I know lots of people may asked this question . i have also find the solution but i am not able to understand what is wrong in my code ?
popcontroller.swift:
protocol DataSendDelegate {
func sendgetattid(pop_att_id: Int, pop_in_time: String)
}
var delegate: DataSendDelegate? = nil
if statuss == "200" {
let send_pop_att_id = att_id
let send_pop_in_time = in_time
self.navigationController?.popViewController(animated: true)
self.dismiss(animated: true) {
self.delegate?.sendgetattid(pop_att_id: send_pop_att_id, pop_in_time: send_pop_in_time)
}
}
In the above code i get the correct value but it does not dismiss and go to next view controller .
attendanceViewController.swift:
class attendanceViewController: UIViewController , DataSendDelegate {
func sendgetattid(pop_att_id: Int, pop_in_time: String) {
DispatchQueue.main.async {
self.inTimeTextField.text = pop_in_time
self.get_att_id = pop_att_id
self.in_time_button.isEnabled = false
self.out_time_button.isEnabled = true
}
}
override func prepare(for segue: UIStoryboardSegue, sender: Any?) {
if let popVC = segue.destination as? PopUpViewController
{
popVC.popEmailID = att_emp_id
popVC.delegate = self
}
}
}
Update from your comment:
You didn't present viewController. You have pushed some view controller. So Just pop it. discard the dismiss
self.delegate?.sendgetattid(pop_att_id: send_pop_att_id, pop_in_time: send_pop_in_time)
self.navigationController?.popViewController(animated: true)
If you did self.present(ViewController, animated: true, completion: nil) from the previous ViewController to show the current viewcontroller, you must do
self.dismiss(animated: true) {
self.delegate?.sendgetattid(pop_att_id: send_pop_att_id, pop_in_time: send_pop_in_time)
}
or if you did self.navigationController?.pushViewController(ViewController, animated: true) you must do self.navigationController?.popViewController(animated: true)
Related
I've followed the instructions here but I'm still unsure about this part:
modalVC.delegate=self;
self.presentViewController(modalVC, animated: true, completion: nil)
I've tried instantiating the view controller programmatically but still to no avail.
here's my code for when dismissing the modal view controller:
#IBAction func dismissViewController(_ sender: UIBarButtonItem) {
self.dismiss(animated: true) {
//
}
}
I'm using storyboard to segue with modal view.
This is the data I wish to transfer back to the parent view controller:
var typeState = "top"
var categoryState = "casual"
Which are two String values.
I've tried to pass data from the modal view controller as shown:
#IBAction func dismissViewController(_ sender: UIBarButtonItem) {
self.dismiss(animated: true, completion: nil)
delegate?.sendValue(value: "success")
if let presenter = presentingViewController as? OOTDListViewController {
presenter.receivedValue = "test"
}
}
whereas on the parent view controller I did as such:
func sendValue(value: NSString) {
receivedValue = value as String
}
#IBAction func printReceivedValue(_ sender: UIButton) {
print(receivedValue)
}
I still couldnt receive any value when I hit the print button.
Modal view controller:
protocol ModalViewControllerDelegate
{
func sendData(typeState: String, categoryState: String)
}
var delegate:ModalViewControllerDelegate!
var typeState = "top"
var categoryState = "casual"
#IBAction func dismissViewController(_ sender: UIBarButtonItem) {
self.dismiss(animated: true, completion: nil)
delegate?.sendData(typeState: typeState as String, categoryState: categoryState as String)
}
Parent view controller:
class parentViewController: UICollectionViewController, ModalViewControllerDelegate {
var typeState: String?
var categoryState: String?
