Here how this piece of code works:
ListTimerViewshows a list ofTimerentity stored using Core Data. In this view there is a (+) button on the toolbar.- Clicking on the (+) button a new empty
Timeris created using current contextnewTimerToAdd = Timer(context: viewContext). TimerEditViewis called and an empty Entity is passed to the view usingObservedObject.TimerEditViewcan edit the entity. In the toolbar there are two buttons,SaveorDiscardchanged. If I click onSaveeverything goes right. The error occurs only if I click onDiscardbutton.
The logic behind is:
- Create a temporary entity
- Pass the entity to an Edit view and then Save in current context or Discard it
Here the "complete" code, and at the end the error printed in the console.
//***************************************************************
// TimerListView
//***************************************************************
import SwiftUI
import CoreData
struct TimerListView: View {
@Environment(\.managedObjectContext) private var viewContext
@FetchRequest(
sortDescriptors: [NSSortDescriptor(keyPath: \Timer.id, ascending: true)],
animation: .default)
private var timers: FetchedResults<Timer>
@State private var isPresentingSheet = false
@State private var showFavoritesOnly = false
@State private var sheetView: SheetView = .setting
@State var newTimerToAdd: Timer = Timer()
var body: some View {
// Include NavigationLinkk into NavigationView, otherwise it will look disabled
NavigationView{
List {
ForEach(timers) { timer in
NavigationLink(destination: TimerDetailView(timer: timer)) {
TimerCardView(timer: timer)
}
}
}
.navigationTitle("Timer")
.toolbar {
ToolbarItem(placement: .confirmationAction) {
Button(action: {
newTimerToAdd = Timer(context: viewContext)
newTimerToAdd.id = UUID()
newTimerToAdd.name = "Timer name"
newTimerToAdd.secondsOn = 0
newTimerToAdd.secondsOff = 0
newTimerToAdd.rounds = 1
newTimerToAdd.cycles = 1
newTimerToAdd.secondsOffBetweenCycles = 0
newTimerToAdd.favourite = false
sheetView = .newTimer
isPresentingSheet = true
}) {
Label("New timer", systemImage: "plus")
}
}
}
.sheet(isPresented: $isPresentingSheet) {
if (sheetView == .newTimer) {
NavigationView {
TimerEditView(timer: newTimerToAdd)
.toolbar {
//*********************************************************
//Here where the error occurs. If I debug this piece of code, the error occurs after
//the last line of code.
//*********************************************************
ToolbarItem(placement: .cancellationAction) {
Button("Dismiss") {
viewContext.delete(newTimerToAdd)
do {
try viewContext.save()
} catch {
// Replace this implementation with code to handle the error appropriately.
// fatalError() causes the application to generate a crash log and terminate. You should not use this function in a shipping application, although it may be useful during development.
viewContext.rollback()
//print("Failed to save context \(nsError.localizedDescription)")
let nsError = error as NSError
fatalError("CAZZO Unresolved error \(nsError), \(nsError.userInfo)")
}
isPresentingSheet = false
}
}
ToolbarItem(placement: .confirmationAction) {
Button("Add") {
do {
try viewContext.save()
} catch {
// Replace this implementation with code to handle the error appropriately.
// fatalError() causes the application to generate a crash log and terminate. You should not use this function in a shipping application, although it may be useful during development.
let nsError = error as NSError
fatalError("Unresolved error \(nsError), \(nsError.userInfo)")
}
//timers.append(newTimerToAdd)
isPresentingSheet = false
//newTimer = Timer()
}
}
} // .toolbar
} // NavigationView
} else {
NavigationView {
SettingsView()
.toolbar {
ToolbarItem(placement: .confirmationAction) {
Button("Salva") {
isPresentingSheet = false
}
}
}
}
}
} //.sheet
}
}
}
//***************************************************************
// TimerEditView
//***************************************************************
import SwiftUI
struct TimerEditView: View {
@ObservedObject var timer:Timer
@State private var isPresentingEditView = false
@State private var whichTimer:String = ""
@State private var data:Int = 0
var body: some View {
Form {
Section(header: Text("Timer Info")) {
TextField("Name", text: Binding($timer.name)!)
