Foundation

RSS for tag

Access essential data types, collections, and operating-system services to define the base layer of functionality for your app using Foundation.

Posts under Foundation tag

178 Posts

Post

Replies

Boosts

Views

Activity

How to call decoder with the right types ?
I have defined a class : class Item: NSObject, NSSecureCoding { var name : String = "" var color : ColorTag = .black // defined as enum ColorTag: Int var value : Int = 0 static var supportsSecureCoding: Bool { return true } Its decoder includes the following print statement to start: required init(coder decoder: NSCoder) { print(#function, "item should not be nil", decoder.decodeObject(of: Item.self, forKey: someKey))   Another class uses it: class AllItems: NSObject, NSSecureCoding { var allItems : [Item]? static var supportsSecureCoding: Bool { return true } and decodes as follows required init(coder decoder: NSCoder) { super.init() // Not sure it is necessary allItems = decoder.decodeObject(of: NSArray.self, forKey: mykey) as? [Item] print(#function, allItems) // <<-- get nil } I note: decoder returns nil at line 5 I have tried to change to decoder.decodeObject(of: [NSArray.self, NSString.self, NSColor.self, NSNumber.self], forKey: mykey)) Still get nil And, decoder of class Item is not called (no print in the log) What am I missing ?
1
0
158
Jan ’26
Requesting guidance on long-running background BLE control triggered by server-side events
Hello Apple Forums, We are developing an iOS application that connects to a custom BLE accessory and sends control commands to it. Our system architecture is as follows: A separate hardware device collects data and sends it to our backend server via Wi-Fi. The backend evaluates state changes and determines when the BLE accessory should update its display. The iOS app acts purely as a BLE command executor for this accessory. Our goal is to: Maintain a BLE connection with the accessory while the app is in the background. Receive state-change events from our backend server. Upon receiving such events, send a BLE command to the accessory to update its state. We understand that iOS does not allow arbitrary background execution. We would like to confirm whether there is any supported mechanism, entitlement, or program that allows: Long-running background execution for BLE control, or Server-originated events (other than APNs) to trigger background BLE actions. If this is not supported, we would appreciate confirmation that APNs (silent push) is the only supported way to trigger such background BLE actions, or guidance on any recommended alternative architectures. Thank you for your guidance.
0
0
129
Jan ’26
How to encode / decode Array < Array < SomeStruct > >
I need to encode and decode Array<Array> SomeStruct is multiplexed in an Int The former API did work: if let format = decoder.decodeObject(forKey: someKey) as? Array<Array<SomeStruct>> { } But using the new API if let format = decoder.decodeObject(of: Array<Array<Int>>.self, forKey: someKey) { generates an error: Cannot convert value of type 'Array<Array<Int>>.Type' to expected argument type '[AnyClass]' (aka 'Array<any AnyObject.Type>') encoding is done as follows: var format = Array(repeating: Array(repeating: 0, count: 4), count: 4) // initialize the var coder.encode(format, forKey: someKey) What is the correct syntax ?
2
0
177
Jan ’26
Is there any way to control alarm volume independently when using AlarmKit?
Is there any supported or recommended way to achieve user-configurable alarm volume while still using AlarmKit? Hi there! I’m currently building an alarm app on iOS using AlarmKit, and I’m running into a fundamental limitation around volume control. When using AlarmKit, alarm sounds are played at the system ringer volume. My goal is simple in concept: Allow users to set an alarm volume inside the app, and have the alarm sound play at that volume when triggered. However, AlarmKit does not provide any API to control or override the alarm volume. I’ve explored several approaches(AVSystemController, MPVolumeView...), but none achieved the desired result. Is there any supported or recommended way to achieve user-configurable alarm volume while still using AlarmKit? Any insights from developers who’ve shipped alarm apps, or from Apple engineers, would be greatly appreciated. Thanks in advance 🙏
1
0
253
Jan ’26
NSKeyedArchiving issue
