README

完全测试，符合phpstan级别9。

安装

composer require zrnik/php-attribtue-reflection

用法及该库存在的理由。

我经常在枚举实例上使用属性。这是一种在实例上放置元数据的好方法。让我们看看这个例子

<?php

namespace Zrnik\Example;

use ReflectionClass;
use RuntimeException;

enum CaseToSolve
{
    #[AttributeToFind('AnyParameter')]
    case FirstCase;

    #[AttributeToFind('DifferentParameter')]
    #[AnotherAttribute('WhateverIsHere')]
    case SecondCase;

    case ThirdCase;

    public function getParameter(): string
    {
        $reflection = new ReflectionClass(self::class);
        $caseReflection = $reflection->getReflectionConstant($this->name);

        if($caseReflection === false) {
            throw new RuntimeException('case not found');
        }

        foreach ($caseReflection->getAttributes() as $reflectionAttribute) {
            if ($reflectionAttribute->getName() === AttributeToFind::class) {
                /** @var AttributeToFind $attributeToFindInstance */
                $attributeToFindInstance = $reflectionAttribute->newInstance();
                return $attributeToFindInstance->customValue;
            }
        }

        throw new RuntimeException(
            sprintf(
                'attribute "%s" not found on "%s"!',
                AttributeToFind::class,
                $this->name
            )
        );
    }
}

你可能知道它打算做什么

CaseToSolve::FirstCase->getParameter(); // 'AnyParameter'
CaseToSolve::SecondCase->getParameter(); // 'DifferentParameter'
CaseToSolve::ThirdCase->getParameter(); // RuntimeException

这就是这个库的作用，它只返回属性值。现在让我们看看使用这个库的代码将如何工作

<?php

namespace Zrnik\Example;

use Zrnik\AttributeReflection\AttributeReflection;
use Zrnik\AttributeReflection\AttributeReflectionException;

enum SolvedCase
{
    #[AttributeToFind('AnyParameter')]
    case FirstCase;

    #[AttributeToFind('DifferentParameter')]
    #[AnotherAttribute('WhateverIsHere')]
    case SecondCase;

    case ThirdCase;

    /**
     * @return string
     * @throws AttributeReflectionException
     */
    public function getParameter(): string
    {
       return AttributeReflection::getClassConstantAttribute(
           AttributeToFind::class,
           self::class,
           $this->name
       )->customValue;
    }
}

getParameter方法要好得多，不是吗？工作方式相同

SolvedCase::FirstCase->getParameter(); // 'AnyParameter'
SolvedCase::SecondCase->getParameter(); // 'DifferentParameter'
SolvedCase::ThirdCase->getParameter(); // \Zrnik\AttributeReflection\AttributeReflectionException