Consider this simple miniature of my iOS Share Extension:
import SwiftUI
import Photos
class ShareViewController: UIViewController {
override func viewDidLoad() {
super.viewDidLoad()
if let itemProviders = (extensionContext?.inputItems.first as? NSExtensionItem)?.attachments {
let hostingView = UIHostingController(rootView: ShareView(extensionContext: extensionContext, itemProviders: itemProviders))
hostingView.view.frame = view.frame
view.addSubview(hostingView.view)
}
}
}
struct ShareView: View {
var extensionContext: NSExtensionContext?
var itemProviders: [NSItemProvider]
var body: some View {
VStack{}
.task{
await extractItems()
}
}
func extractItems() async {
guard let itemProvider = itemProviders.first else { return }
guard itemProvider.hasItemConformingToTypeIdentifier(UTType.url.identifier) else { return }
do {
guard let url = try await itemProvider.loadItem(forTypeIdentifier: UTType.url.identifier) as? URL else { return }
try await downloadAndSaveMedia(reelURL: url.absoluteString)
extensionContext?.completeRequest(returningItems: [])
}
catch {}
}
}
On the line 34
guard let url = try await itemProvider.loadItem
...
I get these warnings:
Passing argument of non-sendable type '[AnyHashable : Any]?' outside of main actor-isolated context may introduce data races; this is an error in the Swift 6 language mode
1.1. Generic enum 'Optional' does not conform to the 'Sendable' protocol (Swift.Optional)
Passing argument of non-sendable type 'NSItemProvider' outside of main actor-isolated context may introduce data races; this is an error in the Swift 6 language mode
2.2. Class 'NSItemProvider' does not conform to the 'Sendable' protocol (Foundation.NSItemProvider)
How to fix them in Xcode 16?
Please provide a solution which works, and not the one which might (meaning you run the same code in Xcode, add your solution and see no warnings).
I tried
Decorating everything with @MainActors
Using @MainActor in the .task
@preconcurrency import
Decorating everything with @preconcurrency
Playing around with nonisolated
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Hello,
While watching WWDC25: Code-along: Elevate an app with Swift concurrency at timestamp 25:48, I noticed something in the slide/diagram that might be incorrect.
The diagram shows ExtractSticker twice, but based on the code context and spoken explanation, I think it was meant to be ExtractSticker and ExtractColor.
Reasoning:
The surrounding code and narration describe the use of async let and a Sendable Data object.
From the flow, one task extracts a sticker while the other extracts a color, so it seems like the diagram is inconsistent.
I do understand that with @concurrent, having two ExtractSticker operations on the same Data is technically possible (with two concurrent process executing their respective ExtractSticker) — but that would be a different meaning than what the talk was describing.
Since concurrency is already a subtle and error-prone topic, I thought it was worth pointing this out. If I’m mistaken, I’d love clarification. Otherwise, this could be a small correction to keep things aligned and clearer for everyone.
Minor point overall, but Swift 6’s concurrency model is doing a fantastic job at helping us write safer code—so thank you to the team for that!
(Attaching screenshots for reference)
Hello, I was hoping to clarify my understanding of the use of for await with an AsyncStream. My use case is, I'd like to yield async closures to the stream's continuation, with the idea that, when I use for await with the stream to process and execute the closures, it would only continue on to the following closure once the current closure has been run to completion.
At a high level, I am trying to implement in-order execution of async closures in the context of re-entrancy. An example of asynchronous work I want to execute is a network call that should write to a database:
func syncWithRemote() async -> Void {
let data = await fetchDataFromNetwork()
await writeToLocalDatabase(data)
}
For the sake of example, I'll call the intended manager of closure submission SingleOperationRunner.
where, at a use site such as this, my desired outcome is that call 1 of syncWithRemote() is always completed before call 2 of it:
let singleOperationRunner = SingleOperationRunner(priority: nil)
singleOperationRunner.run {
syncWithRemote()
}
singleOperationRunner.run {
syncWithRemote()
}
My sketch implementation looks like this:
public final class SingleOperationRunner {
private let continuation: AsyncStream<() async -> Void>.Continuation
public init(priority: TaskPriority?) {
let (stream, continuation) = AsyncStream.makeStream(of: (() async -> Void).self)
self.continuation = continuation
Task.detached(priority: priority) {
// Will this loop only continue when the `await operation()` completes?
for await operation in stream {
await operation()
}
}
}
public func run(operation: @escaping () async -> Void) {
continuation.yield(operation)
}
deinit {
continuation.finish()
}
}
The resources I've found are https://developer.apple.com/videos/play/wwdc2022-110351/?time=1445 and https://forums.swift.org/t/swift-async-func-to-run-sequentially/60939/2 but do not think I have fully put the pieces together, so would appreciate any help!
