PHP 常用设计模式

<?php
namespace DesignPatterns\More\Delegation;

// 初始化 TeamLead 并委托辅助者 JuniorDeveloper
$teamLead = new TeamLead(new JuniorDeveloper());

// TeamLead 将编写代码的任务委托给 JuniorDeveloper
echo $teamLead->writeCode();

<?php
namespace DesignPatterns\More\Delegation;

/**
 * TeamLead类
 * @package DesignPatterns\Delegation
 * `TeamLead` 类将工作委托给 `JuniorDeveloper`
 */
class TeamLead
{
    /** @var JuniorDeveloper */
    protected $slave;

    /**
     * 在构造函数中注入初级开发者JuniorDeveloper
     * @param JuniorDeveloper $junior
     */
    public function __construct(JuniorDeveloper $junior)
    {
        $this->slave = $junior;
    }

    /**
     * TeamLead 喝咖啡, JuniorDeveloper 工作
     * @return mixed
     */
    public function writeCode()
    {
        return $this->slave->writeBadCode();
    }
}

<?php
namespace DesignPatterns\More\Delegation;

/**
 * JuniorDeveloper 类
 * @package DesignPatterns\Delegation
 */
class JuniorDeveloper
{
    public function writeBadCode()
    {
        return "Some junior developer generated code...";
    }
}

<?php
namespace DesignPatterns\More\Delegation\Tests;

use DesignPatterns\More\Delegation;

/**
 * DelegationTest 用于测试委托模式
 */
class DelegationTest extends \PHPUnit_Framework_TestCase
{
    public function testHowTeamLeadWriteCode()
    {
        $junior = new Delegation\JuniorDeveloper();
        $teamLead = new Delegation\TeamLead($junior);
        $this->assertEquals($junior->writeBadCode(), $teamLead->writeCode());
    }
}

<?php
namespace DesignPatterns\More\Repository;

/**
 * Post 类
 * @package DesignPatterns\Repository
 */
class Post
{
    /**
     * @var int
     */
    private $id;

    /**
     * @var string
     */
    private $title;

    /**
     * @var string
     */
    private $text;

    /**
     * @var string
     */
    private $author;

    /**
     * @var \DateTime
     */
    private $created;

    /**
     * @param int $id
     */
    public function setId($id)
    {
        $this->id = $id;
    }

    /**
     * @return int
     */
    public function getId()
    {
        return $this->id;
    }

    /**
     * @param string $author
     */
    public function setAuthor($author)
    {
        $this->author = $author;
    }

    /**
     * @return string
     */
    public function getAuthor()
    {
        return $this->author;
    }

    /**
     * @param \DateTime $created
     */
    public function setCreated($created)
    {
        $this->created = $created;
    }

    /**
     * @return \DateTime
     */
    public function getCreated()
    {
        return $this->created;
    }

    /**
     * @param string $text
     */
    public function setText($text)
    {
        $this->text = $text;
    }

    /**
     * @return string
     */
    public function getText()
    {
        return $this->text;
    }

    /**
     * @param string $title
     */
    public function setTitle($title)
    {
        $this->title = $title;
    }

    /**
     * @return string
     */
    public function getTitle()
    {
        return $this->title;
    }
}

<?php
namespace DesignPatterns\More\Repository;

use DesignPatterns\More\Repository\Storage;

/**
 * Post 对应的 Repository
 * 该类介于数据实体层(Post) 和访问对象层(Storage)之间
 *
 * Repository 封装了持久化对象到数据存储器以及在展示层显示面向对象的视图操作
 *
 * Repository 还实现了领域层和数据映射层的分离和单向依赖
 *
 * PostRepository 类
 * @package DesignPatterns\Repository
 */
class PostRepository
{
    private $persistence;

    public function __construct(Storage $persistence)
    {
        $this->persistence = $persistence;
    }

    /**
     * 通过指定id返回Post对象
     *
     * @param int $id
     * @return Post|null
     */
    public function getById($id)
    {
        $arrayData = $this->persistence->retrieve($id);
        if (is_null($arrayData)) {
            return null;
        }

