我如何在工厂解析器中使用相同的抽象接口注册2个依赖项？

Question

我有一个依赖容器，看起来像这样-

public protocol DependencyContainer {
  typealias FactoryClosure = (Self) -> AnyObject
  func register<Service>(type: Service.Type, closure: @escaping FactoryClosure)
  func resolve<Service>(type: Service.Type) -> Service
}

public final class CoreDependencyContainer: DependencyContainer {

  private var services: Dictionary<ObjectIdentifier, FactoryClosure> = [:]

  public func register<Service>(type: Service.Type, closure: @escaping FactoryClosure) {
    services[ObjectIdentifier(type)] = closure
  }

  public func resolve<Service>(type: Service.Type) -> Service {
    if let service = services[ObjectIdentifier(type)]?(self) as? Service {
      return service
    }
    preconditionFailure("Could not resolve service for \(type)")
  }

}

我注册了一些服务，如下所示：

dependencies.register(type: RemoteImageDataLoader.self, closure: { container in
  let httpClient = container.resolve(type: HTTPClient.self)
    return RemoteImageDataLoader(client: httpClient)
})

但是我想注册2个符合抽象类型RemoteImageDataLoader的服务。

dependencies.register(type: RemoteImageDataLoader.self, closure: { container in
  let httpClient = container.resolve(type: HTTPClient.self)
    return RemoteImageDataLoader(client: httpClient)
})

dependencies.register(type: RemoteImageDataLoader.self, closure: { container in
  let httpClient = container.resolve(type: AuthenticatedHTTPClient.self)
    return RemoteImageDataLoader(client: httpClient)
})

这显然不起作用，因为第二个条目将替换services词典中的第一个条目。

我试图创建一个typealias来代替使用，但是这不起作用。

dependencies.register(type: RemoteImageDataLoader.self, closure: { container in
  let httpClient = container.resolve(type: HTTPClient.self)
    return RemoteImageDataLoader(client: httpClient)
})

typealias AuthRemoteImageLoader = RemoteImageDataLoader

dependencies.register(type: AuthRemoteImageLoader.self, closure: { container in
  let httpClient = container.resolve(type: AuthenticatedHTTPClient.self)
    return RemoteImageDataLoader(client: httpClient)
})

在这种情况下如何注册第二个依赖项？

我想避免创建RemoteImageDataLoader的2个版本，因为唯一的区别是注入的HTTPClient实例。

Answer 1

[当您在字典中使用ObjectIdentifier作为键，typealias不变时，它当前不起作用。