php8.4-属性钩子 #848

guanhui07 · 2024-11-24T08:16:10Z

属性钩子

属性钩子提供对计算属性的支持，这些属性可以被 IDE 和静态分析工具直接理解，而无需编写可能会失效的 docblock 注释。此外，它们允许可靠地预处理或后处理值，而无需检查类中是否存在匹配的 getter 或 setter。

PHP < 8.4

class Locale
{
    private string $languageCode;
    private string $countryCode;

    public function __construct(string $languageCode, string $countryCode)
    {
        $this->setLanguageCode($languageCode);
        $this->setCountryCode($countryCode);
    }

    public function getLanguageCode(): string
    {
        return $this->languageCode;
    }

    public function setLanguageCode(string $languageCode): void
    {
        $this->languageCode = $languageCode;
    }

    public function getCountryCode(): string
    {
        return $this->countryCode;
    }

    public function setCountryCode(string $countryCode): void
    {
        $this->countryCode = strtoupper($countryCode);
    }

    public function setCombinedCode(string $combinedCode): void
    {
        [$languageCode, $countryCode] = explode('_', $combinedCode, 2);

        $this->setLanguageCode($languageCode);
        $this->setCountryCode($countryCode);
    }

    public function getCombinedCode(): string
    {
        return \sprintf("%s_%s", $this->languageCode, $this->countryCode);
    }
}

$brazilianPortuguese = new Locale('pt', 'br');
var_dump($brazilianPortuguese->getCountryCode()); // BR
var_dump($brazilianPortuguese->getCombinedCode()); // pt_BR

php8.4

class Locale
{
    public string $languageCode;

    public string $countryCode
    {
        set (string $countryCode) {
            $this->countryCode = strtoupper($countryCode);
        }
    }

    public string $combinedCode
    {
        get => \sprintf("%s_%s", $this->languageCode, $this->countryCode);
        set (string $value) {
            [$this->countryCode, $this->languageCode] = explode('_', $value, 2);
        }
    }

    public function __construct(string $languageCode, string $countryCode)
    {
        $this->languageCode = $languageCode;
        $this->countryCode = $countryCode;
    }
}

$brazilianPortuguese = new Locale('pt', 'br');
var_dump($brazilianPortuguese->countryCode); // BR
var_dump($brazilianPortuguese->combinedCode); // pt_BR

class BookViewModel
{
    public function __construct(
        private array $authors,
    ) {}

    public string $credits {
        get {
            return implode(', ', array_map(
                fn (Author $author) => $author->name, 
                $this->authors,
            ));
        }
    }
    
    public Author $mainAuthor {
        set (Author $mainAuthor) {
            $this->authors[] = $mainAuthor;
            $this->mainAuthor = $mainAuthor;
        }
        
        get => $this->mainAuthor;
    }
}