When I simulate an app on an iOS device, the app gets installed, and is available for later use. When I do so on the mac and interrupt the simulation, I can still find the app afterwards, but, if I click on it, I get an alert that says that the app is not supported. My app's supported destinations are iPhone, iPad and Mac (designed for iPad). How do I install an Xcode app on a mac with an apple silicon chip?

Xcode's test scheme "info", "arguments", "options" and "diagnostics" tabs were once visible by pressing Command + Option + U, but they've been moved. Where do I find the corresponding sections, now? Here's the old UI (credit: https://betterprogramming.pub/easy-unit-testing-for-firebase-in-xcode-874842f79d84): Here is the new one:

Usually the only options that is available is "Rename", but I would also like to be able to refactor (Swift) methods so that each parameter is on a separate line.

Each time I run an app, which usually takes some 10 seconds, I normally go on working on it, but then I'm jumped to the simulator once the app has launched, which is especially annoying when I'm on full screen. Is there a way to stay on Xcode, instead?

In the following code, test 1 (test_postNotification) fails while test 2 (test_notificationsArePostedOnTheMainQueue) passes. What concerns me, though, is that if I substitute the lines "let result = XCTWaiter.wait(for: [expectation], timeout: 0); XCTAssertEqual(result, .timedOut)" of test 2 with "wait(for: [expectation], timeout: 0.1)", then test number 1 passes. I have cleaned the build folder and restarted Xcode and my computer, but the issue persists. This concerns me because I would have said that the tests of the NotificationPosterTests class were isolated, but apparently they are not, since changing test 2 makes test 1 go from failing to passing. Is this expected behavior? import Foundation import XCTest extension Notification.Name { static let menuPostRequest = Notification.Name("menuPostRequest") static let editingOrderError = Notification.Name("editingOrderError") } class NotificationPoster { let notificationCenter: NotificationCenter init(notificationCenter: NotificationCenter = .default) { self.notificationCenter = notificationCenter } func postNotification(_ notification: Notification) { let _notificationCenter = notificationCenter // you can't use optional chaining nor conditional unwrapping on self to reference self.notificationCenter in the dispatch block because self is nil when self.postNotification(_:) is called DispatchQueue.main.async { _notificationCenter.post(notification) } } } final class NotificationPosterTests: XCTestCase { private var sut: NotificationPoster! private var notificationCenter: NotificationCenter! override func setUp() { super.setUp() notificationCenter = NotificationCenter() sut = NotificationPoster(notificationCenter: notificationCenter) } override func tearDown() { notificationCenter = nil sut = nil super.tearDown() } func test_postNotification() { let notification = Notification(name: .menuPostRequest) let expectation = XCTNSNotificationExpectation( name: notification.name, object: notification.object, notificationCenter: notificationCenter ) sut.postNotification(notification) wait(for: [expectation], timeout: 0.1) // don't make it 0.01 } func test_notificationsArePostedOnTheMainQueue() { let notification = Notification(name: .editingOrderError) let expectation = XCTNSNotificationExpectation( name: notification.name, object: notification.object, notificationCenter: notificationCenter ) sut.postNotification(notification) let result = XCTWaiter.wait(for: [expectation], timeout: 0) XCTAssertEqual(result, .timedOut) } }

Hello, I am a UIKit developer and I would like to try out SwiftUI. Unfortunately, my previews don't load. My situation is like the one described in this blog post: https://forums.developer.apple.com/forums/thread/704036. Unfortunately I can't update Xcode like that developer did. What I've tried: quitting and restarting Xcode, restarting my computer, resetting the simulator, deleting the derived data folder, creating new projects without storage options, test bundles or source control, editing the content view of the initial Hello World file. To be clear, I've just started learning about SwiftUI, just yesterday evening, and the previews have never loaded. Is the problem solvable? If so, how?

