I am having some issues with segueing to a new viewcontroller via the show segue. I have been able to use the present segue, but want to use a push/show navigation stack. I am getting this error... "an existing transition or presentation is occurring; the navigation stack will not be updated." Thanks for any help in advance!
// segue to searchVC from homecontroller
func handleSearch() {
let vc = SearchVC()
show(vc, sender: self)
}
// setup search bar in searchVC class
func loadPlacesSearchBar() {
searchController?.searchBar.isHidden = false
resultsViewController = GMSAutocompleteResultsViewController()
resultsViewController?.delegate = self
searchController = UISearchController(searchResultsController: resultsViewController)
searchController?.searchResultsUpdater = resultsViewController
// Put the search bar in the navigation bar.
searchController?.searchBar.sizeToFit()
navigationItem.titleView = searchController?.searchBar
searchController?.searchBar.placeholder = "search places"
// When UISearchController presents the results view, present it in
// this view controller, not one further up the chain.
definesPresentationContext = true
// Prevent the navigation bar from being hidden when searching.
searchController?.hidesNavigationBarDuringPresentation = false
}
// extension from SearchVC
extension SearchVC: GMSAutocompleteResultsViewControllerDelegate {
func resultsController(_ resultsController: GMSAutocompleteResultsViewController,
didAutocompleteWith place: GMSPlace) {
searchController?.isActive = false
// Do something with the selected place.
let autocompleteController = GMSAutocompleteViewController()
autocompleteController.delegate = self as? GMSAutocompleteViewControllerDelegate
print("Place name: \(place.name)")
print("Place address: \(String(describing: place.formattedAddress))")
print("Place attributions: \(String(describing: place.attributions))")
self.dismiss(animated: true, completion: nil)
let mapView = MapViewController()
show(mapView, sender: self)
// let mapView = MapViewController()
// let navController = UINavigationController(rootViewController: mapView)
// present(navController, animated: true, completion: nil)
DispatchQueue.main.async {
self.dismiss(animated: true, completion: nil)
}
}
func resultsController(_ resultsController: GMSAutocompleteResultsViewController,
didFailAutocompleteWithError error: Error){
// TODO: handle the error.
print("Error: ", error.localizedDescription)
}
// Turn the network activity indicator on and off again.
func didRequestAutocompletePredictions(_ viewController: GMSAutocompleteViewController) {
UIApplication.shared.isNetworkActivityIndicatorVisible = true
}
func didUpdateAutocompletePredictions(_ viewController: GMSAutocompleteViewController) {
UIApplication.shared.isNetworkActivityIndicatorVisible = false
}
}
The reason you're running into this is that the searchController will be dismissed when you make your selection, and thus, be in the middle of an animation when you're trying to push that new view controller.
A very simple solution that works for me is setting your view controller as a UISearchControllerDelegate, and then calling your segue after the searchController has been dismissed.
searchController = UISearchController(searchResultsController: resultsViewController)
searchController?.searchResultsUpdater = resultsViewController
searchController?.delegate = self //<- add this
Then conform to the Delegate and implement this
extension YourViewController:UISearchControllerDelegate {
func didDismissSearchController(_ searchController: UISearchController) {
// perform your segue, or push/present your view controller here
}
Related
I have some problems displaying a viewcontroller in my IOS app.
Sometimes it works and the view is displayed, but sometimes and I guess when the context is a bit different it will not work. No errors or warnings in the debugger and it can find the ViewController from the Main storyboard (at least it is not nil)
It use to work with self.present but that seems not to work anymore.
#IBAction func showHistoryButton(_ sender: MDCButton) {
let exercisesHistoryVC = ExercisesHistoryViewController.instantiate(from: .Main)
exercisesHistoryVC.modalPresentationStyle = .fullScreen
let appDeligate = UIApplication.shared.delegate as! AppDelegate
appDeligate.window?.rootViewController!.present(exercisesHistoryVC,animated: true,completion: nil)
// parent?.present(exercisesHistoryVC, animated: true, completion: nil)
}
Use the code like below,while Present New View Controller
#IBAction func showHistoryButton(_ sender: MDCButton) {
let exercisesHistoryVC = ExercisesHistoryViewController.instantiate(from: .Main)
exercisesHistoryVC.modalPresentationStyle = .fullScreen
UIApplication.topViewController()?.present(exercisesHistoryVC, animated: false, completion: nil)
}
extension UIApplication {
static func topViewController(base: UIViewController? = UIApplication.shared.delegate?.window??.rootViewController) -> UIViewController? {
if let nav = base as? UINavigationController {
return topViewController(base: nav.visibleViewController)
}
if let tab = base as? UITabBarController, let selected = tab.selectedViewController {
return topViewController(base: selected)
}
if let presented = base?.presentedViewController {
return topViewController(base: presented)
}
return base
}
}
Good day everyone,
I have root view controller set up as my HomeViewController, in this project i am using token based authentication ( which i am storing in user defaults ) and i am using token for all my API calls.
