Question

我目前正在学习如何实现通用功能。我正在尝试创建一个函数，该函数将返回具有通用类型的回调

这是我的代码

static func performPOST<T: DomainEntity>(action: Module, completion: @escaping (CallbackResponse, DomainObjectWrapper<T>?) -> Void) {

     //logic implementation at first

     switch action { 
          case .getMenuItem:
          self.alamofireManager.request(urlRequest, encoding: URLEncoding.default, headers: headers).responseObject { (response: DataResponse<DomainObjectWrapper<MenuItemDO>>) in
                var validateRequestResponse = RestHelper.validateRequestResponse(response: response)
                let responseObject = validateRequestResponse.responseObject

                if validateRequestResponse.isSuccess {}
                else {
                    if let errorMessage = responseObject?.error {
                        validateRequestResponse.message = errorMessage
                    }
                    else if let warningMessage = responseObject?.warning {
                        validateRequestResponse.message = warningMessage
                    }
                }
                callbackResponse = RestHelper.bindValidateRequestResponse(validateRequestResponse: validateRequestResponse)
                completion(callbackResponse, responseObject)
            }
          case .makeSales: break
          case .attendance: break
     }
}

我从Xcode收到此错误。它不会让我编译。

completion(callbackResponse, responseObject) <<-- This Line

Cannot convert value of type 'DomainObjectWrapper<MenuItemDO>?' to expected argument type 'DomainObjectWrapper<_>?'

这是我的其他课程

public class DomainObjectWrapper<T: Mappable>: Mappable {
     public var data = [T]()
}

public class DomainEntity: Mappable {
     public var id = UUID().uuidString
     public var isDeleted = false
}

public class MenuItemDO: DomainEntity {
     public var categoryId: String?
     public var categoryName: String?
}

有人能指导我我所缺少的吗？

谢谢

Answer 1

最近我为泛型参数函数做了一个不错的解决方案。这是命令模式的示例。这样你就可以使用这种模式接收带有泛型参数的回调。

protocol ParameterCommand {
    func execute(with parameter: Any)
}

protocol CallbackCommand: ParameterCommand {
    associatedtype CallBackParameterType
    func execute(with callback: @escaping (CallBackParameterType) -> Void)
}

extension CallbackCommand {
    func execute(with parameter: Any) {
        if let parameter = parameter as? (CallBackParameterType) -> Void {
            execute(with: parameter)
        }
    }
}

快速通用回调

1 个答案: