README

这个库实现了规范模式，可用于任何项目。

通过将决策封装在遵循 SpecificationInterface 的类中，创建可组合的逻辑。

安装

$ composer require emarref/spec

用法

给定以下规范

<?php

use Emarref\Spec\SpecificationInterface;
use Emarref\Spec\LogicalSpecificationTrait;

class MorningSpecification implements SpecificationInterface
{
    use LogicalSpecificationTrait;

    public function isSatisfiedBy($subject): bool
    {
        if (!$subject instanceof \DateTimeInterface) {
            throw new \InvalidArgumentException('Subject must be a date time object.');
        }

        $hour = (int) $subject->format('G');

        return $hour < 12;
    }
}

class AfternoonSpecification implements SpecificationInterface
{
    use LogicalSpecificationTrait;

    public function isSatisfiedBy($subject): bool
    {
        if (!$subject instanceof \DateTimeInterface) {
            throw new \InvalidArgumentException('Subject must be a date time object.');
        }

        $hour = (int) $subject->format('G');

        return $hour > 12 && $hour < 18;
    }
}

class NightSpecification implements SpecificationInterface
{
    use LogicalSpecificationTrait;

    public function isSatisfiedBy($subject): bool
    {
        if (!$subject instanceof \DateTimeInterface) {
            throw new \InvalidArgumentException('Subject must be a date time object.');
        }

        $hour = (int) $subject->format('G');

        return $hour > 17;
    }
}

我们可以测试一个日期是否在上午

<?php

$morning = new \DateTime('8am');
$isMorning = new MorningSpecification();

$isMorning->isSatisfiedBy($morning); // true

或下午

<?php

$isAfternoon = new AfternoonSpecification();
$isAfternoon->isSatisfiedBy($morning); // false

我们可以将规范链在一起

<?php

$night = new \DateTime('11pm');

$isMorning->or($isAfternoon)->isSatisfiedBy($morning); // true
$isMorning->or($isAfternoon)->isSatisfiedBy($night); // false

链可以很深

<?php

$isMorning->or($isAfternoon->andNot($isNight))->isSatisfiedBy($morning); // true

业务逻辑可以通过自定义规范进行封装。创建一个实现 Emarref\Spec\SpecificationInterface 的类。使用 Emarref\Spec\LogicalSpecificationTrait 来实现大部分模板代码。

<?php

class StoreIsOpen implements SpecificationInterface
{
    use LogicalSpecificationTrait;

    public function isSatisfiedBy($subject): bool
    {
        if (!$subject instanceof \DateTimeInterface) {
            throw new \InvalidArgumentException('Subject must be a date time object.');
        }

        $isMorning = new MorningSpec();
        $isAfternoon = new AfternoonSpec();

        return $isMorning->or($isAfternoon)->isSatisfiedBy($subject);
    }
}

$storeIsOpen = new StoreIsOpen();
$storeIsOpen->isSatisfiedBy(new DateTime('10am')); // true
$storeIsOpen->isSatisfiedBy(new DateTime('11pm')); // false