How do I open a ViewController from #IBAction. In below #IBAction I tried to open a ViewController but I am getting Property 'self.navigation' not initialized at super.init call error:
// MARK: - IBActions
#IBAction func doAddCard() {
// OTHER CODE GOES HERE
let viewController = PaymentsStoryboard.confirmKyc()
navigation.pushViewController(viewController, animated: true)
//...
}
Full Code:
import UIKit
final class ManualCardAddView: UIView, XibInitializable, DialogKeyboardDelegate {
var completionHandler: ((CreditCard, String) -> Void)?
private unowned let navigation: UINavigationController
override init(frame: CGRect) {
super.init(frame: frame)
setup()
}
required init?(coder aDecoder: NSCoder) {
super.init(coder: aDecoder)
setup()
}
private func setup() {
loadFromXib()
// ...
}
#IBAction func doAddCard() {
let viewController = PaymentsStoryboard.confirmKyc()
navigation.pushViewController(viewController, animated: true)
// ...
}
}
How do I resolve above issue?
Thank You!
You need to change navigation to a mutable optional property, since it only gets set after the initialisation. All immutable properties (and mutable non-optional ones as well) must be set during initialisation.
So change
private unowned let navigation: UINavigationController
to
private unowned var navigation: UINavigationController?
Related
Either there is something weird in my project (Mojave, XCode10) or I am missing something very basic.
This is my whole code:
import Foundation
import Cocoa
class ViewController: NSViewController {
public init () {
super.init(nibName: nil, bundle: nil)
self.view = ConfigView(rect: NSRect(x: 0, y: 0, width: 400, height: 300))
print("2")
}
required init?(coder: NSCoder) {
fatalError("init(coder:) has not been implemented")
}
override func loadView() {
super.loadView()
print("3")
}
override func viewDidLoad() {
super.viewDidLoad()
print("4")
}
override func viewWillAppear() {
super.viewWillAppear()
print("5")
}
override func viewDidAppear() {
super.viewDidAppear()
print("6")
print("Is loaded: \(isViewLoaded)")
}
}
class ConfigView: NSView {
public init(rect: NSRect) {
super.init(frame: rect)
print("1")
}
required public init?(coder decoder: NSCoder) {
fatalError("init(coder:) has not been implemented")
}
}
I want to setup stuff in the viewDidLoad() method, but this method is never called. The console shows:
1
2
5
6
Is loaded: true
So, obviously loadView() and viewDidLoad() are not called, but afterwards when the view appeared isViewLoaded() shows true.
Why is that lifecycle method being ignored?
I suspect what is happening here is that since you are initializing the view property in the init function, when loadView() is called, it detects that the view has already been loaded and therefore does not call the viewDidLoad().
Have you tried putting the view instantiation into the loadView() function instead of the init? In any case, I would not recommend creating the view in the init function.
If you implement loadView, you must not call super. And you must make a view and assign it as self.view. Fix that and all will be well. Of course, in real life, you would never implement loadView, so all this is academic.
How to navigate PushViewController from UIView class to New View Controller, Till now what I tried with delegate/ protocol but still no success from button click, below is the swift code what I tried to navigate from uiview class
protocol MyViewDelegate {
func didTapButton()
}
class Ticket : UIView {
static let instance = Ticket()
#IBOutlet var parentView: UIView!
