I am working on user authentication process but i stuck in the moment when reciving data from rest with token. Whenever i create the new task it does not enter on the first time into the function but after creating it skipping doing smth else which is showing a next hooked up UIViewController to segue.
My rest service with post method hashing user password, creating json, URL request and at the end creating URLSession. How could i wait for finish of this task ? To not let to do anything else before it is not complited ?
EDIT
I've added OpeartionQueue to liquidate nil's from next view.
func postLogin(name:String, pass:String, completion: #escaping (Bool) -> () ) {
let md5Data = self.MD5(string:pass)
let hashPass = md5Data!.map { String(format: "%02hhx", $0) }.joined()
let json: [String: Any] = ["username": name,
"passwordHash": hashPass ]
let jsonData = try? JSONSerialization.data(withJSONObject: json)
// create post request
let url = URL(string: LOGIN_URL)!
var request = URLRequest(url: url)
request.httpMethod = "POST"
// insert json data to the request
request.httpBody = jsonData
request.setValue("application/json;charest=utf-8", forHTTPHeaderField: "Content-Type")
let task = URLSession.shared.dataTask(with: request) { data, response, error in
guard let data = data, error == nil else {
print(error?.localizedDescription ?? "No data")
return
}
let responseJSON = try? JSONSerialization.jsonObject(with: data, options: [])
if let responseJSON = responseJSON as? [String: Any] {
print(responseJSON)
let message:String = responseJSON["message"] as! String
if !(message.range(of: "ERROR") != nil){
SessionMenager.Instance.token = message
completion(true)
}
} else{
print(error.debugDescription)
}
}
task.resume()
}
Then simply in my LoginViewController action with button :
#IBAction func LoginButton(_ sender: Any) {
let username = usernameTextField.text
let password = passwordTextField.text
if username == "" {
AlertWindow(title: "Username", message: "Wrong username")
} else if password == "" {
AlertWindow(title: "Password", message: "Wrong password")
} else {
let usernameToUpper = username!.uppercased()
RestService.Instance.postLogin(name: usernameToUpper, pass: password!, completion: { sth in
if sth {
OperationQueue.main.addOperation {
[weak self] in
self?.performSegue(withIdentifier: "mapSegue", sender: self)
}
} else {
return
}
})
}
}
The segue was hooked up into LoginButton which took me instantly to the next page. I've changed it into hooking up all view controllerr.
Thanks!
Because your segue is hooked up into LoginButton, it will automatically show the next viewController once you press the button.
Just hoop up the segue to the whole viewController and it should work.
Related
I have created a POST request which validates if the username and password are correct through a StatusCode: 0 that comes from the response of the POST request if the data are correct, At the signInViewController class I have created the button signInSegueToDashboard which when pressed must validate the data and if the data are valid then the user will be logged in without any problem.
The button sender at signInViewController:
#IBAction func signInSegueToDashboard(_ sender: Any) {
APICallerPOST.shared.signInToAccount(username: emailTextField.text!, password: passwordTextField.text!) { (result, error) in
if let result = result {
if result.StatusCode == 0 {
guard let mainTabBarController = self.storyboard?.instantiateViewController(withIdentifier: "mainTabBarController") else {
return
}
Timer.scheduledTimer(withTimeInterval: 1, repeats: false) {_ in
mainTabBarController.modalPresentationStyle = .custom
self.present(mainTabBarController, animated: true, completion: nil)
}
}else if result.StatusCode == 5 {
print("error: \(error!.localizedDescription)")
}
}
}
}
When i press the button after typing the correct data it just does nothing and just shows a purple warning that is saying to put it on Main thread, When i did put on main thread the segue part then it doesn't validate the data at all instead it just logs you in without any validation.
the POST request from APICallerPOST class:
func signInToAccount(username: String, password: String, completion: #escaping (SignInResponse?, Error?) -> Void) {
//declare parameter as a dictionary which contains string as key and value combination.
let parameters = ["User": username, "Password": password]
//create the url with NSURL
let url = URL(string: "https://censoredurl/Signin")!
