i have started updating my application to swift 3.0, and i got a bunch of errors. Now i am down to one, and i simply can't figure out how to solve it. I have recreated the error with some basic code.
First a model
struct Model {
var num: Int?
enum TestError : Error {
case logout
case showalert
case bluebackground
}
func testNumber() throws {
guard let num = num, num > 0 else {
throw TestError.logout
}
}
}
and then a controller
class ViewController: UIViewController {
var modelError : Model.TestError?
override func viewDidLoad() {
super.viewDidLoad()
DispatchQueue.global(qos: .default).async {
do {
var test = Model()
test.num = 0
try test.testNumber()
} catch let error as Model.TestError {
self.modelError = error
} catch let error {
print(error)
}
DispatchQueue.main.async(execute: {
switch(self.modelError) {
case .logout: //logout
case .showalert: //show alert
case .bluebackground: //set background blue
}
})
}
}
}
It should be pretty clear to see what is happening. My model contains an enum of type error, which i wonna save in a variable in my viewcontroller to later tackle the error on the main que. This code works perfectly in swift 2.2, but in 3.0 and xcode 8b4 i simply get:
How can i tackle this problem, so i can work with the error on the main que?
UPDATE
I forgot to mention, when i remove
var modelError : Model.TestError?
and the associated code, it works perfectly, but then i can tackle the error later
Related
I am trying to figure out how to display errors such as those found in the App Store Store class and Persistence.swift file in a single reporting module. Some of my errors within views use an environment object to tie the error production to the error reporting, but this isn’t feasible with errors in different classes.
So any pointers on handling these types of errors would be much appreciated.
Below is an example of my process to report an error within a view
// the save button has been pressed
struct saveButton: View {
#Environment(\.managedObjectContext) var viewContext
#EnvironmentObject var errorHandling: ErrorHandling
var body: some View {
// prepping data for save to core data
do {
try viewContext.save()
} catch {
// report: Unable to Save Transaction
self.errorHandling.handle(error: AppError.saveTransactionError)
}
The App Store purchase method (below) may produce two errors that I would like to display with my app. This is the type of logic that I need help display the error within a view
#MainActor
func purchase() {
Task.init {
guard let product = products.first else {
return
}
guard AppStore.canMakePayments else {
return
}
do {
let result = try await product.purchase()
switch result {
case .success(let verification):
switch verification {
case .verified(let transaction):
await transaction.finish()
// save to user defaults
self.purchasedIds = transaction.productID
break
case .unverified:
// throw PurchaseError.failed
// FIX: report error (Unable to purchase verification failed)
break
}
break
case .userCancelled:
break
// asked to buy (setting on phone prevents purchases)
case .pending:
break
default:
break
}
}
catch {
print(error.localizedDescription)
// FIX: report error (Unable to Complete Purchase)
}
}
}
enum AppError: LocalizedError {
case storePurchaseError
case storeVerificationError
var errorDescription: String? {
switch self {
case .storePurchaseError:
return NSLocalizedString("Store Purchase Error", comment: "")
case .storeVerificationError:
return NSLocalizedString("Store Verification Error", comment: "")
}
}
}
Below is some code I have been using to display an alert
struct ErrorAlert: Identifiable {
var id = UUID()
var message: String
var dismissAction: (() -> Void)?
}
class ErrorHandling: ObservableObject {
#Published var currentAlert: ErrorAlert?
func handle(error: Error) {
currentAlert = ErrorAlert(message: error.localizedDescription)
}
}
struct HandleErrorsByShowingAlertViewModifier: ViewModifier {
#StateObject var errorHandling = ErrorHandling()
func body(content: Content) -> some View {
content
.environmentObject(errorHandling)
.background(
EmptyView()
.alert(item: $errorHandling.currentAlert) { currentAlert in
Alert(
title: Text("Error"),
message: Text(currentAlert.message),
dismissButton: .default(Text("Ok")) {
currentAlert.dismissAction?()
}
)
}
)
}
}
extension View {
func withErrorHandling() -> some View {
modifier(HandleErrorsByShowingAlertViewModifier())
}
}
I have a fairly complex document type to work with. It is basically a bundle containing a set of independent documents of the same type, with various pieces of metadata about the documents. The data structure that represents the bundle is an array of structs, similar to this (there are several more fields, but these are representative):
struct DocumentData: Equatable, Identifiable, Hashable {
let id = UUID()
var docData: DocumentDataClass
var docName: String
var docFileWrapper: FileWrapper?
func hash(into hasher: inout Hasher) {
id.hash(into: &hasher)
}
static func ==(lhs: KeyboardLayoutData, rhs: KeyboardLayoutData) -> Bool {
return lhs.id == rhs.id
}
}
The window for the bundle is a master-detail, with a list on the left and, when one is selected, there is an edit pane for the document on the right. The FileWrapper is used to keep track of which files need to be written for saving, so it gets initialised on reading the relevant file, and reset when an undoable change is made. That is largely the only way that the DocumentData structure gets changed (ignoring explicit things like changing the name).
