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PHP属性注入实战：构建声明式编程框架的核心技术

资深开发工程师 php

2025-07-31 0 443

PHP属性注入实战：构建声明式编程框架的核心技术

一、技术优势

属性注入使业务代码减少70%，可读性提升300%

#[Model(table: 'users')]
class User {
    #[Column(type: 'string', length: 32)]
    public string $name;
    
    #[Validate(type: 'int', min: 18)]
    public int $age;
}

二、基础实现

1. 自定义属性类

#[Attribute(Attribute::TARGET_PROPERTY)]
class Column {
    public function __construct(
        public string $type,
        public ?int $length = null
    ) {}
}

#[Attribute(Attribute::TARGET_CLASS)]
class Model {
    public function __construct(public string $table) {}
}

2. 属性解析器

class AttributeParser {
    public static function parseClass(string $className): array {
        $reflection = new ReflectionClass($className);
        $attributes = [];
        
        // 解析类属性
        if ($attrs = $reflection->getAttributes(Model::class)) {
            $attributes['model'] = $attrs[0]->newInstance();
        }
        
        // 解析属性注解
        foreach ($reflection->getProperties() as $property) {
            if ($attrs = $property->getAttributes(Column::class)) {
                $attributes['columns'][$property->getName()] = $attrs[0]->newInstance();
            }
        }
        
        return $attributes;
    }
}

三、高级应用

1. 声明式ORM实现

class EntityManager {
    public function createTable(string $entityClass): void {
        $meta = AttributeParser::parseClass($entityClass);
        $columns = array_map(fn($col) => 
            "{$col->name} {$col->type}".($col->length ? "({$col->length})" : ''),
            $meta['columns']
        );
        
        $sql = "CREATE TABLE {$meta['model']->table} (".implode(',', $columns).")";
        DB::execute($sql);
    }
}

2. 自动验证器

class Validator {
    public function validate(object $entity): bool {
        $reflection = new ReflectionObject($entity);
        foreach ($reflection->getProperties() as $property) {
            if ($attrs = $property->getAttributes(Validate::class)) {
                $rule = $attrs[0]->newInstance();
                $value = $property->getValue($entity);
                
                if ($rule->type === 'int' && !is_int($value)) {
                    throw new ValidationError("{$property->name}必须是整数");
                }
                // 其他验证规则...
            }
        }
        return true;
    }
}

四、完整案例

声明式API控制器

#[Route(prefix: '/api/v1')]
class UserController {
    #[GET(path: '/users/{id}')]
    public function get(int $id): Response {
        $user = User::find($id);
        return new JsonResponse($user);
    }
    
    #[POST(path: '/users')]
    #[Middleware(AuthMiddleware::class)]
    public function create(#[FromBody] User $user): Response {
        if ((new Validator())->validate($user)) {
            $user->save();
            return new JsonResponse($user, 201);
        }
    }
}

// 自动路由注册
$routes = AttributeParser::parseControllers();
Router::registerRoutes($routes);

function runDemo() {
alert(‘需要PHP8.0+环境运行示例代码，使用Reflection API解析属性’);
}