//create the session object
let session = URLSession.shared
//now create the Request object using the url object
var request = URLRequest(url: url)
request.httpMethod = "POST" //set http method as POST
do {
request.httpBody = try JSONSerialization.data(withJSONObject: parameters, options: .prettyPrinted) // pass dictionary to data object and set it as request body
} catch let error {
print(error.localizedDescription)
completion(nil, error)
}
//HTTP Headers
request.addValue("application/json; charset=utf-8", forHTTPHeaderField: "Content-Type")
request.addValue("application/json; charset=utf-8", forHTTPHeaderField: "Accept")
//create dataTask using the session object to send data to the server
let task = session.dataTask(with: request, completionHandler: { data, response, error in
guard error == nil else {
completion(nil, error)
return
}
guard let data = data else {
completion(nil, NSError(domain: "dataNilError", code: -100001, userInfo: nil))
return
}
do {
//create json object from data
let decoder = JSONDecoder()
guard let json = try? decoder.decode(SignInResponse.self, from: data) else {
completion(nil, NSError(domain: "invalidJSONTypeError", code: -100009, userInfo: nil))
return
}
print(json)
completion(json, nil)
} catch let error {
print(error.localizedDescription)
completion(nil, error)
}
})
task.resume()
}
Confused a lot.
The dataTask is asynchronous, and so is the code it runs in the completion handler. However all updates to UI need to be performed on the main thread, and so the parts of the completion handler that update the UI need to be pushed back onto the main thread.
In your case you could do it like this:
if result.StatusCode == 0 {
DispatchQueue.main.async {
guard let mainTabBarController = self.storyboard?.instantiateViewController(withIdentifier: "mainTabBarController")
else {
return
}
Timer.scheduledTimer(withTimeInterval: 1, repeats: false) {_ in
mainTabBarController.modalPresentationStyle = .custom
self.present(mainTabBarController, animated: true, completion: nil)
}
}
// ...
However it seems you are trying to use the Timer to delay presentation of the viewController, and there is a better way of doing this than using the Timer. You can use a delayed execution with DispatchQueue's asyncAfter(deadline:qos:flags:execute:) method:
DispatchQueue.main.asyncAfter(deadline: .now() + 1) {
// do your UI work
}
I need to get a value from an extension before i click on a button that goes to another screen, how can i do that?
This is the IBAction inside viewController. When i click it makes a request to an API then send a value to global variable on the second screen:
#IBAction func enter(_ sender: UIButton) {
if let login = loginTextfield.text, let password = passwordTextfield.text {
loginManager.performLoginRequest(login, password)
resultsViewController.receivedToken = token
navigationController?.pushViewController(resultsViewController, animated: true)
}
}
extension LoginViewController: LoginManagerDelegate {
func didUpdateLogin(with login: LoginModel) -> (Bool, String) {
success = login.success
token = login.token
return (success, token)
}
}
Manager:
import Foundation
protocol LoginManagerDelegate {
func didUpdateLogin(with login: LoginModel) -> (Bool, String)
}
struct LoginManager {
var delegate: LoginManagerDelegate?
func performLoginRequest(_ login: String, _ password: String) {
let url = URL(string: "https://private-anon-1a0df64d9c-ibmfc.apiary-mock.com/login")!
var request = URLRequest(url: url)
request.httpMethod = "POST"
request.addValue("application/json", forHTTPHeaderField: "Content-Type")
request.httpBody = """
{\n "username": "\(login)",\n "password": "\(password)"\n}
""".data(using: .utf8)
let task = URLSession.shared.dataTask(with: request) { data, response, error in
if let response = response {
print(response)
if let data = data, let body = String(data: data, encoding: .utf8) {
print(body)
if let login = self.parseJSON(loginData: data) {
self.delegate?.didUpdateLogin(with: login)
}
}
} else {
print(error ?? "Unknown error")
}
}
task.resume()
}
func parseJSON(loginData: Data) -> LoginModel? {
let decoder = JSONDecoder()
do {
let decodedData = try decoder.decode(LoginData.self, from: loginData)
let success = decodedData.success
let token = decodedData.data.token
let login = LoginModel(success: success, token: token)
return login
} catch {
print(error.localizedDescription)
return nil
}
}
}
My problem is, this extension is just being called after i click the button. This way resultsViewController.receivedToken is not getting the value from token.