        $post = new Post();
        $post->setId($arrayData['id']);
        $post->setAuthor($arrayData['author']);
        $post->setCreated($arrayData['created']);
        $post->setText($arrayData['text']);
        $post->setTitle($arrayData['title']);

        return $post;
    }

    /**
     * 保存指定对象并返回
     *
     * @param Post $post
     * @return Post
     */
    public function save(Post $post)
    {
        $id = $this->persistence->persist(array(
            'author' => $post->getAuthor(),
            'created' => $post->getCreated(),
            'text' => $post->getText(),
            'title' => $post->getTitle()
        ));

        $post->setId($id);
        return $post;
    }

    /**
     * 删除指定的 Post 对象
     *
     * @param Post $post
     * @return bool
     */
    public function delete(Post $post)
    {
        return $this->persistence->delete($post->getId());
    }
}

<?php
namespace DesignPatterns\More\Repository;

/**
 * Storage接口
 *
 * 该接口定义了访问数据存储器的方法
 * 具体的实现可以是多样化的，比如内存、关系型数据库、NoSQL数据库等等
 *
 * @package DesignPatterns\Repository
 */
interface Storage
{
    /**
     * 持久化数据方法
     * 返回新创建的对象ID
     *
     * @param array() $data
     * @return int
     */
    public function persist($data);

    /**
     * 通过指定id返回数据
     * 如果为空返回null
     *
     * @param int $id
     * @return array|null
     */
    public function retrieve($id);

    /**
     * 通过指定id删除数据
     * 如果数据不存在返回false，否则如果删除成功返回true
     *
     * @param int $id
     * @return bool
     */
    public function delete($id);
}

<?php
namespace DesignPatterns\More\Repository;

use DesignPatterns\More\Repository\Storage;

/**
 * MemoryStorage类
 * @package DesignPatterns\Repository
 */
class MemoryStorage implements Storage
{

    private $data;
    private $lastId;

    public function __construct()
    {
        $this->data = array();
        $this->lastId = 0;
    }

    /**
     * {@inheritdoc}
     */
    public function persist($data)
    {
        $this->data[++$this->lastId] = $data;
        return $this->lastId;
    }

    /**
     * {@inheritdoc}
     */
    public function retrieve($id)
    {
        return isset($this->data[$id]) ? $this->data[$id] : null;
    }

    /**
     * {@inheritdoc}
     */
    public function delete($id)
    {
        if (!isset($this->data[$id])) {
            return false;
        }

        $this->data[$id] = null;
        unset($this->data[$id]);

        return true;
    }
}

<?php 
namespace DesignPatterns\More\EAV;

use SplObjectStorage;

class Entity
{
    /**
     * @var SplObjectStorage<Value,Value>
     */
    private $values;

    /**
     * @var string
     */
    private $name;

    /**
     * @param string $name
     * @param Value[] $values
     */
    public function __construct(string $name, $values)
    {
        /** @var SplObjectStorage<Value,Value> values */
        $this->values = new SplObjectStorage();
        $this->name = $name;

        foreach ($values as $value) {
            $this->values->attach($value);
        }
    }

    public function __toString(): string
    {
        $text = [$this->name];

        foreach ($this->values as $value) {
            $text[] = (string) $value;
        }

        return join(', ', $text);
    }
}

<?php 
namespace DesignPatterns\More\EAV;

use SplObjectStorage;

class Attribute
{
    /**
     * @var SplObjectStorage
     */
    private $values;

    /**
     * @var string
     */
    private $name;

    public function __construct(string $name)
    {
        $this->values = new SplObjectStorage();
        $this->name = $name;
    }

    public function addValue(Value $value)
    {
        $this->values->attach($value);
    }

    public function getValues(): SplObjectStorage
    {
        return $this->values;
    }

    public function __toString(): string
    {
        return $this->name;
    }
}

<?php
namespace DesignPatterns\More\EAV;

class Value
{
    /**
     * @var Attribute
     */
    private $attribute;

    /**
     * @var string
     */
    private $name;

    public function __construct(Attribute $attribute, string $name)
    {
        $this->name = $name;
        $this->attribute = $attribute;

        $attribute->addValue($this);
    }

    public function __toString(): string
    {
        return sprintf('%s: %s', (string) $this->attribute, $this->name);
    }
}

