SplSubject::attach

(PHP 5 >= 5.1.0)

SplSubject::attach — Attach an SplObserver

说明

abstract public void SplSubject::attach ( SplObserver $observer )

Attaches an SplObserver so that it can be notified of updates.

Warning

本函数还未编写文档，仅有参数列表。

参数

observer: The SplObserver to attach.

返回值

没有返回值。

PHP手册 - N: Attach an SplObserver

用户评论:

workspace dot development at yahoo dot com (02-Dec-2011 04:46)

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(); ?>

goran (17-Oct-2011 08:54)

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)]);