Christoph Boget wrote:
Ok, so why isn't this working as (I, at the very least) expected?
class singleTon
{
private static $thisObj = NULL;
private $thisProp = NULL;
public function __construct()
{
echo 'singleTon::__construct()<br>';
if( !is_null( singleTon::$thisObj ))
{
echo '$thisObj already set. returning it...<br>';
return singleTon::$thisObj;
}
singleTon::$thisObj = $this;
}
public static function singleton()
{
echo 'singleTon::singleton()<br>';
if( is_null( singleTon::$thisObj ))
{
$retval = new singleTon();
}
return singleTon::$thisObj;
}
public function setThisProp( $sVal )
{
$this->thisProp = $sVal;
}
public function getThisProp()
{
return $this->thisProp;
}
}
$one = singleTon::singleton();
$one->setThisProp( 'Joe' );
echo '$one->getThisProp();: [' . $one->getThisProp() . ']<br>';
echo '$one: [<pre>' . var_export( $one, TRUE ) . '</pre>]<br>';
$two = new singleTon();
echo '$two->getThisProp();: [' . $two->getThisProp() . ']<br>';
$two->setThisProp( 'Bob' );
echo '$two: [<pre>' . var_export( $two, TRUE ) . '</pre>]<br>';
echo '$one->getThisProp();: [' . $one->getThisProp() . ']<br>';
echo '$two->getThisProp();: [' . $two->getThisProp() . ']<br>';
echo '$one->getThisProp();: [' . $one->getThisProp() . ']<br>';
I would have thought that both $one and $two would be referencing the
same object but they aren't. Apart from making the constructor
private, is there any way I can ensure that there is ever only one
instance of an object?
thnx,
Christoph
you can't return from a constructor; thus always use the static
singleton method()
i.e.: $two = singleTon::singleton();
--
nathan ( nathan@xxxxxxxxxxx )
{
Senior Web Developer
php + java + flex + xmpp + xml + ecmascript
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