#IBOutlet weak var ticketView: UIView!
var delegate : MyViewDelegate?
override init (frame: CGRect) {
super.init(frame: frame)
Bundle.main.loadNibNamed("Ticket", owner: self, options: nil)
}
#IBAction func btnHistoryTicket(_ sender: ThemeButtonTicket) {
}
#IBAction func btnNewTicket(_ sender: ThemeButtonTicket) {
func buttonTapAction() {
delegate?.didTapButton() // Expect to navigate
}
}
required init?(coder: NSCoder) {
fatalError("init(coder:) has not been implemented")
}
func showTicket(){
UIApplication.shared.windows.first{$0.isKeyWindow}?.addSubview(parentView)
}
}
class ViewController: UIViewController, MyViewDelegate {
override func viewDidLoad() {
super.viewDidLoad()
let ticket = Ticket()
ticket.delegate = self
}
func didTapButton() {
let vc = kMainStoryboard.instantiateViewController(withIdentifier: "SubmitTicketVC") as! SubmitTicketVC
self.navigationController?.pushViewController(vc, animated: true)
}
}
I have the following swift file which controls a xib file
import UIKit
protocol SelectProfile: class {
func selectionUp(id: Int, selected: Bool)
}
class Component: UIView {
#IBOutlet weak var name: UILabel!
#IBOutlet weak var selection: UIView!
var selected: Bool = false
var profileId: Int = 6
weak var delegate: SelectProfile?
#IBAction func selProfile(_ sender: Any) {
selected = !selected
selection.isHidden = !selected
delegate?.selectionUp(id: profileId, selected: selected)
}
let nibName = "Component"
required init?(coder aDecoder: NSCoder) {
super.init(coder: aDecoder)
commonInit()
}
override init(frame: CGRect) {
super.init(frame: frame)
commonInit()
}
func commonInit() {
guard let view = loadViewFromNib() else { return }
view.frame = self.bounds
self.addSubview(view)
selection.isHidden = true
name.text = String(profileId)
}
func loadViewFromNib() -> UIView? {
let nib = UINib(nibName: nibName, bundle: nil)
return nib.instantiate(withOwner: self, options: nil).first as? UIView
}
}
In my UIViewController where I want to interact with the component I have the following code (shortened for brevity)
import UIKit
class Home: UIViewController, SelectProfile {
#IBOutlet weak var profileComponent: Component!
func selectionUp(id: Int, selected: Bool) {
print(id, selected)
}
override func viewDidLoad() {
profileComponent.delegate = self
profileComponent.profileId = 2
}
}
My delegate works nicely and I'm able to change the values for IBOutlets but I can't pass a value to variables. This line doesn't pass the data to my xib profileComponent.profileId = 2.
It seems like I have an issue with initialization of the xib but I don't know how to fix it.
The viewDidLoad of controller is called after view's init, so when you change profileId as you do, it is changed, but not reflected anywhere.
I assume the following, at least, missed:
var profileId: Int = 6 {
didSet {
name.text = String(profileId)
// call delegate here if needed as well
}
}
I have instantiated and initialized a subclass of NSDatePicker in AppDelegate -> applicationDidFinishLaunching and overrode mouseDown(with event: NSEvent)in the datePicker subclass. When I press the mouse button in the datePicker and break in its overridden mouseDown func the instance is not the one I instantiated in applicationDidFinishLaunching and so is not initialized.
I've tried creating the instance at different entry points thinking it might be a timing thing but I've gotten nowhere. I'm out of ideas and feeling a little feeble. Any Help?
The datePicker:
import Cocoa
class AlarmIVDatePicker: NSDatePicker {
var viewController: ViewController!
override func draw(_ dirtyRect: NSRect) {
super.draw(dirtyRect)
}
override func acceptsFirstMouse(for event: NSEvent?) -> Bool {
return true
}
override func mouseDown(with event: NSEvent) {
let stop = 0
}
}
The ViewController:
class ViewController: NSViewController, NSWindowDelegate{
var alarmIVDatePicker: AlarmIVDatePicker!
override func viewDidLoad() {
super.viewDidLoad()
alarmIVDatePicker = AlarmIVDatePicker()
alarmIVDatePicker.viewController = self
}
I expected I could access the values I had set but the instance is not the one I created and all the values are nil
Okay. Here's what you can do to track this down. Add this code to your AlarmIVDatePicker class:
override init(frame frameRect: NSRect) {
Swift.print("AlarmIVDatePicker being called here")
super.init(frame: frameRect)
}
convenience init() {
self.init(frame: .zero)
}
required init?(coder: NSCoder) {
Swift.print("hey, you DID drop this into a storyboard or XIB file!")
super.init(coder: coder)
}
If you set breakpoints inside these init methods, you'll catch when and where they are being called where you did not expect.
