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General:
Forums topic: Programming Languages
Swift:
Forums subtopic: Programming Languages > Swift
Forums tags: Swift
Developer > Swift website
Swift Programming Language website
The Swift Programming Language documentation
Swift Forums website, and specifically Swift Forums > Using Swift
Swift Package Index website
Concurrency Resources, which covers Swift concurrency
How to think properly about binding memory Swift Forums thread
Other:
Forums subtopic: Programming Languages > Generic
Forums tags: Objective-C
Programming with Objective-C archived documentation
Objective-C Runtime documentation
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Does SwiftUI now support the ability for a chart to have two different Y Axes? ChaptGPT seems to think it does, but I keep getting compiler errors in XCode.
Hello together,
since Xcode Version > 15 the following error handling causes following error "Pattern of type 'DecodingError' cannot match 'Never'
func getSupportedCountries() async {
// fetch all documents from collection "seasons" from firestore
let queryCountries = try? await db.collection("countries").getDocuments()
if queryCountries != nil {
self.countries = (queryCountries!.documents.compactMap({ (queryDocumentSnapshot) -> Country? in
let result = Result { try? queryDocumentSnapshot.data(as: Country.self) }
switch result {
case .success(let country):
if let country = country {
// A country value was successfully initialized from the DocumentSnapshot
self.errorMessage = nil
return country
}
else {
// A nil value was successfully initialized from the DocumentSnapshot,
// or the DocumentSnapshot was nil
self.errorMessage = "Document doesn't exist."
return nil
}
case .failure(let error):
// A Country value could not be initialized from the DocumentSnapshot
switch error {
case DecodingError.typeMismatch(_, let context):
self.errorMessage = "\(error.localizedDescription): \(context.debugDescription)"
case DecodingError.valueNotFound(_, let context):
self.errorMessage = "\(error.localizedDescription): \(context.debugDescription)"
case DecodingError.keyNotFound(_, let context):
self.errorMessage = "\(error.localizedDescription): \(context.debugDescription)"
case DecodingError.dataCorrupted(let key):
self.errorMessage = "\(error.localizedDescription): \(key)"
default:
self.errorMessage = "Error decoding document: \(error.localizedDescription)"
}
return nil
}
}))
} else {
self.errorMessage = "No documents in 'countries' collection"
return
}
}
the interesting part of the code where XCODE shows an error is from "switch error" downwards.
Does anyone of you have an idea what's wrong?
Ay help appreciated !
Thx, Peter
Hi guys,
I've been struggling for a few days with this really weird behaviour.
We made an app for our e-commerce website and found out that a part of the product page is missing.
For any reason, the header and first blocks of the page and footer are displayed, but then a massive part of the content is missing. This content is not loaded through ajax; that's why I don't understand why it's not displayed.
You can see here 2 screenshots of what the page should look like and what the page looks like with WKWebView.
I've been inspecting this with Safari; there isn't any blocking error in the console, and html elements are just empty. There is the div with class row and nothing in it.
The same website is working perfectly with native Android Webview.
If anyone has any clue to find out what's going wrong
Topic:
Programming Languages
SubTopic:
Swift
Considering below dummy codes:
@MainActor var globalNumber = 0
@MainActor
func increase(_ number: inout Int) async {
// some async code excluded
number += 1
}
class Dummy: @unchecked Sendable {
@MainActor var number: Int {
get { globalNumber }
set { globalNumber = newValue }
}
@MainActor
func change() async {
await increase(&number) //Actor-isolated property 'number' cannot be passed 'inout' to 'async' function call
}
}
I'm not really trying to make an increasing function like that, this is just an example to make everything happen. As for why number is a computed property, this is to trigger the actor-isolated condition (otherwise, if the property is stored and is a value type, this condition will not be triggered).
Under these conditions, in function change(), I got the error: Actor-isolated property 'number' cannot be passed 'inout' to 'async' function call.
My question is: Why Actor-isolated property cannot be passed 'inout' to 'async' function call? What is the purpose of this design? If this were allowed, what problems might it cause?
I'm primarily an AppleScript writer and only a novice programmer, using ChatGPT to help me with the legwork. It has helped me to write a functioning app that builds a menu structure based on the scripts I have in the Scripts directory used in the script menu and then runs the applescripts. When I distribute the app to my desktop and run it, the scripts that access other apps, like InDesign will cause it to launch, but not actually do anything. I included the ids for each app in the entitlements dictionary and have given the app full disk access in system settings, but it's not functioning as I'd expect.
