Delete item from a section list on SwiftUI - ios

Question

Overview
im doing a simple app with core data I have two entity users and territory the app shows a list of the users in sections by territory the problem is In the delete action the list delete the user from the first section if I try to delete the second user from the second section it delete the second user from the first section.
I think index set is getting wrong sending the index of the section but when I try to change the onDelete to my nested forEach don't work
Here is the code
import SwiftUI
struct ContentView: View {
#Environment(\.managedObjectContext) var moc
#FetchRequest(entity: User.entity(), sortDescriptors: [NSSortDescriptor(keyPath: \User.name, ascending: true)]) var users: FetchedResults<User>
#FetchRequest(entity: Territory.entity(), sortDescriptors: [NSSortDescriptor(keyPath: \Territory.name, ascending: true)]) var territories: FetchedResults<Territory>
#State private var showAddUser = false
var body: some View {
GeometryReader{ geometry in
NavigationView {
ZStack {
List {
ForEach(self.territories, id: \.self) { territorie in
Section(header: Text(territorie.wrappedName)) {
ForEach(territorie.usersArray, id: \.self) { user in
NavigationLink(destination: UserView(user: user)) {
VStack{
HStack{
Text("user")
Spacer()
Text(user.dayLastVisit)
.padding(.horizontal)
}
HStack {
Text(user.wrappedEmoji)
.font(.largeTitle)
VStack(alignment: .leading) {
Text("\(user.wrappedName + " " + user.wrappedLastName)")
.font(.headline)
Text(user.wrappedType)
}
Spacer()
}
}
}
}.onDelete(perform: self.deleteItem)
}
}
}
.listStyle(GroupedListStyle())
.environment(\.horizontalSizeClass, .regular)
VStack {
Button(action:{ self.showAddRUser.toggle()}){
ButtonPlus(icon:"plus")}
.offset(x: (geometry.size.width * 0.40), y: (geometry.size.height * 0.38))
.sheet(isPresented: self.$showAddUser){
NewUserView().environment(\.managedObjectContext, self.moc)
}
}
}
.navigationBarTitle("Users")
.navigationBarItems( trailing: HStack {
EditButton()
Button(action:{self.showAddUser.toggle()}){
ButtonNew(text:"Nueva")}
}
.sheet(isPresented: self.$showAddUser){
NewUserView().environment(\.managedObjectContext, self.moc)
}
)
}
}
}
func deleteItem(at offsets: IndexSet) {
for offset in offsets {
let user = users[offset]
//borarlo del context
moc.delete(user)
}
try? moc.save()
}
}
struct ContentView_Previews: PreviewProvider {
static var previews: some View {
ContentView()
}
}
im learning swift and swiftui so im would appreciate any help

Answer 1

You’ll need to pass in a section index as well as the row index, so that you know which nested item to delete. Something like this.
.onDelete { self.deleteItem(at: $0, in: sectionIndex) }
And change your function to accept that section index:
func deleteItem(at offsets: IndexSet, in: Int)
In your case you can probably pass in something like territorie.id as the section index, and use that to delete the correct item. Or pass in the territorie object - whatever you need to get to the correct user. Only the index won’t get you there. Hope it all makes sense!

Answer 2

For me, the solution was the following:
ForEach(self.territories, id: \.self) { territorie in
Section(header: Text(territorie.wrappedName)) {
ForEach(territorie.usersArray, id: \.self) { user in
// your code here
}
.onDelete { indexSet in
for index in indexSet {
moc.delete(territorie[user])
}
// update the view context
moc.save()
}
}
}
The index in indexSet returns the item that should be deleted in that specific section. So if I delete the first item of a section, it returns 0.
The territorie returns a list of all the items that are contained in that section. So using territorie[index] will return the specific user object you want to delete.
Now that we have the object we want to delete, we can pass it to moc.delete(territorie[index]). Finally, we save it with moc.save().
Sidenote: although Misael used the variable 'territorie', I prefer to use the variable name section.

Answer 3

So thanks to the help of Kevin Renskers who found a solution. I just add a .onDelete { self.deleteItem(at: $0, in: territorie)} to my function then I use the same arrayUsers from the territory.
func deleteItem(at offsets: IndexSet, in ter: Territory) {
for offset in offsets {
let user = ter.usersArray[offset]
moc.delete(user)
}
try? moc.save()
}