FetchRequest and reset in SwiftUI View? - core-data

Question

I tried around with reset() of the context and found a strange behavior. I use the property wrapper for the fetch request in the SwiftUI View. When resetting the context why are there still the objects in the list? Does it only reset all objects which aren't saved? But what is the difference to rollback()? While testing I found a strange behavior which could have to do with the Discussion part of the Docs but how should it be handled with the property wrapper, or is it better to use rollback()?
And after clicking the reset button the list doesn't get updated, also there is one persons name setted to nil, which is strange too.
Link to Video: https://imgur.com/a/tUCPHUl
From Doc:
Summary
Returns the context to its base state. Declaration
func reset()
Discussion
All the receiver's managed objects are “forgotten.” If you use this
method, you should ensure that you also discard references to any
managed objects fetched using the receiver, since they will be invalid
afterwards.
My Code:
import SwiftUI
struct ContentView: View {
#Environment(\.managedObjectContext) var context
#FetchRequest(sortDescriptors: [SortDescriptor(\.name)]) var persons: FetchedResults<Person>
func saveContext(){
do{
try context.save()
}catch{}
}
var body: some View {
VStack{
Text("\(persons.count)")
if persons.isEmpty{
Text("No persons defined")
}else{
ScrollView{
LazyVStack{
ForEach(persons){p in
Text(p.name ?? "NO NAME").background(Color.green)
}
}
}
}
Spacer()
Button("Add Person without save"){
let p = Person(context: context)
p.id = UUID()
p.name = "Test Without save \(persons.count)"
}
Button("Add Person with save"){
let p = Person(context: context)
p.id = UUID()
p.name = "Test with save \(persons.count)"
saveContext()
}
Button("reset"){
context.reset()
}
Button("rollback"){
context.rollback()
}
Button("delete All"){
for p in persons{
context.delete(p)
}
saveContext()
}
Button("save Context"){
saveContext()
}
}
}
}