I have a large code that I try to update to change deprecated APIs. In the former version, I used forWritingWith and forReadingWith let data = NSMutableData() let archiver = NSKeyedArchiver(forWritingWith: data) archiver.encode(myObject, forKey: theKey) if let data = NSMutableData(contentsOf: anURL) { let unarchiver = NSKeyedUnarchiver(forReadingWith: data as Data) let myObject = unarchiver.decodeObject(forKey: theKey) as! TheObjectType // <<-- returns the object That I changed to let data = NSMutableData() let archiver = NSKeyedArchiver(requiringSecureCoding: true) archiver.encode(myObject, forKey: theKey) if let data = NSMutableData(contentsOf: anURL) { do { let unarchiver = try NSKeyedUnarchiver(forReadingFrom: data as Data) let myObject = unarchiver.decodeObject(forKey: theKey) as? TheObjectType // <<-- This returns nil This builds correctly. But on execution, unarchiver.decodeObject now returns nil. I have searched extensively to find the cause to no avail. I may probably change the design to avoid NSKeyedArchiver, but that would be a huge refactoring. I probably miss something obvious. Could someone hint at the possible cause ?
3
0
161
Jan ’26
Custom @Observable RandomAcccessCollection List/ForEach issues
I'm trying to understand the behavior I'm seeing here. In the following example, I have a custom @Observable class that adopts RandomAccessCollection and am attempting to populate a List with it. If I use an inner collection property of the instance (even computed as this shows), the top view identifies additions to the list. However, if I just use the list as a collection in its own right, it detects when a change is made, but not that the change increased the length of the list. If you add text that has capital letters you'll see them get sorted correctly, but the lower list retains its prior count. The choice of a List initializer with the model versus an inner ForEach doesn't change the outcome, btw. If I cast that type as an Array(), effectively copying its contents, it works fine which leads me to believe there is some additional Array protocol conformance that I'm missing, but that would be unfortunate since I'm not sure how I would have known that. Any ideas what's going on here? The new type can be used with for-in scenarios fine and compiles great with List/ForEach, but has this issue. I'd like the type to not require extra nonsense to be used like an array here. import SwiftUI fileprivate struct _VExpObservable6: View { @Binding var model: ExpModel @State private var text: String = "" var body: some View { NavigationStack { VStack(spacing: 20) { Spacer() .frame(height: 40) HStack { TextField("Item", text: $text) .textFieldStyle(.roundedBorder) .textContentType(.none) .textCase(.none) Button("Add Item") { guard !text.isEmpty else { return } model.addItem(text) text = "" print("updated model #2 using \(Array(model.indices)):") for s in model { print("- \(s)") } } } InnerView(model: model) OuterView(model: model) } .listStyle(.plain) .padding() } } } // - displays the model data using an inner property expressed as // a collection. fileprivate struct InnerView: View { let model: ExpModel var body: some View { VStack { Text("Model Inner Collection:") .font(.title3) List { ForEach(model.sorted, id: \.self) { item in Text("- \(item)") } } .border(.darkGray) } } } // - displays the model using the model _as the collection_ fileprivate struct OuterView: View { let model: ExpModel var body: some View { VStack { Text("Model as Collection:") .font(.title3) // - the List/ForEach collections do not appear to work // by default using the @Observable model (RandomAccessCollection) // itself, unless it is cast as an Array here. List { // ForEach(Array(model), id: \.self) { item in ForEach(model, id: \.self) { item in Text("- \(item)") } } .border(.darkGray) } } } #Preview { @Previewable @State var model = ExpModel() _VExpObservable6(model: $model) } @Observable fileprivate final class ExpModel: RandomAccessCollection { typealias Element = String var startIndex: Int { 0 } var endIndex: Int { sorted.count } init() { _listData = ["apple", "yellow", "about"] } subscript(_ position: Int) -> String { sortedData()[position] } var sorted: [String] { sortedData() } func addItem(_ item: String) { _listData.append(item) _sorted = nil } private var _listData: [String] private var _sorted: [String]? private func sortedData() -> [String] { if let ret = _sorted { return ret } let ret = _listData.sorted() _sorted = ret return ret } }
2
0
227
Jan ’26
URL.startAccessingSecurityScopedResource() returns false for "On My iPad" after a while