I know there are apps like Alfred that allow you to run scripts from a keystroke, but I'm building this for others I work with so they can also access info about each script, what it does, and how to use it from the menu, as well as key commands to run them.
Not sure what else to say, but if this sounds like a simple fix to anyone, please let me know.
func textField(
_ textField: UITextField,
shouldChangeCharactersIn range: NSRange,
replacementString string: String
) -> Bool {
if
let delegate = delegate,
let shouldChangeCharactersIn = delegate.textField {
return shouldChangeCharactersIn(textField, range, string)
}
return true
}
This is from an extension
extension TextInput: UITextFieldDelegate, ObservableTextFieldDelegateProtocol {
The delegate is already a UITextFieldDelegate, but when you click on the error, it returns 7 instances of:
"Found this candidate in module 'UIKit' (UIKit.UITextFieldDelegate.textField)"
This doesn't give an error in Xcode 16. Is this an Xcode 26 bug?
iOS18.2 / iPhone 16pro / Xcode 16.2
'traitCollectionDidChange'
This function has been deprecated since ios17.
However, in ios18, when I changed the app to the background state or changed it to the foreground state again, it was confirmed that the function worked.
It hasn't been confirmed in ios17, but why is it only confirmed in ios18?
❌ Could not find email_ai.py in the app bundle. Available files: []
The error above is what I’m encountering.
I’ve placed the referenced file both in the project directory and inside the app. However, every time I remove and reinsert the file into the folder within the app, it prompts me to designate the targets—I select all, but this doesn’t resolve the issue.
I’m unsure how to properly reference the file so that it is recognised and included in the bundle. Any guidance would be greatly appreciated.
this is my build phase:
#!/bin/sh
set -x # Prints each command before running it (for debugging)
pwd # Shows the current working directory
echo "$SRCROOT" # Shows what Xcode thinks is the project root
ls -l "$SRCROOT/EmailAssistant/EmailAssistant/PythonScripts" # Lists files in the script folder
export PYTHONPATH="/Users/caesar/.pyenv/versions/3.11.6/bin"
/Users/caesar/.pyenv/versions/3.11.6/bin/python3 "$SRCROOT/EmailAssistant/EmailAssistant/PythonScripts/email_ai.py"
echo "Script completed."
Hello, I have an issue with importing some .mp3 files into a swift playground project (in Xcode, not in the Playground app). They worked fine in the Xcode project, but for some reason playgrounds isn't able to find them. I imported them the exact same way as I did in the Xcode project.
I have an xcode project which has both cpp and swift code. In one of my usecase I am passing primitive type variables from swift to cpp by reference( primitives types list here as per the new cpp-swift interop documentation)
swift code:
// primitive check code:Bool
var x : Bool = true
// When we are passing a variable as a Reference, we need to use explicitly use'&'
student.PassBoolAsReferenceType (&x) // interop call to cpp code
print (x)
Cpp code:
void
Student::PassBoolAsReferenceType(bool &pValue) noexcept
{
std::cout << pValue << std::endl;
pValue = false;
}
The above code fails during compilation with no clear error message "Command SwiftCompile failed with a nonzero exit code"
However, all the other primitive types that I tested worked for the above code like Int, Float, Double etc. Only the Bool interop fails. Can someone explain why is it not possible for bool? I m using the new interop introduced in swift 5.9.
I have been trying to integrate a UIKit view into SwiftUI, specifically a WKWebView. However, I keep encountering a does not conform to protocol error.
Here's my code:
import SwiftUI
import WebKit
struct SimpleWebView: View {
var body: some View {
WebViewContainerRepresentable()
.edgesIgnoringSafeArea(.all)
}
}
struct WebViewContainerRepresentable: UIViewRepresentable {
typealias UIViewType = WKWebView
func makeUIView(context: Context) -> WKWebView {
let webView = WKWebView()
if let url = Bundle.main.url(forResource: "index", withExtension: "html") {
webView.loadFileURL(url, allowingReadAccessTo: url.deletingLastPathComponent())
}
return webView
}
func updateUIView(_ uiView: WKWebView, context: Context) {
// Updates not required for this use case
}
}
I tried this with other views as well, and it turns out this is not WKWebView-specific.
The minimum deployment version is iOS 15.
Any help would be much appreciated. Let me know if I need to add any more information.
Hi,
I'm struggling to understand using Swift-C++ in the same project. I have an existing code-base that makes heavy use of Swift-Objective-C interoperability.
