简单工厂模式（Simple Factory）

2018

2018

1.7.1. 目的

简单工厂模式是一个精简版的工厂模式。

它与静态工厂模式最大的区别是它不是『静态』的。因为非静态，所以你可以拥有多个不同参数的工厂，你可以为其创建子类。甚至可以模拟（Mock）他，这对编写可测试的代码来讲至关重要。这也是它比静态工厂模式受欢迎的原因！

1.7.2. UML 图

1.7.3. 代码

你可以在 GitHub 查看这段代码。

SimpleFactory.php


<?php

namespace DesignPatterns\Creational\SimpleFactory;

class SimpleFactory
{
    public function createBicycle(): Bicycle
    {
        return new Bicycle();
    }
}

Bicycle.php


<?php

namespace DesignPatterns\Creational\SimpleFactory;

class Bicycle
{
    public function driveTo(string $destination)
    {
        return $destination;
    }
}

1.7.4. 用法


 $factory = new SimpleFactory();
 $bicycle = $factory->createBicycle();
 $bicycle->driveTo('Paris');

1.7.5. 测试

Tests/SimpleFactoryTest.php


<?php

namespace DesignPatterns\Creational\SimpleFactory\Tests;

use DesignPatterns\Creational\SimpleFactory\Bicycle;
use DesignPatterns\Creational\SimpleFactory\SimpleFactory;
use PHPUnit\Framework\TestCase;

class SimpleFactoryTest extends TestCase
{
    public function testCanCreateBicycle()
    {
        $bicycle = (new SimpleFactory())->createBicycle();
        $this->assertInstanceOf(Bicycle::class, $bicycle);
    }
}