I am writing a SPM based project for MacOS. In this project? I need to access MacOS Keychain.
I am write a swift test built by SPM testTarget(). I can see it generates a bundle ./.build/x86_64-apple-macosx/debug/MyProjectTests.xctest with an executable:
% file ./.build/x86_64-apple-macosx/debug/MyProjectPackageTests.xctest/Contents/MacOS/MyProjectPackageTests
./.build/x86_64-apple-macosx/debug/MyProjectPackageTests.xctest/Contents/MacOS/MyProjectPackageTests: Mach-O 64-bit bundle x86_64
This bundle file cannot be executed. How can I execute its tests?
I tried with xcodebuild test-without-building -xctestrun ./.build/x86_64-apple-macosx/debug/MyProjectPackageTests.xctest -destination 'platform=macOS' without any chance.
Obviously the next question is can I 'simply' add entitlement to this bundle with codesign to fix my enttilement error.
My error when running the test is A required entitlement isn't present.
We have FrameworkA which needs to use another FrameworkB internally to fetch a token.
Now when I try to use this FrameworkA, we are seeing an issue with internal framework i.e. No such module 'FrameworkB'.
But when I use @_implementationOnly import for the internal FrameworkB, I didn't see any issues.
So just wanted to check If I can go ahead and use this @_implementationOnly import flag in Production?
i am trying to build my code and have ran into this error.
"Trailing closure passed to parameter of type 'DispatchWorkItem' that does not accept a closure"
i have been trying to figure it out for so long, and even ai cant figure it out. is this a bug, or am i missing some obvious way to fix this ?
func loadUser(uid: String, completion: (() -> Void)? = nil) {
db.collection("users").document(uid).getDocument { [weak self] snapshot, error in
guard let data = snapshot?.data(), error == nil else { completion?(); return }
DispatchQueue.main.async {
self?.currentUser = User(
username: data["username"] as? String ?? "Learner",
email: data["email"] as? String ?? "",
profileImageName: "person.circle.fill",
totalXP: data["totalXP"] as? Int ?? 0,
currentStreak: data["currentStreak"] as? Int ?? 0,
longestStreak: data["longestStreak"] as? Int ?? 0,
level: data["level"] as? Int ?? 1,
levelProgress: data["levelProgress"] as? Double ?? 0.0,
xpToNextLevel: data["xpToNextLevel"] as? Int ?? 100,
completedLessons: data["completedLessons"] as? [String] ?? []
)
self?.saveUser()
completion?()
}
}
}
Hello,
I have a json array showing in Xcode debugger (from the line "print(dataString)"):
Optional("[{\"id\":\"8e8tfdcssu4u2hn7a71tkveahjhn8xghqcfkwf1bzvtrw5nu0b89w\",\"name\":\"Ameliana\",\"country\":\"France\",\"type\":\"Private\\/Corporate\",\"overallrecsit\":\"Positive\",\"dlastupd\":\"1741351633\",\"doverallrecsit\":\"1546848000\"},{\"id\":\"z69718a1a5z2y5czkwrhr1u37h7h768v05qr3pf1fegh4r4yrt5a68\",\"name\":\"Timberland\",\"country\":\"Switzerland\",\"type\":\"Charter\",\"overallrecsit\":\"Negative\",\"dlastupd\":\"1741351615\",\"doverallrecsit\":\"1740434582\"},
But my JSON decoder is throwing the catch error "Error in JSON parsing"
This is the code:
super.viewDidLoad()
let urlString = "https://www.pilotjobsnetwork.com/service_ios.php"
let url = URL(string: urlString)
guard url != nil else {
return
}
let session = URLSession.shared
let dataTask = session.dataTask(with: url!) { (data, response, error) in
var dataString = String(data: data!, encoding: String.Encoding.utf8)
print(dataString)
if error == nil && data != nil {
// Parse JSON
let decoder = JSONDecoder()
do {
let newsFeed = try decoder.decode(NewsFeed.self, from: data!)