func sendData(typeState: String, categoryState: String) {
self.typeState = typeState as String
self.categoryState = categoryState as String
}
#IBAction func printReceivedValue(_ sender: UIButton) {
print(typeState)
}
Here's my new code without using delegate method:
Modal view Controller:
#IBAction func dismissViewController(_ sender: UIBarButtonItem) {
self.dismiss(animated: true, completion: nil)
if let presenter = presentingViewController as? OOTDListViewController {
presenter.typeState = typeState
presenter.categoryState = categoryState
}
}
OOTDListViewController:
#IBAction func presentModalView(_ sender: UIBarButtonItem) {
let modalView = storyboard?.instantiateViewController(withIdentifier: "filterViewController") as! ModalViewController
let navModalView: UINavigationController = UINavigationController(rootViewController: modalView)
self.present(navModalView, animated: true, completion: nil)
}
#IBAction func printValue(_ sender: UIButton) {
print(typeState)
print(categoryState)
}
Depending on the data you want to pass, you can create a property in the presenting view controller, which you can set when dismissing the modal view controller, so you can spare yourself the delegate.
For example, you have a ContactsViewController, holding a var contacts: [Contact] = [] property. When you want to create a new contact, you present a modal view controller with the different values you need to create a new Contact object. When you are done and want to dismiss the view controller, you call the function as you did in your code, but set the property in the ContactsViewController. It will look something like this:
#IBAction func dismissViewController(_ sender: UIBarButtonItem) {
if let presenter = presentingViewController as? ContactsViewController {
presenter.contacts.append(newContact)
}
dismiss(animated: true, completion: nil)
}
If you don't want to use a delegate, this is how you go about it:
In your OOTDListViewController :
var testValue: String = ""
#IBAction func printReceivedValue(_ sender: UIButton) {
print(testValue)
}
In your modal view controller (I'll call it PresentedViewController) :
#IBAction func dismissViewController(_ sender: UIBarButtonItem) {
// if your OOTDListViewController is part of a UINavigationController stack, this check will probably fail.
// you need to put a breakpoint here and check if the presentingViewController is actually a UINavigationController.
// in that case, you will need to access the viewControllers variable and find your OOTDListViewController
if let presenter = presentingViewController as? OOTDListViewController {
presenter.testValue = "Test"
}
dismiss(animated: true, completion: nil)
}
If you want to use a delegate, this is how to do it:
In your OOTDListViewController:
protocol ModalDelegate {
func changeValue(value: String)
}
class OOTDListViewController: ModalDelegate {
var testValue: String = ""
#IBAction func presentViewController() {
// here, you either create a new instance of the ViewController by initializing it, or you instantiate it using a storyboard.
// for simplicity, I'll use the first way
// in any case, you cannot use a storyboard segue directly, bevause you need access to the reference of the presentedViewController object
let presentedVC = PresentedViewController()
presentedVC.delegate = self
present(presentedVC, animated: true, completion: nil)
}
func changeValue(value: String) {
testValue = value
print(testValue)
}
}
In your PresentedViewController:
class PresentedViewController {
var delegate: ModalDelegate?
var testValue: String = ""
#IBAction func dismissViewController(_ sender: UIBarButtonItem) {
if let delegate = self.delegate {
delegate.changeValue(testValue)
}
dismiss(animated: true, completion: nil)
}
}
If using a navigation controller you will have to first grab the UINavigation Controller and then get the correct ViewController from the Navigation Controller stack.
Here's how my code looked in that case.
#IBAction func dismissViewController(_ sender: UIBarButtonItem) {
if let navController = presentingViewController as? UINavigationController {
let presenter = navController.topViewController as! OOTDListViewController
presenter.testValue = "Test"
}
dismiss(animated: true, completion: nil)
}
I am using the a tab bar so the working code is as below:
if let tabBar = self.presentingViewController as? UITabBarController {
let homeNavigationViewController = tabBar.viewControllers![0] as? UINavigationController
let homeViewController = homeNavigationViewController?.topViewController as! HomeController
homeViewController._transferedLocationID = self.editingLocationID!
