $this -> createTextNode($replace_info[$i]);
$v -> replaceChild($new_content,$v -> lastChild);
$i++;
}
$this -> save(self::file_name);
echo "";
}
}
?>