print(newsFeed)
print(error)
}
catch{
print("Error in JSON parsing")
}
}
}
// Make the API Call
dataTask.resume()
}
And this is my Codable file NewsFeed.swift:
struct NewsFeed: Codable {
var id: String
var name: String
var country: String
var type: String
var overallrecsit: String
var dlastupd: String
var doverallrecsit: String
}
Please do you know why the parsing may be failing? Is it significant that in the debugging window the JSON is displaying backslashes before the quotation marks?
Thank you for any pointers :-)
I’m trying to create a property wrapper that that can manage shared state across any context, which can get notified if changes happen from somewhere else.
I'm using mutex, and getting and setting values works great. However, I can't find a way to create an observer pattern that the property wrappers can use.
The problem is that I can’t trigger a notification from a different thread/context, and have that notification get called on the correct thread of the parent object that the property wrapper is used within.
I would like the property wrapper to work from anywhere: a SwiftUI view, an actor, or from a class that is created in the background. The notification preferably would get called synchronously if triggered from the same thread or actor, or otherwise asynchronously. I don’t have to worry about race conditions from the notification because the state only needs to reach eventuall consistency.
Here's the simplified pseudo code of what I'm trying to accomplish:
// A single source of truth storage container.
final class MemoryShared<Value>: Sendable {
let state = Mutex<Value>(0)
func withLock(_ action: (inout Value) -> Void) {
state.withLock(action)
notifyObservers()
}
func get() -> Value
func notifyObservers()
func addObserver()
}
// Some shared state used across the app
static let globalCount = MemoryShared<Int>(0)
// A property wrapper to access the shared state and receive changes
@propertyWrapper
struct SharedState<Value> {
public var wrappedValue: T {
get { state.get() }
nonmutating set { // Can't set directly }
}
var publisher: Publisher {}
init(state: MemoryShared) {
// ...
}
}
// I'd like to use it in multiple places:
@Observable
class MyObservable {
@SharedState(globalCount)
var count: Int
}
actor MyBackgroundActor {
@SharedState(globalCount)
var count: Int
}
@MainActor
struct MyView: View {
@SharedState(globalCount)
var count: Int
}
What I’ve Tried
All of the examples below are using the property wrapper within a @MainActor class. However the same issue happens no matter what context I use the wrapper in: The notification callback is never called on the context the property wrapper was created with.
I’ve tried using @isolated(any) to capture the context of the wrapper and save it to be called within the state in with unchecked sendable, which doesn’t work:
final class MemoryShared<Value: Sendable>: Sendable {
// Stores the callback for later.
public func subscribe(callback: @escaping @isolated(any) (Value) -> Void) -> Subscription
}
@propertyWrapper
struct SharedState<Value> {
init(state: MemoryShared<Value>) {
MainActor.assertIsolated() // Works!
state.subscribe {
MainActor.assertIsolated() // Fails
self.publisher.send()
}
}
}
I’ve tried capturing the isolation within a task with AsyncStream. This actually compiles with no sendable issues, but still fails:
@propertyWrapper
struct SharedState<Value> {
init(isolation: isolated (any Actor)? = #isolation, state: MemoryShared<Value>) {
let (taskStream, continuation) = AsyncStream<Value>.makeStream()
// The shared state sends new values to the continuation.
subscription = state.subscribe(continuation: continuation)
MainActor.assertIsolated() // Works!
let task = Task {
_ = isolation
for await value in taskStream {
_ = isolation
MainActor.assertIsolated() // Fails
}
}
}
}
I’ve tried using multiple combine subjects and publishers:
final class MemoryShared<Value: Sendable>: Sendable {
let subject: PassthroughSubject<T, Never> // ...
var publisher: Publisher {} // ...
}
@propertyWrapper
final class SharedState<Value> {
var localSubject: Subject
init(state: MemoryShared<Value>) {
MainActor.assertIsolated() // Works!
handle = localSubject.sink {
MainActor.assertIsolated() // Fails
}
stateHandle = state.publisher.subscribe(localSubject)
}
}
I’ve also tried:
Using NotificationCenter
Making the property wrapper a class
Using NSKeyValueObserving
Using a box class that is stored within the wrapper.