}
You need to call the delegate method in dismissViewController method
#IBAction func dismissViewController(_ sender: UIBarButtonItem) {
delegate?.sendData(typeState: "top", categoryState: "casual")
self.dismiss(animated: true) {
//
}
}
in you Modal ViewController class create delegate
weak var delegate: MyProtocol?
create a protocol with the method name sendData in MyProtocol and in your presentingViewController where you are assigning the delegate, implement the MyProtocol method
protocol MyProtocol: AnyObject {
func sendData(typeState: String, categoryState: String)
}
class ViewController: UIViewController, MyProtocol {
var typeState: String?
var categoryState: String?
override func viewDidApear() {
super.viewDidApear()
presentNewModalVC()
}
func presentNewModalVC() {
let modalVC = NewModalViewControllerToBePresented()
modalVC.delegate = self
present(modalVC, animated: true)
}
func sendData(typeState: String, categoryState: String) {
self.typeState = typeState
self.categoryState = categoryState
}
}
I want to make a weather application by adding a city name with openweathermap api. But I could not send the city I added in AddCityViewController back to HomeViewController. Because, self?.delegate is nil, in AddCityViewController.swift
#objc private func didTapSaveButton() {
print("clicked save button")
if let city = cityTextfield.text {
let weatherURL = URL(string: "https://api.openweathermap.org/data/2.5/weather?q=\(city)&APPID=b4251cb51691654da529bccf471596bc&units=imperial")!
let weatherResource = Resource<WeatherViewModel>(url: weatherURL) { data in
let weatherVM = try? JSONDecoder().decode(WeatherViewModel.self, from: data)
return weatherVM
}
Webservice().load(resource: weatherResource) { [weak self] result in
if let weatherVM = result {
if let delegate = self?.delegate {
delegate.addWeatherDidSave(vm: weatherVM)
self?.dismiss(animated: true, completion: nil)
}
}
}
}
}
When I debug the prepare function in HomeViewController.swift was not getting called.
override func prepare(for segue: UIStoryboardSegue, sender: Any?) {
guard let nav = segue.destination as? UINavigationController else {
fatalError("NavigationController not found")
}
guard let addWeatherCityVC = nav.viewControllers.first as? AddCityViewController else {
fatalError("AddWeatherCityController not found")
}
addWeatherCityVC.delegate = self
}
What I want is, I want to pass the city name back to HomeViewController when user press the save button.
extension HomeViewController: AddWeatherDelegate {
func addWeatherDidSave(vm: WeatherViewModel) {
print(vm.name)
}
}
Source code in GitHub
You are not using segue for navigation, so the prepareForSegue method won't get triggered. In your code, you are manually initialising an instance of AddCityViewController and presenting it. So to fix the issue, you have to set delegate to that instance.
#objc private func didTapAddButton() {
let vc = AddCityViewController()
vc.title = "Add City"
vc.delegate = self
let nav = UINavigationController(rootViewController: vc)
nav.modalPresentationStyle = .fullScreen
present(nav, animated: true)
}
Or else you can use segue for navigation.
I've followed the instructions here but I'm still unsure about this part:
modalVC.delegate=self;
self.presentViewController(modalVC, animated: true, completion: nil)
I've tried instantiating the view controller programmatically but still to no avail.
here's my code for when dismissing the modal view controller:
#IBAction func dismissViewController(_ sender: UIBarButtonItem) {
self.dismiss(animated: true) {
//
}
}
I'm using storyboard to segue with modal view.
This is the data I wish to transfer back to the parent view controller:
var typeState = "top"
var categoryState = "casual"
Which are two String values.
I've tried to pass data from the modal view controller as shown:
#IBAction func dismissViewController(_ sender: UIBarButtonItem) {
self.dismiss(animated: true, completion: nil)
delegate?.sendValue(value: "success")
if let presenter = presentingViewController as? OOTDListViewController {
presenter.receivedValue = "test"
}
}
whereas on the parent view controller I did as such:
func sendValue(value: NSString) {
receivedValue = value as String
}
#IBAction func printReceivedValue(_ sender: UIButton) {
print(receivedValue)
}
I still couldnt receive any value when I hit the print button.
