使用Alamofire和ObjectMapper的通用网络调用

Question

我使用Alamofire和AlamofireObject Mapper来发出网络请求并对其进行序列化。我们总是得到与以下示例相同的响应形状，包括result、isSuccessfull和message。

{
"Result": {
"WaitingCount": 0,
"ApprovedCount": 0,
"RejectedCount": 0
},
"IsSuccessfull": true,
"Message": null
}

我创建了一个基类来防止以下代码的代码重复。

struct BaseObjectResponseParser<T:Mappable>: Mappable {
public var item: T?
public var isSuccessful:Bool?
public var message: String?
init?(map: Map){
}
mutating func mapping(map: Map) {
item <- map["Result"]
isSuccessful <- map["IsSuccessfull"]
message <- map["Message"]
}
}

然后，对于每个不同的模型，我创建了一个具有以下内容的模型类。

class UnitWorkOrdersCount: Mappable {
var waitingCount: Int = 0
var approvedCount: Int = 0
var rejectedCount: Int = 0
required init?(map: Map) {
}
func mapping(map: Map) {
waitingCount <- map["WaitingCount"]
approvedCount <- map["ApprovedCount"]
rejectedCount <- map["RejectedCount"]
}    
}

我使用以下代码片段从服务器进行网络调用并序列化响应。

typealias HandlerGetUnitWorkOrdersCount = (UnitWorkOrdersCount?, _ message: String?) -> ()
func getUnitWorkOrdersCount(by identifier: Int, handler: @escaping HandlerGetUnitWorkOrdersCount) {
let parameters: Parameters = ["identifier": identifier]
Alamofire.request(URL_GET_UNIT_WORK_ORDER_COUNT, method: .get, parameters: parameters).responseObject { (response: DataResponse<BaseObjectResponseParser<UnitWorkOrdersCount>>) in
switch response.result {
case .success:
if let result = response.result.value {
if result.isSuccessful ?? false {
handler(result.item, nil)
} else {
handler(nil, result.message)
}
}
case .failure(let error):
print(error)
handler(nil, error.localizedDescription)
}
}
}

然而，我有很多网络请求，我的代码与上面的代码重复。我正在努力使它通用，但我不可能成功。如何使networkRequest函数和我的完成处理程序通用并防止其重复？

Answer 1

您可以尝试使其通用，如下所示，

class MyService {
public static func request<T: Mappable>(_ urlString: String,
method: HTTPMethod,
params: Parameters?,
type: T.Type,
completion: @escaping (T?, String?) -> Void) {
Alamofire.request(urlString, method: method, parameters: params).responseObject { (response: DataResponse<BaseObjectResponseParser<T>>) in
switch response.result {
case .success:
if let result = response.result.value {
if result.isSuccessful ?? false {
completion(result.item, nil)
} else {
completion(nil, result.message)
}
}
case .failure(let error):
completion(nil, error.localizedDescription)
}
}
}
}

用法

MyService.request("urlPathString", method: .get, params: nil,
type: UnitWorkOrdersCount.self) { (unitWork, message) in
if let message = message {
print(message)
return
}
print(unitWork!.waitingCount)
}