I have a check in my viewWillAppear method to check if there is access token present and then i make the api call in viewDidAppear to populate the collection view, and this works perfectly fine at all times except the first time.
If I log in for the first time it hits the viewWillAppear, viewDidAppear and then login screen pops up and once i authenticate the user and save it in the UserDefaults, dismiss the login screen and in the HomeViewController all i get is a spinner ( which means that viewDidAppear is also been called ) but if i close the app and open it again it all works fine.
What can i change in my code to make it work in the first time please and thank you!!
class HomeViewController: UIViewController {
// MARK: - Properties
let refreshControl = UIRefreshControl()
var publishedReportList: [ReportListDetail] = []
private let reportsCollectionView: UICollectionView = {
let viewLayout = UICollectionViewFlowLayout()
let collectionView = UICollectionView(frame: .zero, collectionViewLayout: viewLayout)
collectionView.register(ReportsCollectionViewCell.self, forCellWithReuseIdentifier: ReportsCollectionViewCell.identifier)
collectionView.backgroundColor = .systemBackground
return collectionView
}()
// MARK: - Initialisation
override func viewDidLoad() {
super.viewDidLoad()
reportsCollectionView.delegate = self
reportsCollectionView.dataSource = self
print(publishedReportList.count)
refreshControl.tintColor = .blue
refreshControl.addTarget(self, action: #selector(pullToRefresh), for: .valueChanged)
reportsCollectionView.addSubview(refreshControl)
reportsCollectionView.alwaysBounceVertical = true
}
override func viewWillAppear(_ animated: Bool) {
super.viewWillAppear(animated)
// check auth status
handleNotAuthenticated()
}
override func viewDidAppear(_ animated: Bool) {
// call for reports
getReportUserLayout()
}
// MARK: - Handlers
#objc func pullToRefresh() {
// Code to refresh table view
getReportUserLayout()
}
fileprivate func getReportUserLayout() {
// publishedReportList.removeAll()
whySuchEmptyLabel.isHidden = true
spinner.show(in: view)
spinner.textLabel.text = "Loading Reports.."
DispatchQueue.main.async {
ReportsManager.shared.getReportData { [weak self] (listOfReports) in
guard let strongSelf = self else { return }
strongSelf.publishedReportList = listOfReports
if listOfReports.count == 0 {
strongSelf.whySuchEmptyLabel.isHidden = false
}
strongSelf.reportsCollectionView.reloadData()
strongSelf.spinner.dismiss()
strongSelf.refreshControl.endRefreshing()
}
}
}
private func handleNotAuthenticated() {
if UserDefaults.standard.string(forKey: "accessToken") == nil {
// show login view controller
let loginVC = LoginViewController()
loginVC.modalPresentationStyle = .overCurrentContext
present(loginVC, animated: false)
}
}
}
You are in the HomeViewController and presenting loginVC, so it will not trigger viewDidAppear or viewWillAppear because it is not disappeared from the app. You have to use closure or delegate or notification to communicate back to the HomeViewController. You can also use the Combine framework and save the state. Here is an example of using delegate.
// Add protocol
protocol ViewControllerDelegate {
func loggedIn()
}
class HomeViewController: UIViewController, ViewControllerDelegate {
private func handleNotAuthenticated() {
if UserDefaults.standard.string(forKey: "accessToken") == nil {
let loginVC = LoginViewController()
loginVC.modalPresentationStyle = .overCurrentContext
loginVC.viewDelegate = self
present(loginVC, animated: false)
}
}
}
class LoginViewController: UIViewController {
var viewDelegate: ViewControllerDelegate? = nil
func userLoggedIn() {
self.viewDelegate?.loggedIn()
}
}
Hey I am showing a controller (A) in main controller with presentation style (not push), and I want to button tapped and push another controller (B) after dismiss this (A) controller, this situation occurred in main controller. I am using protocol for this situation. Any idea for that ? Code like below.`
//this is dismiss button action
var segueDelegate: segueFromController?
