Error handling in swift 3 using objectMapper and alamofire - swift3

Question

How i can handle error in completion block if get error from server side.Here is object mapper class for login.
class Login: Mappable {
var result: LoginData?
var success: Bool?
var error: String?
required init?(map: Map){
}
func mapping(map: Map) {
result <- map["data"]
success <- map["success"]
error <- map["error"]
}
}
class LoginData: Mappable {
var name: String?
var title: String?
var token: String?
var imageUrl: String?
required init?(map: Map){
}
func mapping(map: Map) {
name <- map["name"]
title <- map["title"]
token <- map["token"]
name <- map["name"]
imageUrl <- map["imageUrl"]
}
}
Here is my api calling from view controller.
func loginMethod(){
let postData = ["username":loginDict.object(forKey: KUserUserId) as! String,
"password": loginDict.object(forKey: KUserPass) as! String]
userLoginHttp(parameters: postData){ completion in
self.getUserLoginResponse(result: completion)
}
}
func getUserLoginResponse(result: LoginData) {
// Here i do further
}
This is Network class mthod from where i fire the service
//User login web service
func userLoginHttp(parameters:Parameters, completion:#escaping (_
result:LoginData)->()) {
let defaultObject = UserDefaults.standard
var headerToken = String()
if let x = defaultObject.object(forKey: KDeviceToken)
{
headerToken = x as! String
}
else{
headerToken = ""
}
let headers = ["fcmToken": headerToken]
Alamofire.request(KLoginUrl, method: .post, parameters: parameters,encoding: JSONEncoding.default, headers: headers)
.validate()
.responseObject{ (response: DataResponse<Login>) in
switch response.result{
case .success:
let value = response.result.value
completion((value?.result)!)
case .failure(let error):
print(error.localizedDescription)
}
}
}
So how i can handle error in my view controller completion block?

Answer 1

you can just create another handler for errors and call it in error case
func userLoginHttp(parameters:Parameters,
completion:#escaping (_ result:LoginData)->(),
errorHandler:#escaping (_ result:Error,_ statusCode:Int?)->()//error handler
) {
let defaultObject = UserDefaults.standard
var headerToken = String()
if let x = defaultObject.object(forKey: KDeviceToken)
{
headerToken = x as! String
}
else{
headerToken = ""
}
let headers = ["fcmToken": headerToken]
Alamofire.request(KLoginUrl, method: .post, parameters: parameters,encoding: JSONEncoding.default, headers: headers)
.validate()
.responseObject{ (response: DataResponse<Login>) in
switch response.result{
case .success:
let value = response.result.value
completion((value?.result)!)
case .failure(let error):
errorHandler(error,response.response?.statusCode)//call error handler
print(response.response?.statusCode)
print(error.localizedDescription)
}
}
}
usage
func loginMethod(){
let postData = ["username":loginDict.object(forKey: KUserUserId) as! String,
"password": loginDict.object(forKey: KUserPass) as! String]
userLoginHttp(
parameters: postData,
completion:{ completion in
self.getUserLoginResponse(result: completion)
},
errorHandler:{ error,code in
//do your error stuff
})
}
func getUserLoginResponse(result: LoginData) {
// Here i do further
}