unwind segue in UIAlert not working - ios

Question

I am trying to present an alert to the user if they need to be logged in to access a feature but when I press the login button in the alert self.self.performSegueWithIdentifier("tryonToLogin", sender:self) does not appear to do anything.
LoginViewController
#IBAction func unwindToLogin(segue:UIStoryboardSegue){
}
UIAlert
#IBAction func goToGallery(sender: UIButton){
if(isLoggedIn){
performSegueWithIdentifier("ShowGallery", sender: sender)
}else{
showMessage("You must login to view access this feature", sender:sender)
}
}
func showMessage(popUpMessageText : String, sender:UIButton){
let messageTitle = "Error"
print("prepreform segue")
performSegueWithIdentifier("unwindToLogin", sender:sender)
let refreshAlert = UIAlertController(title: messageTitle, message: popUpMessageText, preferredStyle: UIAlertControllerStyle.Alert)
refreshAlert.addAction( UIAlertAction(title: "Login", style: .Default, handler: { (action: UIAlertAction!) in
print("Handle Login redirect logic here")
self.performSegueWithIdentifier("unwindToLogin", sender: self)
print("after Handle Login redirect logic here")
}))
refreshAlert.addAction(UIAlertAction(title: "Cancel", style: .Default, handler: { (action: UIAlertAction!) in
print("Handle Cancel logic here")
}))
presentViewController(refreshAlert, animated: true, completion: nil)
}
override func prepareForSegue(segue: UIStoryboardSegue, sender: AnyObject?) {
// Get the new view controller using segue.destinationViewController.
// Pass the selected object to the new view controller.
print("prepare for segue called")
self.camera = nil
}
There are no errors. it is getting called as if ii put in a id that does not exist i get the no segue with specified identifier found error message.
Does the UIAlert affect the calling of the performSegueWithIdentifier()
The following post uses this approach so I think it should work. what am i missing.
**IB Screenshots **
Edit
I have tried moving self.performSegueWithIdentifier("unwindToLogin", sender:self) to view did appear and it still is snot working.

Answer 1

The self inside the block is the UIAlertController, not the UIViewController. Create a weak reference to the UIViewController, and call the method on that object.
weak var weakSelf = self
let refreshAlert = UIAlertController(title: messageTitle, message: popUpMessageText, preferredStyle: UIAlertControllerStyle.Alert)
refreshAlert.addAction( UIAlertAction(title: "Login", style: .Default, handler: { (action: UIAlertAction!) in
print("Handle Login redirect logic here")
dispatch_async(dispatch_get_main_queue()) {
weakSelf?.performSegueWithIdentifier("unwindToLogin", sender:self)
}
}))

Answer 2

Seeing that you have not provide sufficient informations, I present you this 'solution'.
Create an extension of UIViewController in order to implement facility function to implement an alertView-
I suppose that you put your code on "viewDidLoad": you have to move code on "viewDidAppear".
please check what operation you do in prepareForSegue
I think this will be sufficient.
extension UIViewController {
/**
Show alert view with OK/Cancel button.
- parameter title: alert title
- parameter message: alert message
- parameter onOk: callback on ok button tapped
- parameter onCancel: callback on cancel button tapped
- returns: alert controller
*/
func showAlert(title title: String, message: String, onOk: (() -> ())?, onCancel: (() -> ())? = nil) -> UIAlertController {
let alertController = UIAlertController(title: title, message: message, preferredStyle: .Alert)
let okAction = UIAlertAction(title: "Ok", style: .Default) { (alert: UIAlertAction!) -> Void in
onOk?()
}
let cancelAction = UIAlertAction(title: "Cancel"), style: .Default) { (alert: UIAlertAction!) -> Void in
onCancel?()
}
alertController.addAction(okAction)
alertController.addAction(cancelAction)
self.presentViewController(alertController, animated: true, completion: nil)
return alertController
}
}
class LoginViewController: UIViewController {
override func viewDidAppear(animated: Bool) {
super.viewDidAppear(animated)
let title = "Login"
let message = messageTitle
self.showAlert(title: title, message: message, onOk: { () -> () in
self.performSegueWithIdentifier("unwindToLogin", sender: self)
})
}
}