Provide views, controls, and layout structures for declaring your app's user interface using SwiftUI.

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Async/Await and updating state
When using conformance to ObservableObject and then doing async work in a Task, you will get a warning courtesy of Combine if you then update an @Published or @State var from anywhere but the main thread. However, if you are using @Observable there is no such warning. Also, Thread.current is unavailable in asynchronous contexts, so says the warning. And I have read that in a sense you simply aren't concerned with what thread an async task is on. So for me, that begs a question. Is the lack of a warning, which when using Combine is rather important as ignoring it could lead to crashes, a pretty major bug that Apple seemingly should have addressed long ago? Or is it just not an issue to update state from another thread, because Xcode is doing that work for us behind the scenes too, just as it manages what thread the async task is running on when we don't specify? I see a lot of posts about this from around the initial release of Async/Await talking about using await MainActor.run {} at the point the state variable is updated, usually also complaining about the lack of a warning. But ow years later there is still no warning and I have to wonder if this is actually a non issue. On some ways similar to the fact that many of the early posts I have seen related to @Observable have examples of an @Observable ViewModel instantiated in the view as an @State variable, but in fact this is not needed as that is addressed behind the scenes for all properties of an @Observable type. At least, that is my understanding now, but I am learning Swift coming from a PowerShell background so I question my understanding a lot.
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1.5k
Dec ’24
No ObservableObject of Type "" found.
Im building an recipe app for the social media of my mother. i already have the functionality for the users, when a user gets created an empty array gets initiated at the database named favoriteRecipes, which stores the id of his favorite recipes to show in a view. This is my AuthViewModel which is relevant for the user stuff: import Firebase import FirebaseAuth import FirebaseFirestore protocol AuthenticationFormProtocol { var formIsValid: Bool { get } } @MainActor class AuthViewModel : ObservableObject { @Published var userSession: FirebaseAuth.User? @Published var currentUser: User? @Published var currentUserId: String? init() { self.userSession = Auth.auth().currentUser Task { await fetchUser() } } func signIn(withEmail email: String, password: String) async throws { do { let result = try await Auth.auth().signIn(withEmail: email, password: password) self.userSession = result.user await fetchUser() // fetch user sonst profileview blank } catch { print("DEBUG: Failed to log in with error \(error.localizedDescription)") } } func createUser(withEmail email: String, password: String, fullName: String) async throws { do { let result = try await Auth.auth().createUser(withEmail: email, password: password) self.userSession = result.user let user = User(id: result.user.uid, fullName: fullName, email: email) let encodedUser = try Firestore.Encoder().encode(user) try await Firestore.firestore().collection("users").document(result.user.uid).setData(encodedUser) await fetchUser() } catch { print("Debug: Failed to create user with error \(error.localizedDescription)") } } func signOut() { do { try Auth.auth().signOut() // sign out user on backend self.userSession = nil // wipe out user session and take back to login screen self.currentUser = nil // wipe out current user data model } catch { print("DEBUG: Failed to sign out with error \(error.localizedDescription)") } } func deleteAcocount() { let user = Auth.auth().currentUser user?.delete { error in if let error = error { print("DEBUG: Error deleting user: \(error.localizedDescription)") } else { self.userSession = nil self.currentUser = nil } } } func fetchUser() async { guard let uid = Auth.auth().currentUser?.uid else { return } currentUserId = uid let userRef = Firestore.firestore().collection("users").document(uid) do { let snapshot = try await userRef.getDocument() if snapshot.exists { self.currentUser = try? snapshot.data(as: User.self) print("DEBUG: current user is \(String(describing: self.currentUser))") } else { // Benutzer existiert nicht mehr in Firebase, daher setzen wir die userSession auf nil self.userSession = nil