Using @_inheritActorContext.
All of these don’t work, because the event is never called from the thread the property wrapper resides in.
Is it possible at all to create an observation system that notifies the observer from the same context as where the observer was created?
Any help would be greatly appreciated!
Hello Everyone! I started programming 6 months ago and started Swift / IOS last month. My learning so far has mainly been with Python. I learned a lot of the package ‘SQLAlchemy’, which has very ‘example based’ documentation. If I wanted to learn how to make a many to many relationship, there was a demonstration with code. But going into Swift and Apple packages, I notice most of the documentation is definitions of structures, modifiers, functions, etc. I wanted to make the equivalent of python ‘date times’ in my swift app. I found the section in the documentation “Foundation->Dates & Times”, but I couldn’t figure how to use that in my code.
I assume my goal should not be to memorize every Swift and apple functionality by memory to be an app developer. So I would appreciate advice on how to approach this aspect of learning programming.
Topic:
Programming Languages
SubTopic:
Swift
Undefined symbols for architecture arm64:
"_swift_coroFrameAlloc", referenced from:
NvMobileCore.Constraint.isActive.modify : Swift.Bool in NvMobileCore[5]
NvMobileCore.Constraint.isActive.modify : Swift.Bool in NvMobileCore[5]
NvMobileCore.NvMobileCoreManager.delegate.modify : NvMobileCore.NvPublicInterface? in NvMobileCore[53]
NvMobileCore.NvMobileCoreManager.delegate.modify : NvMobileCore.NvPublicInterface? in NvMobileCore[53]
NvMobileCore.NvMobileCoreManager.language.modify : Swift.String in NvMobileCore[53]
NvMobileCore.NvMobileCoreManager.language.modify : Swift.String in NvMobileCore[53]
ld: symbol(s) not found for architecture arm64
clang: error: linker command failed with exit code 1 (use -v to see invocation)
Hello,
Please see the test project at https://we.tl/t-aWAu7kk9lD
I have a json array showing in Xcode debugger (from the line "print(dataString)"):
Optional("[{\"id\":\"8e8tcssu4u2hn7a71tkveahjhn8xghqcfkwf1bzvtrw5nu0b89w\",\"name\":\"Test name 0\",\"country\":\"Test country 0\",\"type\":\"Test type 0\",\"situation\":\"Test situation 0\",\"timestamp\":\"1546848000\"},{\"id\":\"z69718a1a5z2y5czkwrhr1u37h7h768v05qr3pf1h4r4yrt5a68\",\"name\":\"Test name 1\",\"country\":\"Test country 1\",\"type\":\"Test type 1\",\"situation\":\"Test situation 1\",\"timestamp\":\"1741351615\"},{\"id\":\"fh974sv586nhyysbhg5nak444968h7hgcgh6yw0usbvcz9b0h69\",\"name\":\"Test name 2\",\"country\":\"Test country 2\",\"type\":\"Test type 2\",\"situation\":\"Test situation 2\",\"timestamp\":\"1741351603\"},{\"id\":\"347272052385993\",\"name\":\"Test name 3\",\"country\":\"Test country 3\",\"type\":\"Test type 3\",\"situation\":\"Test situation 3\",\"timestamp\":\"1741351557\"}]")
But my JSON decoder is throwing a catch error
Line 57, Error in JSON parsing
typeMismatch(Swift.Dictionary<Swift.String, Any>, Swift.DecodingError.Context(codingPath: [], debugDescription: "Expected to decode Dictionary<String, Any> but found an array instead.", underlyingError: nil))
This is the code:
let urlString = "https://www.notafunnyname.com/jsonmockup.php"
let url = URL(string: urlString)
guard url != nil else {
return
}
let session = URLSession.shared
let dataTask = session.dataTask(with: url!) { (data, response, error) in
var dataString = String(data: data!, encoding: String.Encoding.utf8)
print(dataString)
if error == nil && data != nil {
// Parse JSON
let decoder = JSONDecoder()
do {
let newsFeed = try decoder.decode(NewsFeed.self, from: data!)
print("line 51")
print(newsFeed)
print(error)
}
catch{
print("Line 57, Error in JSON parsing")
print(error)
}
}
}
// Make the API Call
dataTask.resume()
}
And this is my Codable file NewsFeed.swift:
struct NewsFeed: Codable {
var id: String
var name: String
var country: String
var type: String
var situation: String
var timestamp: String
}
Please do you know how to resolve the typeMismatch error?