So, how can i call didUpdateLogin (to pass it values to success and token) before clicking on the IBAction?
THe reason for this behaviour is the background thread you are using:
(1) You call loginManager.performLoginRequest(login, password) which then starts a background thread to actually work on that request.
(2) In the meantime your code continues to run, executing resultsViewController.receivedToken = token.
(3) Since (1) is not done yet, your token is still nil (or an old token).
One of many possible solutions:
Add a block to the parameters of performLoginRequest in which you call
resultsViewController.receivedToken = token
navigationController?.pushViewController(resultsViewController, animated: true)
This way you make sure that code is only called after(!) the login was successful because you wait for it. In the meantime you could show a loading spinner or something similar. Login is a task where a user simply has to wait, there is usually (depending on the app) no way around it.
The code could look something like this in the end:
loginManager.performLoginRequest(login, password) {
resultsViewController.receivedToken = token
navigationController?.pushViewController(resultsViewController, animated: true)
}
whereas your LoginManager would have a method like
func performLoginRequest(_ login: String,
_ password: String,
completion: #escaping () -> Void)
which is then used later in your Dispatch:
DispatchQueue.main.async {
let loginVC = LoginViewController()
loginVC.didUpdateLogin(login: login)
completion()
}
I have a function that connects to an API to retrieve data. The API takes two parameters accessCode (provided by user in a text box) and then UDID (UDID of their device). I can parse the data from within the function, but only locally. I need to store the values that are returned but am unsure on how to return them properly. Essentially I need this to return the json object as a dictionary (I think...) so it can be parsed outside of the async task. I've read through the swift documentation and that's where I found out how to do the requests, but I can't find a way to store the returned values in memory for access outside of the function.
func getResponse(accessCode:String, UDID:String, _ completion: #escaping (NSDictionary) -> ()) {
let urlPath = "https://apihosthere.com/api/validate?accessCode=" + accessCode + "&UDID=" + UDID
guard let url = URL(string: urlPath) else { return }
let task = URLSession.shared.dataTask(with: url) { (data, response, error) in
guard let data = data else { return }
do {
if let jsonResult = try JSONSerialization.jsonObject(with: data, options: JSONSerialization.ReadingOptions.mutableContainers) as? NSDictionary {
let results = jsonResult as? NSDictionary
print(results)
completion(results!)
}
} catch {
//Catch Error here...
}
}
task.resume()
}
First of all don't use NSDictionary in Swift, use native [String:Any] and declare the type as optional to return nil if an error occurs.
And never use .mutableContainers in Swift, the option is useless.
func getResponse(accessCode:String, UDID:String, completion: #escaping ([String:Any]?) -> Void)) {
let urlPath = "https://apihosthere.com/api/validate?accessCode=" + accessCode + "&UDID=" + UDID
guard let url = URL(string: urlPath) else { return }
let task = URLSession.shared.dataTask(with: url) { (data, response, error) in
if let error = error else {
print(error)
completion(nil)
return
}
do {
if let jsonResult = try JSONSerialization.jsonObject(with: data!) as? [String:Any] {
print(jsonResult)
completion(jsonResult)
} else {
completion(nil)
}
} catch {
print(error)
completion(nil)
}
}
task.resume()
}
Your mistake is that you don't consider the closure, you have to execute the entire code inside the completion handler
#IBAction func StartWizard(_ sender: UIButton) {
//Store entered access code
let accessCode = AccessCodeField.text!
