2
我试图在RequestManager
中创建一个通用函数,通过ServiceManager
将接收到的JSON从服务器转换为指定类型。这是我的代码:泛型类型错误:无法明确地专门化泛型
RequestManager:
typealias ResultResponseManager = (_ data: AnyObject?, _ error: ErrorPortage?) -> Void
typealias SuccessResponseManager = (_ success: Bool, _ error: ErrorPortage?) -> Void
typealias objectBlock<T:GenericModel> = (_ object: T?, _ error: ErrorPortage?) -> Void
extension RequestManager {
static func getObject<T: GenericModel>(endpoint: String, completionBlock: objectBlock<T>? = nil){
RequestHelper(url: "\(getAPIURL())\(endpoint))")
.performJSONLaunchRequest { (result, error) in
if let result = result as? NSDictionary,
error == nil {
let object = T(dic: result)
completionBlock?(object, nil)
}
else {
completionBlock?(nil, error)
}
}
}
}
ServiceManger:
typealias ObjectResult = (GenericModel?, ErrorPortage?) -> Void
typealias ObjectsResult = ([GenericModel]?, ErrorPortage?) -> Void
extension ServiceManager {
static func getUser(_ id: Int? = nil, _ completion: ObjectResult? = nil) {
guard let userId: Int = id ?? UserManager.shared.userId else {
return
}
RequestManager.getObject<User>(endpoint: "users/\(userId)") { (user, error) in
if user = user {
//update userdefault
if userId == UserManager.shared.userId {
UserDefaults.standard.set(result, forKey: "currentUser")
}
}
}
}
}
上线RequestManager.getObject<User> ...
我得到这个错误:
Cannot explicitly specialise a generic type
那么我在这里错过了什么?
The problem was solved thanks to luk2302
更新 任何想法如何可能改善这种代码或使其更干净! 注意:这不是一个问题,它只是关于良好的编程习惯
谢谢:)你可以检查我的更新(它只是有干净的代码,也许能够更好地组织我的代码) – Chlebta
@Chlebta我会去与相关的值枚举为'错误'和'成功'案例。这样你就有一种编译器强制的方式来接收错误信息或实际的对象。有一些关于SO的文章(现在找不到它们),对于评论部分来说更详细的内容太多了。除了枚举,我认为你的代码很好。 – luk2302