We make use of swift classes in our project. When I enable swift-objective c interoperability I am running into numerous build errors in the generated bridging header.
I'm trying to understand why these errors exist and what to do to get around them.
I have a project that I've set up with some test code, and I'm running into an error here:
public class Foo {
let name: String
public init(name: String) {
self.name = name
}
}
public class Bar {
let name: String
public init(name : String) {
self.name = name;
}
public func getFoo() -> Foo {
return Foo(name: self.name);
}
}
In the header file:
Unknown type name 'Foo'
SWIFT_INLINE_THUNK Foo getFoo() SWIFT_SYMBOL("s:13ForestBuilder3BarC6getFooAA0E0CyF");
This error goes away if I use structs, but for the purposes of porting my codebase, I'd prefer to use classes. Do classes not play nice here? Or am I misunderstanding something.
Thanks.
Hello,
I have integrated LZMA2 compression into my iOS app, Hogs, and successfully implemented compression. However, when attempting to upload the app for TestFlight, I encountered an error:
"The app references non-public symbols in Payload/Hogs.app/Hogs: _lzma_code, _lzma_end."
These functions are part of the LZMA compression library (specifically LZMA2). Here's a detailed description of the issue:
What I Have Done:
LZMA2 Integration: I integrated LZMA2 compression into the app and created a wrapper around the LZMA functions (_lzma_code, _lzma_end) to prevent direct references.
App Build Configuration:
I ensured the LZMA2 library is linked correctly with the -lzma flag in the linker settings.
I wrapped the LZMA functions in custom functions (my_lzma_code, my_lzma_end) in an attempt to avoid using the non-public symbols directly.
Error Message:
During the app submission process, I received the following error:
"The app references non-public symbols in Payload/Hogs.app/Hogs: _lzma_code, _lzma_end."
Steps Taken to Resolve:
Checked if any LZMA functions were exposed incorrectly.
Ensured that all non-public symbols were properly encapsulated in a wrapper.
Verified linker settings to ensure the proper inclusion of the LZMA2 library.
Request:
Could anyone provide suggestions or best practices to resolve this issue and avoid references to non-public symbols? Should I use a different method for linking LZMA2 or encapsulating these symbols?
Thank You:
I appreciate your help in resolving this issue so I can move forward with submitting the app for TestFlight.
Topic:
Programming Languages
SubTopic:
Swift
Tags:
Swift Packages
Apple Archive
Compression
TestFlight
I'm using xcode 16.1 withSwift. I want to know how to call a function passing in an array. Also I need to know how to declare the function receiving the array. I currently have:
func myfunc(costa: [Double]) {
}
I call it like this:
myfunc(costa:[ ])
It's an array of Doubles. I don't get any errors but the array is always empty. Please help. Thank you.
Topic:
Programming Languages
SubTopic:
Swift
Crashed: com.apple.root.user-initiated-qos.cooperative
0 libswift_Concurrency.dylib 0x67f40 swift_task_create_commonImpl(unsigned long, swift::TaskOptionRecord*, swift::TargetMetadataswift::InProcess const*, void (swift::AsyncContext* swift_async_context) swiftasynccall*, void*, unsigned long) + 528
1 libswift_Concurrency.dylib 0x64d78 swift_asyncLet_begin + 40
2 AAAA 0x47aef28 (1) suspend resume partial function for ActivityContextModule.fetchRecord(startDate:endDate:) + 50786796
3 libswift_Concurrency.dylib 0x60f5c swift::runJobInEstablishedExecutorContext(swift::Job*) + 252
4 libswift_Concurrency.dylib 0x62514 swift_job_runImpl(swift::Job*, swift::SerialExecutorRef) + 144
5 libdispatch.dylib 0x15ec0 _dispatch_root_queue_drain + 392
6 libdispatch.dylib 0x166c4 _dispatch_worker_thread2 + 156
7 libsystem_pthread.dylib 0x3644 _pthread_wqthread + 228
8 libsystem_pthread.dylib 0x1474 start_wqthread + 8
Everyone knows that dictionaries in swift are unordered collections, there is no problem with that.
I've noticed some behavior that I can't explain and hope someone can help me.
