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 — Adjuntar un SplObserver
Descripción
Adjunta un SplObserver de esta forma puede ser notificado cuando hayan actualizaciones.
Advertencia
Esta función no está documentada actualmente, solamente se encuentra disponible la lista de parámetros.
Valores devueltos
No devuelve ningún valor.
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User Contributed Notes 2 notes
workspace dot development at yahoo dot com ¶
13 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)]);
