i think that Observer pattern is always implemented as "static" to be called from any scope, for example:
<?php
class Observer {
//attach here the caller's scope
private static $stackTrace = array( );
public static function wasTriggeredOnce() {
//...if is not in the stack, then:
self::$stackTrace[] = max( debug_backtrace( ) );
}
}
class YourFramework {
public function launchPlatform() {
//could not let user to launch application twice!
Observer::wasTriggeredOnce();
}
}
//cause is static
Observer::hereIsnoNeedToInstantiateAgain();
?>
SplSubject::attach
(PHP 5 >= 5.1.0, PHP 7, PHP 8)
SplSubject::attach — Attache un SplObserver
Description
Attache un SplObserver. Il sera ainsi notifier des mises à jour.
Avertissement
Cette fonction est actuellement non documentée ; seule la liste des arguments est disponible.
Valeurs de retour
Aucune valeur n'est retournée.
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User Contributed Notes 2 notes
workspace dot development at yahoo dot com ¶
12 years ago
goran ¶
13 years ago
The most obvious storage type for observers (stored in attach()) is array. In order to be able to detach attached objects, you should be able to identify it inside observer storage.
I suggest you attach observers this way:
$this->_observers[spl_object_hash($observer)] = $observer;
so you can detach it later if you need:
unset($this->_observers[spl_object_hash($observer)]);