#objc func dismissController() {
self.dismiss(animated: true) {
self.segueDelegate?.segueFromController()
}
//and this one is protocol function in main controller
func segueFromController() {
let contProfile = ContViewController(collectionViewLayout: UICollectionViewFlowLayout())
navigationController?.pushViewController(contProfile, animated: true)
}
// and I am making "self" this protocol in main controller's didload
let aCont = AController()
override func viewDidLoad() {
super.viewDidLoad()
AController.segueDelegate = self
}
// protocol
protocol segueFromController {
func segueFromController()
}
// this is presenting (A) controller code in main page
func openController() {
let preController = AController()
preController.modalPresentationStyle = .fullScreen
self.present(preController, animated: true, completion: nil)
}
First you need to make this segueDelegate weak
protocol segueFromController : class {
func segueFromController()
}
weak var segueDelegate: segueFromController?
func openController() {
let preController = AController()
preController.segueDelegate = self
preController.modalPresentationStyle = .fullScreen
self.present(preController, animated: true, completion: nil)
}
Try to dismiss without animation
self.dismiss(animated: false) {
self.segueDelegate?.segueFromController()
}
I need to present a modal VC that sets a property in my presenting VC, and then I need to do something with that value back in the presenting VC. I have to be able to pass pointers to different properties to this function, so that it's reusable. I have the code below (KeyPickerTableViewController is the modal VC).
It should work, except not, because the line after present(picker... gets executed immediately after the picker is presented.
How do I get my presenting VC to "wait" until the modal VC is dismissed?
#objc func fromKeyTapped(_ button: UIBarButtonItem) {
print("from tapped")
setKey(for: &sourceKey, presentingFrom: button)
}
#objc func toKeyTapped(_ button: UIBarButtonItem) {
print("from tapped")
setKey(for: &destKey, presentingFrom: button)
}
fileprivate func setKey(for key: inout Key!, presentingFrom buttonItem: UIBarButtonItem) {
let picker = KeyPickerTableViewController()
picker.delegate = self
picker.modalPresentationStyle = .popover
picker.popoverPresentationController?.barButtonItem = buttonItem
present(picker, animated: true, completion: nil)
if let delKey = delegatedKey {
key = delKey
}
}
You could use delegate pattern or closure.
I would do the following
1. I would not use inout pattern, I would first call the popover and then separately update what is needed to be updated
2. In KeyPickerTableViewController define property var actionOnDismiss: (()->())? and setting this action to what we need after initialisation of KeyPickerTableViewController
I could show it in code, but the abstract you've shown is not clear enough to come up with specific amendments. Please refer the illustration below.
import UIKit
class FirstVC: UIViewController {
var key = 0
#IBAction func buttonPressed(_ sender: Any) {
let vc = SecondVC()
vc.action = {
print(self.key)
self.key += 1
print(self.key)
}
present(vc, animated: true, completion: nil)
}
}
class SecondVC: UIViewController {
var action: (()->())?
override func viewDidLoad() {
onDismiss()
}
func onDismiss() {
action?()
}
}
While presenting VC, add dismissing modal VC action in its completion handler, so that Viewcontroller will be presented after dismissal is completed
present(picker, animated: true, completion: { (action) in
//dismissal action
if let delKey = delegatedKey {
key = delKey
}
})
I'm having some trouble getting a UIPopover to appear using swift. The code that is commented out works fine in Objective-C, but doesn't work using Swift. When I tap the + in my view controller I do get the "click" in my debugger, however no popover appears.
class PlayerInformationTableViewController: UITableViewController, NSFetchedResultsControllerDelegate, UIPopoverControllerDelegate {
#IBOutlet weak var addBarButtonItem: UIBarButtonItem!
var playerInformationViewController = PlayerInformationViewController()
var popover:UIPopoverController? = nil
override func viewDidLoad() {
super.viewDidLoad()
/*
//setup the popover
_cuesPopoverViewController = [self.storyboard instantiateViewControllerWithIdentifier:#"CuesPopoverViewController"];
self.cuesPopover = [[UIPopoverController alloc] initWithContentViewController:_cuesPopoverViewController];
self.cuesPopover.popoverContentSize = CGSizeMake(540, 300);
self.cuesPopover.delegate = self;
*/
playerInformationViewController.storyboard?.instantiateViewControllerWithIdentifier("PlayerInformationViewController")
popover?.contentViewController = playerInformationViewController
popover?.popoverContentSize = CGSizeMake(300, 300)
popover?.delegate = self
// Uncomment the following line to preserve selection between presentations
// self.clearsSelectionOnViewWillAppear = false
// Uncomment the following line to display an Edit button in the navigation bar for this view controller.