My app allows to save user-selected URLs in a list and browse them with a tap. A user reported that the app often shows that when browsing their saved entry for "On My iPad", it's apparently empty (it contains no files). I saved "On My iPad" in my own list some time ago and noticed that the same issue occurs. The URL seems to be correctly resolved from the saved bookmark data, but I noticed that url.startAccessingSecurityScopedResource() returns false. The other URL I saved some time ago is iCloud Drive, which I can access without issues. If I select "On My iPad" again in a file importer, create new bookmark data from it and resolve the URL from it, access works correctly. I create bookmark data like this: let data = try url.bookmarkData(includingResourceValuesForKeys: [.localizedNameKey, .pathKey, .volumeIsLocalKey]) and resolve URLs like this: let url = try URL(resolvingBookmarkData: data, bookmarkDataIsStale: &bookmarkDataIsStale) bookmarkDataIsStale is false for both the working and not working URLs for "On My iPad". The two bookmark data are different though, even if url.path is the same. What could be the issue?
2
0
168
Jan ’26
Crash in libicucore via NSDateFormatter dateFromString: on iOS 26.2
Introduction: I’m encountering a consistent crash in production on iOS 26.2 (build 23C55). The crash occurs deep within libicucore when calling [NSDateFormatter dateFromString:]. Crash Summary: Exception Type: SIGSEGV (SEGV_ACCERR) Fault Address: 0xffffffff Thread: Crashed on Main Thread (Thread 0) Library: libicucore.A.dylib Code Snippet: The crash is triggered by the following method. It converts a string to an NSDate using a specific format and locale: // 获取日期date - (NSDate *)getDateWithTime:(NSString *)time formatter:(NSString *)formatterStr { NSDateFormatter *formatter = [[NSDateFormatter alloc] init]; [formatter setDateFormat:formatterStr]; formatter.timeZone = [NSTimeZone timeZoneWithName:@"Asia/Shanghai"]; formatter.locale = [[NSLocale alloc] initWithLocaleIdentifier:@"en_US_POSIX"]; return [formatter dateFromString:time]; } Backtrace: Here is the relevant part of the crash report: Incident Identifier: E24485B6-C53E-4115-A6CF-A7E4A952AD50 CrashReporter Key: 21FAC1CF-F56B-409A-98AA-351D3D2EB06C Hardware Model: iPhone18,2 Code Type: ARM-64 Parent Process: [1] Date/Time: 2026-01-12T01:32:25Z OS Version: iPhone OS 26.2 (23C55) Report Version: 105 SDK Version: 0.0.4 Exception Type: SIGSEGV Exception Codes: SEGV_ACCERR at 0xffffffff Crashed Thread: 0 Thread 0 Crashed: 0 libicucore.A.dylib 0x000000019b81def8 0x19b74a000 + 868088 1 libicucore.A.dylib 0x000000019b7da91c 0x19b74a000 + 592156 2 libicucore.A.dylib 0x000000019b8d8340 0x19b74a000 + 1631040 3 libicucore.A.dylib 0x000000019b8eae18 0x19b74a000 + 1707544 4 libicucore.A.dylib 0x000000019b8eb600 0x19b74a000 + 1709568 5 libicucore.A.dylib 0x000000019b878be4 0x19b74a000 + 1240036 6 libicucore.A.dylib 0x000000019b87ae84 0x19b74a000 + 1248900 7 libicucore.A.dylib 0x000000019b87b2dc 0x19b74a000 + 1250012 8 libicucore.A.dylib 0x000000019b9564ac 0x19b74a000 + 2147500 9 libicucore.A.dylib 0x000000019b954afc 0x19b74a000 + 2140924 10 libicucore.A.dylib 0x000000019b952794 0x19b74a000 + 2131860 11 libicucore.A.dylib 0x000000019b98689c 0x19b74a000 + 2345116 12 CoreFoundation 0x00000001895dbfe0 0x18953d000 + 651232 13 CoreFoundation 0x00000001895dbaa0 0x18953d000 + 649888 14 Foundation 0x0000000186d2029c 0x186b88000 + 1671836 15 Foundation 0x00000001874a62dc 0x186b88000 + 9560796 16 Foundation 0x00000001874a6384 0x186b88000 + 9560964 17 xxxx 0x0000000105ea6e30 -[xxxxx getDateWithTime:formatter:] + 168 and Thread 0 crashed with ARM-64 Thread State: pc: 0x000000019b81def8 fp: 0x000000016f96bc10 sp: 0x000000016f96bbd0 x0: 0x00000000ffffffff x1: 0x000000019ba1e8e0 x2: 0x0000000000000002 x3: 0x000000000000000b x4: 0x0000000000000074 x5: 0x0000000000000069 x6: 0x0000000000000000 x7: 0xfffff0003ffff800 x8: 0x000000009ba18014 x9: 0x00000001148dffd0 x10: 0x0000000000000002 x11: 0x0000000000000004 x12: 0x0000000000000220 x13: 0x0000000000000030 x14: 0x000000015b6f36b8 x15: 0x000000015cfe0000 x16: 0x00000002a19d0ff0 x17: 0x00000001f5590a70 x18: 0x0000000000000000 x19: 0x000000016f96bc30 x20: 0x0000000000000000 x21: 0x000000015cfe3200 x22: 0x000000019ba18014 x23: 0x0000000000000000 x24: 0x000000015cfe32a0 x25: 0x0000000000000003 x26: 0x0000000000000000 x27: 0x0000000000000000 x28: 0x000000015cfe3200 lr: 0x000000019b7da958 cpsr: 0x00000000a0000000
6
0
223
Jan ’26
Extend Measurement to support inverse units
There are many units which are inverse of standard units, e.g. wave period vs Hz, pace vs speed, Siemens vs Ohms, ... Dimension can be subclassed to create the custom units. How to extend Measurement.converted( to: )? I was looking at somehow using UnitConverter and subclass to something like UnitConverterInverse. Thoughts?