self.currentUser = nil } } catch { print("DEBUG: Fehler beim Laden des Benutzers: \(error.localizedDescription)") } } } This is the code to fetch the favorite recipes, i use the id of the user to access the collection and get the favoriteRecipes out of the array: import SwiftUI @MainActor class FavoriteRecipeViewModel: ObservableObject { @Published var favoriteRecipes: [Recipe] = [] @EnvironmentObject var viewModel: AuthViewModel private var db = Firestore.firestore() init() { Task { await fetchFavoriteRecipes() } } func fetchFavoriteRecipes() async{ let userRef = db.collection("users").document(viewModel.userSession?.uid ?? "") do { let snapshot = try await userRef.collection("favoriteRecipes").getDocuments() let favoriteIDs = snapshot.documents.map { $0.documentID } let favoriteRecipes = try await fetchRecipes(recipeIDs: favoriteIDs) } catch { print("DEBUG: Failed to load favorite recipes for user: \(error.localizedDescription)") } } func fetchRecipes(recipeIDs: [String]) async throws -> [Recipe] { var recipes: [Recipe] = [] for id in recipeIDs { let snapshot = try await db.collection("recipes").document(id).getDocument() if let recipe = try? snapshot.data(as: Recipe.self) { recipes.append(recipe) } } return recipes } } Now the Problem occurs at the build of the project, i get the error SwiftUICore/EnvironmentObject.swift:92: Fatal error: No ObservableObject of type AuthViewModel found. A View.environmentObject(_:) for AuthViewModel may be missing as an ancestor of this view. I already passed the ViewModel instances as EnvironmentObject in the App Struct. import SwiftUI import FirebaseCore class AppDelegate: NSObject, UIApplicationDelegate { func application(_ application: UIApplication, didFinishLaunchingWithOptions launchOptions: [UIApplication.LaunchOptionsKey : Any]? = nil) -> Bool { FirebaseApp.configure() return true } } @main struct NimetAndSonApp: App { @StateObject var viewModel = AuthViewModel() @StateObject var recipeViewModel = RecipeViewModel() @StateObject var favoriteRecipeViewModel = FavoriteRecipeViewModel() @UIApplicationDelegateAdaptor(AppDelegate.self) var delegate var body: some Scene { WindowGroup { ContentView() .environmentObject(viewModel) .environmentObject(recipeViewModel) .environmentObject(favoriteRecipeViewModel) } } }
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626
Nov ’24
Hide TabItems?
Is there really no way to hide a TabItem using the built-in TabView? I have 6 pages, but the 6th one I want hidden from the bottom tab bar, because I have a button that programmatically navigates to it on the navigation bar. I did not want to have to code a custom tab bar due to losing some useful features like pop to root in Navigation Stack.
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243
Nov ’24
Elementos no responden a un toque xcode
Desarrolle una app en xcode 16 para version minima de ios 16, todo funcionaba bien hasta la version 17 de ios, pero para ios 18 empezaron los problemas, los botones no responden a un toque, se deben sostener con un toque largo para que funcionen, ahora de un momento a otro ya no funciona para ninguna version de ios, los eventos tactiles deben ser prolongados para que se activen, en los botones o elementos que usan el tapgesture, he probado de todo versiones de xcode, versiones de swiftui, dispostivos reales, emuladores de todo y nada funciona, algun consejo o solucion gracias
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286
Nov ’24
MacCatalyst - How to share Userdefaults between widget and app
Hi, Firstly: The whole question is about MacCatalyst (in IOS it works as intended) In my Maccatalyst app I want to share Userdefaults between app and widget. I have added an app group to the widget and the app and have set up Userdefauls accordingly. Here is the problem: Xcode claims that the app group should start with "group.***" because Catalyst is based on iOS. If I do so, my Catalyst app rises the "App wants to access data from other apps" requester on EVERY launch. So, I can't use it in production. Even if I would accept the requester, the widget isn't able to access the defaults at all because it does not rise that requester, but silently ignores the access. In contrast, if I setup the app group name with our TeamID (instead of group.*) then the requester vanishes, but Xcode does not accept it, issuing a warning and displaying the app group in red. I don't think this is advisable 'state' for production code. Even then widget can't see the data either. What is the recommended way of sharing Userdefaults between Catalyst app and Catalyst Widget (not the iOS widget which displays the "open on iPhone warning" when clicked) on macOS ? Thanks