Error occurs when I set UITextField delegate.
My code is:
import UIKit
class UserAlertVC: UIView , UITextFieldDelegate {
/*
// Only override draw() if you perform custom drawing.
// An empty implementation adversely affects performance during animation.
override func draw(_ rect: CGRect) {
// Drawing code
}
*/
override init(frame: CGRect) {
super.init(frame: frame)
}
required init(coder aDecoder: NSCoder) {
super.init(coder: aDecoder)!
self.addBehavior()
}
func addBehavior (){
print("Add all the behavior here")
userNameTxtField.delegate = self
passwordTxtField.delegate = self
}
func textFieldShouldReturn(textField: UITextField) -> Bool {
return true
}
func textFieldDidBeginEditing(textField: UITextField) {
}
#available(tvOS 10.0, *)
func textFieldDidEndEditing(textField: UITextField, reason: UITextFieldDidEndEditingReason) {
}
#IBAction func actionOnCancel(sender: UIButton) {
self .removeFromSuperview()
}
#IBAction func actionOnProceed(sender: UIButton) {
self .removeFromSuperview()
UserAlertVC.showAlertForUser()
}
#IBOutlet var userNameTxtField: UITextField!
#IBOutlet var passwordTxtField: UITextField!
static func showAlertForUser() {
let alert = NSBundle.mainBundle().loadNibNamed("KeyboardViewController", owner: self, options: nil)!.last as! UIView
let windows = UIApplication.sharedApplication().windows
let lastWindow = windows.last
alert.frame = UIScreen.mainScreen().bounds
lastWindow?.addSubview(alert)
}
}
Error message is:
fatal error: unexpectedly found nil while unwrapping an Optional value
I have used Custom Alert View using XIB.pls suggest any solution.
Firstly take a look at life cycle of the view. Depending on this it is possible to highlight that method awakeFromNib is quite suitable because:
The nib-loading infrastructure sends an awakeFromNib message to each
object recreated from a nib archive, but only after all the objects in
the archive have been loaded and initialized. When an object receives
an awakeFromNib message, it is guaranteed to have all its outlet and
action connections already established.
Make sure to put an #IBOutlet for the .Xib content view, also you need to add the Nib code. Last, make sure in your ViewController you set your UIView Outlet to be UserAlertVC and you add the awakeFromNib method. Please find attached the code. Let me know if you need further help.
Here is the code related to the .xib file.
import UIKit
class UserAlertVC: UIView, UITextFieldDelegate {
//MARK: - Outlets
#IBOutlet var contentView: UIView!
#IBOutlet var userNameTxtField: UITextField!
#IBOutlet var passwordTxtField: UITextField!
//MARK: - Loads
override init(frame: CGRect) {
super.init(frame: frame)
commonInit()
}
required init(coder aDecoder: NSCoder) {
super.init(coder: aDecoder)!
commonInit()
}
//MARK: - Functions
func commonInit() {
Bundle.main.loadNibNamed("UserAlertVC", owner: self, options: nil)
userNameTxtField.delegate = self
passwordTxtField.delegate = self
contentView.translatesAutoresizingMaskIntoConstraints = false
addSubview(contentView)
// add constraints programmatically
}
// add the rest of your code
}
Here is the code related to the ViewController.
class ViewController: UIViewController {
//MARK: - Outlets
#IBOutlet weak var userAlertVC: UserAlertVC!
//MARK: - Loads
override func viewDidLoad() {
super.viewDidLoad()
}
override func awakeFromNib() {
super.awakeFromNib()
}
}