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();
?>