At the moment, Users will get a "No internet connection" error, when the cloudfunctions API to get the Twilio token is offline or faulty. This should return a different error message. how do i refine the error message according to the kind of error encountered in swift?
class Token {
let value: String
init (url: String = "userTokenURL") throws {
guard let requestURL = URL(string: url) else {
throw Token.Error.invalidURL
}
do {
let data = try Data(contentsOf: requestURL)
guard let stringToken = String(data: data, encoding: .utf8) else {
throw Token.Error.couldNotConvertDataToString
}
value = stringToken
} catch let error as NSError {
print ("Error fetching token data, \(error)")
throw Token.Error.noInternet
}
}
}
extension Token {
enum Error: Swift.Error {
case invalidURL
case couldNotConvertDataToString
case noInternet
var description: String? {
switch self {
case .invalidURL:
return NSLocalizedString("Token URL is invalid.", comment: "")
case .couldNotConvertDataToString:
return NSLocalizedString("Token Data could not be converted to String.", comment: "")
case .noInternet:
return NSLocalizedString("Internet connection failed.", comment: "")
}
}
}
}
Related
I am following Ray Wanderlich's book 'Server Side Swift with Vapor' and I am at chapter 26: Adding profile pictures.
First, I defined this struct:
struct ImageUploadData: Content {
var picture: Data
}
Then, in a route I try to decode it:
func postProfilePictureHandler(_ req: Request) throws -> EventLoopFuture<User> {
let data = try req.content.decode(ImageUploadData.self)
...
From the client side, I use Alamofire:
#discardableResult func uploadProfilePicture(for user: User, data: Data) async throws -> User {
enum Error: LocalizedError {
case missingUserID
}
guard let userID = user.id else {
throw Error.missingUserID
}
let appendix = "\(userID)/profilePicture"
let parameters = [
"picture": data
]
return try await withCheckedThrowingContinuation { continuation in
Task {
AF.request(baseUrl + appendix, method: .post, parameters: parameters).responseData { response in
switch response.result {
case .success(let data):
do {
let user = try JSONDecoder().decode(User.self, from: data)
continuation.resume(returning: user)
} catch {
continuation.resume(throwing: error)
}
case .failure(let error):
continuation.resume(throwing: error)
}
}
}
}
}
In my integration tests, I create the picture's data like this:
guard let data = image?.pngData() else {
throw Error.missingPictureData
}
And then I pass it to the above method. The problem is that in the server side, the decoding fails with this error:
The data couldn’t be read because it is missing.
Just to understand if I was doing something else wrong, I tried the above methods with one difference: I replace the type 'Data' with 'String':
struct ImageUploadData: Content {
var picture: String
}
This wouldn't be useful for me because I need a data object, but just as a test to see if this doesn't produce an error, I tried and indeed this is decoded successfully. So I suspect that the problem is in how I encode the data before sending it to the server, but I don't know what's wrong.
I am having problem displaying custom error message on Swift.
The scenario is basic user authentication with Dictionary data, input entered is validated with the Dictionary data, if username and password matches, return true, else an error message as "Invalid Credentials" with AuthenticationError appears (argument message CustomErrors enum)
Here is the code I have come up with so far:
import Foundation
//Editable code starts here
let authDict:Dictionary = ["admin":"admin123","user":"someone123","guest":"guest999","you":"yourpass","me":"mypass190"]
//create CustomErrors enum
public enum CustomErrors: Error {
case AuthenticationError(message:String)
//case invalidCredentials
}
extension CustomErrors: LocalizedError {
public var errorDescription: String? {
switch self{
//case .invalidCredentials:
// return NSLocalizedString("Invalid Credentials", comment: "Invalid Credentials")
//return "Invalid Credentials"
case .AuthenticationError(message:let message):
print(message)
return "Invalid Credentials"
}
}
}
// create authenticate(userName:user,pass:pass) with return type Boolean
func authenticate(user:String,pass:String) -> Bool{
print(user)
print(pass)
for(u,p) in authDict {
if((u == user) && (p == pass)) {
return true
}
}
print("Invalid Credentials")
return false
}
//Editable code ends here
//Uneditable code starts here
let stdout = ProcessInfo.processInfo.environment["OUTPUT_PATH"]!
FileManager.default.createFile(atPath: stdout, contents: nil, attributes: nil)
let fileHandle = FileHandle(forWritingAtPath: stdout)!
guard let user = readLine() else { fatalError("Bad input") }
guard let pass = readLine() else { fatalError("Bad input") }
do{
let result = try authenticate(user:user,pass:pass)
fileHandle.write((result ? "1" : "0").data(using: .utf8)!)
}catch CustomErrors.AuthenticationError(let message){
fileHandle.write(message.data(using: .utf8)!)
}
//Uneditable code ends here
The above code works perfect for all positive test cases like :
1. "admin":"admin123"
2. "user":"someone123"
3. "guest":"guest999"
4. "you":"yourpass"
5. "me":"mypass190"
The output is 1 for all above, but for negative test cases, I should get Invalid Credentials printed as output, instead I get 0
I am not sure what I am missing in the CustomErrors enum but its not working.