The first variant
We have a very simple code:
struct Test {
let dict = [1: “1”, 2: “2”, 3: “3”, 4: “4”, 5: “5”]
func test() {
for i in dict {
print(i)
}
}
}
If you call test() several times in a row, the output to the console on my computer looks something like this:
(key: 5, value: “5”)
(key: 1, value: “1”)
(key: 2, value: “2”)
(key: 3, value: “3”)
(key: 4, value: “4”)
(key: 2, value: “2”)
(key: 3, value: “3”)
(key: 1, value: “1”)
(key: 4, value: “4”)
(key: 5, value: “5”)
(key: 1, value: “1”)
(key: 3, value: “3”)
(key: 2, value: “2”)
(key: 5, value: “5”)
(key: 4, value: “4”)
At each new for loop we get a random order of elements
It seemed logical to me, because a dictionary is an unordered collection and this is correct behavior.
However
The second variant
the same code on my colleague's computer, but in the console we see something like this:
(key: 2, value: “2”)
(key: 3, value: “3”)
(key: 1, value: “1”)
(key: 4, value: “4”)
(key: 5, value: “5”)
(key: 2, value: “2”)
(key: 3, value: “3”)
(key: 1, value: “1”)
(key: 4, value: “4”)
(key: 5, value: “5”)
(key: 2, value: “2”)
(key: 3, value: “3”)
(key: 1, value: “1”)
(key: 4, value: “4”)
(key: 5, value: “5”)
always, within the same session, we get the same order in print(i)
We didn't use Playground, within which there may be differences, but a real project.
swift version 5+
we tested on Xcode 14+, 15+ (at first I thought it was because the first version had 14 and the second version had 15, but then a third colleague with Xcode 15 had the behavior from the first scenario)
we did a lot of checks, several dozens of times and always got that on one computer random output of items to the console, and in another case disordered only in the first output to the console
Thanks
I'm trying to fix some Swift6 warnings, this one seems too strict, I'm not sure how to fix it. The variable path is a String, which should be immutable, it's a local variable and never used again inside of the function, but still Swift6 complains about it being a race condition, passing it to the task
What should I do here to fix the warning?
These helper methods allow to use modifier methods in standard for SwiftUI short way.
extension View {
@inline(__always)
func modify(_ block: (_ view: Self) -> some View) -> some View {
block(self)
}
@inline(__always)
func modify<V : View, T>(_ block: (_ view: Self, _ data: T) -> V, with data: T) -> V {
block(self, data)
}
}
_
DISCUSSION
Suppose you have modifier methods:
func addBorder(view: some View) -> some View {
view.padding().border(Color.red, width: borderWidth)
}
func highlight(view: some View, color: Color) -> some View {
view.border(Color.red, width: borderWidth).overlay { color.opacity(0.3) }
}
_
Ordinar Decision
Your code may be like this:
var body: some View {
let image = Image(systemName: "globe")
let borderedImage = addBorder(view: image)
let highlightedImage = highlight(view: borderedImage, color: .red)
let text = Text("Some Text")
let borderedText = addBorder(view: text)
let highlightedText = highlight(view: borderedText, color: .yellow)
VStack {
highlightedImage
highlightedText
}
}
This code doesn't look like standard SwiftUI code.
_
Better Decision
Described above helper methods modify(:) and modify(:,with:) allow to write code in typical for SwiftUI short way:
var body: some View {
VStack {
Image(systemName: "globe")
.modify(addBorder)
.modify(highlight, with: .red)
Text("Some Text")
.modify(addBorder)
.modify(highlight, with: .yellow)
}
}
iOS18.2 / iPhone16 pro / xcode16.2
'traitCollectionDidChange'
This function has been deprecated in iOS17.
However, when I debugged it, I confirmed that it is not called on iOS17, but it is called on iOS18.2.
What is the reason?
I am an SDK provider working with Swift Package Manager (SPM) to deliver libraries for iOS developers. My SDK currently uses SPM targets to modularize functionality. However, SPM enforces strict resource bundling, which prevents me from efficiently offering multiple targets—each with a different set of localization files—in a single package.
Current Limitation:
When multiple SPM targets share the same source and resource directory but require distinct sets of .lproj localization folders (for app size or client requirements), SPM raises “overlapping sources” errors. The only workaround is to manually split resource directories or have clients prune localizations post-build, which is inefficient and error-prone.
Feature Request:
Please consider adding native support in Swift Package Manager for:
Defining multiple targets within a single package that can process overlapping source/resource directories,
Each target specifying a distinct subset of localization resource files via the exclude or a new designated parameter,
Enabling efficient modular delivery of SDKs to clients needing different localization payloads, without redundant resource duplication or error-prone manual pruning.
Support for this feature would greatly ease SDK distribution, lower app sizes, and improve package maintainability for iOS and all Swift platforms.