SwiftUI TabView with List not refreshing after objected deleted from / added to Core Data - swift

Question

Description:
When an object in a list (created from a fetchrequest) is deleted from a context, and the context is saved, the list does not properly update.
Error:
Thread 1: Fatal error: Unexpectedly found nil while unwrapping an Optional value (Thrown on line 5 below)
struct DetailView: View {
#ObservedObject var event: Event
var body: some View {
Text("\(event.timestamp!, formatter: dateFormatter)")
.navigationBarTitle(Text("Detail"))
}
}
Steps to reproduce:
Create a new Master Detail App project with SwiftUI and Core Data.
In the ContentView, set the body to a TabView with the first tab being the prebuilt NavigationView, and add a second arbitrary tab.
struct ContentView: View {
#Environment(\.managedObjectContext)
var viewContext
var body: some View {
TabView {
NavigationView {
MasterView()
.navigationBarTitle(Text("Master"))
.navigationBarItems(
leading: EditButton(),
trailing: Button(
action: {
withAnimation { Event.create(in: self.viewContext) }
}
) {
Image(systemName: "plus")
}
)
Text("Detail view content goes here")
.navigationBarTitle(Text("Detail"))
}
.navigationViewStyle(DoubleColumnNavigationViewStyle())
.tabItem { Text("Main") }
Text("Other Tab")
.tabItem { Text("Other Tab") }
}
}
}
Add a few items. Interact with those items in any way.
Change tabs.
Change back to Main Tab.
Attempt to delete an item.

Answer 1

I found a pure SwiftUI working solution:
/// This View that init the content view when selection match tag.
struct SyncView<Content: View>: View {
#Binding var selection: Int
var tag: Int
var content: () -> Content
#ViewBuilder
var body: some View {
if selection == tag {
content()
} else {
Spacer()
}
}
}
You can use it then in this way:
struct ContentView: View {
#State private var selection = 0
var body: some View {
TabView(selection: $selection) {
SyncView(selection: $selection, tag: 0) {
ViewThatNeedsRefresh()
}
.tabItem { Text("First") }
.tag(0)
Text("Second View")
.font(.title)
.tabItem { Text("Second") }
.tag(1)
}
}
}
You can use the SyncView for each view that needs a refresh.