HStack {
Text("Preferito")
Spacer()
FavoriteButton(isSet: $timer.favourite)
}
}
Section {
HStack {
Text("Lavoro")
Spacer()
Button {
whichTimer = "workTimer"
data = Int(timer.secondsOn)
isPresentingEditView = true
}
label: {
Text(timer.labelSecondsOn)
}
}
HStack {
Text("Riposo")
Spacer()
Button {
whichTimer = "restTimer"
data = Int(timer.secondsOff)
isPresentingEditView = true
}
label: {
Text(timer.labelSecondsOff)
}
}
HStack {
Stepper("Round: \(timer.rounds)", value: $timer.rounds, in: 1...30)
}
} header: {
Text("Round")
} footer: {
Text("Un round è un allenamento seguito da un riposo")
}
Section {
HStack {
Stepper("Cicli: \(timer.cycles)", value: $timer.cycles, in: 1...30)
}
HStack {
Text("Riposo tra cicli")
Spacer()
Button {
whichTimer = "restTimerBetweenCycles"
data = Int(timer.secondsOffBetweenCycles)
isPresentingEditView = true
}
label: {
Text(timer.labelSecondsOffBetweenCycles)
}
}
}
header: {
Text("Cicli")
} footer: {
Text("Un ciclo corrisponde ad un round")
}
}
.sheet(isPresented: $isPresentingEditView) {
NavigationView {
ChangeTimerView(totalSeconds: $data)
.navigationTitle("Tempo")
.toolbar {
ToolbarItem(placement: .cancellationAction) {
Button("Cancel") {
isPresentingEditView = false
}
}
ToolbarItem(placement: .confirmationAction) {
Button("Done") {
switch whichTimer {
case "workTimer":
timer.secondsOn = Int16(data)
case "restTimer":
timer.secondsOff = Int16(data)
case "restTimerBetweenCycles":
timer.secondsOffBetweenCycles = Int16(data)
default:
timer.secondsOn = Int16(data)
}
isPresentingEditView = false
}
}
}
}//NavigationView
}//.sheet
}
}
//***************************************************************
// Main App
//***************************************************************
import SwiftUI
@main
struct Advanced_TimerApp: App {
let persistenceController = PersistenceController.shared
var body: some Scene {
WindowGroup {
TimerListView()
.environment(\.managedObjectContext, persistenceController.container.viewContext)
//.environmentObject(AdvancedTimer())
}
}
}
//***************************************************************
// Persistence (basically the default provided by Apple)
//***************************************************************
import CoreData
struct PersistenceController {
static let shared = PersistenceController()
static var preview: PersistenceController = {
let result = PersistenceController(inMemory: true)
let viewContext = result.container.viewContext
for i in 0..<10 {
let newTimerToAdd = Timer(context: viewContext)
//let newTimerToAdd = Timer(id: UUID(), name: newTimer.name, secondsOn: newTimer.secondsOn, secondsOff: newTimer.secondsOff, rounds: newTimer.rounds, cycles: newTimer.cycles, secondsOffBetweenCycles: newTimer.secondsOffBetweenCycles, favourite: newTimer.favourite)
newTimerToAdd.id = UUID()
newTimerToAdd.name = "Timer \(i)"
newTimerToAdd.secondsOn = 60
newTimerToAdd.secondsOff = 30
newTimerToAdd.rounds = 2
newTimerToAdd.cycles = 1
newTimerToAdd.secondsOffBetweenCycles = 0
newTimerToAdd.favourite = (i % 2 == 0) ? true : false
}
do {
try viewContext.save()
} catch {
// Replace this implementation with code to handle the error appropriately.
// fatalError() causes the application to generate a crash log and terminate. You should not use this function in a shipping application, although it may be useful during development.
let nsError = error as NSError
fatalError("Unresolved error \(nsError), \(nsError.userInfo)")
}
return result
}()
let container: NSPersistentContainer
init(inMemory: Bool = false) {
container = NSPersistentContainer(name: "Model")
if inMemory {
container.persistentStoreDescriptions.first!.url = URL(fileURLWithPath: "/dev/null")
}
container.loadPersistentStores(completionHandler: { (storeDescription, error) in
if let error = error as NSError? {
// Replace this implementation with code to handle the error appropriately.
// fatalError() causes the application to generate a crash log and terminate. You should not use this function in a shipping application, although it may be useful during development.
/*
Typical reasons for an error here include:
* The parent directory does not exist, cannot be created, or disallows writing.
* The persistent store is not accessible, due to permissions or data protection when the device is locked.
* The device is out of space.
* The store could not be migrated to the current model version.
Check the error message to determine what the actual problem was.
*/
fatalError("Unresolved error \(error), \(error.userInfo)")
}
})
container.viewContext.automaticallyMergesChangesFromParent = true
}
}
2022-09-06 21:01:01.498482+0200 Advanced Timer[53782:3631004] [error] error: CoreData: error: Failed to call designated initializer on NSManagedObject class 'Timer'
CoreData: error: CoreData: error: Failed to call designated initializer on NSManagedObject class 'Timer'
2022-09-06 21:01:01.500029+0200 Advanced Timer[53782:3631004] [UIFocus] _TtGC7SwiftUI14_UIHostingViewGVS_15ModifiedContentVS_7AnyViewVS_12RootModifier__ implements focusItemsInRect: - caching for linear focus movement is limited as long as this view is on screen.
