On Mon, Feb 9, 2009 at 8:46 AM, Andrew Williams
<andrew4williams@xxxxxxxxx>wrote:
> Hi,
>
> I am working on a back end OOP project with about about 18 classes of
> Object
> but some of the Objects shear one or two functions in common, like external
> login system . What is the best way to avoid a repeatable function among
> the
> classes without using global object instance.
>
> class a{
>
> function ExtractRawData()
> {
> global loginObj;
> *if($loginObj;->GetLoginSession(){*
> ///process
> }
> }
>
> }
>
> class b{
>
> function JohnXchange()
> {
> global loginObj;
> *if($loginObj;->GetLoginSession(){*
> ///process
> }
> }
> }
>
> class login(
>
> function loginSession($pwd, $acc, $customerAcc)
> {
> $this ->validate = connect to externalServerObject($pwd, $acc,
> $customerAcc);
> }
> *GetLoginSession()*
> {
> return $this ->validate;
> }
> }
just make your login class into a singleton.
class login {
private static $instance = null;
private function __construct() {} // restrict access to constructor
public static function getInstance() {
if(is_null(self::$instance)
self::$instance = new login();
return self::$instance;
}
// ....
}
then from your other classes, you just call the login::getInstance() method
to get a handle to the 'global' or single instance of the login class. from
there you can invoke public instance methods like GetLoginSession().
class a {
function ExtractRawData() {
if(login::getInstance()->GetLoginSession()) {
// process
}
}
class b {
function JohnXchange() {
if(login::getInstance()->getLoginSession()) {
// process
}
}
}
you can read about the singleton pattern in many places on the web and there
are lots of written books about design patterns which you might find useful.
-nathan