// self.navigationItem.rightBarButtonItem = self.editButtonItem()
}
#IBAction func addPopover(sender: AnyObject) {
println("Click")
popover?.presentPopoverFromBarButtonItem(addBarButtonItem, permittedArrowDirections: UIPopoverArrowDirection.Any, animated: true)
}
Solution
override func viewDidLoad() {
super.viewDidLoad()
}
#IBAction func addPopover(sender: AnyObject) {
var popoverViewController = self.storyboard?.instantiateViewControllerWithIdentifier("PlayerInformationViewController") as UIViewController
popoverViewController.modalPresentationStyle = .Popover
popoverViewController.preferredContentSize = CGSizeMake(450, 450)
let popoverPresentationViewController = popoverViewController.popoverPresentationController
popoverPresentationViewController?.permittedArrowDirections = .Any
popoverPresentationViewController?.delegate = self
popoverPresentationViewController?.barButtonItem = sender as UIBarButtonItem
presentViewController(popoverViewController, animated: true, completion: nil)
}
Here is a simple example for iOS 8. Popover are presented using adaptivity apis in iOS 8.
class PlayerInformationTableViewController: UITableViewController, UIPopoverPresentationControllerDelegate, NSFetchedResultsControllerDelegate{
...
#IBAction func addPopover(sender: UIBarButtonItem){
let playerInformationViewController = PlayerInformationViewController()
playerInformationViewController.modalPresentationStyle = .Popover
playerInformationViewController.preferredContentSize = CGSizeMake(300, 300)
let popoverPresentationViewController = playerInformationViewController.popoverPresentationController
popoverPresentationViewController?.permittedArrowDirections = .Any
popoverPresentationViewController?.delegate = self
popoverPresentationController?.barButtonItem = sender
presentViewController(playerInformationViewController, animated: true, completion: nil)
}
func adaptivePresentationStyleForPresentationController(controller: UIPresentationController!) -> UIModalPresentationStyle{
return .None
}
}
Display Popover with contentView from xib
func showPopover(sender: AnyObject) {
let contentViewController = UINib(nibName: "ContentVC", bundle: nil).instantiateWithOwner(nil, options: nil)[0] as ContentVC
contentViewController.modalPresentationStyle = UIModalPresentationStyle.Popover
var detailPopover: UIPopoverPresentationController = contentViewController.popoverPresentationController!
detailPopover.delegate = self
detailPopover.barButtonItem = sender as UIBarButtonItem
detailPopover.permittedArrowDirections = UIPopoverArrowDirection.Any
presentViewController(contentViewController,
animated: true, completion:nil)
}
Next allows to make not full screen PopoverView on iPhone
for this do not forget to inherit MainViewController: UIPopoverPresentationControllerDelegate and set delegate to PopoverView
func adaptivePresentationStyleForPresentationController(controller: UIPresentationController!) -> UIModalPresentationStyle
{
return .None
}
It looks like your popover is nil. Where are you assigning/instantiating it?
Try changing this:
popover?.presentPopoverFromBarButtonItem(addBarButtonItem, permittedArrowDirections: UIPopoverArrowDirection.Any, animated: true)
To this:
if let pop = popover {
pop.presentPopoverFromBarButtonItem(addBarButtonItem, permittedArrowDirections: UIPopoverArrowDirection.Any, animated: true)
} else {
NSLog("Error: Popover was nil")
}
I imagine you'll see that error message in your console. In the .XIB for your PlayerInformationTableViewController, do you have a UIPopoverController?
If so, you probably need to ensure that the var popover is either (1) being manually instantiated in your awakeFromNib, or that it's an #IBOutlet and is being connected properly.
Alternatively, can you simply use the popover already present in your playerInformationViewController?