Delegate Method is not called in Swift? - swift

Question

I want to pass a Bool value from on view controller to another without the help of segues. So i referred & got Delegates.
I have applied delegates in my App. But the Delegate method is not being called. I don't know where i am making the mistake.
So Please help me.
MainViewController
class MainViewController: UIViewController, WriteValueBackDelegate {
#IBOutlet weak var LoginButton: UIButton!
var LoggedInL :Bool?
override func viewDidLoad() {
super.viewDidLoad()
}
func writeValueBack(value: Bool) {
println("Delegate Method")
if (value == true){
LoginButton.setTitle("My Profile", forState:UIControlState.Normal)
}
}
Second View Controller
class LoginController: UIViewController {
#IBOutlet weak var LoginLabel: UILabel!
#IBOutlet weak var email: UITextField!
#IBOutlet weak var pwd: UITextField!
var LoggedInL :Bool?
var mydelegate: WriteValueBackDelegate?
override func viewDidLoad() {
super.viewDidLoad() }
override func didReceiveMemoryWarning() {
super.didReceiveMemoryWarning()
// Dispose of any resources that can be recreated.
}
#IBAction func onSubmit(sender: AnyObject) {
Alamofire.request(.GET, "http://www.jive.com/index.php/capp/user_verification/\(email.text)/\(pwd.text)")
.responseJSON { (_, _, data, _) in
println(data)
let json = JSON(data!)
let name = json["first_name"].stringValue
let status = json["valid_status"].intValue
println(status)
var e = self.email.text
println(e)
self.LoginLabel.text = "Hey \(name)!"
if status == 1{
println("Correect")
self.LoggedInL = true
self.mydelegate?.writeValueBack(true)
}else {
self.LoggedInL = false
println("Error")
}
}
navigationController!.popViewControllerAnimated(true)
}
}
protocol WriteValueBackDelegate {
func writeValueBack(value: Bool)
}

Answer 1

you didn't initialize the delegate, and no need to, delegates are usually for async callbacks. do that instead:
class MainViewController: UIViewController {
static var sharedInstace : MainViewController?;
#IBOutlet weak var LoginButton: UIButton!
var LoggedInL :Bool?
override func viewDidLoad() {
super.viewDidLoad()
MainViewController.sharedInstace = self; //this is better from init function
}
func writeValueBack(value: Bool) {
println("Delegate Method")
if (value == true){
LoginButton.setTitle("My Profile", forState:UIControlState.Normal)
}
}
}
in login view controller
MainViewController.sharedInstance?.writeValueBack(true)

Answer 2

In MainViewControlleryou need a reference of the LoginController instance maybe with an IBOutlet and then set the delegate in viewDidLoad
#IBOutlet weak var loginController : LoginController!
override func viewDidLoad() {
super.viewDidLoad()
loginController.mydelegate = self
}