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620
Nov ’24
Sheet presentationDetents breaks after rapid open/dismiss cycles
Basic Information Please provide a descriptive title for your feedback: Sheet presentationDetents breaks after rapid open/dismiss cycles Which platform is most relevant for your report? iOS Description Steps to Reproduce: Create a sheet with presentationDetents([.medium]) Rapidly perform these actions multiple times (usually 3-4 times): a. Open the sheet b. Immediately scroll down to dismiss Open the sheet again Observe that the sheet now appears at .large size, ignoring the .medium detent Expected Result: Sheet should consistently maintain .medium size regardless of how quickly it is opened and dismissed. Actual Result: After rapid open/dismiss cycles, the sheet ignores .medium detent and appears at .large size. Reproduction Rate: Occurs consistently after 3-4 rapid open/dismiss cycles More likely to occur with faster open/dismiss actions Configuration: iOS 18 Xcode 16.0 (16A242d) SwiftUI Device: iPhone 14
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1.1k
Mar ’25
SwiftUI FormView not updating after value creation/updating in a SubView
I'm developing a SwiftUI, CoreData / CloudKit App with Xcode 16.2 & Sequoia 15.2. The main CoreData entity has 20 NSManaged vars and 5 derived vars, the latter being computed from the managed vars and dependent computed vars - this somewhat akin to a spreadsheet. The data entry/updating Form is complex for each managed var because the user needs to be able to enter data in either Imperial or Metric units, and then switch (by Button) between units for viewing equivalents. This has to happen on an individual managed var basis, because some source data are in Imperial and others Metric. Consequently, I use a generalised SubView on the Form for processing the managed var (passed as a parameter with its identity) and then updating the CoreData Entity (about 100 lines of code in total): i.e. there are 20 uses of the generalised SubView within the Main Form. However, none of the SubViews triggers an update of the managed var in the Form, nor computations of the derived vars. On initial load of the app, the CoreData entity is retrieved and the computations happen correctly: thereafter not. No technique for refreshing either View works: e.g. trigger based on NSManagedObjectContextDidSave; nor does reloading the CoreData entity after Context Save (CoreData doesn't recognise changes at the attribute level anyway). If the SubView is removed and replaced with code within the Form View itself, then it works. However, this will require about 40 @State vars, 20 onCommits, etc - so it's not something I'm keen to do. Below is a much-simplified example of the problem. Form{ Section(header: Text("Test Record")){ Text(testRec.dateString ?? "n/a") TextField("Notes",text:$text) .onSubmit{ testRec.notes = text dataStore.contextSave() } //DoubleNumberEntry(testRec: testRec) - doesn't work TextField("Double",value:$numDbl,format: .number) // This works .onSubmit{ testRec.dblNum = numDbl dataStore.contextSave() } TextField("Integer",value: $numInt,format: .number) .onSubmit{ testRec.intNum = Int16(numInt) dataStore.contextSave() } Text(String(format:"%.2f",testRec.computation)) Section(header: Text("Computations")) { Text(String(format:"%.2f",testRec.computation)) Text(String(format:"%.2f",testRec.anotherComputation)) } } } A much simplified version of my NSManaged var entry/updating. struct DoubleNumberEntry: View { let dataStore = MainController.shared.dataStore var testRec : TestRec @State private var numDbl: Double init(testRec: TestRec) { self.testRec = testRec self.numDbl = testRec.dblNum } var body: some View { TextField("Double",value:$numDbl,format: .number) .onSubmit{ testRec.dblNum = numDbl dataStore.contextSave() } } } I'd appreciate any offered solution or advice. Regards, Michaela
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442
Nov ’24
Widget Intent Configuration doesn't work in Swift 6
macOS: Sequoia Xcode: 16.1 I am working on a macOS app and it has a widget feature. When I use Swift 6 (Build Settings > Swift Language Version) in IntentExtension, the intent configuration won't show up in macOS Sequoia. If I downgrade to Swift 5, it works without any other changes. Is it a bug or am I missing something? How can I use Swift 6 with IntentExtension.
