I have an application that when user login I get data from the server with singleton class but the problem is when user logout(exit from login not exit from application) I can't renew singleton class, is there a way that when user log out clear all data and class?
My singleton class is as follows
import Foundation
class GetloginData{
static let instance = GetloginData()
private let personData : PersonData = generateLoginData()
func getLoginData () -> PersonData {
return personData
}
}
func generateLoginData() -> PersonData {
name = service.getname
balance = service.balance
return PersonData(name: name, balance: balance)
}
service is soap webservice
You can simply change the personData to optional and add a method to resetLoginData
import Foundation
class GetloginData {
static let instance = GetloginData()
private var personData : PersonData? = generateLoginData()
func getLoginData () -> PersonData? {
return personData
}
func resetLoginData() {
personData = nil
}
}
And on your logout button put it like
GetloginData.instance.resetLoginData()
Also, use guard else to check for the logged in or not and handle it accordingly.
guard let loggedInPerson = GetloginData.instance.getLoginData() else {
// HANDLE CODE TO RETURN TO LOGIN SCREEN.
return
}
Hope it helps
Related
In my swift code below the goal is to get the amount of core data attributes saved into core data. I am receiving the error message No exact matches in call to initializer at indexBox.text = String(info?). I don't know what to do next.
class ViewController: UIViewController {
override func viewDidLoad() {
super.viewDidLoad()
let info = CoredataHandler.fetchObject()?.count
indexBox.text = String(info?)
}
}
class CoredataHandler : NSManagedObject {
class func fetchObject() -> [User]?
{
let context = getContext()
var user : [User]? = nil
do {
user = try context.fetch(User.fetchRequest())
return user
} catch {
return user
}
}
}
I have a usermodel that checks the backend if the email exists - then I drill back into a viewcontroller and set a boolean value that should trigger a function run. However the value is unchanged and I am trying to change this value from the usermodel but it is not accessible. I understand why it does not work.. but do not know how to resolve the issue.
static func sendEmailWithResetLink(email: String) {
let params : Parameters = [
PARAM_EMAIL : email
]
request(URL_RESET_PASSWORD as String, method: .post, parameters: params, headers: nil).responseJSON {
(response: DataResponse<Any>) in
hideProgress()
print("this is response \(response)")
switch(response.result)
{
case .success(_):
print("it did not fail")
let passwordResetVC = PasswordResetViewController()
passwordResetVC.hasFailed = false
break
case .failure(_):
print("it failed")
let passwordResetVC = PasswordResetViewController()
//here boolean is set that I am trying to access in viewcontroller
passwordResetVC.hasFailed = true
break
}
}
}
Here's what I would suggest. You probably have some of these in place already:
Create an PasswordResetViewController object has an #IBAction func resetButtonClicked triggered by a button or whatever, which kicks off the password reset process.
Create a UserManager class. This class is responsible for all profile management activies in your app. Among other things, it has the ability to reset user passwords. This UserManager would probably be a singleton, that' sprobably good enough for now.
Create a new UserManagerDelegate protocol. Add to it all capabilities that are required by the UserManager to inform them of whatever happened. For example: var passwordResetHasFailed: Bool { get set }.
Extend your PasswordResetViewController conform to this protocol.
Your VC gets a reference to the singleton UserManager object, stores it in an instance variable, and uses that to access the shared object from then on.
Make your PasswordResetViewController register itself as the delegate to the user manager, with userManager.delegate = self
The #IBAction func resetButtonClicked will just call userManager.resetPassword()
Your UserManager does whatever it needs to do to reset the user's password.
When it's done, it'll call self.delegate?.passwordResetHasFailed = true/false.
Since your PasswordResetViewController registered itself as the delegate of the UserManager, when the operation is done, its passwordResetHasFailed property will be changed, giving it a chance to respond (by updating some UI or whatever).
There are some limitations to this approach, but it's a decent way to get started. Some thing to note:
This lets you unit test your PasswordResetViewController. You can create a MockUserManager, and set tesPasswordResetViewController.userManager = MockUserManager(), allowing you to separate out the user manager, and test PasswordResetViewController in isolation.