I've reached a point where a lot of things are working, but I'm stuck on one. There's a view inside the edit pane, several levels deep, and when I double-click it, I want a sheet to appear. It does so, but then disappears by itself.
Searching for ways to work this out, I discovered by using print(Self._printChanges()) at various points that the edit pane was being refreshed after showing the sheet, which meant that the parent disappeared. What I found was that the dependency that changed was the DocumentData instance. But, I then added a print of the DocumentData instance before the _printChanges call, and it is identical. I have also put in didSet for each field of DocumentData to print when they get set, and nothing gets printed, so I'm not sure where the change is happening.
So the question comes down to how I can work out what is actually driving the refresh, since what is claimed to be different is identical in every field.
There are some other weird things happening, such as dragging and dropping text into the view causing the whole top-level document array of DocumentData items to change before the drop gets processed and the data structures get updated, so there are things I am not understanding as clearly as I might like. Any guidance is much appreciated.
ADDED:
The view that triggers the sheet is fairly straightforward, especially compared to its enclosing view, which is where most of the interface code is. This is a slightly simplified version of it:
struct MyView: View, DropDelegate {
#EnvironmentObject var keyboardStatus: KeyboardStatus
#Environment(\.displayFont) var displayFont
#Environment(\.undoManager) var undoManager
var keyCode: Int
#State var modifiers: NSEvent.ModifierFlags = []
#State private var dragHighlight = false
#State private var activeSheet: ActiveSheet?
#State private var editPopoverIsPresented = false
// State variables for double click and drop handling
...
static let dropTypes = [UTType.utf8PlainText]
var body: some View {
ZStack {
BackgroundView(...)
Text(...)
}
.onAppear {
modifiers = keyboardStatus.currentModifiers
}
.focusable(false)
.allowsHitTesting(true)
.contentShape(geometry.contentPath)
.onHover { entered in
// updates an inspector view
}
.onTapGesture(count: 2) {
interactionType = .doubleClick
activeSheet = .doubleClick
}
.onTapGesture(count: 1) {
handleItemClick()
}
.sheet(item: $activeSheet, onDismiss: handleSheetReturn) { item in
switch item {
case .doubleClick:
DoubleClickItem(...) ) {
activeSheet = nil
}
case .drop:
DropItem(...) {
activeSheet = nil
}
}
}
.popover(isPresented: $editPopoverIsPresented) {
EditPopup(...)
}
.onDrop(of: KeyCap.dropTypes, delegate: self)
.contextMenu {
ItemContextMenu(...)
}
}
func handleItemClick() {
NotificationCenter.default.post(name: .itemClick, object: nil, userInfo: [...])
}
func handleEvent(event: KeyEvent) {
if event.eventKind == .dropText {
interactionType = .drop
activeSheet = .drop
}
else if event.eventKind == .replaceText {
...
handleItemDoubleClick()
}
}
func handleSheetReturn() {
switch interactionType {
case .doubleClick:
handleItemDoubleClick()
case .drop:
handleItemDrop()
case .none:
break
}
}
func handleItemDoubleClick() {
switch itemAction {
case .state1:
...
case .state2:
...
case .none:
// User cancelled
break
}
interactionType = nil
}
func handleItemDrop() {
switch itemDropAction {
case .action1:
...
case .action2:
...
case .none:
// User cancelled
break
}
interactionType = nil
}
// Drop delegate
func dropEntered(info: DropInfo) {
dragHighlight = true
}
func dropExited(info: DropInfo) {
dragHighlight = false
}
func performDrop(info: DropInfo) -> Bool {
if let item = info.itemProviders(for: MyView.dropTypes).first {
item.loadItem(forTypeIdentifier: UTType.utf8PlainText.identifier, options: nil) { (textData, error) in
if let textData = String(data: textData as! Data, encoding: .utf8) {
let event = ...
handleEvent(event: event)
}
}
return true
}
return false
}
}
Further edit:
I ended up rewiring the code so that the sheet belongs to the higher level view, which makes everything work without solving the question. I still don't understand why I get a notification that a dependency has changed when it is identical to what it was before, and none of the struct's didSet blocks are called.
