I am performing a conditional segue in UIButton Click event listener. My segue is drawn between "pathanViewController" and "dekhunViewController" in storyboard with "pathanToDekhun" identifier. But i am getting NsInternalInconsistencyException as
*** Assertion failure in -[UIKeyboardTaskQueue waitUntilAllTasksAreFinished], /SourceCache/UIKit_Sim/UIKit-3318.16.14/Keyboard/UIKeyboardTaskQueue.m:374
*** Terminating app due to uncaught exception 'NSInternalInconsistencyException', reason: '-[UIKeyboardTaskQueue waitUntilAllTasksAreFinished] may only be called from the main thread.'
After button click i have performed a external api call and after successful return message, i called the segue with performSegueWithIdentifier. But the segue never happen actually. Below is my code portion in pathanViewController. Please let me know what i am doing wrong.
#IBAction func sendBtnListener(sender: AnyObject) {
if !self.commentSection.text.isEmpty {
var submitVoganti = DataSerialization(brandName: self.brandName!, rating: Int(self.sliderStatus.value*5), commentText: self.commentSection.text, anonymous: switchBox.on ? true : false)
var dataSet = DataSet()
dataSet.postComment(submitVoganti.toJson(),{
(id) in
self.performSegueWithIdentifier("pathanToDekhun", sender: self)
println(id)
})
} else{
println("Comment field should not be empty")
}
}
//Check whether a segue should be triggered or not
override func shouldPerformSegueWithIdentifier(identifier: String?, sender: AnyObject?) -> Bool {
if identifier == "pathanToDekhun" {
return false
}
// by default, transition
return true
}
// In a storyboard-based application, you will often want to do a little preparation before navigation
override func prepareForSegue(segue: UIStoryboardSegue, sender: AnyObject?) {
var dekhunScene = segue.destinationViewController as ThirdViewController
dekhunScene.keyword = self.brandName
}
What i am doing wrong is my performSegueWithIdentifier is not called in main queue. Thats why it throws exception. What i am doing now is just editing my code as below -
dataSet.postComment(submitVoganti.toJson(),{
(id) in
dispatch_async(dispatch_get_main_queue()){
self.performSegueWithIdentifier("pathanToDekhun", sender: self)
}
println(id)
})
and comment out "override func shouldPerformSegueWithIdentifier" function. Thats it.
Related
I am trying to transfer my object from HockeyDetailVC to my FavouritesVC using a button but my object is nil when I reach my second VC FavouritesVC. Why is it like that when I set the variable in my firstVC with my func transferObj()?
HockeyDetailVC
var item: CurrentPlayers?
override func viewDidLoad() {
super.viewDidLoad()
gonnaLoadView()
tableV.bounces = false
tableV.alwaysBounceVertical = false
favButton.layer.cornerRadius = 10
print(item) *//prints my current players object*
}
func transferObj() {
let otherVC = FavouritesVC()
otherVC.currentFav = item
print(item). *//prints my current player object*
}
#IBAction func addToFav(_ sender: Any) {
transferObj()
print("Favourite button Pressed")
}
FavouritesVC
var currentFav: CurrentPlayers?
override func viewDidLoad() {
super.viewDidLoad()
if currentFav == nil {
//display nil
self.tableView.separatorStyle = UITableViewCell.SeparatorStyle.none
print(favArr) *//prints empty array*
print(currentFav) *//nil*
} else {
favArr.append(currentFav!)
print(favArr)
}
}
As #Martin stated, let otherVC = FavouritesVC() creates a new instance of the controller, but it is not the instance that you will eventually display. So you are effectively setting the currentFav of a random FavouritesVC that will never actually be displayed, while the one you eventually do navigate to has it's currentFav property still unset.
To set the appropriate FavouritesVC instance, you need to access it in one of several ways (depending on how you present it). If it is through a segue, then you can reference it in the prepare(for segue: sender:) method. (When you create a Cocoa Touch Class file, the below method template is pre-populated. As it states, reference the new view controller using segue.destination.)
/*
// MARK: - Navigation
// In a storyboard-based application, you will often want to do a little preparation before navigation
override func prepare(for segue: UIStoryboardSegue, sender: Any?) {
// Get the new view controller using segue.destination.
// Pass the selected object to the new view controller.
}
*/
Alternatively, if you create and present the new view controller programmatically with something like
// 1.
let otherVC = storyboard?.instantiateViewController(withIdentifier: "yourFavouritesVCIdentifier")
// 2.
// 3.
self.show(otherVC, sender: self)
you can insert your otherVC.currentFav = item at line // 2..
