php xml operation class (customized)

/**
 php xml operation class
 link: http://bbs.it-home.org
*/
class requirelog
{
    protected static $requirelog;
    //get ready for xml,if xml is not found ,create xml
    static function _initializeLog()
    {
       if(file_exists('requirelog.xml'))
       {
           self::$requirelog = DOMDocument::load('requirelog.xml');
       }
       else
       {
           self::$requirelog = new DOMDocument('1.0', 'iso-8859-1');
           self::$requirelog->loadXML('');
           self::$requirelog->save('requirelog.xml');
       }
    }
    //获取finish字段全部为0的所有节点
    public static function get_entrys()
    {
            self::_initializeLog();
            $entrys = self::$requirelog->getElementsByTagName('entry');
            $entry_arrays = array();
            foreach($entrys as $entry)
            {
                if($entry->getElementsByTagName('finish')->item(0)->nodeValue == 0)
                {
                    $entry_array = array();
                    $entry_array['id'] = $entry->getElementsByTagName('id')->item(0)->nodeValue;
                    $entry_array['time'] = $entry->getElementsByTagName('time')->item(0)->nodeValue;
                    $entry_array['operator'] = $entry->getElementsByTagName('operator')->item(0)->nodeValue;
                    $entry_array['byoperator'] = $entry->getElementsByTagName('byoperator')->item(0)->nodeValue;
                    $entry_array['parameters1'] = $entry->getElementsByTagName('parameters1')->item(0)->nodeValue;
                    $entry_array['parameters2'] = $entry->getElementsByTagName('parameters2')->item(0)->nodeValue;
                    $entry_array['parameters3'] = $entry->getElementsByTagName('parameters3')->item(0)->nodeValue;
                    $entry_array['type'] = $entry->getElementsByTagName('type')->item(0)->nodeValue;
                    $entry_array['module'] = $entry->getElementsByTagName('module')->item(0)->nodeValue;
                    $entry_array['finish'] = $entry->getElementsByTagName('finish')->item(0)->nodeValue;
                    $entry_arrays[] = $entry_array;
                }
            }
            return  $entry_arrays;
    }