How do I fix my editable code to work with the below uneditable code, what should I add/delete to achieve the end result:
do{
let result = try authenticate(user:user,pass:pass)
fileHandle.write((result ? "1" : "0").data(using: .utf8)!)
}catch CustomErrors.AuthenticationError(let message){
fileHandle.write(message.data(using: .utf8)!)
}
Modify the authenticate function as:
func authenticate(user:String,pass:String) throws -> Bool{
print(user)
print(pass)
guard authDict[user] == pass else {
throw CustomErrors.AuthenticationError(message: "Invalid Credentials")
}
return true
}
Now the function throws a CustomErrors error if user and pass do not match those stored in the authDict Dictionary.
I'm trying to implement SMB into my app and found this https://github.com/amosavian/AMSMB2. I'm not sure how to implement this code into the UI of my app. For example, do I connect the connect function to a button and if so how would I proceed to do so. What would I put into the parameters of connect() when I call it if I call it.
Here's the code from the repository:
import AMSMB2
class SMBClient {
/// connect to: `smb://guest#XXX.XXX.XX.XX/share`
let serverURL = URL(string: "smb://XXX.XXX.XX.XX")!
let credential = URLCredential(user: "guest", password: "", persistence: URLCredential.Persistence.forSession)
let share = "share"
lazy private var client = AMSMB2(url: self.serverURL, credential: self.credential)!
private func connect(handler: #escaping (Result<AMSMB2, Error>) -> Void) {
// AMSMB2 can handle queueing connection requests
client.connectShare(name: self.share) { error in
if let error = error {
handler(.failure(error))
} else {
handler(.success(self.client))
}
}
}
func listDirectory(path: String) {
connect { result in
switch result {
case .success(let client):
client.contentsOfDirectory(atPath: path) { result in
switch result {
case .success(let files):
for entry in files {
print("name:", entry[.nameKey] as! String,
", path:", entry[.pathKey] as! String,
", type:", entry[.fileResourceTypeKey] as! URLFileResourceType,
", size:", entry[.fileSizeKey] as! Int64,
", modified:", entry[.contentModificationDateKey] as! Date,
", created:", entry[.creationDateKey] as! Date)
}
case .failure(let error):
print(error)
}
}
case .failure(let error):
print(error)
}
}
}
func moveItem(path: String, to toPath: String) {
self.connect { result in
switch result {
case .success(let client):
client.moveItem(atPath: path, toPath: toPath) { error in
if let error = error {
print(error)
} else {
print("\(path) moved successfully.")
}
// Disconnecting is optional, it will be called eventually
// when `AMSMB2` object is freed.
// You may call it explicitly to detect errors.
client.disconnectShare(completionHandler: { (error) in
if let error = error {
print(error)
}
})
}
case .failure(let error):
print(error)
}
}
}
}
late but for reference as i couldnt find much when i tried
add the amsmb2 library and that template class file to your project
in the class file set serverurl, share, credential correctly for your smb server
then
declare a variable of class smb_client
then from your button or whatever
var myclient:smb_client=smb_client()
myclient.connect()
to connect to your smb server for example
you can extend that class templete to download/upload items etc
the operations are asynchronous
I currently have a network client that looks like the below:
class Client<R: ResourceType> {
let engine: ClientEngineType
var session: URLSession
init(engine: ClientEngineType = ClientEngine()) {
self.engine = engine
self.session = URLSession.shared
}
func request<T: Codable>(_ resource: R) -> Single<T> {
let request = URLRequest(resource: resource)
return Single<T>.create { [weak self] single in
guard let self = self else { return Disposables.create() }
let response = self.session.rx.response(request: request)
return response.subscribe(
onNext: { response, data in
if let error = self.error(from: response) {
single(.error(error))
return
}
do {
let decoder = JSONDecoder()
let value = try decoder.decode(T.self, from: data)
single(.success(value))
} catch let error {
single(.error(error))
}
},
onError: { error in
single(.error(error))
})
}
}
struct StatusCodeError: LocalizedError {
let code: Int
var errorDescription: String? {
return "An error occurred communicating with the server. Please try again."
}
}
private func error(from response: URLResponse?) -> Error? {
guard let response = response as? HTTPURLResponse else { return nil }
let statusCode = response.statusCode
if 200..<300 ~= statusCode {
return nil
} else {
return StatusCodeError(code: statusCode)
}
}
}
Which I can then invoke something like
let client = Client<MyRoutes>()
client.request(.companyProps(params: ["collections": "settings"]))
.map { props -> CompanyModel in return props }
.subscribe(onSuccess: { props in
// do something with props
}) { error in
print(error.localizedDescription)
}.disposed(by: disposeBag)
I'd like to start handling 401 responses and refreshing my token and retrying the request.
I'm struggling to find a nice way to do this.
I found this excellent gist that outlines a way to achieve this, however I am struggling to implement this in my current client.
Any tips or pointers would be very much appreciated.