Maybe someone can help, just want to use Segue for Login button to made a transfer to second ViewController only after authorization with Touch ID but application still performing the Segue after user pressing on the button.
import UIKit
import LocalAuthentication
class LoginWindowViewController: UIViewController {
#IBAction func loginButton(_ sender: Any) {
let context: LAContext = LAContext()
if context.canEvaluatePolicy(.deviceOwnerAuthenticationWithBiometrics, error: nil){
context.evaluatePolicy(LAPolicy.deviceOwnerAuthenticationWithBiometrics, localizedReason: "For login you need to use your TouchID", reply: {(wasSuccessful, error) in if wasSuccessful {
DispatchQueue.main.async {
self.shouldPerformSegue(withIdentifier: "LoginComplete", sender: self.navigationController)
}
}else{
print ("Bad TouchID")
}
})
}
}
Thanks
Try implementing this function and checking from where it's being called:
override func shouldPerformSegue(withIdentifier identifier: String, sender: Any?) -> Bool {
}
Remember that as you're calling the segue from your code, if you have already added a segue action from your button to the next ViewController in the storyboard you should remove it and only create a connection between your LoginViewController to the one you want to call
As the documentation states, if you do not override the shouldPerformSegue method, the default implementation returns true for all segues.
The shouldPerformSegue(withIdentifier:sender:) method should determine whether a segue with the specified identifier will or will not be called depending on the return value of your implementation.
Since you already check whether the TouchID authorization was successful, you don't actually need to call shouldPerformSegue, but rather you need to call performSegue.
context.evaluatePolicy(LAPolicy.deviceOwnerAuthenticationWithBiometrics, localizedReason: "For login you need to use your TouchID", reply: {(wasSuccessful, error) in
if wasSuccessful {
DispatchQueue.main.async {
self.performSegue(withIdentifier: "LoginComplete", sender: self.navigationController)
}
}else{
print ("Bad TouchID")
}
})
I've been debugging my code and found that my manager was deinitialised (that was cause of my bug - not calling delegate methods).
What's strange, that during debugging process I've used "po" command after setting the manager's delegate (weak) and it prevented it from being deinitialised (delegate methods were called).
Why is that? Is it proper behaviour?
Xcode 8.3, swift 3.1
EDIT:
//a tap starts everything :)
#IBAction func shareButtonPressed(_ sender: Any) {
let requestManager = FacebookPostRouteRequest() //bug fixed by changing to instance variable
requestManager.delegate = self
requestManager.showShareBadgeDialog(self.badge!, onViewController: self)
}
//in FacebookPostRouteRequest
final weak var delegate: FacebookPostRouteRequestDelegate?
func showShareBadgeDialog(_ badge: Badge, onViewController viewController: UIViewController) {
let dialog = self.initDialog(onViewController: viewController)
guard let imageURL = badge.imageURL else {
self.delegate?.facebookPostRouteRequest(self, didCompleteWithResult: false)
return
}
dialog.shareContent = self.generateImageShareContent(imageURL)
self.show(dialog)
}
private func show(_ dialog: FBSDKShareDialog) {
OperationQueue.main.addOperation {
dialog.delegate = self //when printed out dialog.delegate delegate methods were called! Deinit of FacebookPostRouteRequest is not called.
let showResult = dialog.show()
...
}
}
extension FacebookPostRouteRequest: FBSDKSharingDelegate {
func sharer(_ sharer: FBSDKSharing!, didCompleteWithResults results: [AnyHashable : Any]!) {
...
}
//other delegate methods implemented as well
}
Your problem is here:
#IBAction func shareButtonPressed(_ sender: Any) {
let requestManager = FacebookPostRouteRequest()
requestManager.delegate = self
requestManager.showShareBadgeDialog(self.badge!, onViewController: self)
}
After the last line, the requestManager object will be disposed because it's no longer referenced and will not call any of the delegate methods.
Make requestManager an instance variable:
let requestManager = FacebookPostRouteRequest()
#IBAction func shareButtonPressed(_ sender: Any) {
requestManager.delegate = self
requestManager.showShareBadgeDialog(self.badge!, onViewController: self)
}
Your issues with the debugger are probably race conditions for stopping the main thread.
I am working on an iOS application that is built around a Tab View Controller. I have created a "Contacts" tab, where a user can find and select a contact from a list. When the user selects the contact, it takes the contact's name and passes it to a different tab. That function is being done like so:
func passName(name: String) {
let navTab = self.tabBarController!.viewControllers![2] as! UINavigationController
let homeTab = navTab.viewControllers[0] as! MainController
homeTab.passedName = name
tabBarController?.selectedIndex = 2
}
Everything works as it should so far (name is loaded into text field). My issue is that the value seems to keep coming back every time I change tabs and then go back to my Home tab. For example, if I select "John" from my contacts, it will take me to the Home Tab and put John's name in a textfield. Let's say I delete the last two letters of the name, so now it is "Jo". If I load a different tab and come back, the name field has been reset to "John". It's as if the value gets re-passed every time I open the Home Tab. Also, every time I load the Home Tab after passing a name, my console prints: "Name Passed: John", so it shows that this is being processed every single time the tab appears. Here is my code for processing the name:
var passedName: String!
override func viewWillAppear(animated: Bool) {
super.viewWillAppear(animated)
//Checks if name was passed to controller
if let validName = passedName {
print("Name passed: \(validName)")
nameTextField.text = validName
}
}
Am I passing the data incorrectly? I was thinking it might be because I have the above code being called in the viewWillAppear method, but that doesn't make sense, as essentially the data is only being passed one time from the Contacts tab. Thanks!