Topic:
Programming Languages
SubTopic:
Swift
Is there any way to retrieve the memory pressure percentage using native libraries?
When I run the memory-pressure command, I can see the percentage of free memory, but I’d like to retrieve the same information using a native library.
Topic:
Programming Languages
SubTopic:
Swift
Hey there-
I'm having a quite interesting bug on Swift Playgrounds.
I am trying to run my app with this following code snippet which does not compile on Swift Playgrounds, yet compiles on XCode (note: this is a Swift Playground app)
if #available(iOS 18.0, *) {
//simple function to get the indices of other items that have the same date as the "date" variable
let indices = data!.indices(where: { item in
let sameMonth = Calendar.current.component(.month, from: item.time) == Calendar.current.component(.month, from: date)
let sameYear = Calendar.current.component(.year, from: item.time) == Calendar.current.component(.year, from: date)
let sameDay = Calendar.current.component(.day, from: item.time) == Calendar.current.component(.year, from: date)
return sameDay && sameMonth && sameYear
})
However, the indices(where:) codeblock seems to stop the app from compiling (ONLY on Swift Playgrounds - it works perfectly fine on XCode).
I am getting the following error:
Cannot call value of non-function type 'Range<Array<Int>.Index>' (aka 'Range<Int>')
Please let me know if you have any insight regarding this issue.
-ColoredOwl
Topic:
Programming Languages
SubTopic:
Swift
Tags:
Swift Playground
Xcode
Playground Support
SwiftUI
In trying to convert some Objective-C to Swift, I have a subclass of NSWindowController and want to write a convenience initializer. The documentation says
You can also implement an NSWindowController subclass to avoid requiring client code to get the corresponding nib’s filename and pass it to init(windowNibName:) or init(windowNibName:owner:) when instantiating the window controller. The best way to do this is to override windowNibName to return the nib’s filename and instantiate the window controller by passing nil to init(window:).
My attempt to do that looks like this:
class EdgeTab: NSWindowController
{
override var windowNibName: NSNib.Name? { "EdgeTab" }
required init?(coder: NSCoder)
{
super.init(coder: coder)
}
convenience init()
{
self.init( window: nil )
}
}
But I'm getting an error message saying "Incorrect argument label in call (have 'window:', expected 'coder:')". Why the heck is the compiler trying to use init(coder:) instead of init(window:)?
I have a simple shell script as follows:
#!/bin/bash
OUTPUT="network.$(date +'%d-%m-%y').info.txt"
SUPPORT_ID="email"
echo "---------------------------------------------------" > $OUTPUT
echo "Run date and time: $(date)" >> $OUTPUT
echo "---------------------------------------------------" >> $OUTPUT
ifconfig >> $OUTPUT
echo "---------------------------------------------------" >> $OUTPUT
echo "Network info written to file: $OUTPUT."
echo "Please email this file to: $SUPPORT_ID."
It just dumps the network config into a file. At some point I will have the file emailed out, but right now I'm just trying to figure out why the output looks like the following?
bash ./test.sh
.etwork info written to file: network.26-01-25.info.txt
.lease email this file to: email
Why in the world does the initial character of the last couple of "echo" commands get clipped and turned into periods? The echos for the output of the commands piped into the output file are fine. Strange...
Any ideas?
Topic:
Programming Languages
SubTopic:
General
I tried to build the project with Xcode 16.3 and I initially got an error that TARGET_IPHONE_SIMULATOR does not exist, then I changed this flag to TARGET_OS_SIMULATOR, but it did not solve the problem
Hi, I'm trying to add Swift code to my Obj-C project. I've gone through all the tutorials and troubleshooting advice I can find online, no dice. I would appreciate any help, thank you so much in advance.