2022-09-06 21:01:01.532761+0200 Advanced Timer[53782:3631004] [UIFocus] _TtGC7SwiftUI14_UIHostingViewGVS_15ModifiedContentGVS_17_UnaryViewAdaptorVS_9EmptyView_GVS_18StyleContextWriterVS_14NoStyleContext___ implements focusItemsInRect: - caching for linear focus movement is limited as long as this view is on screen.
2022-09-06 21:01:01.535611+0200 Advanced Timer[53782:3631004] [UIFocus] _TtGC7SwiftUI14_UIHostingViewGVS_15ModifiedContentGS1_VVS_22_VariadicView_Children7ElementVS_24NavigationColumnModifier_GVS_18StyleContextWriterVS_19SidebarStyleContext___ implements focusItemsInRect: - caching for linear focus movement is limited as long as this view is on screen.
2022-09-06 21:01:01.558195+0200 Advanced Timer[53782:3631004] [UIFocus] _TtGC7SwiftUI16UIKitBarItemHostVS_11BarItemView_ implements focusItemsInRect: - caching for linear focus movement is limited as long as this view is on screen.
2022-09-06 21:01:01.576846+0200 Advanced Timer[53782:3631004] [UIFocus] _TtGC7SwiftUI16UIKitBarItemHostVS_11BarItemView_ implements focusItemsInRect: - caching for linear focus movement is limited as long as this view is on screen.
2022-09-06 21:01:01.589925+0200 Advanced Timer[53782:3631004] [UIFocus] _TtGC7SwiftUI15CellHostingViewGVS_15ModifiedContentVS_14_ViewList_ViewVS_26CollectionViewCellModifier__ implements focusItemsInRect: - caching for linear focus movement is limited as long as this view is on screen.
2022-09-06 21:01:01.600503+0200 Advanced Timer[53782:3631004] [UIFocus] _TtGC7SwiftUI15CellHostingViewGVS_15ModifiedContentVS_14_ViewList_ViewVS_26CollectionViewCellModifier__ implements focusItemsInRect: - caching for linear focus movement is limited as long as this view is on screen.
2022-09-06 21:01:01.603573+0200 Advanced Timer[53782:3631004] [UIFocus] _TtGC7SwiftUI15CellHostingViewGVS_15ModifiedContentVS_14_ViewList_ViewVS_26CollectionViewCellModifier__ implements focusItemsInRect: - caching for linear focus movement is limited as long as this view is on screen.
2022-09-06 21:01:01.606157+0200 Advanced Timer[53782:3631004] [UIFocus] _TtGC7SwiftUI15CellHostingViewGVS_15ModifiedContentVS_14_ViewList_ViewVS_26CollectionViewCellModifier__ implements focusItemsInRect: - caching for linear focus movement is limited as long as this view is on screen.
2022-09-06 21:01:01.608962+0200 Advanced Timer[53782:3631004] [UIFocus] _TtGC7SwiftUI15CellHostingViewGVS_15ModifiedContentVS_14_ViewList_ViewVS_26CollectionViewCellModifier__ implements focusItemsInRect: - caching for linear focus movement is limited as long as this view is on screen.
2022-09-06 21:01:05.097483+0200 Advanced Timer[53782:3631004] [UIFocus] _TtGC7SwiftUI15CellHostingViewGVS_15ModifiedContentVS_14_ViewList_ViewVS_26CollectionViewCellModifier__ implements focusItemsInRect: - caching for linear focus movement is limited as long as this view is on screen.
2022-09-06 21:01:05.105100+0200 Advanced Timer[53782:3631004] [UIFocus] _TtGC7SwiftUI14_UIHostingViewVS_7AnyView_ implements focusItemsInRect: - caching for linear focus movement is limited as long as this view is on screen.
2022-09-06 21:01:05.114845+0200 Advanced Timer[53782:3631004] [UIFocus] _TtGC7SwiftUI14_UIHostingViewVVS_P10$109b5d55821BridgedNavigationView8RootView_ implements focusItemsInRect: - caching for linear focus movement is limited as long as this view is on screen.
2022-09-06 21:01:05.132879+0200 Advanced Timer[53782:3631004] [UIFocus] _TtGC7SwiftUI16UIKitBarItemHostVS_11BarItemView_ implements focusItemsInRect: - caching for linear focus movement is limited as long as this view is on screen.