The location of my derived data folder differs between Xcode and Finder. How do I change Xcode's path to match my Finder path? MacOS Sonoma 14.2.1, MacBook Air M1, 8GB Xcode 15.2

Note: I'd like the solution to work for iOS 15 as well. With the following implementation, tapping on the stepper from iPhone (iOS 15.8 (physical device) as well as iOS 17.2 (simulator and canvas)) presents ModalView, instead of changing the stepper's value as one would expect. It's a somewhat real-life example but still basic, as I felt that having a view with just a stepper would have made the problem unrealistically easy. struct CategoryView: View { @State private var modalIsPresented = false @State private var stepperValue = 0 var body: some View { List { StepperRow(value: self.$stepperValue) .onTapGesture { modalIsPresented = true } } .sheet(isPresented: $modalIsPresented) { modalIsPresented = false } content: { ModalView() } } } struct StepperRow: View { @Binding var value: Int var body: some View { VStack(alignment: .leading) { Stepper( "\(value) Name of the article", value: $value, in: 0...Int.max ) Text("Item description, which could be long and I'd like to go under the stepper.") .font(.caption) } } } What doesn't work: setting the stepper's style to .plain or BorderlessButtonStyle(), as might work for a button. The following code is a working solution, though it's ugly. struct CategoryView: View { @State private var stepperValue = 0 var body: some View { List { StepperRow(value: self.$stepperValue) } } } struct StepperRow: View { @Binding var value: Int @State private var modalIsPresented = false var body: some View { ZStack(alignment: .leading) { VStack(alignment: .leading) { HStack { Text("\(value) Name of the article") Spacer() Stepper( "", value: $value, in: 0...Int.max ) .labelsHidden() .hidden() } Text("Item description, which could be long and I'd like to go under the stepper.") .font(.caption) } .onTapGesture { modalIsPresented = true } VStack(alignment: .leading) { HStack { Text("\(value) Name of the article") .hidden() Spacer() Stepper( "", value: $value, in: 0...Int.max ) .labelsHidden() } Text("Item description, which could be long and I'd like to go under the stepper.") .font(.caption) .hidden() } } .sheet(isPresented: $modalIsPresented) { modalIsPresented = false } content: { ModalView() } } } Basically I've put the stepper above the view to which I've added the onTapGesture recognizer, but to do so I had to duplicate the view code, so that everything laid out correctly, and hide the appropriate subviews, so that VoiceOver would ignore the duplicates, and also because it felt right. Can anyone come up with a better solution?

For instance, executing the following code, in which a stepper is injected in a table view cell and the cell is reloaded when the user changes the stepper's value, causes the memory usage to grow pretty quickly (I stopped the simulation at 1GB) when you tap on the stepper. Also the CPU usage jumps straight at 99%, and the UI freezes. Note: I'd like to know exactly what I asked, not how to make a table view cell with a stepper in general. I know that calling reloadData() or reconfigureRows(at:) doesn't cause any of the mentioned issues. Also please don't reply with questions like "Have you tried to use weak references?". The code is short: please reply with a working solution if you can. class ViewController: UIViewController { let tableView = UITableView() let stepper = UIStepper() override func viewDidLoad() { super.viewDidLoad() view.addSubview(tableView) tableView.register(UITableViewCell.self, forCellReuseIdentifier: "cell") tableView.dataSource = self stepper.addTarget(self, action: #selector(stepperValueChanged), for: .valueChanged) } override func viewDidLayoutSubviews() { super.viewDidLayoutSubviews() tableView.frame = view.bounds } @objc private func stepperValueChanged() { tableView.reloadRows(at: [IndexPath(row: 0, section: 0)], with: .automatic) } } extension ViewController: UITableViewDataSource { func tableView(_ tableView: UITableView, numberOfRowsInSection section: Int) -> Int { 1 } func tableView(_ tableView: UITableView, cellForRowAt indexPath: IndexPath) -> UITableViewCell { let cell = tableView.dequeueReusableCell(withIdentifier: "cell", for: indexPath) cell.accessoryView = stepper var configuration = cell.defaultContentConfiguration() configuration.text = "\(stepper.value)" cell.contentConfiguration = configuration return cell } }