You'll run into issues if you need multiple objects to subscribe to receive delegate call backs (since there can only be 1 delegate object). At that point, you can switch to using something like Promises, RxSwift or Combine. But that's a problem for a later time, and the migration would be easy.
Going off of #Alexander - Reinstate Monica and what I assume what the code to look like to approach your problem.
Using MVC:
In Models folder (data/ logic part)
public class User {
private var name: String!
private var userEmail: String!
public var hasFailed: Bool?
init() {
name = ""
userEmail = ""
hasFailed = nil
}
public func setName(name: String) { self.name = name }
public func getName() -> String { return name }
public func setEmail(email: String) { userEmail = email }
public func getEmail() ->String { return userEmail }
public static func sendEmailWithRestLing(email: String) {
// your other code
switch response.result {
case .success(_):
//your code
hasFailed = false
break
case .failuare(_):
// your code
hasFailed = true
break
}
}
}
User Manager class applying singleton design
final class UserManager {
private var user = User()
static let instance = UserManager()
private init(){}
public func userName(name: String) {
if (name.count > 3) {
user.setName(name: name)
}
else { print("user name is too short") }
}
public func userEmail(email: String) {
if (email.count > 3) {
user.setEmail(email: email)
}
else { print("user email is too short") }
}
public func getUserName() -> String {
let name = user.getName()
if (name.isEmpty) { return "user name is Empty" }
return name
}
public func getUserEmail() -> String {
let email = user.getEmail()
if (email.isEmpty) { return "user email is Empty" }
return email
}
public func doKatieTask(link: String) -> Int {
guard let myValue = user.hasFailed else {
return -1
}
if (myValue) { return 1}
return 0
}
}
So, Now in the Controllers folder and since we a one-to-one relation we will use delegate design pattern. If had had one-to-many with the view controller. Use observers.
class ViewController: UIViewController {
#IBOutlet weak var nameTextField: UITextField!
#IBOutlet weak var emailTextField: UITextField!
var _hasFail: Bool!
override func viewDidLoad() {
super.viewDidLoad()
// Do any additional setup after loading the view.
}
#IBAction func doTask() {
UserManager.instance.userName(name: nameTextField.text!)
UserManager.instance.userEmail(email: emailTextField.text!)
switch UserManager.instance.doKatieTask(link: emailTextField.text!) {
case 0:
_hasFail = false
break
case 1:
_hasFail = true
break
default:
print("hasFailed is nil")
break
}
if let vc = storyboard?.instantiateViewController(identifier: "passwordVC") as? PasswordResetViewController {
vc.modalPresentationStyle = .fullScreen
vc.delegate = self
self.present(vc, animated: true, completion: nil)
}
}
}
extension ViewController: KatieDelegate {
var hasFailed: Bool {
get {
return _hasFail
}
set {
_hasFail = newValue
}
}
}
In PasswordReset UIViewController
protocol KatieDelegate {
var hasFailed: Bool { get set }
}
class PasswordResetViewController: UIViewController {
#IBOutlet weak var nameLabel: UILabel!
#IBOutlet weak var emailLabel: UILabel!
var delegate: KatieDelegate?
override func viewDidLoad() {
super.viewDidLoad()
nameLabel.text = UserManger.instance.getUserName()
emailLabel.text = UserManger.instance.getUserEmail()
if let delegate = delegate {
print("The value for has failed is: .....\(delegate.hasFailed)!")
}
else { print("error with delegate") }
}
}
I'm implementing my login-logic using Firebase with just Facebook as provider.
How can I save my CurrentUser after the login in order to use personal data during the app experience later?
At the moment I'm using a singleton with an instance of User. Something like this:
CurrentUser.swift
class CurrentUser {
static let i: CurrentUser = CurrentUser()
var cUser: User?
private init() {
}
func setCurrentUser(u: User) {
cUser = u
}
func getCurrentUser() -> User {
return cUser!