Modal view controller:
protocol ModalViewControllerDelegate
{
func sendData(typeState: String, categoryState: String)
}
var delegate:ModalViewControllerDelegate!
var typeState = "top"
var categoryState = "casual"
#IBAction func dismissViewController(_ sender: UIBarButtonItem) {
self.dismiss(animated: true, completion: nil)
delegate?.sendData(typeState: typeState as String, categoryState: categoryState as String)
}
Parent view controller:
class parentViewController: UICollectionViewController, ModalViewControllerDelegate {
var typeState: String?
var categoryState: String?
func sendData(typeState: String, categoryState: String) {
self.typeState = typeState as String
self.categoryState = categoryState as String
}
#IBAction func printReceivedValue(_ sender: UIButton) {
print(typeState)
}
Here's my new code without using delegate method:
Modal view Controller:
#IBAction func dismissViewController(_ sender: UIBarButtonItem) {
self.dismiss(animated: true, completion: nil)
if let presenter = presentingViewController as? OOTDListViewController {
presenter.typeState = typeState
presenter.categoryState = categoryState
}
}
OOTDListViewController:
#IBAction func presentModalView(_ sender: UIBarButtonItem) {
let modalView = storyboard?.instantiateViewController(withIdentifier: "filterViewController") as! ModalViewController
let navModalView: UINavigationController = UINavigationController(rootViewController: modalView)
self.present(navModalView, animated: true, completion: nil)
}
#IBAction func printValue(_ sender: UIButton) {
print(typeState)
print(categoryState)
}
Depending on the data you want to pass, you can create a property in the presenting view controller, which you can set when dismissing the modal view controller, so you can spare yourself the delegate.
For example, you have a ContactsViewController, holding a var contacts: [Contact] = [] property. When you want to create a new contact, you present a modal view controller with the different values you need to create a new Contact object. When you are done and want to dismiss the view controller, you call the function as you did in your code, but set the property in the ContactsViewController. It will look something like this:
#IBAction func dismissViewController(_ sender: UIBarButtonItem) {
if let presenter = presentingViewController as? ContactsViewController {
presenter.contacts.append(newContact)
}
dismiss(animated: true, completion: nil)
}
If you don't want to use a delegate, this is how you go about it:
In your OOTDListViewController :
var testValue: String = ""
#IBAction func printReceivedValue(_ sender: UIButton) {
print(testValue)
}
In your modal view controller (I'll call it PresentedViewController) :
#IBAction func dismissViewController(_ sender: UIBarButtonItem) {
// if your OOTDListViewController is part of a UINavigationController stack, this check will probably fail.
// you need to put a breakpoint here and check if the presentingViewController is actually a UINavigationController.
// in that case, you will need to access the viewControllers variable and find your OOTDListViewController
if let presenter = presentingViewController as? OOTDListViewController {
presenter.testValue = "Test"
}
dismiss(animated: true, completion: nil)
}
If you want to use a delegate, this is how to do it:
In your OOTDListViewController:
protocol ModalDelegate {
func changeValue(value: String)
}
class OOTDListViewController: ModalDelegate {
var testValue: String = ""
#IBAction func presentViewController() {
// here, you either create a new instance of the ViewController by initializing it, or you instantiate it using a storyboard.
// for simplicity, I'll use the first way
// in any case, you cannot use a storyboard segue directly, bevause you need access to the reference of the presentedViewController object
let presentedVC = PresentedViewController()
presentedVC.delegate = self
present(presentedVC, animated: true, completion: nil)
}
func changeValue(value: String) {
testValue = value
print(testValue)
}
}
In your PresentedViewController:
class PresentedViewController {
var delegate: ModalDelegate?
var testValue: String = ""
#IBAction func dismissViewController(_ sender: UIBarButtonItem) {
if let delegate = self.delegate {
delegate.changeValue(testValue)
}
dismiss(animated: true, completion: nil)
}
}
If using a navigation controller you will have to first grab the UINavigation Controller and then get the correct ViewController from the Navigation Controller stack.
