Why custom delegate protocol contains an optional value - SWIFT - ios

Question

I am trying to create a custom delegate that sends an integer value to the main parent ViewController class. I set up a protocol and implemented on the parent class. The optional binding code always shows an optional value. Why is this happening although i have set the delegate value from my UIViewController class?
protocol SendMessage{
func sendViewMessage(Int)
}
class BankLoginView: UIView,UITextFieldDelegate {
var delegate1 : SendMessage?
// var accountViewController:UIViewController=AccountLanding()
override init(frame: CGRect) {
super.init(frame: frame)
}
#IBAction func btnTickAction(sender: AnyObject) {
if let temp = self.delegate1 {
delegate1?.sendViewMessage(2)
}else{
println("optional value contains nill value")
}
}
}
and i am setting the value of delegate as
class BankLogin: UIViewController ,SendMessage{
override func viewDidLoad() {
super.viewDidLoad()
let rect: CGRect = CGRect (x: 0, y :10 , width: self.view.frame.size.width-50, height: self.view.frame.size.height-10)
var a = BankLoginView(frame : rect)
a.delegate1 = BankLogin()
}
}

Answer 1

What you are doing is creating a new view of class BankLoginView
var a = BankLoginView(frame : rect)
The delegate of it will be a new BankLogin instance:
a.delegate1 = BankLogin()
When viewDidLoad() finishes var a is destroyed cause is not retained with any object.
Probably in the storyboard or nib file you've setted the view class of BankLogin as BankLoginView, but that view is not the same of that one you created in this line:
var a = BankLoginView(frame : rect)
Therefore, the delegate is not assigned and it prints "optional value contains nill value"
Declare BankLoginView as IBOutlet property:
#IBOutlet weak var bankLoginView: BankLoginView? (ensure the view is linked with the nib file)
and then in viewDidLoad() do:
bankLoginView.delegate1 = self; (you can do this in Interface Builder too)

Answer 2

A couple of things i noticed abut this code.
First you are unwrapping your optional delegate variable. but then using the optional variable rather than the unwrapped one. I would call the delegate like this:
#IBAction func btnTickAction(sender: AnyObject) {
if let actualDelegate = self.delegate1 {
actualDelegate.sendViewMessage(2)
}else{
println("optional value contains nill value")
}
Secondly you look like you are creating a new instance of the BankLogin view controller and setting that as the the delegate.
class BankLogin: UIViewController ,SendMessage{
override func viewDidLoad() {
super.viewDidLoad()
let rect: CGRect = CGRect (x: 0, y :10 , width: self.view.frame.size.width-50, height: self.view.frame.size.height-10)
var a = BankLoginView(frame : rect)
//Do you want to create a new instance of Bank login here?
//a.delegate1 = BankLogin()
// Perhaps should be
a.delegate1 = self
}