1
1
219
Jan ’26
iOS 26 fails to automatically switch to [system settings - personal hotspot ] directly from application ]
On iOS 18 and lower version, my application supports automatically switching to [System settings - Personal Hotspot] directly. But on iOS 26, my application will be redirected to [System settings- Apps]. Does iOS 26 disable the behavior of directly jumping to the system hotspot page? If support, could you share the API for iOS 26?
7
0
529
Jan ’26
iOS UserDefaults Intermittently Returns Nil After getPreferences() Call - Race Condition?
iOS Intermittent Bug: UserDefaults Preferences Loading Issue Problem Summary We're experiencing an intermittent issue where UserPreferences.shared.preferences returns inconsistent values even after calling getPreferences(). The behavior is unpredictable and affects critical functionality. Environment iOS Version: 15+ Language: Objective-C with Swift interop Storage: UserDefaults with App Group (group.com.jci.tyco.glss) Architecture: Singleton pattern for UserPreferences (Swift class) The Issue When a push notification arrives and triggers the showEvent: method, user preferences are sometimes loaded correctly and sometimes return nil or default values: Scenario A (Works - ~60% of time): Scenario B (Fails - ~40% of time): Observed Pattern From extensive logging over multiple test runs: Key Observation: At app launch: Preferences often load successfully Seconds later when push arrives: Same preferences become unavailable User navigates to another screen and back: Preferences suddenly work again Code Structure Objective-C AppDelegate.m - (void)showEvent:(FMEvent *)event eventReadSource:(FMEventReadSourceType)eventSource { BOOL isUserRoleEndUser = [[FMUserRolesRepository instance] userRoleAvailable:FMUserRoleEndUser]; UserPreferences *userPrefs = [UserPreferences shared]; [userPrefs getPreferences]; // ← Called here // Immediately after, sometimes nil! bool hasFireAudio = [userPrefs.preferences.fireAudio.lowercaseString isEqual:@"true"]; NSLog(@"isUserRoleEndUser: %d | Fire Audio: %d", isUserRoleEndUser, hasFireAudio); // Decision logic based on preferences if ([FMConstants getUserRegion] == UserRegionUK && isUserRoleEndUser && userPrefs.preferences && // ← Sometimes nil here hasFireAudio) { // Show Screen A } else { // Show Screen B } } ```class UserPreferences: NSObject { static let shared = UserPreferences() var preferences: FMUserPreferencesInfo? // ← This becomes nil intermittently func getPreferences() { let userDefaults = UserDefaults(suiteName: "group.com.jci.tyco.glss") if let data = userDefaults?.data(forKey: "UserPreferences") { // Decode and set preferences self.preferences = // decoded object } else { // Create default preferences with fireAudio = "false" self.preferences = FMUserPreferencesInfo() } } }
1
0
112
Jan ’26
Disable HTTP/3 QUIC Forcibly with URLSession
Is there any way to forcibly disable using QUIC? I've noticed this ends up causing issues with our ISP / router, and noticed for many of our customers as well. Creating an ephemeral session doesn't change things, and setting the request to "assumeHttp3Capable" to false doesn't fix things either. We are using Cloudflare Workers as the URL we are hitting, and thus aren't able to disable this server-side.
4
0
1.1k
Jan ’26
During the process of uploading a large file, I moved it to the trash can. How can I directly interrupt this upload process
I am currently encountering a problem: during the process of uploading a large file, I have moved the file that was not successfully uploaded to the trash can. These two operations have been tested to be serial (triggering the 'create Item' callback first, followed by the 'modify Item' callback), which means that the file must be uploaded before it can be moved to the recycle bin (which can also result in the file being stored in the cloud recycle bin). I want to implement: directly interrupt this upload process and then do not complete the upload. How can I achieve this? Please help me. Thank you
2
0
132
Jan ’26
Scanning Macintosh HD produces single .nofollow file since update to macOS 26.1