<?php
namespace DesignPatterns\More\EAV\Tests;

use DesignPatterns\More\EAV\Attribute;
use DesignPatterns\More\EAV\Entity;
use DesignPatterns\More\EAV\Value;
use PHPUnit\Framework\TestCase;

class EAVTest extends TestCase
{
    public function testCanAddAttributeToEntity()
    {
        $colorAttribute = new Attribute('color');
        $colorSilver = new Value($colorAttribute, 'silver');
        $colorBlack = new Value($colorAttribute, 'black');

        $memoryAttribute = new Attribute('memory');
        $memory8Gb = new Value($memoryAttribute, '8GB');

        $entity = new Entity('MacBook Pro', [$colorSilver, $colorBlack, $memory8Gb]);

        $this->assertEquals('MacBook Pro, color: silver, color: black, memory: 8GB', (string) $entity);
    }
}

<?php
namespace DesignPatterns\More\ServiceLocator;

interface ServiceLocatorInterface
{
    /**
     * Checks if a service is registered.
     *
     * @param string $interface
     *
     * @return bool
     */
    public function has($interface);

    /**
     * Gets the service registered for the interface.
     *
     * @param string $interface
     *
     * @return mixed
     */
    public function get($interface);
}

<?php
namespace DesignPatterns\More\ServiceLocator;

class ServiceLocator implements ServiceLocatorInterface
{
    /**
     * All services.
     *
     * @var array
     */
    private $services;

    /**
     * The services which have an instance.
     *
     * @var array
     */
    private $instantiated;

    /**
     * True if a service can be shared.
     *
     * @var array
     */
    private $shared;

    public function __construct()
    {
        $this->services     = array();
        $this->instantiated = array();
        $this->shared       = array();
    }

    /**
     * Registers a service with specific interface.
     *
     * @param string $interface
     * @param string|object $service
     * @param bool $share
     */
    public function add($interface, $service, $share = true)
    {
        /**
         * When you add a service, you should register it
         * with its interface or with a string that you can use
         * in the future even if you will change the service implementation.
         */

        if (is_object($service) && $share) {
            $this->instantiated[$interface] = $service;
        }
        $this->services[$interface] = (is_object($service) ? get_class($service) : $service);
        $this->shared[$interface]   = $share;
    }

    /**
     * Checks if a service is registered.
     *
     * @param string $interface
     *
     * @return bool
     */
    public function has($interface)
    {
        return (isset($this->services[$interface]) || isset($this->instantiated[$interface]));
    }

    /**
     * Gets the service registered for the interface.
     *
     * @param string $interface
     *
     * @return mixed
     */
    public function get($interface)
    {
        // Retrieves the instance if it exists and it is shared
        if (isset($this->instantiated[$interface]) && $this->shared[$interface]) {
            return $this->instantiated[$interface];
        }

        // otherwise gets the service registered.
        $service = $this->services[$interface];

        // You should check if the service class exists and
        // the class is instantiable.

        // This example is a simple implementation, but
        // when you create a service, you can decide
        // if $service is a factory or a class.
        // By registering a factory you can create your services
        // using the DependencyInjection pattern.

        // ...

        // Creates the service object
        $object = new $service();

        // and saves it if the service must be shared.
        if ($this->shared[$interface]) {
            $this->instantiated[$interface] = $object;
        }
        return $object;
    }
}

<?php
namespace DesignPatterns\More\ServiceLocator;

interface LogServiceInterface
{
}

<?php
namespace DesignPatterns\More\ServiceLocator;

class LogService implements LogServiceInterface
{
}

<?php
namespace DesignPatterns\More\ServiceLocator;

interface DatabaseServiceInterface
{
}

<?php
namespace DesignPatterns\More\ServiceLocator;

class DatabaseService implements DatabaseServiceInterface
{
}

<?php
namespace DesignPatterns\More\ServiceLocator\Tests;

use DesignPatterns\More\ServiceLocator\DatabaseService;
use DesignPatterns\More\ServiceLocator\LogService;
use DesignPatterns\More\ServiceLocator\ServiceLocator;
use \PHPUnit_Framework_TestCase as TestCase;

class ServiceLocatorTest extends TestCase
{
    /**
     * @var LogService
     */
    private $logService;