Here's how my code looked in that case.
#IBAction func dismissViewController(_ sender: UIBarButtonItem) {
if let navController = presentingViewController as? UINavigationController {
let presenter = navController.topViewController as! OOTDListViewController
presenter.testValue = "Test"
}
dismiss(animated: true, completion: nil)
}
I am using the a tab bar so the working code is as below:
if let tabBar = self.presentingViewController as? UITabBarController {
let homeNavigationViewController = tabBar.viewControllers![0] as? UINavigationController
let homeViewController = homeNavigationViewController?.topViewController as! HomeController
homeViewController._transferedLocationID = self.editingLocationID!
}
You need to call the delegate method in dismissViewController method
#IBAction func dismissViewController(_ sender: UIBarButtonItem) {
delegate?.sendData(typeState: "top", categoryState: "casual")
self.dismiss(animated: true) {
//
}
}
in you Modal ViewController class create delegate
weak var delegate: MyProtocol?
create a protocol with the method name sendData in MyProtocol and in your presentingViewController where you are assigning the delegate, implement the MyProtocol method
protocol MyProtocol: AnyObject {
func sendData(typeState: String, categoryState: String)
}
class ViewController: UIViewController, MyProtocol {
var typeState: String?
var categoryState: String?
override func viewDidApear() {
super.viewDidApear()
presentNewModalVC()
}
func presentNewModalVC() {
let modalVC = NewModalViewControllerToBePresented()
modalVC.delegate = self
present(modalVC, animated: true)
}
func sendData(typeState: String, categoryState: String) {
self.typeState = typeState
self.categoryState = categoryState
}
}
My table view cell displays an entity with two different button elements. I want to be able to launch a view controller that displays a selection of food items if I click on the first button and a different view controller that displays a selection of beverages when I click on the second button.
I am able to correctly pass the data to the new view controllers, but can't seem to dismiss the current view and load the new one. My code is like this:
In the table view cell
#IBAction func foodBtnPressed(_ sender: Any) {
print("foodBtn pressed")
print("customer is \(customer?.name)")
vc.loadChooserScreen(toChoose: "Food", forCustomer: customer!)
}
#IBAction func beverageBtnPressed(_ sender: UIButton) {
print("beverageBtn pressed")
print("customer is \(customer?.name)")
vc.loadChooserScreen(toChoose: "Beverage", forCustomer: customer!)
}
In the table view controller
func loadChooserScreen(toChoose: String, forCustomer: Customer) {
print("Choose \(toChoose)")
print("For \(forCustomer.name)")
if toChoose == "Food" {
let foodVC = UIStoryboard(name: "Main", bundle: nil).instantiateViewController(withIdentifier: "foodMenu") as? FoodVC
foodVC?.loadCustomerToEdit(customer: forCustomer)
dismissVC(sender: Any.self)
}
else if toChoose == "Beverage" {
let beverageVC = UIStoryboard(name: "Main", bundle: nil).instantiateViewController(withIdentifier: "beverageMenu") as? BeverageVC
beverageVC?.loadCustomerToEdit(customer: forCustomer)
dismissVC(sender: Any.self)
}
else {
// do nothing
}
}
func dismissVC(sender: Any) {
print("Reached dismissVC function in selectionMenu")
dismiss(animated: true, completion: {
self.delegate!.dismissViewController()
})
}
In this view controller I also have the following protocol
protocol OrderVCProtocol {
func dismissViewController()
}
and have defined
var delegate: OrderVCProtocol!