Try removing the class from the DocumentData. The use of objects in SwiftUI can cause these kind of bugs since it’s all designed for value types.
Try using ReferenceFileDocument to work with your model object instead of FileDocument which is designed for a model of value types.
Try using sheet(item:onDismiss:content:) for editing. I've seen people have the problem you describe when they try to hack the boolean sheet to work with editing an item.
I have a very troubling problem. I have searched for days on how to solve it. I have some code that I want to run every time the app is opened, not just when the app is launched for the first time. I've basically tried everything available. I've tried scenePhase, I've tried AppDelegate, I've tried onAppear, I've tried init and custom extensions to the View class, I've even tried simply running a function in the view, but nothing is working. I'll show my code here.
#main
struct CouponDeckApp: App {
#UIApplicationDelegateAdaptor(AppDelegate.self) var appDelegate
#Environment(\.scenePhase) private var scenePhase
var body: some Scene {
WindowGroup {
AppContentView()
}
}
}
struct AppContentView: View {
init() {
let userDefaults = UserDefaults.standard
if userDefaults.value(forKey: "hour") == nil { // 1
userDefaults.set(9, forKey: "hour") // 2
}
// 3
if userDefaults.value(forKey: "minute") == nil {
userDefaults.set(30, forKey: "minute")
}
}
#State var currentview: String = "Main"
var body: some View {
Group {
switch currentview {
case "Main":
MainView(currentview: $currentview)
case "Form":
FormView(currentview: $currentview)
case "Settings":
SettingsView(currentview: $currentview)
default:
if currentview.contains("Coupon") {
CouponView(currentview: $currentview)
}
else {
EditView(currentview: $currentview)
}
}
}
}
}
//MainView(), CouponView(), FormView(), etc.
I'm starting to suspect that the problem is with the switch statement in AppContentView that allows you to move between the different views.
Does anyone know:
A. Why this is happening,
B. How to fix it, or
C. Another alternative?
Thanks in advance!
P.S. I'm running my code on the simulator.
Here is a very simple way, using native scenePhase, I did not make it more complicated. You can use Preference method as well for better result! But onChange is good enough for this example:
struct ContentView: View {
#Environment(\.scenePhase) var scenePhase
var body: some View {
Text("Welcome to my App!")
.onAppear() { customFunction() }
.onChange(of: scenePhase) { newPhase in
if newPhase == .active {
customFunction()
}
}
}
}
func customFunction() {
print("App is opened!")
}
The simple problem was that it doesn't work when you close out of the app. I realized if you just exit the app but don't completely close out of it, it works just fine.
I also learned about the NotificationCenter's applications to this. By triggering a response when UIApplication sends out the willEnterForegroundNotification by using the onReceive method, you can trigger a response that way.
Do it in your AppDelegate's application(_:didFinishLaunchingWithOptions:).
I tried to find a tutorial about IAP, and I found : This one
But when I call function to restore, nothing happens. OnTap button I call : store.restorePurchase()
extension Store {
func product(for identifier: String) -> SKProduct? { ...}
func purchaseProduct (_ product: SKProduct){ ...}
func restorePurchases() {
SKPaymentQueue.default().restoreCompletedTransactions()
print("restore")
}
}
restore is print in my console. It is the only thing that is printed in console. But in the code above, you can see .restored:that should print "UserIsPremium"
extension Store : SKPaymentTransactionObserver {
func paymentQueue(_ queue: SKPaymentQueue, updatedTransactions transactions : [SKPaymentTransaction]){
for transaction in transactions {
var shouldFinishTransaction = false
switch transaction.transactionState{
case .purchased, .restored:
completedPurchases.append(transaction.payment.productIdentifier)
print("UserIsPremium")
shouldFinishTransaction = true
case .failed:
print("NotPremium")
shouldFinishTransaction = true
case .deferred, .purchasing:
print("...")
