SplSubject::attach

(PHP 5 >= 5.1.0, PHP 7, PHP 8)

SplSubject::attach — Attach an SplObserver

说明

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

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

警告

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。

add a note

User Contributed Notes 2 notes

down

workspace dot development at yahoo dot com ¶

10 years ago


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(); 
?>

down

goran ¶

10 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)]);

add a note

官方地址：https://www.php.net/manual/en/splsubject.attach.php

有任何技术问题请点击这里网站运营推广招聘

IT PHP 编程语言 Linux 开发编程科技 Elasticsearch HTML/CSS/XML 网络数据库 JAVA 面试 NoSQL C/C++ Golang Git 算法操作系统正则表达式 Redis 互联网 MySql JavaScript 运维软件国际架构设计 Mac OS TCP/IP Excel Vim Windows Socket Oracle VR MongoDB Python 运营 MemCache 商业硬件电子娱乐设计 nginx 摄影游戏 WordPress HTTP 团建数码电器

php7 安装fileinfo扩展 preg_split — 通过一个正则表达式分隔字符串 php位值,解决 PHP 中 usort 在值相同时改变原始位置的问题 [PHP] inet_pton/inet_ntop IP地址转换函数 PHP 8.1 [鸟哥]PHP_INT_MIN 和 -9223372036854775808 ADORecordSet对象 adodb手册 opcache预加载 Composer的Packagist资源 array_multisort() 多字段排序 PHPMailer设置utf8 PHPMailer字符集CharSet PHP json解析（json_decode）页面工具 mysql面试题 [原创]诡异的php-fpm超时问题 php中几种注释规范纯php实现DES以及TripleDES加密算法 php 修改图片大小支持php7的性能采集扩展 PHP mkdir()写出来的权限与mode值不符合

略微加速

PHP官方手册 - 互联网笔记

SplSubject::attach

说明

参数

返回值

User Contributed Notes 2 notes