In my root view controller
func dismissViewController() {
print("Reached dismissViewController function in rootView")
if let foodVC = self.storyboard?.instantiateViewController(withIdentifier: "foodMenu") {
self.present(foodVC, animated: true, completion: nil)
}
if let beverageVC = self.storyboard?.instantiateViewController(withIdentifier: "beverageMenu") {
self.present(beverageVC, animated: true, completion: nil)
}
}
And the delegate is set when the table view controller is called here
#IBAction func loadOrderView(_ sender: Any) {
let orderVC = self.storyboard?.instantiateViewController(withIdentifier: "orderView") as! OrderVC
orderVC.delegate = self
self.present(orderVC, animated: true, completion: nil)
}
Within my target view controllers I have the following function
func loadCustomerToEdit(customer: Customer) {
self.customerToEdit = customer
print("IN FoodVC THE CUSTOMER TO EDIT IS \(self.customerToEdit.name)")
}
and a corresponding one in the BeverageVC.
When I run the app, no errors are thrown and I get the following sample output in the console from my print statements:
foodBtn pressed
customer is Optional("John")
Choose Food
For Optional("John")
IN FoodVC THE CUSTOMER TO EDIT IS Optional("John")
Reached dismissVC function in selectionMenu
and a corresponding response if the beverage button is clicked.
Then nothing happens. So I know the data is correctly being passed to the new view controllers but I don't know how to dismiss the current screen and display the new one with the choices.
I hope my question is clear enough? I'm not sure what's wrong, but the console output clearly shows that the code runs fine until it tries to dismiss the current view.
EDITED TO ADD:
If I modify my dismissVC function in my tableview controller like this:
func dismissVC(sender: Any) {
print("Reached dismissVC function in selectionMenu")
delegate.dismissViewController()
}
the console view now throws
fatal error: unexpectedly found nil while unwrapping an Optional value
And if I modify it again to the following, It goes back to throwing no errors and getting stuck at the same place (i.e. printing the line "Stuck where delegate dismisses view"), showing that the delegate is still nil... but why is it nil when I'd set it in the root view and loaded it in this view?
func dismissVC(sender: Any) {
print("Reached dismissVC function in selectionMenu")
if delegate != nil {
delegate?.dismissViewController()
} else {
print("Stuck where delegate dismisses view")
}
I have solved my problem by implementing notifications via notification centre and delegates. Firstly, in my AppDelegate file I added this line at the bottom
let notifyCnt = NotificationCenter.default
Next, I modified my tableview cell functions to this
#IBAction func foodBtnPressed(_ sender: Any) {
notifyCnt.post(name: NSNotification.Name(rawValue: "toChoose"), object: nil, userInfo: ["toChoose": "Food", "forCustomer": customer])
}
#IBAction func beverageBtnPressed(_ sender: UIButton) {
notifyCnt.post(name: NSNotification.Name(rawValue: "toChoose"), object: nil, userInfo: ["toChoose": "Beverage", "forCustomer": customer])
}
Then, in the tableview controller I modified it to this:
protocol ChooserViewDelegate: class {
func loadChooserView(choice: String, forCustomer: Customer)
}
and defined
weak var delegate: ChooserViewDelegate?