Steppers overlap with the disclosure indicator if you try to add them to a UICollectionViewListCell using: cell.accessories = [.disclosureIndicator(), .customView(configuration: .init(customView: UIStepper(), placement: .trailing()))]. What's the correct way to add a stepper to the accessories of a cell then? Example that you can run: class GridViewController: UIViewController { enum Section { case main } var dataSource: UICollectionViewDiffableDataSource<Section, Int>! = nil var collectionView: UICollectionView! = nil override func viewDidLoad() { super.viewDidLoad() navigationItem.title = "VC" configureHierarchy() configureDataSource() } } extension GridViewController { private func createLayout() -> UICollectionViewLayout { let config = UICollectionLayoutListConfiguration(appearance: .insetGrouped) return UICollectionViewCompositionalLayout.list(using: config) } } extension GridViewController { private func configureHierarchy() { collectionView = UICollectionView(frame: view.bounds, collectionViewLayout: createLayout()) collectionView.autoresizingMask = [.flexibleWidth, .flexibleHeight] collectionView.backgroundColor = .black view.addSubview(collectionView) } private func configureDataSource() { let cellRegistration = UICollectionView.CellRegistration<UICollectionViewListCell, Int> { (cell, indexPath, identifier) in cell.accessories = [.disclosureIndicator(), .customView(configuration: .init(customView: UIStepper(), placement: .trailing()))] } dataSource = UICollectionViewDiffableDataSource<Section, Int>(collectionView: collectionView) { (collectionView: UICollectionView, indexPath: IndexPath, identifier: Int) -> UICollectionViewCell? in return collectionView.dequeueConfiguredReusableCell(using: cellRegistration, for: indexPath, item: identifier) } var snapshot = NSDiffableDataSourceSnapshot<Section, Int>() snapshot.appendSections([.main]) snapshot.appendItems([1]) dataSource.apply(snapshot, animatingDifferences: false) } }

I can't override the show(_:sender:) of UIViewController or else my app freezes when the method is called (Xcode 15.3 simulator, iOS 17.4, macOS Sonoma 14.3.1, MacBook Air M1 8GB). Is there any workaround? override func show(_ vc: UIViewController, sender: Any?) { super.show(vc, sender: sender) }