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746
Nov ’24
How To Create Dual Screen of AR using RealityView and SwiftUI iOS 18
I have this code to make ARVR Stereo View To Be Used in VR Box Or Google Cardboard, it uses iOS 18 New RealityView but it is not Act as an AR but rather Static VR on a Camera background so as I move the iPhone the cube move with it and that's not suppose to happen if its Anchored in a plane or to world coordinate. import SwiftUI import RealityKit struct ContentView : View { let anchor1 = AnchorEntity(.camera) let anchor2 = AnchorEntity(.camera) var body: some View { HStack (spacing: 0){ MainView(anchor: anchor1) MainView(anchor: anchor2) } .background(.black) } } struct MainView : View { @State var anchor = AnchorEntity() var body: some View { RealityView { content in content.camera = .spatialTracking let item = ModelEntity(mesh: .generateBox(size: 0.25), materials: [SimpleMaterial()]) anchor.addChild(item) content.add(anchor) anchor.position.z = -1.0 anchor.orientation = .init(angle: .pi/4, axis:[0,1,1]) } } } the thing is if I remove .camera like this let anchor1 = AnchorEntity() let anchor2 = AnchorEntity() It would work as AR Anchored to world coordinates but on the other hand is does not work but on the left view only not both views Meanwhile this was so easy before RealityView and SwiftUI by cloning the view like in ARSCNView Example : import UIKit import ARKit class ViewController: UIViewController, ARSCNViewDelegate, ARSessionDelegate { //create Any Two ARSCNView's in Story board // and link each to the next (dont mind dimensions) @IBOutlet var sceneView: ARSCNView! @IBOutlet var sceneView2: ARSCNView! override func viewDidLoad() { super.viewDidLoad() // Do any additional setup after loading the view. sceneView.delegate = self sceneView.session.delegate = self // Create SceneKit box let box = SCNBox(width: 0.1, height: 0.1, length: 0.1, chamferRadius: 0.01) let item = SCNNode(geometry: box) item.geometry?.materials.first?.diffuse.contents = UIColor.green item.position = SCNVector3(0.0, 0.0, -1.0) item.orientation = SCNVector4(0, 1, 1, .pi/4.0) // retrieve the ship node sceneView.scene.rootNode.addChildNode(item) } override func viewDidLayoutSubviews() // To Do Add the 4 Buttons { // Stop Screen Dimming or Closing While The App Is Running UIApplication.shared.isIdleTimerDisabled = true let screen: CGRect = UIScreen.main.bounds let topPadding: CGFloat = self.view.safeAreaInsets.top let bottomPadding: CGFloat = self.view.safeAreaInsets.bottom let leftPadding: CGFloat = self.view.safeAreaInsets.left let rightPadding: CGFloat = self.view.safeAreaInsets.right let safeArea: CGRect = CGRect(x: leftPadding, y: topPadding, width: screen.size.width - leftPadding - rightPadding, height: screen.size.height - topPadding - bottomPadding) DispatchQueue.main.async { if self.sceneView != nil { self.sceneView.frame = CGRect(x: safeArea.size.width * 0 + safeArea.origin.x, y: safeArea.size.height * 0 + safeArea.origin.y, width: safeArea.size.width * 0.5, height: safeArea.size.height * 1) } if self.sceneView2 != nil { self.sceneView2.frame = CGRect(x: safeArea.size.width * 0.5 + safeArea.origin.x, y: safeArea.size.height * 0 + safeArea.origin.y, width: safeArea.size.width * 0.5, height: safeArea.size.height * 1) } } } override func viewDidAppear(_ animated: Bool) { super.viewDidAppear(animated) let configuration = ARWorldTrackingConfiguration() sceneView.session.run(configuration) sceneView2.scene = sceneView.scene sceneView2.session = sceneView.session } } And here is the video for it
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491
Nov ’24
Storing SwiftUI Views to operate on it
I am creating a UIKit application but that contains SwiftUI Views embedded using the hostingcontroller. I have a particular approach for it..but it requires instantiating a swiftUI view, creating a hostingcontroller object from it and storing a reference to it. So that later If I wanted to update the view, I can simply get the reference back and update the swiftUI view using it. I wanted to understand what does apple recommends on this. Can we store a swiftUI instance? Does it cause any issue or it is okay to do so?
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413
Nov ’24
BLE Module Connection Issues with iPhone 12 – Random Disconnects Every 3 Minutes
Hello, I'm using an HMSoft Bluetooth module that connects reliably to Android devices, maintaining a stable connection. However, when I try to connect it to my iPhone 12, the connection randomly disconnects after a few minutes (usually around 3 minutes). This issue occurs even when using apps like LightBlue and other BLE-based medical equipment apps, so it doesn't seem related to my app code. Any suggestions on what I can do to prevent these unexpected disconnects? Should I change any specific settings on my iPhone or the module itself?