    //获取所有的节点
    public static function get_count_entrys()
    {
            self::_initializeLog();
            $entrys = self::$requirelog->getElementsByTagName('entry');
            $entry_arrays = array();
            foreach($entrys as $entry)
            {
                $entry_array = array();
                $entry_array['id'] = $entry->getElementsByTagName('id')->item(0)->nodeValue;
                $entry_array['time'] = $entry->getElementsByTagName('time')->item(0)->nodeValue;
                $entry_array['operator'] = $entry->getElementsByTagName('operator')->item(0)->nodeValue;
                $entry_array['byoperator'] = $entry->getElementsByTagName('byoperator')->item(0)->nodeValue;
                $entry_array['parameters1'] = $entry->getElementsByTagName('parameters1')->item(0)->nodeValue;
                $entry_array['parameters2'] = $entry->getElementsByTagName('parameters2')->item(0)->nodeValue;
                $entry_array['parameters3'] = $entry->getElementsByTagName('parameters3')->item(0)->nodeValue;
                $entry_array['type'] = $entry->getElementsByTagName('type')->item(0)->nodeValue;
                $entry_array['module'] = $entry->getElementsByTagName('module')->item(0)->nodeValue;
                $entry_array['finish'] = $entry->getElementsByTagName('finish')->item(0)->nodeValue;
                $entry_arrays[] = $entry_array;
            }
            return  $entry_arrays;
    }
    //根据ID获取节点
    public static function get_entry($id)
    {
        self::_initializeLog();
        $count=count(self::get_count_entrys());
        if($count > 0)
        {
            $entrys = self::$requirelog->getElementsByTagName('entry');
            foreach($entrys as $entry)
            {
                if ($id == $entry->getElementsByTagName('id')->item(0)->nodeValue)
                {
                    $entry_array = array();
                    $entry_array['id'] = $entry->getElementsByTagName('id')->item(0)->nodeValue;
                    $entry_array['time'] = $entry->getElementsByTagName('time')->item(0)->nodeValue;
                    $entry_array['operator'] = $entry->getElementsByTagName('operator')->item(0)->nodeValue;
                    $entry_array['byoperator'] = $entry->getElementsByTagName('byoperator')->item(0)->nodeValue;
                    $entry_array['parameters1'] = $entry->getElementsByTagName('parameters1')->item(0)->nodeValue;
                    $entry_array['parameters2'] = $entry->getElementsByTagName('parameters2')->item(0)->nodeValue;
                    $entry_array['parameters3'] = $entry->getElementsByTagName('parameters3')->item(0)->nodeValue;
                    $entry_array['type'] = $entry->getElementsByTagName('type')->item(0)->nodeValue;
                    $entry_array['module'] = $entry->getElementsByTagName('module')->item(0)->nodeValue;
                    $entry_array['finish'] = $entry->getElementsByTagName('finish')->item(0)->nodeValue;
                    return $entry_array;
                }
            }
        }
        else
            return null;
    }
    //执行完用户请求，更改finsh字段
    public static function do_finsh($id)
    {
        self::_initializeLog();
        $entrys = self::$requirelog->getElementsByTagName('entry');
        $entry_arrays = array();
        foreach($entrys as $entry)
        {
            if($entry->getElementsByTagName('id')->item(0)->nodeValue == $id)
            {
                $entry->getElementsByTagName('finish')->item(0)->nodeValue = 1;
            }
        }
        self::$requirelog->save('requirelog.xml');
    }
 //Add a new node, $operator is the operator, $byoperator is the operated object, $parameters1,2,3 are extensible parameters, $type is the type, $module is the influence Module
 static function add_entry($operator,$byoperator,$parameters1,$parameters2,$parameters3,$type,$module)
 {
 //$contents = self::$restlog->getElementsByTagName('contents') ;
 self::_initializeLog();
 $count=count(self::get_count_entrys());
 $entry = self::$requirelog ->createElement('entry');
 $id = self::$requirelog->createElement('id');
 $idvalue = self::$requirelog-> createTextNode($count+1);
 $id->appendChild($idvalue);
 $time = self::$requirelog->createElement('time');
 $ timevalue = self::$requirelog->createTextNode(date("Y-m-d H:i:s",time()));
 $time->appendChild($timevalue);
createElement('operator');
 $opvalue = self::$requirelog->createTextNode($operator);
 $op->appendChild($opvalue);< ;/p>
 $bop = self::$requirelog->createElement('byoperator');
 $bopvalue = self::$requirelog->createTextNode($byoperator);
 $bop-> ;appendChild($bopvalue);
 $ps1 = self::$requirelog->createElement('parameters1');
 $ps1value = self::$requirelog->createTextNode($ parameters1);
 $ps1->appendChild($ps1value);
 $ps2 = self::$requirelog->createElement('parameters2');
 $ps2value = self:: $requirelog->createTextNode($parameters2);
 $ps2->appendChild($ps2value);
 $ps3 = self::$requirelog->createElement('parameters3') ;
 $ps3value = self::$requirelog->createTextNode($parameters3);
 $ps3->appendChild($ps3value);

 $tp = self::$requirelog ->createElement('type');
 $tpvalue = self::$requirelog->createTextNode($type);
 $tp->appendChild($tpvalue);
 $md = self::$requirelog->createElement('module');
 $mdvalue = self::$requirelog->createTextNode($module);
 $md->appendChild($mdvalue);< /p>
 $fi = self::$requirelog->createElement('finish');
 $fivalue = self::$requirelog->createTextNode(0);
 $fi->appendChild ($fivalue);
 $entry->appendChild($id);
 $entry->appendChild($time);
 $entry->appendChild($op);
 $entry->appendChild($bop);
 $entry->appendChild($ps1);
 $entry->appendChild($ps2);
 $entry->appendChild($ps3);
 $ entry->appendChild($tp);
 $entry->appendChild($md);
 $entry->appendChild($fi);
 self::$requirelog- >documentElement->appendChild($entry);
 self::$requirelog->save('requirelog.xml');
 return 1;
 }
}
?> ;

2、requirelog.xml文件，参考格式如下：

      1
      2009-11-21 16:56:33
      peng.zhou
      zxcxzcxzczxcxz
      cxzcxzc


      add_group
      cn_group
      1


      2
      2009-11-21 16:56:53
      peng.zhou
      sales



      add_member
      mail_group
      1