and added this within my ViewDidLoad section
notifyCnt.addObserver(forName: Notification.Name(rawValue: "toChoose"), object: nil, queue: nil, using: loadChooserScreen)
and finally modified my chooser function like so:
func loadChooserScreen(notification: Notification) {
guard let userInfo = notification.userInfo,
let toChoose = userInfo["toChoose"] as? String,
let planToEdit = userInfo["customer"] as? Customer else {
print("No userInfo found in notification")
return
}
delegate?.loadChooserView(choice: toChoose, forCustomer: customer)
}
Then in my root view controller I have the following to replace what I had earlier:
/*Conform to ChooserViewDelegate Protocol */
func loadChooserView(choice: String, forCustomer: Customer) {
self.customer = forCustomer
dismiss(animated: false, completion: {
if choice == "Food" {
self.performSegue(withIdentifier: "food", sender: self.customer)
}
if choice == "Beverage" {
self.performSegue(withIdentifier: "beverage", sender: self.customer)
}
})
}
and I send over the data via prepareForSegue:
override func prepare(for segue: UIStoryboardSegue, sender: Any?) {
if segue.identifier == "food" {
if let foodVC = segue.destination as? FoodVC {
storyboard?.instantiateViewController(withIdentifier: "food")
foodVC.customerToEdit = self.customerToEdit
foodVC.delegate = self
}
}
if segue.identifier == "beverage" {
if let beverageVC = segue.destination as? BeverageVC {
storyboard?.instantiateViewController(withIdentifier: "beverage")
beverageVC.customerToEdit = self.customerToEdit
beverageVC.delegate = self
}
}
}
So now everything loads and views correctly :)
I used the Objective-C code below to pop a specific ViewController.
for (UIViewController *controller in self.navigationController.viewControllers) {
if ([controller isKindOfClass:[AnOldViewController class]]) {
//Do not forget to import AnOldViewController.h
[self.navigationController popToViewController:controller
animated:YES];
break;
}
}
How can I do that in Swift?
Try following code:
for controller in self.navigationController!.viewControllers as Array {
if controller.isKind(of: ViewController.self) {
self.navigationController!.popToViewController(controller, animated: true)
break
}
}
Swift 5
To pop to the latest instance of a specific class, for example SomeViewController:
navigationController?.popToViewController(ofClass: SomeViewController.self)
But you need to add ths UINavigationController extension:
extension UINavigationController {
func popToViewController(ofClass: AnyClass, animated: Bool = true) {
if let vc = viewControllers.last(where: { $0.isKind(of: ofClass) }) {
popToViewController(vc, animated: animated)
}
}
}
For Swift 3+
let viewControllers: [UIViewController] = self.navigationController!.viewControllers
for aViewController in viewControllers {
if aViewController is YourViewController {
self.navigationController!.popToViewController(aViewController, animated: true)
}
}
From Swift 4.0 and Above
for controller in self.navigationController!.viewControllers as Array {
if controller.isKind(of: DashboardVC.self) {
_ = self.navigationController!.popToViewController(controller, animated: true)
break
}
}
This is working Perfect.
I prefer a generic way to do it.
I have this extension for the UINavigationController :
extension UINavigationController {
func backToViewController(vc: Any) {
// iterate to find the type of vc
for element in viewControllers as Array {
if "\(element.dynamicType).Type" == "\(vc.dynamicType)" {
self.popToViewController(element, animated: true)
break
}
}
}
}
Let's say I have a FOHomeVC class (who is a UIViewController) instantiated in the navigation stack.
So I would do this in my code:
self.navigationController?.backToViewController(FOHomeVC.self)
I have added an extension to UINavigationController which helps you to find if that controller exist in navigation stack. If yes then it will be popped to that controller or else you pass new controller to push with pushController param.
extension UINavigationController {
func containsViewController(ofKind kind: AnyClass) -> Bool {
return self.viewControllers.contains(where: { $0.isKind(of: kind) })
}
func popPushToVC(ofKind kind: AnyClass, pushController: UIViewController) {
if containsViewController(ofKind: kind) {
for controller in self.viewControllers {
if controller.isKind(of: kind) {
popToViewController(controller, animated: true)
break
}
}
} else {
pushViewController(pushController, animated: true)
}
}
}
Swift 4 / Swift 5
for controller in self.navigationController!.viewControllers as Array {
if controller.isKind(of: HomeViewController.self) {
self.navigationController!.popToViewController(controller, animated: true)
break
}
}
I prefer a "real generic" and more functional approach.
So I came up with following UINavigationController extension functions. You can also use the first function, for anything else, where you just need to access a specific VC in the navigation stack.
