[php] 싱글톤 패턴 구현

<?

class singleT

{

private $data=array();

private $url="";

public $msg = '';

static private $instance = NULL;

static function getInstance()

{

if (self::$instance == NULL) 

{

self::$instance = new singleT();

}

return self::$instance;

}

function setUrl($url)

{

$this->url=$url;

}

function setData($arr)

{

$this->data=$arr;

}

function getData()

{

       $getdata = '알아서 처리';

return $getdata;

}

function _how_to_log()

{

self::_alert('?');

}

//class alert

function _alert($m){

$this->msg = $m;

$printMsg .= '<meta charset="utf-8""/>';

$printMsg .= '<script>'."\n";

$printMsg .= 'alert("'.$this->msg.'")';

$printMsg .= '</script>';

echo $printMsg;

}

}

?>

/* 

how to use..?

$a = singleT::getInstance();

$data = array('id' => '101'.$i,  'name'=>'11', 'value' =>'123');

$a->setData($data);

$aString = $a->getData();

*/