That's my gist! (Thanks for calling it excellent.) Did you see the article that went with it? https://medium.com/#danielt1263/retrying-a-network-request-despite-having-an-invalid-token-b8b89340d29
There are two key elements in handling 401 retries. First is that you need a way to insert tokens into your requests and start your request pipeline with Observable.deferred { tokenAcquisitionService.token.take(1) }. In your case, that means you need a URLRequest.init that will accept a Resource and a token, not just a resource.
The second is to throw a TokenAcquisitionError.unauthorized error when you get a 401 and end your request pipeline with .retryWhen { $0.renewToken(with: tokenAcquisitionService) }
So, given what you have above, in order to handle token retries all you need to do is bring my TokenAcquisitionService into your project and use this:
func getToken(_ oldToken: Token) -> Observable<(response: HTTPURLResponse, data: Data)> {
fatalError("this function needs to be able to request a new token from the server. It has access to the old token if it needs that to request the new one.")
}
func extractToken(_ data: Data) -> Token {
fatalError("This function needs to be able to extract the new token using the data returned from the previous function.")
}
let tokenAcquisitionService = TokenAcquisitionService<Token>(initialToken: Token(), getToken: getToken, extractToken: extractToken)
final class Client<R> where R: ResourceType {
let session: URLSession
init(session: URLSession = URLSession.shared) {
self.session = session
}
func request<T>(_ resource: R) -> Single<T> where T: Decodable {
return Observable.deferred { tokenAcquisitionService.token.take(1) }
.map { token in URLRequest(resource: resource, token: token) }
.flatMapLatest { [session] request in session.rx.response(request: request) }
.do(onNext: { response, _ in
if response.statusCode == 401 {
throw TokenAcquisitionError.unauthorized
}
})
.map { (_, data) -> T in
return try JSONDecoder().decode(T.self, from: data)
}
.retryWhen { $0.renewToken(with: tokenAcquisitionService) }
.asSingle()
}
}
Note, it could be the case that the getToken function has to, for example, present a view controller that asks for the user's credentials. That means you need to present your login view controller (or a UIAlertController) to gather the data. Or maybe you get both an authorization token and a refresh token from your server when you login. In that case the TokenAcquisitionService should hold on to both of them (i.e., its T should be a (token: String, refresh: String). Either is fine.
The only problem with the service is that if acquiring the new token fails, the entire service shuts down. I haven't fixed that yet.
I have an app where I used RxSwift for my networking by extending ObservableType this works well but the issue I am having now is when I make an API request and there is an error, I am unable to show the particular error message sent from the server. Now how can I get the particular error response sent from the server
extension ObservableType {
func convert<T: EVObject>(to observableType: T.Type) -> Observable<T> where E: DataRequest {
return self.flatMap({(request) -> Observable<T> in
let disposable = Disposables.create {
request.cancel()
}
return Observable<T>.create({observer -> Disposable in
request.validate().responseObject { (response: DataResponse<T>) in
switch response.result {
case .success(let value):
if !disposable.isDisposed {
observer.onNext(value)
observer.onCompleted()
}
case .failure(let error):
if !disposable.isDisposed {
observer.onError(NetworkingError(httpResponse: response.response,
networkData: response.data, baseError: error))
observer.onCompleted()
}
}
}
return disposable
})
})
}
}
let networkRetryPredicate: RetryPredicate = { error in
if let err = error as? NetworkingError, let response = err.httpResponse {
let code = response.statusCode
if code >= 400 && code < 600 {
return false
}
}
return true
}
// Use this struct to pass the response and data along with
// the error as alamofire does not do this automatically
public struct NetworkingError: Error {
let httpResponse: HTTPURLResponse?
let networkData: Data?
let baseError: Error
}
response from the server could be
{
"status" : "error",
"message" : " INSUFFICIENT_FUNDS"
}
or
{
"status" : "success",
"data" : " gghfgdgchf"
}
my response is handled like this
class MaxResponse<T: NSObject>: MaxResponseBase, EVGenericsKVC {
var data: T?
public func setGenericValue(_ value: AnyObject!, forUndefinedKey key: String) {
switch key {
case "data":
data = value as? T
default:
print("---> setGenericValue '\(value)' forUndefinedKey '\(key)' should be handled.")
}
}
public func getGenericType() -> NSObject {
return T()
}
}
the error is
return ApiClient.session.rx.request(urlRequest: MaxApiRouter.topupWall(userId: getUser()!.id!, data: body))
.convert(to: MaxResponse<Wall>.self)
In the official Alamofire docs it is mentioned that validate(), without any parameters:
Automatically validates status code within 200..<300 range, and that
the Content-Type header of the response matches the Accept header of
the request, if one is provided.
So if you do not include Alamofire's validate() you are saying that no matter the status code, if the request did get through, you will consider it successful, so that's why it shows nothing in the failure block.
However if you prefer to use it, yes, it will give you an ResponseValidationFailureReason error, but you still have access to the response.data. Try printing it, you should see the expected error response from the server:
if let responseData = response.data {
print(String(data: responseData, encoding: .utf8))
}