}
func clearUser() {
cUser = nil
}
func userIsLogged() -> Bool {
return cUser != nil
}
}
And I'm using that singleton this way:
LoginViewController.swift
class LoginViewController: UIViewController {
...
func createCurrentUser(authData: FAuthData) {
let u = User(uid: authData.uid, displayName: authData.providerData["displayName"] as! String, email: authData.providerData["email"] as! String)
u.wrapperFromFacebookData(authData.providerData)
ref.childByAppendingPath("users").childByAppendingPath(u.uid).setValue(u.toDict())
CurrentUser.i.setCurrentUser(u)
}
...
}
I don't think this is the best practice. Before Firebase I'm used to deal with Parse builtin user logic, that was pretty easier.
I am facing the exact problem and this link helped a lot: http://totallyswift.com/ios-app-development-part-2/
What he did was create a singleton (currentUser) that conforms with User class.
class var currentUser: User
{
struct Static
{
static var instance: User?
}
if Static.instance == nil
{
if let load: AnyObject = NSUserDefaults.standardUserDefaults().objectForKey(kUserDataKey)
{
Static.instance = User(data: load as [String: AnyObject])
}
else
{
Static.instance = User()
}
}
return Static.instance!
}
I am trying to create a common class for storing and retrieving data in Parse. I made the ParseProcessing class a singleton class. From my main View Controller I load the data and store it into a dictionary in the ParseProcessing. I do this by creating a shared instance of the ParseProcessing class. From another view controller I try to access the data from the dictionary. I assumed that because ParseProcessing is a singleton class that I have a single copy of the dictionary. This does not appear to be correct. How should I declare the variables inside the ParseProcessing so that they are shared? The code is shown below:
import UIKit
var gSep = ","
class QwikFileViewController: UIViewController {
var loadData = ParseProcessing.sharedInstance
override func viewDidLoad() {
super.viewDidLoad()
// load data from Parse
loadData.loadCategorySubcategoryData()
loadData.loadRecordsFromParse()
}
override func didReceiveMemoryWarning() {
super.didReceiveMemoryWarning()
}
}
ParseProcessing Singleton Class
import UIKit
import Parse
class ParseProcessing: Parse {
var dictMenuList = [String:String]()
var noteTitle = [String]()
var notes = [String]()
var thumbnailFiles = [PFFile]()
var objectIds = [String]()
var noteImage = UIImage()
class var sharedInstance:ParseProcessing {
struct singleton {
static let instance:ParseProcessing = ParseProcessing()
}
return singleton.instance
}
// Load Category/Subcategory data from Parse Data Base
func loadRecordsFromParse () -> Bool{
var tmpFile = [PFFile]()
var loadComplete = false
var query = PFQuery(className:"Record")
query.findObjectsInBackgroundWithBlock {
(objects, error) -> Void in
if error == nil {
// The find succeeded.
println("Successfully retrieved \(objects!.count) items.")
for object in objects! {
self.noteTitle.append(object["title"] as! String)
self.notes.append(object["notes"] as! String)
self.thumbnailFiles.append(object["thumbnail"] as! PFFile)
self.objectIds.append(String(stringInterpolationSegment: object.objectId))
}
} else {
println("\(error)")
}
loadComplete = true
}
return loadComplete
}
// Load Category/Subcategory data from Parse Data Base
func loadCategorySubcategoryData () // -> Dictionary <String,String>
{
var success : Bool = false
var d : Dictionary <String,String> = ["":""]
var menu = PFQuery(className: "Classification")
println("ParseProcessing: loadCategory...")
