1.1. 抽象工厂

1.1.1. 目的

创建一系列互相关联或依赖的对象时，不指定他们具体的类。因为这些创建的类通常都实现了同一个接口。抽象工厂的客户端并不关心对象是如何创建的，而只知道它们是怎样组合的。

1.1.2. UML 图

Alt AbstractFactory UML Diagram

1.1.3. 代码

在 GitHub 上查看代码

WriterFactory.php

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<?php

namespace DesignPatterns\Creational\AbstractFactory;

interface WriterFactory
{
    public function createCsvWriter(): CsvWriter;
    public function createJsonWriter(): JsonWriter;
}

CsvWriter.php

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<?php

namespace DesignPatterns\Creational\AbstractFactory;

interface CsvWriter
{
    public function write(array $line): string;
}

JsonWriter.php

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<?php

namespace DesignPatterns\Creational\AbstractFactory;

interface JsonWriter
{
    public function write(array $data, bool $formatted): string;
}

UnixCsvWriter.php

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<?php

namespace DesignPatterns\Creational\AbstractFactory;

class UnixCsvWriter implements CsvWriter
{
    public function write(array $line): string
    {
        return join(',', $line) . "\n";
    }
}

UnixJsonWriter.php

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<?php

namespace DesignPatterns\Creational\AbstractFactory;

class UnixJsonWriter implements JsonWriter
{
    public function write(array $data, bool $formatted): string
    {
        $options = 0;

        if ($formatted) {
            $options = JSON_PRETTY_PRINT;
        }

        return json_encode($data, $options);
    }
}

UnixWriterFactory.php

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<?php

namespace DesignPatterns\Creational\AbstractFactory;

class UnixWriterFactory implements WriterFactory
{
    public function createCsvWriter(): CsvWriter
    {
        return new UnixCsvWriter();
    }

    public function createJsonWriter(): JsonWriter
    {
        return new UnixJsonWriter();
    }
}

WinCsvWriter.php

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<?php

namespace DesignPatterns\Creational\AbstractFactory;

class WinCsvWriter implements CsvWriter
{
    public function write(array $line): string
    {
        return join(',', $line) . "\r\n";
    }
}

WinJsonWriter.php

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<?php

namespace DesignPatterns\Creational\AbstractFactory;

class WinJsonWriter implements JsonWriter
{
    public function write(array $data, bool $formatted): string
    {
        $options = 0;

        if ($formatted) {
            $options = JSON_PRETTY_PRINT;
        }

        return json_encode($data, $options);
    }
}

WinWriterFactory.php

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<?php

namespace DesignPatterns\Creational\AbstractFactory;

class WinWriterFactory implements WriterFactory
{
    public function createCsvWriter(): CsvWriter
    {
        return new WinCsvWriter();
    }

    public function createJsonWriter(): JsonWriter
    {
        return new WinJsonWriter();
    }
}

1.1.4. 测试

Tests/AbstractFactoryTest.php

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<?php

declare(strict_types=1);

namespace DesignPatterns\Creational\AbstractFactory\Tests;

use DesignPatterns\Creational\AbstractFactory\CsvWriter;
use DesignPatterns\Creational\AbstractFactory\JsonWriter;
use DesignPatterns\Creational\AbstractFactory\UnixWriterFactory;
use DesignPatterns\Creational\AbstractFactory\WinWriterFactory;
use DesignPatterns\Creational\AbstractFactory\WriterFactory;
use PHPUnit\Framework\TestCase;

class AbstractFactoryTest extends TestCase
{
    public function provideFactory()
    {
        return [
            [new UnixWriterFactory()],
            [new WinWriterFactory()]
        ];
    }

    /**
     * @dataProvider provideFactory
     */
    public function testCanCreateCsvWriterOnUnix(WriterFactory $writerFactory)
    {
        $this->assertInstanceOf(JsonWriter::class, $writerFactory->createJsonWriter());
        $this->assertInstanceOf(CsvWriter::class, $writerFactory->createCsvWriter());
    }
}