I thought I could easily display a toolbar in UIKit, but I was wrong, or at least I can't do so without getting "Unable to simultaneously satisfy constraints." console messages. Here is my code: import UIKit class ViewController: UIViewController { let toolbar = UIToolbar() override func viewDidLoad() { super.viewDidLoad() view.backgroundColor = .systemBackground toolbar.items = [ UIBarButtonItem(title: "Title", style: .plain, target: nil, action: nil), UIBarButtonItem(barButtonSystemItem: .flexibleSpace, target: nil, action: nil) ] view.addSubview(toolbar) toolbar.translatesAutoresizingMaskIntoConstraints = false NSLayoutConstraint.activate([ toolbar.bottomAnchor.constraint(equalTo: view.safeAreaLayoutGuide.bottomAnchor), toolbar.leadingAnchor.constraint(equalTo: view.safeAreaLayoutGuide.leadingAnchor), toolbar.trailingAnchor.constraint(equalTo: view.safeAreaLayoutGuide.trailingAnchor), toolbar.heightAnchor.constraint(equalToConstant: 44) ]) } } And here is the console log: Unable to simultaneously satisfy constraints. Probably at least one of the constraints in the following list is one you don't want. Try this: (1) look at each constraint and try to figure out which you don't expect; (2) find the code that added the unwanted constraint or constraints and fix it. (Note: If you're seeing NSAutoresizingMaskLayoutConstraints that you don't understand, refer to the documentation for the UIView property translatesAutoresizingMaskIntoConstraints) ( "<NSAutoresizingMaskLayoutConstraint:0x600002107b10 h=--& v=--& _UIToolbarContentView:0x104008e40.height == 0 (active)>", "<NSLayoutConstraint:0x600002122e90 V:|-(0)-[_UIButtonBarStackView:0x10250d8b0] (active, names: '|':_UIToolbarContentView:0x104008e40 )>", "<NSLayoutConstraint:0x600002121ef0 _UIButtonBarStackView:0x10250d8b0.bottom == _UIToolbarContentView:0x104008e40.bottom (active)>", "<NSLayoutConstraint:0x600002107a70 UIButtonLabel:0x10250f280.centerY == _UIModernBarButton:0x1027059c0'Title'.centerY + 1.5 (active)>", "<NSLayoutConstraint:0x60000210ea30 'TB_Baseline_Baseline' _UIModernBarButton:0x1027059c0'Title'.lastBaseline == UILayoutGuide:0x600003b0ca80'UIViewLayoutMarginsGuide'.bottom (active)>", "<NSLayoutConstraint:0x60000210ea80 'TB_Top_Top' V:|-(>=0)-[_UIModernBarButton:0x1027059c0'Title'] (active, names: '|':_UIButtonBarButton:0x102607120 )>", "<NSLayoutConstraint:0x60000210e8f0 'UIButtonBar.maximumAlignmentSize' _UIButtonBarButton:0x102607120.height == UILayoutGuide:0x600003b00380'UIViewLayoutMarginsGuide'.height (active)>", "<NSLayoutConstraint:0x60000212c960 'UIView-bottomMargin-guide-constraint' V:[UILayoutGuide:0x600003b00380'UIViewLayoutMarginsGuide']-(0)-| (active, names: '|':_UIButtonBarStackView:0x10250d8b0 )>", "<NSLayoutConstraint:0x60000210ec60 'UIView-bottomMargin-guide-constraint' V:[UILayoutGuide:0x600003b0ca80'UIViewLayoutMarginsGuide']-(11)-| (active, names: '|':_UIButtonBarButton:0x102607120 )>", "<NSLayoutConstraint:0x60000212d6d0 'UIView-topMargin-guide-constraint' V:|-(0)-[UILayoutGuide:0x600003b00380'UIViewLayoutMarginsGuide'] (active, names: '|':_UIButtonBarStackView:0x10250d8b0 )>" ) Will attempt to recover by breaking constraint <NSLayoutConstraint:0x600002107a70 UIButtonLabel:0x10250f280.centerY == _UIModernBarButton:0x1027059c0'Title'.centerY + 1.5 (active)> Make a symbolic breakpoint at UIViewAlertForUnsatisfiableConstraints to catch this in the debugger. The methods in the UIConstraintBasedLayoutDebugging category on UIView listed in <UIKitCore/UIView.h> may also be helpful. Unable to simultaneously satisfy constraints. Probably at least one of the constraints in the following list is one you don't want. Try this: (1) look at each constraint and try to figure out which you don't expect; (2) find the code that added the unwanted constraint or constraints and fix it. (Note: If you're seeing NSAutoresizingMaskLayoutConstraints that you don't understand, refer to the documentation for the UIView property translatesAutoresizingMaskIntoConstraints) ( "<NSAutoresizingMaskLayoutConstraint:0x600002106710 h=--& v=--& _UIToolbarContentView:0x104008e40.width == 0 (active)>", "<NSLayoutConstraint:0x600002120b40 H:|-(0)-[_UIButtonBarStackView:0x10250d8b0] (active, names: '|':_UIToolbarContentView:0x104008e40 )>", "<NSLayoutConstraint:0x600002122e40 H:[_UIButtonBarStackView:0x10250d8b0]-(0)-| (active, names: '|':_UIToolbarContentView:0x104008e40 )>", "<NSLayoutConstraint:0x60000210eda0 'TB_Leading_Leading' H:|-(16)-[_UIModernBarButton:0x1027059c0'Title'] (active, names: '|':_UIButtonBarButton:0x102607120 )>", "<NSLayoutConstraint:0x60000210eb70 'TB_Trailing_Trailing' H:[_UIModernBarButton:0x1027059c0'Title']-(16)-| (active, names: '|':_UIButtonBarButton:0x102607120 )>", "<NSLayoutConstraint:0x60000210e580 'UISV-canvas-connection' UILayoutGuide:0x600003b00380'UIViewLayoutMarginsGuide'.leading == _UIButtonBarButton:0x102607120.leading (active)>", "<NSLayoutConstraint:0x60000210e5d0 'UISV-canvas-connection' UILayoutGuide:0x600003b00380'UIViewLayoutMarginsGuide'.trailing == UIView:0x10400e480.trailing (active)>", "<NSLayoutConstraint:0x60000210e9e0 'UISV-spacing' H:[_UIButtonBarButton:0x102607120]-(0)-[UIView:0x10400e480] (active)>", "<NSLayoutConstraint:0x60000212c820 'UIView-leftMargin-guide-constraint' H:|-(0)-[UILayoutGuide:0x600003b00380'UIViewLayoutMarginsGuide'](LTR) (active, names: '|':_UIButtonBarStackView:0x10250d8b0 )>", "<NSLayoutConstraint:0x60000212ca00 'UIView-rightMargin-guide-constraint' H:[UILayoutGuide:0x600003b00380'UIViewLayoutMarginsGuide']-(0)-|(LTR) (active, names: '|':_UIButtonBarStackView:0x10250d8b0 )>" ) Will attempt to recover by breaking constraint <NSLayoutConstraint:0x60000210eb70 'TB_Trailing_Trailing' H:[_UIModernBarButton:0x1027059c0'Title']-(16)-| (active, names: '|':_UIButtonBarButton:0x102607120 )> Make a symbolic breakpoint at UIViewAlertForUnsatisfiableConstraints to catch this in the debugger. The methods in the UIConstraintBasedLayoutDebugging category on UIView listed in <UIKitCore/UIView.h> may also be helpful. I tried giving the toolbar a frame rather than constraints, and also to not give it an explicit height. The only thing that works is to comment out UIBarButtonItem(title: "Title", style: .plain, target: nil, action: nil), which isn't really a solution. What am I doing wrong?