    /**
     * @var DatabaseService
     */
    private $databaseService;

    /**
     * @var ServiceLocator
     */
    private $serviceLocator;

    public function setUp()
    {
        $this->serviceLocator  = new ServiceLocator();
        $this->logService      = new LogService();
        $this->databaseService = new DatabaseService();
    }

    public function testHasServices()
    {
        $this->serviceLocator->add(
            'DesignPatterns\More\ServiceLocator\LogServiceInterface',
            $this->logService
        );

        $this->serviceLocator->add(
            'DesignPatterns\More\ServiceLocator\DatabaseServiceInterface',
            $this->databaseService
        );

        $this->assertTrue($this->serviceLocator->has('DesignPatterns\More\ServiceLocator\LogServiceInterface'));
        $this->assertTrue($this->serviceLocator->has('DesignPatterns\More\ServiceLocator\DatabaseServiceInterface'));

        $this->assertFalse($this->serviceLocator->has('DesignPatterns\More\ServiceLocator\FakeServiceInterface'));
    }

    public function testServicesWithObject()
    {
        $this->serviceLocator->add(
            'DesignPatterns\More\ServiceLocator\LogServiceInterface',
            $this->logService
        );

        $this->serviceLocator->add(
            'DesignPatterns\More\ServiceLocator\DatabaseServiceInterface',
            $this->databaseService
        );

        $this->assertSame(
            $this->logService,
            $this->serviceLocator->get('DesignPatterns\More\ServiceLocator\LogServiceInterface')
        );

        $this->assertSame(
            $this->databaseService,
            $this->serviceLocator->get('DesignPatterns\More\ServiceLocator\DatabaseServiceInterface')
        );
    }

    public function testServicesWithClass()
    {
        $this->serviceLocator->add(
            'DesignPatterns\More\ServiceLocator\LogServiceInterface',
            get_class($this->logService)
        );

        $this->serviceLocator->add(
            'DesignPatterns\More\ServiceLocator\DatabaseServiceInterface',
            get_class($this->databaseService)
        );

        $this->assertNotSame(
            $this->logService,
            $this->serviceLocator->get('DesignPatterns\More\ServiceLocator\LogServiceInterface')
        );

        $this->assertInstanceOf(
            'DesignPatterns\More\ServiceLocator\LogServiceInterface',
            $this->serviceLocator->get('DesignPatterns\More\ServiceLocator\LogServiceInterface')
        );

        $this->assertNotSame(
            $this->databaseService,
            $this->serviceLocator->get('DesignPatterns\More\ServiceLocator\DatabaseServiceInterface')
        );

        $this->assertInstanceOf(
            'DesignPatterns\More\ServiceLocator\DatabaseServiceInterface',
            $this->serviceLocator->get('DesignPatterns\More\ServiceLocator\DatabaseServiceInterface')
        );
    }

    public function testServicesNotShared()
    {
        $this->serviceLocator->add(
            'DesignPatterns\More\ServiceLocator\LogServiceInterface',
            $this->logService,
            false
        );

        $this->serviceLocator->add(
            'DesignPatterns\More\ServiceLocator\DatabaseServiceInterface',
            $this->databaseService,
            false
        );

        $this->assertNotSame(
            $this->logService,
            $this->serviceLocator->get('DesignPatterns\More\ServiceLocator\LogServiceInterface')
        );

        $this->assertInstanceOf(
            'DesignPatterns\More\ServiceLocator\LogServiceInterface',
            $this->serviceLocator->get('DesignPatterns\More\ServiceLocator\LogServiceInterface')
        );

        $this->assertNotSame(
            $this->databaseService,
            $this->serviceLocator->get('DesignPatterns\More\ServiceLocator\DatabaseServiceInterface')
        );

        $this->assertInstanceOf(
            'DesignPatterns\More\ServiceLocator\DatabaseServiceInterface',
            $this->serviceLocator->get('DesignPatterns\More\ServiceLocator\DatabaseServiceInterface')
        );
    }
}