//Call API to validate Access Code
getResponse(accessCode:accessCode, UDID:myDeviceUDID) { [weak self] result in
if let accessCodeFound = result?["Found"] as? Bool {
print("Value of Found during function:")
//If access code is valid, go to License view
print(accessCodeFound)
if accessCodeFound {
//Load License View
DispatchQueue.main.async {
let storyboard = UIStoryboard(name: "Main", bundle: nil)
let licenseController = storyboard.instantiateViewController(identifier: "LicenseViewPanel")
self?.show(licenseController, sender: self)
}
}
}
}
}
Your completion closure should handle the obtained data. You would call the function like this:
getResponse(accessCode: "code", UDID: "udid", completion: { result in
// Do whatever you need to do with the dictionary result
}
Also, I'd recommend you to change your NSDictionary with a swift Dictionary.
This is what the API returns as a response
{
AccessCode = 00000000;
Client = "0000 - My Company Name";
EmailAddress = "brandon#brandonthomas.me";
FirstName = Brandon;
Found = 1;
LastName = Thomas;
Status = A;
UDIDregistered = 1;
}
And this is what calls the function. I am calling at after clicking a button after an access code is being entered in a text field.
#IBAction func StartWizard(_ sender: UIButton) {
//Store entered access code
let accessCode = AccessCodeField.text!
var accessCodeFound: Bool? = nil
//Call API to validate Access Code
getResponse(accessCode:accessCode, UDID:myDeviceUDID) { result in
accessCodeFound = result["Found"] as! Bool
print("Value of Found during function:")
print(accessCodeFound)
//accessCodeFound = true
}
//If access code is valid, go to License view
print("Value of Found after function:")
print(accessCodeFound)
//accessCodeFound = nil ???
//it seems the value is getting reset after the function completes
if accessCodeFound == true{
//Load License View
let storyboard = UIStoryboard(name: "Main", bundle: nil)
let licenseController = storyboard.instantiateViewController(identifier: "LicenseViewPanel")
self.show(licenseController, sender: Any?.self)
}
}
I'm a bit confused about credentials and HttpStatus.
I'm making a login page in Swift 4/XCode9, that connects to an api.
Here is what I do when the login button is tapped:
#IBAction func loginTapped(_ sender: Any) {
let loginString = String(format: "%#:%#", usernametext.text!, passwordtext.text!)
let loginData = loginString.data(using: String.Encoding.utf8)!
let base64LoginString = loginData.base64EncodedString()
var Base = base64LoginString
let url = URL(string: "SOME URL")!
var request = URLRequest(url: url)
request.addValue("Basic \(Base)", forHTTPHeaderField: "Authorization")
request.addValue("application/json", forHTTPHeaderField: "Accept")
let task = URLSession.shared.dataTask(with: request) { data, response, error in
guard let data = data, error == nil else {
print("\(error)")
return
}
if let httpStatus = response as? HTTPURLResponse {
print("status code = \(httpStatus.statusCode)")
}
}
task.resume()
view.endEditing(true)
}
Everything works fine but I don't know how to check the httpstatus.
If I get wrong credentials I want to stay on the login page and not perform segue to the next view.
Try this code
func checkStatusCode(response:URLResponse?) -> Bool {
guard let statusCode = (response as? HTTPURLResponse)?.statusCode else {
print("Invalid Response")
return false
}
if statusCode != 200 {
print("Invalid File")
return false
}
return true
}
Usage:
if (self.checkStatusCode(response: response)) {
DispatchQueue.main.async {
self.performSegue(withIdentifier: "showW", sender: self)
}
} else {
//added an alert
}
I currently need to use a web service to do some tasks which are, logging in and receiving a list of information.
After logging in successfully the web service will return 'response' information : {"LoginID":"1","Password":"","Role":"pol","LoginType":"Indevidual","UserID":"6110895204062016","UserRoleID":"20202020202020","RoleID":"999674512042008","PartyId":"1063081525122008","PartyFunctionId":"123123","BranchCode":"10","RoleCode":"123123","Status":{"isError":false,"ErCode":null,"Error":null}}
which is needed to be sent to another web service to get a list of information.