This is a simple collection view with compositional layout and diffable data source. It displays one cell, of type UICollectionViewListCell, whose contentView has a text view as a subview. import UIKit class ViewController: UIViewController { var collectionView: UICollectionView! let textView = UITextView() var dataSource: UICollectionViewDiffableDataSource<Section, Int>! enum Section: CaseIterable { case first } override func viewDidLoad() { super.viewDidLoad() configureHierarchy() configureDataSource() } private func configureHierarchy() { collectionView = UICollectionView(frame: view.bounds, collectionViewLayout: createLayout()) view.addSubview(collectionView) collectionView.autoresizingMask = [.flexibleHeight, .flexibleWidth] textView.delegate = self } func configureDataSource() { let cellRegistration = UICollectionView.CellRegistration<UICollectionViewListCell, Int> { [weak self] cell, indexPath, itemIdentifier in guard let self else { return } cell.contentView.addSubview(textView) textView.pinToSuperviewMargins() } dataSource = .init(collectionView: collectionView) { collectionView, indexPath, itemIdentifier in collectionView.dequeueConfiguredReusableCell(using: cellRegistration, for: indexPath, item: itemIdentifier) } var snapshot = NSDiffableDataSourceSnapshot<Section, Int>() snapshot.appendSections(Section.allCases) snapshot.appendItems([1], toSection: .first) dataSource.apply(snapshot) } func createLayout() -> UICollectionViewLayout { UICollectionViewCompositionalLayout { section, layoutEnvironment in var config = UICollectionLayoutListConfiguration(appearance: .insetGrouped) return NSCollectionLayoutSection.list(using: config, layoutEnvironment: layoutEnvironment) } } } extension ViewController: UITextViewDelegate { func textViewDidChange(_ textView: UITextView) { // Do something here? } } The pinToSuperviewMargins method sets the top, bottom, leading and trailing constraints of the view on which it's called to its superview's and its translatesAutoResizingMaskIntoConstraints property to false: extension UIView { func pinToSuperviewMargins( top: CGFloat = 0, bottom: CGFloat = 0, leading: CGFloat = 0, trailing: CGFloat = 0, file: StaticString = #file, line: UInt = #line ) { guard let superview = self.superview else { let localFilePath = URL(fileURLWithPath: "\(file)").lastPathComponent print(">> \(#function) failed in file: \(localFilePath), at line: \(line): could not find \(Self.self).superView.") return } self.translatesAutoresizingMaskIntoConstraints = false NSLayoutConstraint.activate([ self.topAnchor.constraint(equalTo: superview.topAnchor, constant: top), self.bottomAnchor.constraint(equalTo: superview.bottomAnchor, constant: bottom), self.leadingAnchor.constraint(equalTo: superview.leadingAnchor, constant: leading), self.trailingAnchor.constraint(equalTo: superview.trailingAnchor, constant: trailing), ]) } func pinToSuperviewMargins(constant c: CGFloat = 0, file: StaticString = #file, line: UInt = #line) { self.pinToSuperviewMargins(top: c, bottom: c, leading: c, trailing: c, file: file, line: line) } } I tried calling collectionView.setNeedsLayout() in textViewDidChange(_:) but it doesn't work. I used to accomplish cell resizing with tableView.beginUpdates(); tableView.endUpdates() when dealing with table views.

The following Swift UIKit code produces the warning "Cannot access property 'authController' with a non-sendable type 'AuthController' from non-isolated deinit; this is an error in Swift 6": import UIKit class AuthFormNavC: UINavigationController { let authController: AuthController init(authController: AuthController) { self.authController = authController super.init(rootViewController: ConsentVC()) } required init?(coder aDecoder: NSCoder) { fatalError("init(coder:) has not been implemented") } deinit { authController.signInAnonymouslyIfNecessary() } } Swift 5.10, Xcode 15.3 with complete strict concurrency checking. What is the workaround? Please don't ask me why I'm doing what I'm doing or anything unrelated to the question. If you're wondering why I want to call authController.signInAnonymouslyIfNecessary() when the navigation controller is denitialized, my goal is to call it when the navigation controller is dismissed (or popped), and I think that the deinitializer of a view controller is the only method that is called if and only if the view controller is being dismissed (or popped) in my case. I tried observing variables like isViewLoaded in the past using KVO but I couldn't get it to work passing any combination of options in observe(_:options:changeHandler:).

