Alamofire request cancelled (-999) - swift

Question

I want to make use of the RequestAdapter and RequestRetrier protocols, so I created my own so called AuthenticationHandler class which implements both protocols. I do this because the refresh token may be expired so this mechanism comes in handy.
The RequestAdapter protocol method adapt does get called, but the should RequestRetrier protocol method does not. I have a separate class that does the actual request:
class TestRequest {
var authHandler: AuthenticationHandler?
func executeRequest() {
// For testing purposes a false access token is passed
self.authHandler = AuthenticationHandler(accessToken: "some_default_token")
let sessionManager = SessionManager()
sessionManager.adapter = authHandler
sessionManager.retrier = authHandler
var loginModel : LoginMessage = LoginMessage.init()
loginModel.username = "someUserName"
loginModel.password = "WrongPassword"
do {
let binaryData = try loginModel.serializedData()
// Create a file with this binary data in order to use it as part of the multipart formdata
guard let fileURL = createFileFrom(data: binaryData) else {
print("Error creating file")
return
}
// Note: custom headers have been set in the AuthenticationHandler
sessionManager.upload(multipartFormData: { multipartFormData in
multipartFormData.append(fileURL, withName: "content")
},
to: K.endpointLogin) { (encodingResult) in
switch encodingResult{
case .success(let upload, _, _):
upload.responseJSON { response in
print("Encoding result success...")
print("Statuscode: \(response.response?.statusCode)")
print(response)
}
case .failure(let encodingError):
print("Failure: \(encodingError)")
}
}
} catch {
print(error)
}
}
I have followed the example in the documentation here
I have read several previous posts saying it has to do with retaining the sessionManager. But I think that is also covered. My authentication handler looks like this:
class AuthenticationHandler: RequestAdapter, RequestRetrier {
private typealias RefreshCompletion = (_ succeeded: Bool, _ accessToken: String?) -> Void
private let sessionManager: SessionManager = {
let configuration = URLSessionConfiguration.default
configuration.httpAdditionalHeaders = SessionManager.defaultHTTPHeaders
return SessionManager(configuration: configuration)
}()
private let lock = NSLock()
private var accessToken: String
private var isRefreshing = false
private var requestsToRetry: [RequestRetryCompletion] = []
init(accessToken: String) {
self.accessToken = accessToken
}
// MARK: - RequestAdapter protocol method
func adapt(_ urlRequest: URLRequest) throws -> URLRequest {
var urlRequest = urlRequest
if let urlString = urlRequest.url?.absoluteString, urlString.hasPrefix(K.SERVER_URL) {
urlRequest.setValue("application/json", forHTTPHeaderField: "Accept")
urlRequest.setValue("multipart/form-data", forHTTPHeaderField: "Content-Type")
urlRequest.setValue("Bearer " + accessToken, forHTTPHeaderField: "Authorization")
}
return urlRequest
}
// MARK: - RequestRetrier protocol method
func should(_ manager: SessionManager, retry request: Request, with error: Error, completion: #escaping RequestRetryCompletion) {
lock.lock() ; defer { lock.unlock() }
}
}
My config is as follows:
Alamofire version: 4.7.2
Xcode version: 9.4.1
Swift version: 4
What am I doing wrong here? Why is the request cancelled and is the should method not called?
Any help is greatly appreciated.

Answer 1

Your core issue is that your SessionManager instance is being deinited, which cancels any ongoing tasks. You should keep it around in a singleton or something similar, which will fix the other issue, that of using a new SessionManager for each request, which is an anti pattern.