Currently using the login button to call the webserivce to be able to login.
How do I call another webservice using the information from the first webservice?
Code for a better idea:
#IBAction func GetPolicyListButton(_ sender: Any) {
//I will need the information from the second web service to display after clicking this button.. how?
}
#IBAction func LoginButton(_ sender: Any) {
let postString = "cpr=\(usernameField.text!)&password=\(passwordField.text!)"
let url = URL(string:"http://login")!
let postData:Data = postString.data(using: String.Encoding.utf8, allowLossyConversion: false)!
let postLength:String = String(postData.count) as String
var request:URLRequest = URLRequest(url: url)
request.httpMethod = "POST"
request.httpBody = postData
request.setValue(postLength as String, forHTTPHeaderField: "Content-Length")
request.setValue("application/json", forHTTPHeaderField: "Accept")
let task = URLSession.shared.dataTask(with: request) { data, response, error in
guard let data = data, error == nil else {
print("error=\(error)")
return
}
let httpStatus = response as? HTTPURLResponse
print("statusCode should be 200, but is \(httpStatus!.statusCode)")
print("response = \(response!)")
print(postString)
let responseString = String(data: data, encoding: .utf8)
print("responseString = \(responseString!)")
let start = responseString!.index(responseString!.startIndex, offsetBy: 75)
let end = responseString!.index(responseString!.endIndex, offsetBy: -9)
let range = start..<end
let jsonStr = responseString!.substring(with: range)
print(jsonStr)
let data1 = jsonStr.data(using: .utf8)!
_ = try? JSONSerialization.jsonObject(with: data1) as? [String: Any]
let persondata = try? JSONSerialization.jsonObject(with: data, options: .allowFragments)
let personInfodata = persondata as? [String : Any]
_ = personInfodata?[""] as? [String : Any]
if (responseString?.contains("1001"))!{
DispatchQueue.main.async {
print("incorrect - try again")
let alert = UIAlertController(title: "Try Again", message: "Username or Password Incorrect", preferredStyle: UIAlertControllerStyle.alert)
alert.addAction(UIAlertAction(title: "OK", style: UIAlertActionStyle.default, handler: nil))
self.present(alert, animated: true, completion: nil)
}
}
else{
DispatchQueue.main.async {
print("correct good")
let storyboard = UIStoryboard(name: "Maintest", bundle: nil)
let controller = storyboard.instantiateViewController(withIdentifier: "correctone")
self.present(controller, animated: true, completion: nil)
}
}
}
task.resume()
}
You are experiencing the complexity of not working in MVC. While writing an application if you do not properly use MVC the complexity and unnecessary duplication of code can get out of hand and you lose oversight.
A style for example to use is, is to create a LoginModel and a ItemsModel for lack of a better name. Both will be making web requests so be sure to create a class that handles a generic web request or implement a framework like Alamofire (which has some great examples for authentication and automatic retrying of requests based on Tokens etc)
Now in your ViewController seperate all the handling of your data to a View-Independant LoginClass like this:
#IBAction func LoginButton(_ sender: UIButton) {
guard let username = usernameField.text else { print("no username") ; return }
guard let password = passwordField.text else { print("no password") ; return }
self.loginModel.login(username: username, password: password) { [weak self] success in
if success {
let dataModel = dataModel(credentials: credentialStyle)
dataModel.loadItems { items : [Item]? in
// Dispatch items to main queue
}
}
}
}
Now in your loginModel you handle the login and in a completely separate model you handle the dataModel which you instantiate with the credentials you received from the loginModel. Off course this is a rough example and using Alamofire you can use a Session Manager for example which will take care of the authentication (see the URL of 'automatic retrying of requests', scroll down a little bit and there is an example of authentication.) removing the need of instantiating your dataModel with credentials put this is purely to demonstrate how to split up your code to handle these requests.