If you run the following UIKit app and tap the view controller's right bar button item, the footerText property will change. How should I update the collection view's footer to display the updated footerText? class ViewController: UIViewController { var collectionView: UICollectionView! var footerText = "Initial footer text" var dataSource: UICollectionViewDiffableDataSource<Section, String>! var snapshot: NSDiffableDataSourceSnapshot<Section, String> { var snapshot = NSDiffableDataSourceSnapshot<Section, String>() snapshot.appendSections(Section.allCases) snapshot.appendItems(["A", "a"], toSection: .first) return snapshot } enum Section: CaseIterable { case first } override func viewDidLoad() { super.viewDidLoad() configureHierarchy() configureDataSource() } func configureHierarchy() { navigationItem.rightBarButtonItem = .init(title: "Change footer text", style: .plain, target: self, action: #selector(changeFooterText)) collectionView = UICollectionView(frame: view.bounds, collectionViewLayout: createLayout()) view.addSubview(collectionView) collectionView.autoresizingMask = [.flexibleHeight, .flexibleWidth] } @objc func changeFooterText() { footerText = "Secondary footer text" } func configureDataSource() { let cellRegistration = UICollectionView.CellRegistration<UICollectionViewListCell, String> { cell, indexPath, itemIdentifier in var contentConfiguration = UIListContentConfiguration.cell() contentConfiguration.text = itemIdentifier cell.contentConfiguration = contentConfiguration } dataSource = .init(collectionView: collectionView) { collectionView, indexPath, itemIdentifier in collectionView.dequeueConfiguredReusableCell(using: cellRegistration, for: indexPath, item: itemIdentifier) } configureSupplementaryViewProvider() dataSource.apply(self.snapshot) } func configureSupplementaryViewProvider() { let headerRegistration = UICollectionView.SupplementaryRegistration<UICollectionViewListCell>(elementKind: UICollectionView.elementKindSectionHeader) { headerView, elementKind, indexPath in var contentConfiguration = UIListContentConfiguration.cell() contentConfiguration.text = "Header \(indexPath.section)" headerView.contentConfiguration = contentConfiguration } let footerRegistration = UICollectionView.SupplementaryRegistration<UICollectionViewListCell>(elementKind: UICollectionView.elementKindSectionFooter) { [weak self] headerView, elementKind, indexPath in guard let self else { return } var contentConfiguration = UIListContentConfiguration.cell() contentConfiguration.text = self.footerText headerView.contentConfiguration = contentConfiguration } dataSource.supplementaryViewProvider = { collectionView, kind, indexPath in if kind == UICollectionView.elementKindSectionHeader { collectionView.dequeueConfiguredReusableSupplementary(using: headerRegistration, for: indexPath) } else if kind == UICollectionView.elementKindSectionFooter { collectionView.dequeueConfiguredReusableSupplementary(using: footerRegistration, for: indexPath) } else { nil } } } func createLayout() -> UICollectionViewLayout { UICollectionViewCompositionalLayout { section, layoutEnvironment in var config = UICollectionLayoutListConfiguration(appearance: .insetGrouped) config.headerMode = .supplementary config.footerMode = .supplementary return NSCollectionLayoutSection.list(using: config, layoutEnvironment: layoutEnvironment) } } } What I've tried to do in footerText's didSet: Reconfiguring the supplementary view provider: var footerText = "Initial footer text" { didSet { configureSupplementaryViewProvider() } } Also re-applying the snapshot: var footerText = "Initial footer text" { didSet { configureSupplementaryViewProvider() dataSource.apply(self.snapshot) } } Also re-configuring the items: var footerText = "Initial footer text" { didSet { configureSupplementaryViewProvider() dataSource.apply(self.snapshot, animatingDifferences: true) var snapshot = dataSource.snapshot() snapshot.reconfigureItems(snapshot.itemIdentifiers) dataSource.apply(snapshot, animatingDifferences: false) } }