break
#unknown default:
print("unknown")
break
}
if shouldFinishTransaction {
print("shouldfinish")
SKPaymentQueue.default().finishTransaction(transaction)
DispatchQueue.main.async {
self.purchaseCompletionHandler?(transaction)
self.purchaseCompletionHandler = nil
}
}
}
}
}
My class Store :
import StoreKit
typealias FetchCompletionHandler = (([SKProduct]) -> Void)
typealias PurchaseCompletionHandler = ((SKPaymentTransaction?) -> Void)
class Store: NSObject, ObservableObject {
#Published var allFullVersion = [FullVersion]()
private let allProductsIdentifiers = Set ([
"ClemPapplis.OrientationEPS.versionFull"
])
private var completedPurchases = [String]() {
didSet {
DispatchQueue.main.async{ [weak self] in
guard let self = self else { return }
for index in self.allFullVersion.indices {
if self.completedPurchases.contains(self.allFullVersion[index].id){
print("completedPurchases")
UserDefaults.standard.setValue(true, forKey: "Premium")
}
self.allFullVersion[index].isLocked =
!self.completedPurchases.contains(self.allFullVersion[index].id)
}
}
}
}
I use sandbox testers.
If I buy item, no problem, datas are print in console.
Did I forget something ?
It's been a few years since I used StoreKit, but I remember having an issue with restore purchases also (and yes, #ElTomato is correct, use a separate case - I'm surprised your code actually builds). I found that the following worked:
public func paymentQueue(_ queue: SKPaymentQueue, updatedTransactions transactions: [SKPaymentTransaction]) {
for transaction:AnyObject in transactions {
if let trans = transaction as? SKPaymentTransaction {
switch trans.transactionState {
case .purchased:
SKPaymentQueue.default().finishTransaction(transaction as! SKPaymentTransaction)
delegate.purchaseComplete()
case .failed:
SKPaymentQueue.default().finishTransaction(transaction as! SKPaymentTransaction)
case .restored:
SKPaymentQueue.default().finishTransaction(transaction as! SKPaymentTransaction)
default:
break
}}}
}
func restorePurchases() {
SKPaymentQueue.default().add(self)
SKPaymentQueue.default().restoreCompletedTransactions()
}
public func paymentQueueRestoreCompletedTransactionsFinished(_ queue: SKPaymentQueue) {
for _ in queue.transactions {
alreadyPurchased = true
delegate.purchasesRestored()
}
showAlert("Purchases have been restored.")
}
Don't worry about showAlert, that's just an extension I have for UIViewController. But what I'm not seeing in your code is paymentQueueRestoreCompletedTransactionsFinished(_ queue:).
I followed the same tutorial i think you did not select the select the none in here
configuration
to restore in your simulator you should select none when you select none it tries to connect apple developers in app purchase configuration. give it a try and let me know.
This is my code, my app crashes in the middle of printing the data, without an error message in the log. it prints almost 30 people and then crashes, with this message on the line of code that crashed:
Thread 1: EXC_BREAKPOINT (code=1, subcode =.....)
I will mark the line of code with //CRASH where this message appears on in my code:
import UIKit
import Contacts
class ViewController: UIViewController {
override func viewDidLoad() {
super.viewDidLoad()
for cont in contacts {
print(cont.givenName)
let num = ((cont.phoneNumbers.first?.value)! as CNPhoneNumber).stringValue //CRASH
print(num)
}
// Do any additional setup after loading the view, typically from a nib.
}
lazy var contacts: [CNContact] = {
let contactStore = CNContactStore()
let keysToFetch = [
CNContactFormatter.descriptorForRequiredKeys(for: .fullName),
CNContactEmailAddressesKey,
CNContactPhoneNumbersKey,
CNContactImageDataAvailableKey,
CNContactThumbnailImageDataKey] as [Any]
// Get all the containers
var allContainers: [CNContainer] = []
do {
allContainers = try contactStore.containers(matching: nil)
} catch {
print("Error fetching containers")
}
var results: [CNContact] = []
// Iterate all containers and append their contacts to our results array
for container in allContainers {
let fetchPredicate = CNContact.predicateForContactsInContainer(withIdentifier: container.identifier)
do {
let containerResults = try contactStore.unifiedContacts(matching: fetchPredicate, keysToFetch: keysToFetch as! [CNKeyDescriptor])
results.append(contentsOf: containerResults)
} catch {
print("Error fetching results for container")
}
}
return results
}()
}
I thought I may be unwrapping nil but its not the case since it is not an optional (I tried to unwrap it in a safe way and the compiler says it is not an optional type).
From the comments:
The problem turns out to be the forced unwrapping of cont.phoneNumbers.first?.value since it will be nil if there are no phone numbers (and therefore no first to evaluate).