The problem is that you're not actually passing the value back to the original view. Apple's recommendation for passing information between classes is to use the delegate pattern. This allows the modal view to call the delegate class's function, which changes the name local to the original view because that function is declared in the original view's viewController. You can read more about the pattern in this tutorial, but I've also included a brief example relevant to your use case below.
mainViewController:
class namesTableViewController: UITableViewController, editNameDetailsViewControllerDelegate {
var name : String
#IBAction func editButtonPressed(_ sender: UIBarButtonItem) {
performSegue(withIdentifier: "editPerson", sender: self)
}
override func prepare(for segue: UIStoryboardSegue, sender: Any?) {
if segue.identifier == "editPerson" { //Modal segue
let navController = segue.destination as! UINavigationController
let controller = navController.topViewController as! editNameViewController
controller.delegate = self
if let person = sender as? Person {
print("Sending person to edit")
controller.personToEdit = person
}
} else {
super.prepare(for: segue, sender: sender)
}
}
//Protocol function
func changeName(n: String, controller: UIViewController) {
name = n
dismiss(animated: true, completion: nil)
}
}
editNameViewController:
class editNameViewController: UIViewController {
#IBOutlet weak var personNameTextField: UITextField!
var personToEdit : Person?
weak var delegate : PersonTableViewController?
override func viewDidLoad() {
super.viewDidLoad()
if personToEdit != nil {
personNameTextField.text = personToEdit?.name
}
}
// Button Actions
#IBAction func saveButtonPressed(_ sender: UIBarButtonItem) {
delegate?.personDetailsView(n: personNameTextField.text, controller: self)
}
}
Finally, the protocol class :
protocol editNameDetailsViewControllerDelegate : class {
func personDetailsView(n: String, controller: UIViewController)
}
Hope this helps.
The problem is "passedName" variable doesn't changed its value every time you edit it in your UITextField. Keep in mind that every time you change tabs, the UIViewController will call viewWillAppear and viewDidAppear. So your UITextField will always show passedName value once you select other tab and return.
I suggest that every time you edit the textfield you should update passedName value.
Sorry for my bad english.
I want to open an other view controller, after checking if it is the first run of the app.
It works when I press a button but not when I call the method openMap
class TutorialController: UIViewController {
override func viewDidLoad() {
//check if the app opens for the first time
if(UserDefaults.standard.bool(forKey: "HasLaunchedOnce"))
{
// app already launched
print("not first launch")
openMap()
}
else
{
// This is the first launch ever
UserDefaults.standard.set(true, forKey: "HasLaunchedOnce")
UserDefaults.standard.synchronize()
print("first launch")
openTutorial()
}
}
func openTutorial(){
}
#IBAction func openMap(){
print("openmap opened")
performSegue(withIdentifier: "openMap", sender: nil)
}
}
I assume, you've connected your button to #IBAction func openMap()
if so, you should not call openMap() action inside your viewDidLoad, but use the same code performSegue(withIdentifier: "openMap", sender: nil) instead in your viewDidAppear:
if(UserDefaults.standard.bool(forKey: "HasLaunchedOnce"))
{
// app already launched
print("not first launch")
performSegue(withIdentifier: "openMap", sender: nil)
}
...
If it doesn't work, you've probably made a mistake with creation of your segue and have connected Button to the destination ViewController directly in your storyboard instead of connecting two controllers:
If so, just remove the old segue, and re-crete it in the way as it is on the image above and assign the same segue id "openMap"
EDITED:
Please, move performing of your segue to the viewDidAppear instead of viewDidLoad, because viewDidLoad is called when the ViewController object is created and it's not yet attached to the window.
Ok, from what I understand is that you want to perform a segue "openMap" when it HasLaunchedOnce. Well what you're doing wrong is that you're calling an #IBAction func. This is my suggestion
if you still want to have that button
create a function and name if whatever you want. Inside this function perform this segue. Link this function to the if else statement and the button.
eg:
//if else statement
if(UserDefaults.standard.bool(forKey: "HasLaunchedOnce"))
{
// app already launched
print("not first launch")
anotherFunction()
}
//#ibaction (scrap this if you don't want the button)
#IBAction func openMap()
{
print("openmap opened")
anotherFunction()
}
//another function
func anotherFunction()
{
performSegue(withIdentifier: "openMap", sender: nil)
}
hope this helps