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325
Nov ’24
ARVR RealityView Showing left Camera view Entity near more than the right view
I have this code to make ARVR Stereo View To Be Used in VR Box Or Google Cardboard, it uses iOS 18 New RealityView but for some reason the left side showing the Entity (Box) more near to the camera than the right side which make it not identical, I wonder is this a bug and need to be fixed or what ? thanx Here is the code import SwiftUI import RealityKit struct ContentView : View { let anchor1 = AnchorEntity(.camera) let anchor2 = AnchorEntity(.camera) var body: some View { HStack (spacing: 0){ MainView(anchor: anchor1) MainView(anchor: anchor2) } .background(.black) } } struct MainView : View { @State var anchor = AnchorEntity() var body: some View { RealityView { content in content.camera = .spatialTracking let item = ModelEntity(mesh: .generateBox(size: 0.25), materials: [SimpleMaterial()]) anchor.addChild(item) content.add(anchor) anchor.position.z = -1.0 anchor.orientation = .init(angle: .pi/4, axis:[0,1,1]) } } } And Here is the View
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423
Nov ’24
Modifying SwiftData Object
Hi, The dataModule in code below is a swiftData object being passed to the view and its property as key path but when trying to modify it I'm getting the error ."Cannot assign through subscript: 'self' is immutable" how to solve this issue ? Kind Regards struct ListSel<T: PersistentModel>: View { @Bindable var dataModule: T @Binding var txtValue: String var keyPath: WritableKeyPath<T, String> var turncate: CGFloat? = 94.0 var image = "" var body: some View { HStack { Text(txtValue) .foregroundColor(sysSecondary) .font(.subheadline) .onChange(of: txtValue) { value in dataModule[keyPath: keyPath] = value } Image(systemName: image) .foregroundColor(sysSecondary) .font(.subheadline) .imageScale(.small) .symbolRenderingMode(.hierarchical) .scaleEffect(0.8) } .frame(width: turncate, height: 20, alignment: .leading) .truncationMode(.tail) } }
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431
Nov ’24
Crash calling UIHostingController from a Swift Package
Hello team, We recently found a EXC_BAD_ACCESS crash when using UIHostingControllers on a SPM local Package in our application. This is happening from time to time when we run the app on simulators using Debug configurations. Also, this issue is consistent when we run application tests, there is something weird that we found after making a research... If we disable app test target and only keep packages tests, the crash is not happening, but as soon as we re-enable the app test target from the test suite the crash returns. This is the full error message: Thread 1: EXC_BAD_ACCESS (code=1, address=0xbad4017) A bad access to memory terminated the process. Is this s known issue? We've been performing explorations for some days and couldn't find any real solution for this. A basic call on UIHostingController inside of a SPM local Package is enough to make the app crash, nothing custom being done: UIHostingController(rootView: MyView())
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534
Nov ’24
RealityView to show two screens of AR in iOS 18/macOS 15 using SwiftUI
I have an issue using RealityView to show two screens of AR, while I did succeed to make it as a non AR but now my code not working. Also it is working using Storyboard and Swift with SceneKit, so why it is not working in RealityView? import SwiftUI import RealityKit struct ContentView : View { var body: some View { HStack (spacing: 0){ MainView() MainView() } .background(.black) } } struct MainView : View { @State var anchor = AnchorEntity() var body: some View { RealityView { content in let item = ModelEntity(mesh: .generateBox(size: 0.2), materials: [SimpleMaterial()]) content.camera = .spatialTracking anchor.addChild(item) anchor.position = [0.0, 0.0, -1.0] anchor.orientation = .init(angle: .pi/4, axis:[0,1,1]) // Add the horizontal plane anchor to the scene content.add(anchor) } } }
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513
Nov ’24
Tile & Scale an Image
Working on a macOS app. I need to display user-added images as a background to the view, with all of: Tiling (auto repeat in both axes) Scaling (user-configured scale of the image) Offset (user-configured offset) I've been able to achieve scaling and offset with: Image(nsImage: nsImage) .scaleEffect(mapImage.scale) .offset(mapImage.offset) .frame(width: scaledImageSize.width, height: scaledImageSize.height) But when I try to incorporate tiling into that with .resizable(resizingMode: .tile) everything breaks. Is there a way to position the "anchor" of an image, scale it, and tile it in both axes to fill a container view?
