GoF 23
SOLID in GoF 23
※範囲とはClass式かObject式か
Class式：コンパイル時に静的な関連を決める（親クラスと子クラスの関係）
Object式：ラインタイム時に動的な関連を決める
对象创建型
1.原型模式；2.工厂模式；3.抽象工厂模式；4.单例模式；5.生成器
接口适配型
1.适配器模式；2.桥接模式；3.外观模式
对象去耦型
1.中介者模式；2.观察者模式
抽象集合型
1.组合模式；2.迭代器模式
行为扩展型
1.访问者模式；2.装饰器模式；3.责任链模式
算法封装型
1.模版方法模式；2.策略模式；3.命令模式
性能与对象访问型
1.享元模式；2.代理模式
对象状态型
1.备忘录模式
Iterator Pattern
PHP版
Iteratorの場合
interface IConfiguration {
function get($key);
}
abstract class Configuration implements IConfiguration, Iterator {
private $_items = array();
public function __construct() {
$this->load();
}
abstract protected function load();
protected function add($key, $value) {
$this->_items[$key] = $value;
}
public function get($key) {
return $this->_items[$key];
}
public function rewind() { reset($this->_items); }
public function current() { return current($this->_items); }
public function key() { return key($this->_items); }
public function next() { return next($this->_items); }
public function valid() { return ( $this->current() !== false ); }
}
class DBConfiguration extends Configuration {
function load() {
$this->add('myKey', 'xxx');
}
}
$c = new DBConfiguration();
echo( $c->get('myKey')."\n" );
foreach( $c as $k => $v ) {
echo( $k . " = " . $v . "\n" );
}
ArrayIteratorの場合
class Person
{
private $_name;
private $_age;
public function __construct($name, $age)
{
$this->_name = $name;
$this->_age = $age;
}
public function getAge()
{
return $this->_age;
}
}
class People implements IteratorAggregate
{
private $_people;
public function __construct()
{
$this->_people = new ArrayObject();
}
public function add(Person $person)
{
$this->_people[] = $person;
}
// Override
public function getIterator()
{
return $this->_people->getIterator();
// または
return new ArrayIterator($this->_people);
// FilterIteratorの場合
// return new AgeFilterIterator($this->_people->getIterator());
}
}
FilterIteratorの場合
class AgeFilterIterator extends FilterIterator
{
public function __construct($iterator)
{
parent::__construct($iterator);
}
// Override
public function accept()
{
$person = $this->current();
return ($person->getAge() < 20) ? true : false;
}
}
$people = new People();
$people->add(new Person('Andy', 18));
$people->add(new Person('Tom', 70));
$iterator = $people->getIterator();
foreach ($iterator as $person) {...}
// 参照位置を初期化（先頭に戻す）
$iterator->rewind();
while($iterator->valid()) {
$person = $iterator->current();
echo $person->getAge() . '\n';
$iterator->next();
}
Singleton Pattern
PHP版
class Configuration {
private $_items = array();
private static $_instance;
private function __construct() {
$this->_items['myKey'] = 'xxx';
}
private final function __clone() {}
public static function getInstance() {
if ( !isset(self::$_instance) ) {
self::$_instance = new Configuration(); // new self();
}
return self::$_instance;
}
public static function reset() {
self::$_instance = null;
}
}
$c = Configuration::getInstance();
echo( $c->{'myKey'}."\n" );
C#版(Generics)
public static class Singleton<T> where T : new()
{
private readonly static T instance = new T();
public static T Instance
{
get
{
return instance;
}
}
}
Python版
方式１
class Singleton(object):
def __new__(cls, *args, **kw):
if not hasattr(cls, '_instance'):
orig = super(Singleton, cls)
cls._instance = orig.__new__(cls, *args, **kw)
return cls._instance
class MyClass(Singleton): ...
方式２
class Singleton(object):
_state = {}
def __new__(cls, *args, **kw):
ob = super(Singleton, cls).__new__(cls, *args, **kw)
ob.__dict__ = cls._state
return ob
class MyClass(Singleton): ...
方式３
def singleton(cls, *args, **kw):
instances = {}
def getinstance():
if cls not in instances:
instances[cls] = cls(*args, **kw)
return instances[cls]
return getinstance
@singleton
class MyClass: ...
方式４
# mysingleton.py
class My_Singleton(object):
def foo(self):
pass
my_singleton = My_Singleton()
利用例
from mysingleton import my_singleton
my_singleton.foo()
Command Pattern
PHP版
interface ICommand
{
function onCommand($name, $args);
}
class CommandChain
{
private $_commands = array();
public function addCommand($cmd)
{
$this->_commands[] = $cmd;
}
public function runCommand($name, $args)
{
foreach($this->_commands as $cmd)
{
if ($cmd->onCommand($name, $args)) return;
}
}
}
class UserCommand implements ICommand
{
public function onCommand($name, $args)
{
if ($name != 'addUser') return false;
...
return true;
}
}
class MailCommand implements ICommand
{
public function onCommand($name, $args)
{
if ($name != 'sendMail') return false;
...
return true;
}
}
$cc = new CommandChain();
$cc->addCommand(new UserCommand());
$cc->addCommand(new MailCommand());
$cc->runCommand('addUser', null);
$cc->runCommand('sendMail', null);