Sending a string from one viewcontroller to another using delegate in swift - swift

Question

I'm trying to make a button click in PopupViewController fill a textfield in DagbogsindlaegViewController with a string "svimmelhed, ".
I'm not getting any errors when running the code, but the text is not there when i run the app simulation and press "ButtonPressSvimmelhed" in the class PopupViewController.
Is there a kind stranger who can help me and tell me what i am doing wrong?
Code below:
import UIKit
import EventKit
class DagbogsindlaegViewController: UIViewController{
#IBAction func BackToSVC(_ sender: Any){
self.performSegue(withIdentifier: "BackToSVCSegue", sender: self)
}
#IBAction func ToCalenderButtonPress(_ sender: Any) {
self.performSegue(withIdentifier: "ToCalenderSegue", sender: self)
}
override func viewDidLoad() {
super.viewDidLoad()
TitleTextField.delegate = self
DescriptionTextField.delegate = self
// Do any additional setup after loading the view.
}
#IBOutlet weak var TitleTextField: UITextField!
#IBOutlet weak var DescriptionTextField: UITextField!
func addEventToCalendar(title: String, description: String?, startDate: Date, endDate: Date, completion: ((_ success: Bool, _ error: NSError?) -> Void)? = nil) {
let eventStore = EKEventStore()
eventStore.requestAccess(to: .event, completion: { (granted, error) in
if (granted) && (error == nil) {
let event = EKEvent(eventStore: eventStore)
event.title = title
event.startDate = startDate
event.endDate = endDate
event.notes = description
event.calendar = eventStore.defaultCalendarForNewEvents
do {
try eventStore.save(event, span: .thisEvent)
} catch let e as NSError {
completion?(false, e)
return
}
completion?(true, nil)
} else {
completion?(false, error as NSError?)
}
})
}
#IBAction func ButtonPressGemDagbog(_ sender: Any) {
addEventToCalendar(title: "\(String(describing: TitleTextField.text!))", description: "\(String(describing: DescriptionTextField.text!))", startDate: NSDate() as Date, endDate: NSDate() as Date)
}
#IBAction func ButtonPressPopupMenu(_ sender: Any) {
let popOverVC = UIStoryboard(name: "Main", bundle: nil).instantiateViewController(withIdentifier: "PopupViewControllerID") as! PopupViewController
self.addChild(popOverVC)
popOverVC.view.frame = self.view.frame
self.view.addSubview(popOverVC.view)
popOverVC.didMove(toParent: self)
}
}
extension DagbogsindlaegViewController : UITextFieldDelegate {
func textFieldShouldReturn(_ textField: UITextField) -> Bool {
textField.resignFirstResponder()
return true
}
}
extension DagbogsindlaegViewController : TextFraPopupDelegate {
func Symptomer(Svimmelhed: String) {
TitleTextField.text = Svimmelhed
}
}
And the other view controller:
import UIKit
protocol TextFraPopupDelegate{
func Symptomer(Svimmelhed: String)
}
class PopupViewController: UIViewController {
var symptomDelegate: TextFraPopupDelegate?
override func viewDidLoad() {
super.viewDidLoad()
self.showAnimate()
self.view.backgroundColor = UIColor.black.withAlphaComponent(0.8)
// Do any additional setup after loading the view.
}
#IBAction func ButtonPressBackToDagbogsindlaeg(_ sender: Any) {
self.removeAnimate()
//self.view.removeFromSuperview()
}
func showAnimate()
{
self.view.transform = CGAffineTransform(scaleX: 1.3, y: 1.3)
self.view.alpha = 0.0;
UIView.animate(withDuration: 0.25, animations: {
self.view.alpha = 1.0
self.view.transform = CGAffineTransform(scaleX: 1.0, y: 1.0)
});
}
func removeAnimate()
{
UIView.animate(withDuration: 0.25, animations: {
self.view.transform = CGAffineTransform(scaleX: 1.3, y: 1.3)
self.view.alpha = 0.0;
}, completion:{(finished : Bool) in
if (finished)
{
self.view.removeFromSuperview()
}
});
}
#IBAction func ButtonPressSvimmelhed(_ sender: UIButton) {
if sender.isSelected {
sender.isSelected = false
} else {
sender.isSelected = true
}
symptomDelegate?.Symptomer(Svimmelhed: "Svimmelhed, ")
}
override func prepare(for segue: UIStoryboardSegue, sender: Any?) {
}
}

Answer 1

As mentioned in the comments the delegate is not set.
However in Swift there is a more convenient way to pass the string back to the presenting view controller, a callback closure. You get rid of the protocol and of the duty to set the delegate
Delete
protocol TextFraPopupDelegate{
func Symptomer(Svimmelhed: String)
}
In PopupViewController replace
var symptomDelegate: TextFraPopupDelegate?
with
var callback : ((String) -> Void)?
and
#IBAction func ButtonPressSvimmelhed(_ sender: UIButton) {
if sender.isSelected {
sender.isSelected = false
} else {
sender.isSelected = true
}
symptomDelegate?.Symptomer(Svimmelhed: "Svimmelhed, ")
}
with
#IBAction func ButtonPressSvimmelhed(_ sender: UIButton) {
sender.isSelected.toggle()
callback?("Svimmelhed, ")
}
In DagbogsindlaegViewController in ButtonPressPopupMenu add the closure
#IBAction func ButtonPressPopupMenu(_ sender: Any) {
let popOverVC = UIStoryboard(name: "Main", bundle: nil).instantiateViewController(withIdentifier: "PopupViewControllerID") as! PopupViewController
self.addChild(popOverVC)
popOverVC.view.frame = self.view.frame
popOverVC.callback = { string in
self.TitleTextField.text = string
}
self.view.addSubview(popOverVC.view)
popOverVC.didMove(toParent: self)
}
Finally delete
extension DagbogsindlaegViewController : TextFraPopupDelegate {
func Symptomer(Svimmelhed: String) {
TitleTextField.text = Svimmelhed
}
}
Notes:
The syntax (_ success: Bool, _ error: NSError?) -> Void)? is outdated. Since Swift 3 the parameter labels are gone, this is sufficient: (Bool, NSError?) -> Void)?
Don't use NS... classes in Swift if there are native counterparts for example Date
Please conform to the naming convention to name variables and functions / methods with a starting lowercase letter.
The syntax "\(String(describing: TitleTextField.text!))" is double redundant. You create a string from a string from a string. Replace it with TitleTextField.text!