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433
Nov ’24
Custom 3D Window Using RealityView
I have a RealityView displaying a Reality Composer Pro scene in window. Things are generally working fine, but the content seems to be appearing in front of and blocking the VisionOS window, rather than being contained inside it. Do I need to switch to a volumetric view for this to work? My scene simply contains a flat display which renders 3D content (it has a material that sends different imagery to each eye).
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542
Nov ’24
Register user into app in SwiftUI using Firebase
I am making app which one of functionality is register user with firebase, but sometime when I register user I got app crash but user is added into db. I am getting error like this: EXC_BAD_ACCESS (code=2, address=0x2600000000) or adres = 0x10 which mean the is some memory leak but when I use instrumental leak every thing is ok. Second weird thing is that when I use instrumental leak I am not getting error (I added something like 40 users) but when I close instrumental and rebuilt I got crash in max 3 attempts. // FormComponent.swift // SpaceManager // // Created by Kuba Kromomołowski on 17/04/2024. // import Foundation import SwiftUI struct FormComponent: View { var isRegister: Bool = true @State private var repeatedPassword: String = "" @StateObject private var loginHandler = LoginViewModel() @StateObject private var registerHandler = RegisterViewModel() @EnvironmentObject var permissionViewModel: PermissionViewModel var body: some View { Form { TextField("Email", text: isRegister ? $registerHandler.email : $loginHandler.email) .textFieldStyle(RoundedBorderTextFieldStyle()) .font(.system(size: 25)) .multilineTextAlignment(.center) .autocapitalization(.none) .disableAutocorrection(true) SecureField("Hasło", text: isRegister ? $registerHandler.password : $loginHandler.password) .textFieldStyle(RoundedBorderTextFieldStyle()) .font(.system(size: 25)) .multilineTextAlignment(.center) .autocapitalization(.none) .disableAutocorrection(true) if (isRegister) { SecureField("Powtórz haslo", text: $registerHandler.repeatedPassword) .textFieldStyle(RoundedBorderTextFieldStyle()) .font(.system(size: 25)) .multilineTextAlignment(.center) .autocapitalization(.none) .disableAutocorrection(true) } BtnClearComponet(btnText: isRegister ? "Zarejestruj się" : "Zaloguj się", btnRegister: isRegister, action: { if isRegister { registerHandler.registerUser() { permissionViewModel.getPermission() } } else { loginHandler.userLogin() { permissionViewModel.getPermission() } } }, loginHandler: loginHandler, registerHandler: registerHandler ) .padding(.bottom, 5) } .frame(width:350,height:400) .scrollContentBackground(.hidden) .padding(.top, 50) } } // // RegisterViewModel.swift // SpaceManager // // Created by Kuba Kromomołowski on 03/05/2024. // import Foundation import Firebase import FirebaseAuth import FirebaseFirestore class RegisterViewModel : ObservableObject { @Published var email: String = "" @Published var password: String = "" @Published var repeatedPassword: String = "" @Published var isFail: Bool = false @Published var message: String = "" func registerUser(completion: @escaping () -> Void) { if(!validInput()){ return } Auth.auth().createUser(withEmail: email, password: password) { [weak self] res, err in guard let self = self else { return } if let err = err { self.isFail = true self.message = "Błąd przy rejestracji \(err.localizedDescription)" return } guard let userID = res?.user.uid else { return } // DispatchQueue.main.async { // print("Starting adding...") self.addIntoDatabe(userID: userID, email: self.email) // } completion() } } private func addIntoDatabe(userID: String, email: String) { let newUser = User(uid: userID, email: email, permission: Permission.Admin, itemReads: [["Prop":2]], numberOfAddedItem: 0, numberOfReadItem: 0) let db = Firestore.firestore() db.collection("users") .document(userID) .setData(["uid": newUser.uid, "email": newUser.email, "permission": newUser.permission.rawValue, "itemReads": newUser.itemReads, "numberOfAddedItem": newUser.numberOfAddedItem, "numberOfReadItem": newUser.numberOfReadItem]) print("User has been added into db") } }
2
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482
Nov ’24