2022-09-06 21:01:05.134664+0200 Advanced Timer[53782:3631004] [UIFocus] _TtGC7SwiftUI16UIKitBarItemHostVS_11BarItemView_ implements focusItemsInRect: - caching for linear focus movement is limited as long as this view is on screen.
2022-09-06 21:01:05.143203+0200 Advanced Timer[53782:3631004] [UIFocus] _TtGC7SwiftUI15CellHostingViewGVS_15ModifiedContentVS_14_ViewList_ViewVS_26CollectionViewCellModifier__ implements focusItemsInRect: - caching for linear focus movement is limited as long as this view is on screen.
2022-09-06 21:01:05.150091+0200 Advanced Timer[53782:3631004] [UIFocus] _TtGC7SwiftUI15CellHostingViewGVS_15ModifiedContentVS_14_ViewList_ViewVS_26CollectionViewCellModifier__ implements focusItemsInRect: - caching for linear focus movement is limited as long as this view is on screen.
2022-09-06 21:01:05.153836+0200 Advanced Timer[53782:3631004] [UIFocus] _TtGC7SwiftUI15CellHostingViewGVS_15ModifiedContentVS_14_ViewList_ViewVS_26CollectionViewCellModifier__ implements focusItemsInRect: - caching for linear focus movement is limited as long as this view is on screen.
2022-09-06 21:01:05.155381+0200 Advanced Timer[53782:3631004] [UIFocus] _TtGC7SwiftUI15CellHostingViewGVS_15ModifiedContentVS_14_ViewList_ViewVS_26CollectionViewCellModifier__ implements focusItemsInRect: - caching for linear focus movement is limited as long as this view is on screen.
2022-09-06 21:01:05.156777+0200 Advanced Timer[53782:3631004] [UIFocus] _TtGC7SwiftUI15CellHostingViewGVS_15ModifiedContentVS_14_ViewList_ViewVS_26CollectionViewCellModifier__ implements focusItemsInRect: - caching for linear focus movement is limited as long as this view is on screen.
2022-09-06 21:01:05.163936+0200 Advanced Timer[53782:3631004] [UIFocus] _TtGC7SwiftUI15CellHostingViewGVS_15ModifiedContentVS_14_ViewList_ViewVS_26CollectionViewCellModifier__ implements focusItemsInRect: - caching for linear focus movement is limited as long as this view is on screen.
2022-09-06 21:01:05.166516+0200 Advanced Timer[53782:3631004] [UIFocus] _TtGC7SwiftUI15CellHostingViewGVS_15ModifiedContentVS_14_ViewList_ViewVS_26CollectionViewCellModifier__ implements focusItemsInRect: - caching for linear focus movement is limited as long as this view is on screen.
2022-09-06 21:01:05.168053+0200 Advanced Timer[53782:3631004] [UIFocus] _TtGC7SwiftUI15CellHostingViewGVS_15ModifiedContentVS_14_ViewList_ViewVS_26CollectionViewCellModifier__ implements focusItemsInRect: - caching for linear focus movement is limited as long as this view is on screen.
2022-09-06 21:01:05.169055+0200 Advanced Timer[53782:3631004] [UIFocus] _TtGC7SwiftUI15CellHostingViewGVS_15ModifiedContentVS_14_ViewList_ViewVS_26CollectionViewCellModifier__ implements focusItemsInRect: - caching for linear focus movement is limited as long as this view is on screen.
2022-09-06 21:01:05.170094+0200 Advanced Timer[53782:3631004] [UIFocus] _TtGC7SwiftUI15CellHostingViewGVS_15ModifiedContentVS_14_ViewList_ViewVS_26CollectionViewCellModifier__ implements focusItemsInRect: - caching for linear focus movement is limited as long as this view is on screen.
2022-09-06 21:01:05.171122+0200 Advanced Timer[53782:3631004] [UIFocus] _TtGC7SwiftUI15CellHostingViewGVS_15ModifiedContentVS_14_ViewList_ViewVS_26CollectionViewCellModifier__ implements focusItemsInRect: - caching for linear focus movement is limited as long as this view is on screen.
2022-09-06 21:01:05.171991+0200 Advanced Timer[53782:3631004] [UIFocus] _TtGC7SwiftUI15CellHostingViewGVS_15ModifiedContentVS_14_ViewList_ViewVS_26CollectionViewCellModifier__ implements focusItemsInRect: - caching for linear focus movement is limited as long as this view is on screen.
sono qui
sono qui 2
2022-09-06 21:01:10.843201+0200 Advanced Timer[53782:3631004] [SystemGestureGate] <0x12c107010> Gesture: System gesture gate timed out.