Extensions
extension UINavigationController {
func getViewController<T: UIViewController>(of type: T.Type) -> UIViewController? {
return self.viewControllers.first(where: { $0 is T })
}
func popToViewController<T: UIViewController>(of type: T.Type, animated: Bool) {
guard let viewController = self.getViewController(of: type) else { return }
self.popToViewController(viewController, animated: animated)
}
}
Usage
self.navigationController?.popToViewController(of: YourViewController.self, animated: true)
This should work at least in Swift 4 and 5.
Find your view controller from navigation stack and pop to that view controller if it exists
for vc in self.navigationController!.viewControllers {
if let myViewCont = vc as? VCName
{
self.navigationController?.popToViewController(myViewCont, animated: true)
}
}
swift5
let controllers : Array = self.navigationController!.viewControllers
self.navigationController!.popToViewController(controllers[1], animated: true)
Swift 5 Answer of #PabloR is Here :
extension UINavigationController {
func backToViewController(vc: Any) {
// iterate to find the type of vc
for element in viewControllers as Array {
if "\(type(of: element)).Type" == "\(type(of: vc))" {
self.popToViewController(element, animated: true)
break
}
}
}
}
Usage :
self.navigationController?.backToViewController(vc: TaskListViewController.self)
In latest swift
#IBAction func popToConversationsVC(_ sender: UIButton) {
if (self.navigationController != nil) {
for vc in self.navigationController!.viewControllers {
if vc is ConversationsVC {
self.navigationController?.popToViewController(vc, animated: false)
}
}
}
}
For Swift 4.0 and above Using Filter
guard let VC = self.navigationController?.viewControllers.filter({$0.isKind(of: YourViewController.self)}).first else {return}
self.navigationController?.popToViewController(VC, animated: true)
Please use this below code for Swift 3.0:
let viewControllers: [UIViewController] = self.navigationController!.viewControllers as [UIViewController];
for aViewController:UIViewController in viewControllers {
if aViewController.isKind(of: YourViewController.self) {
_ = self.navigationController?.popToViewController(aViewController, animated: true)
}
}
I needed to use this, because in some cases app crashes:
if let navVC = self.navigationController {
let views = navVC.viewControllers as Array
for controller in views {
if controller.isKind(of: YourVC.self) {
navVC.popToViewController(controller, animated: true)
return
}
}
}
This solution worked for me :)
extension UINavigationController {
func backToViewController(_ viewController: AnyClass, animated: Bool) {
guard let viewController = self.viewControllers.first(where: {$0.isKind(of: viewController)}) else { return }
self.popToViewController(viewController, animated: animated)
}
}
I adapt from all answer above. It look like Yakup Ad answer, because it's very short way.
I force type by using generic for argument, that make sure you must pass only UIViewController to this func.
I search viewController that already in stack by using .first this make me got only one VC then stop the loop.
I also return passing VC back if you need to customize somethings.
Let's enjoy.
extension UINavigationController {
func popToViewController<T: UIViewController>(_ viewController: T.Type, animated: Bool) -> T? {
guard let viewController = self.viewControllers.first(where: {$0 is T}) else { return nil }
self.popToViewController(viewController, animated: animated)
return viewController as? T
}
}
Usage
let poppedVC = self.navigationController?.popToViewController(HomeViewController.self, animated: true)
extension UINavigationController {
func popBack(to vc: AnyClass, animated: Bool = true) {
guard let elementFound = (viewControllers.filter { $0.isKind(of: vc) }).first else {
fatalError("cannot pop back to \(vc) as it is not in the view hierarchy")
}
self.popToViewController(elementFound, animated: animated)
}
}
simple and best solution without force unwrapped is
if let vc = navigationController.viewControllers.filter({$0 is YourViewController}).first as? YourViewController {
self.navigationController.popToViewController(vc, animated: true)
}