Editing a specific core data object in modal view - core-data

Question

Progressing in my Core Data learning, I'm now stuck on the following :
I display a list of core data objects in ContentView.
If the user wants to edit one of them, he long-touches the item in the list which pops up a context sheet with and edit button. So far so good.
The edit Button summons a modal view on which the editing will take place.
In the Edit view, I start by fetching the correct item through its UUID property that I had stored in UserDefaults.
I am able to display the item's name, but I run into an issue with its date (the item has an "eventDate" Date property.
The app builds, I run it on my device, but it crashes as soon as I try to edit an item. An error is thrown in my EditView code when I instantiate the value to be displayed by a picker to the event's date :
Here's what happens inside the edit button :
Button(action: {
self.modalViewCaller = 1 // To tell the sheet which view to display
UserDefaults.standard.set(item.identNumber?.uuidString, forKey: kactiveEventUUID)
self.settingsModalIsPresented = true
})
{ Text("Edit entry")
Image(systemName: "globe")
}
And the way I fetch the event in EditView :
#Environment(\.managedObjectContext) var managedObjectContext
// We get the event to be edited through its UUID :
#FetchRequest(entity: Takeoffs.entity(),
sortDescriptors: [NSSortDescriptor(keyPath: \Takeoffs.eventDate, ascending: false)],
predicate: NSPredicate(format: "identNumber == %#", UUID(uuidString: UserDefaults.standard.string(forKey: kactiveEventUUID)!)! as CVarArg)) var fetchedEvent: FetchedResults<Takeoffs>
// UserDefaults.standard.object(forKey: kactiveEventUUID) as! CVarArg)
#State var selectedDate = Date()
init() { // This sets "selectedDate" to the event's value for the date picker
_selectedDate = State(initialValue: fetchedEvent.first?.eventDate ?? Date()) // The underscore is used here
}
The project is available here if anyone has the courage : https://github.com/Esowes/RecentExp
Thanks for any help...
[Edit :] Trying the .didAppear solution suggested below, but can't seem to find a view that accepts .didAppear in my body :
var body: some View {
NavigationView {
Form {
HStack {
Text("Airport : ")
TextField(String(fetchedEvent.first?.airportName ?? ""), text: $airportNameTextfield)
.disabled(airportNameTextfield.count > 2) // To limit the textField to 3 chars (IATA code)
Button(action: {
self.airportNameTextfield = ""
}) {
Image(systemName: "clear")
}
} // END of Hstack
Picker("", selection: $typeSelectorIndex) {
ForEach(0 ..< types.count) { index in
Text(self.types[index]).tag(index)
}
}
.pickerStyle(SegmentedPickerStyle())
// Text("Selected type is: \(types[typeSelectorIndex])")
VStack {
Button(action: {
self.selectedDate = Date()
}) {
Text("Today")
}
DatePicker("",selection: $selectedDate, displayedComponents: .date)
.padding(30)
.labelsHidden()
}
} // END of Form
.navigationBarItems(
leading:
Button("Done") {
self.saveEdits()
self.presentationMode.wrappedValue.dismiss() // This dismisses the view
} // END of Button "Done"
)
.navigationBarTitle("Event edition")
} // END of Navigation View
} // END of some View

Answer 1

The fetchedEvent is not available yet at View.init call moment, so instead use it in .didAppear, like below
// ... remove that init at all
var body: some View {
Text("Any internal view here")
.onAppear {
// assigned fetched event data, here it is available
self.selectedDate = self.fetchedEvent.first?.eventDate ?? Date()
}
}