I add a new swift file to my Obj-C project
XCode offers to create a bridging header file for me, yes please
New .swift file and .h file are added to my project no problem
Header file shows up in build settings no problem
I add a new class to my new swift file ("@objc class HelloPrinter: NSObject")
When I build the app, nothing is generated in the bridging header file and the class is obviously inaccessible to my obj-c code
Is this supposed to work? My understanding is that it's supposed to work.
Somewhat concerning is the text that XCode puts in the bridging header file when it's created: "Use this file to import your target's public headers that you would like to expose to Swift."
I don't want to use this bridging header file for anything. I want XCode to GENERATE STUFF in the bridging file. I also don't want to expose anything to Swift. I want the opposite to happen. So I don't get this text at all. Thanks in advance again.
Topic:
Programming Languages
SubTopic:
Swift
I'm trying to use FormatStyle from Foundation to format numbers when printing a vector structure. See code below.
import Foundation
struct Vector<T> {
var values: [T]
subscript(item: Int) -> T {
get { values[item] }
set { values[item] = newValue }
}
}
extension Vector: CustomStringConvertible {
var description: String {
var desc = "( "
desc += values.map { "\($0)" }.joined(separator: " ")
desc += " )"
return desc
}
}
extension Vector {
func formatted<F: FormatStyle>(_ style: F) -> String where F.FormatInput == T, F.FormatOutput == String {
var desc = "( "
desc += values.map { style.format($0) }.joined(separator: " ")
desc += " )"
return desc
}
}
In the example below, the vector contains a mix of integer and float literals. The result is a vector with a type of Vector<Double>. Since the values of the vector are inferred as Double then I expect the print output to display as decimal numbers. However, the .number formatted output seems to ignore the vector type and print the values as a mix of integers and decimals. This is fixed by explicitly providing a format style with a fraction length. So why is the .formatted(.number) method ignoring the vector type T which is Double in this example?
let vec = Vector(values: [-2, 5.5, 100, 19, 4, 8.37])
print(vec)
print(vec.formatted(.number))
print(vec.formatted(.number.precision(.fractionLength(1...))))
( -2.0 5.5 100.0 19.0 4.0 8.37 ) // correct output that uses all Double types
( -2 5.5 100 19 4 8.37 ) // wrong output that uses Int and Double types
( -2.0 5.5 100.0 19.0 4.0 8.37 ) // correct output that uses all Double types
I've got a watch app, still with storyboard, WKInterfaceController and WatchConnectivity.
After updating it for swift 6 concurrency I thought I'd keep it for a little while without swift 6 concurrency dynamic runtime check.
So I added -disable-dynamic-actor-isolation in OTHER_SWIFT_FLAGS, but it doesn't seem to have an effect for the Apple Watch target. Without manually marking callbacks where needed with @Sendable in dynamic checks seem to be in place.
swiftc invocation is as (includes -disable-dynamic-actor-isolation):
swiftc -module-name GeoCameraWatchApp -Onone -enforce-exclusivity\=checked ... GeoCameraWatchApp.SwiftFileList -DDEBUG -enable-bridging-pch -disable-dynamic-actor-isolation -D DEBUG -enable-experimental-feature DebugDescriptionMacro -sdk /Applications/Xcode.app/Contents/Developer/Platforms/WatchOS.platform/Developer/SDKs/WatchOS11.2.sdk -target arm64_32-apple-watchos7.0 -g -module-cache-path /Users/stand/Library/Developer/Xcode/DerivedData/ModuleCache.noindex -Xfrontend -serialize-debugging-options -enable-testing -index-store-path /Users/stand/Library/Developer/Xcode/DerivedData/speedo-almhjmryctkitceaufvkvhkkfvdw/Index.noindex/DataStore -enable-experimental-feature OpaqueTypeErasure -Xcc -D_LIBCPP_HARDENING_MODE\=_LIBCPP_HARDENING_MODE_DEBUG -swift-version 6
...
-disable-dynamic-actor-isolation flag seems to be working for the iOS targets, I believe.
The flag is described here
Am I missing something? Should the flag work for both iOS and Apple Watch targets?
I get this red warning in Xcode every time my app is syncing to the iCloud. My model has only basic types and enum that conform to Codable so i'm not sure what is the problem.
App is working well, synchronization works. But the warning doesn't look good.
Maybe someone has idea how to debug it.