Swift & Parse - PFUser currentUser never equals ni

2020-05-24 17:07发布

问题:

I am using Xcode, Swift, and Parse. When I try and logout a PFUser, i never get a return of nil.

In this part of the app, the viewController is simply showing a few buttons one logs in. One sends the user to signup. One sends the user to change details, and one is a simple logout.

The code for the two that matter on logout is;

@IBAction func logout(sender: AnyObject) {

    PFUser.logOut()
    var currentUser = PFUser.currentUser()

    self.displayAlert("You are now logged out", error: "")

    println(currentUser!)
}

@IBAction func changeDetails(sender: AnyObject) {

    var currentUser = PFUser.currentUser()

    println(currentUser!)

        if currentUser != nil {

            let nextView30 = self.storyboard?.instantiateViewControllerWithIdentifier("changeDetails") as! changeUserDetailsViewController

           self.navigationController?.pushViewController(nextView30, animated: true)

    } else {

        self.displayAlert("Please log in", error: "")

    }

}

Once the code runs and I logout, wherever the currentUser gets read I get the following type of response, not nil. The next ViewController is actioned, and this shouldn't happen without a usr logged in.

PFUser: 0x37018fbc0, objectId: new, localId: local_3b5eb7453f9af5ed { }

Am I doing something wrong or is this standard? If it is correct, how do I return no user logged in?

Thanks

回答1:

    if PFUser.currentUser()!.username != nil
    {
        self.performSegueWithIdentifier("loginSegue", sender: self)
    }

The above code worked for the login issue. But i still have the logout issue. After I call PFUser.logout(), PFUser.currentUser() is not becoming nil. Any help?

Thanks



回答2:

I've been struggling with logging out for a little while and I believe I have finally cracked it!

No matter what I did, when I used "PFUser.logOut()" would never set "PFUser.currentUser()" to nil, but it would set "PFUser.currentUser()!.username" to nil...

Because of this I used

var currentUser = PFUser.currentUser()!.username

as a global variable to track is a user is logged in.

On my login/first page I added

override func viewDidAppear(animated: Bool) {

    if currentUser != nil {

        self.performSegueWithIdentifier("login", sender: self)

    }

}

and finally on my logout button i used

override func prepareForSegue(segue: UIStoryboardSegue, sender: AnyObject?) {

    if segue.identifier == "logout" {

        PFUser.logOut() //Log user out

        currentUser = PFUser.currentUser()!.username //Reset currentUser variable to nil

    }

}

I hope that helps!



回答3:

Try commenting out the following line of code in your AppDelegate.swift file -

PFUser.enableAutomaticUser()

enableAutomaticUser() will log in an anonymous user once you call PFUser.logOut(), and the username for an anonymous user is nil.



回答4:

override func viewDidLoad(animated: Bool) {

var currentUser = PFUser.currentUser()?.username if(currentUser != nil){ var loginAlert: UIAlertController = UIAlertController(title: "Signup/ Login", message:"Please Signup or Login" , preferredStyle: UIAlertControllerStyle.Alert) loginAlert.addTextFieldWithConfigurationHandler({ textfield in textfield.placeholder = "Your Username" }) loginAlert.addTextFieldWithConfigurationHandler({ textfield in textfield.placeholder = "Your Password" textfield.secureTextEntry = true }) loginAlert.addAction(UIAlertAction(title: "Login", style: UIAlertActionStyle.Default, handler: {alertAction in let textFields: NSArray = loginAlert.textFields! as NSArray let usernameTextFields: UITextField = textFields.objectAtIndex(0) as! UITextField let passwordTextFields: UITextField = textFields.objectAtIndex(1) as! UITextField PFUser.logInWithUsernameInBackground(usernameTextFields.text as String!, password: passwordTextFields.text as String!){ (loggedInuser: PFUser?, signupError: NSError?) -> Void in if((loggedInuser) != nil){ println("User logged in successfully") }else{ println("User login failed") } } })) loginAlert.addAction(UIAlertAction(title: "SignUp", style: UIAlertActionStyle.Default, handler: {alertAction in let textFields: NSArray = loginAlert.textFields! as NSArray let usernameTextFields: UITextField = textFields.objectAtIndex(0) as! UITextField let passwordTextFields: UITextField = textFields.objectAtIndex(1) as! UITextField var sweeter : PFUser = PFUser() sweeter.username = usernameTextFields.text sweeter.password = passwordTextFields.text sweeter.signUpInBackgroundWithBlock {(sucess,error) -> Void in if !(error != nil){ println("sign up success") }else { println("constant error string\(error)") } } })) self.presentViewController(loginAlert, animated: true, completion: nil) } }