This article introduces the content of PHP design pattern 2: factory mode, singleton mode, and registration tree mode. Now I share it with you. Friends in need can refer to it.
1. Factory Pattern: Generate objects in factory methods or classes instead of directly new in the code
Advantages: When a common class needs new in multiple places, use the factory pattern to facilitate the expansion and maintenance of the class
File directory: Frame/Factory.php
<?php namespace Frame; use Frame\Database; use Frame\Register; class Factory { static function createDatabase() { //$db = new Database(); //正常实例化类 $db = Database::getInstance(); //获取单例模式的类 Register::set('db',$db); //将实例化后的类注册到全局注册树中 return $db; } } //外部调用得到$db对象 $db = Frame\Factory::createDatabase(); //获取全局注册树中的对象 $db = Frame\Register::get('db'); //卸载全局注册树中的对象 $db = Frame\Register::_unset('db'); ?>
2. Singleton mode: Only new instantiation objects are allowed in the class itself
Advantages: The class cannot be new externally, and The object is created once in the class itself, saving resource overhead
File directory: Frame/Database.php
<?php namespace Frame; class Database { protected $db; //单例模式,私有化__construct()方法,不允许外部实例化对象 private function __construct() { } //实例化本类 static function getInstance() { if(self::$db) { return self::$db; } else { self::$db = new self(); return self::$db; } } } //外部调用 $db = Frame\Database::getInstance(); ?>
3. Registration tree mode: Register an object into the global registration tree for convenience Global use
Storage directory: Frame/Register.php
<?php namespace Frame; class Register { protected $objects; /* * 将实例化后的类注册到全局注册树中 * $alias :对象别名 * $object:实例化后的对象 */ static function set($alias,$object) { self::$objects[$alias] = $object; } /* * 卸载实例化后的类 * $alias :对象别名 */ static function _unset($alias) { unset(self::$objects[$alias]); } /* * 获取实例化后的类对象 * $alias : 对象别名 */ static function get($alias) { return self::$objects[$alias]; } } ?>
Related recommendations:
php design pattern one namespace, automatic loading class, PSR-0 Coding Standards
The above is the detailed content of PHP design pattern 2: factory mode, singleton mode, registration tree mode. For more information, please follow other related articles on the PHP Chinese website!