menu.findObjectsInBackgroundWithBlock {
(objects, error) -> Void in
if error == nil {
var category = ""
var subcategory = ""
for object in objects! {
category = object["category"] as! String
println("ParseProcessing: category = \(category)")
subcategory = object["subcategory"] as! String
println("ParseProcessing: subcategory = \(subcategory)")
d[category] = subcategory
}
success = true
self.dictMenuList = d
return
} else {
println("ParseProcessing: error = \(error)")
success = false
}
}
return
}
}
Another View Controller to examine the data
import UIKit
class TestViewController: UIViewController {
var dictMenuList = [String:String]()
var loadData = ParseProcessing.sharedInstance
override func viewDidLoad() {
super.viewDidLoad()
dictMenuList = loadData.dictMenuList
println("dictMenuList: \(dictMenuList)")
}
override func didReceiveMemoryWarning() {
super.didReceiveMemoryWarning()
}
}
The problem is that findObjectsInBackgroundWithBlock is asynchronous method (i.e. it returns immediately but the closure is called later when the query is done). So you cannot return loadComplete in loadRecordsFromParse, for example. This background request will almost certainly never be done by the time loadRecordsFromParse returns.
Instead, you probably want to adopt the completionHandler pattern. For example, this sample loadRecords doesn't try to return anything immediately, but rather will call the completionHandler when the request is done.
func loadRecords(completionHandler:([SomeObject]?, NSError?) -> ()) {
let query = PFQuery(className: "SomeClass")
query.findObjectsInBackgroundWithBlock { objects, error in
// build some model object
completionHandler(objectArray, error)
}
}
And you'd call it like so:
loadData.loadRecords() { objects, error in
// use `objects` (and make sure `error` is `nil`) here
}
// but do not use those variables here, as the above closure probably has not run yet!
Frankly, I'd be inclined to get rid of those properties in your singleton altogether. When you're dealing with asynchronous code, to have public properties that are updated asynchronously is going to be a source of heartache. You can do it, but it wouldn't be my first choice.
For example, when TestViewController is presented, you cannot assume that the asynchronous fetch associated with dictMenuList is done yet. I look at this and wonder if it makes sense for TestViewController to initiate the fetch itself and then use dictMenuList in the completion handler. That's going to be easiest.
If you must initiate the asynchronous request from one view controller and then have another view controller be informed when that asynchronous request is done, then you might have to use some other pattern, such as notifications (e.g. use NSNotificationCenter, and have the singleton post notifications when the various requests are done, and then any view controller that needs to be informed of this fact can add themselves as observers for that notification).
I am writing an app in swift and use a singleton to share a class object, User, across the app.
I want to be able to set this singleton to 'nil' when the user logs out, so that when they log back in the old properties no longer exists (i.e. name, username, etc).
I am hoping there is an easy way to just set the singleton back to nil, instead of having to set each property to nil.
Here is my User class that is used in the app as User.activeUser:
class User: NSObject
{
class var activeUser : User? {
struct Static {
static let instance : User = User()
}
return Static.instance
}
}
How can I change this so that the below code does not give me a warning and actually nils out the singleton object:
User.activeUser = nil
This should work:
private var _SingletonSharedInstance:MyClass! = MyClass()
class MyClass {
let prop = "test"
class var sharedInstance : MyClass {
return _SingletonSharedInstance
}
init () {}
func destroy() {
_SingletonSharedInstance = nil
}
}
But then the references to the object are still kept, so you need to do some additional things to invalidate method calls in the class.
Your activeUser is set up as a read-only computed property. Every time you call User.activeUser it is going to recompute the activeUser for you. In order to set it to nil you'll have to add some logic to determine whether or not a user is logged in outside of the computed property. Something like this would work:
class User: NSObject
{
private struct userStatus { static var isLoggedIn: Bool = true }
class var activeUser : User? {
get {
if userStatus.isLoggedIn {
struct Static {
static let instance : User = User()
}
return Static.instance
} else {
return nil
}
}
set(newUser) {
if newUser != nil {
userStatus.isLoggedIn = true
} else {
userStatus.isLoggedIn = false
}
}
}
}
Here has a solution I used in java, but also works in swift:
class Manager {
private static var manager: Manager?
static func instance() -> Manager {
if Manager.manager == nil {
Manager.manager = Manager()
}
return Manager.manager!
}
func destroy() {
Manager.manager = nil
}
}