A user of one of my apps reported that since the update to macOS 26.1 they are no longer able to scan Macintosh HD: the app used to work, but now always reports that Macintosh HD contains a single empty file named .nofollow, or rather the path is resolved to /.nofollow. Initially I thought this could be related to resolving the file from the saved bookmark data, but even restarting the app and selecting Macintosh HD in an open panel (without resolving the bookmark data) produces the same result. The user tried another app of mine with the same issue, but said that they were able to scan Macintosh HD in other App Store apps. I never heard of this issue before and my apps have been on the App Store for many years, but it looks like I might be doing something wrong, or the APIs that I use are somehow broken. In all my apps I currently use getattrlistbulk because I need attributes that are not available as URLResourceKey in all supported operating system versions. What could be the issue? I'm on macOS 26.1 myself and never experienced it.
6
0
292
Dec ’25
NSURL +resourceValuesForKeys:fromBookmarkData: value always "file:///" for NSURLVolumeURLKey
I try saving the value of NSURLVolumeURLKey when creating a bookmark. When resolving the bookmark later I pass the bookmark data to +resourceValuesForKeys:fromBookmarkData: but always pull out "file:///" which is wrong. In contrast the value for NSURLVolumeURLForRemountingKey is properly saved and restored using the same method.
0
0
127
Dec ’25
How can I keep my app running in the background even after it has been force‑killed?
Recently I noticed an app called “Lookus”. Even if I force‑kill it, it still seems to obtain information such as my charging status and network status, and it can even send real‑time notifications. I’m curious how this is technically possible. Does anyone know how this could be achieved?
1
0
174
Dec ’25
Xcode and Reading documents from a URL connection.
I have an Xcode app where currently txt files in the project display text data as a list. I can search through the lists and have buttons that will swap between different lists of information that you can look through. The next task is I have URL connections to docx files on a SharePoint site. I am trying to use an URLsession function to connect to the URL links to download the documents to the document directory then have the application read the doc information to then be displayed as the txt info would. The idea is that the docx files are a type of online update version of the data. So when the app is used and on wifi, the app can update the list data with the docx files. I have code set up that should access the URL files but I am struggling to figure out how to read the data and access from this Documents directory. I have been looking online and so far I am at a loss on where to go here. If anyone can help or provide some insight I would greatly appreciate it. I can try and provide code samples to help explain things if that is needed.
7
0
266
Dec ’25
Using `NSProcessInfo.systemUptime` to Detect Device Restarts: Feasibility and Background Considerations
"We are developing an application use case that requires us to prompt the user to restart their device. We plan to use the system uptime value provided by [NSProcessInfo processInfo].systemUptime to determine if a restart has occurred. Apple's documentation defines this API as 'The amount of time the system has been awake since the last time it was restarted.' Our questions are: Can we reliably use this API, in conjunction with persistent storage, to detect a device restart? Are there any known limitations or considerations when accessing or relying on this API while the application is running in the background?"
1
0
179
Dec ’25
Issue when creating Bookmark with security scope on macOS 26 RC
With the RC version of macOS 26, an issue persists when you try to create a bookmark with security scope for the root folder "/". This leads to an error "The file couldn’t be opened.". However, you can create bookmark for /Applications, /System, /Users... This is quite annoying for one of my app because a user can create a cartography of his disk usage, and the access to the root folder "/" is the only way to do so! Is there a workaround? PS: reported the issue with ID FB20186406 let openPanel = NSOpenPanel() openPanel.canChooseDirectories = true openPanel.canChooseFiles = false openPanel.beginSheetModal(for: self.view.window!) { (result) in guard result == .OK, let folderURL = openPanel.url else { return } openPanel.close() do { let data = try folderURL.bookmarkData(options: .withSecurityScope, includingResourceValuesForKeys: nil, relativeTo: nil) print("Bookmark data was created for \(folderURL.path)") } catch (let error) { print("Error creating bookmark for \(folderURL.path), with error: \(error.localizedDescription)") } }
5
0
332
Dec ’25