SwiftUI - Delete from Sectioned Dynamic List [duplicate] - swiftui

Question

Goal
I want to delete an item from a SectionedFetchRequest on a ForEach inside a List. The only solutions I have found are for a regular FetchRequest I have managed to delete it from the UIList but not from the CoreData's ViewContext.
My question is unique because I'm trying to delete from a SectionedFetchRequest which is different than a FetchRequest
#SectionedFetchRequest(entity: Todo.entity(), sectionIdentifier: \.dueDateRelative, sortDescriptors: [NSSortDescriptor(keyPath: \Todo.dueDate, ascending: true)], predicate: nil, animation: Animation.linear)
var sections: SectionedFetchResults<String, Todo>
var body: some View {
NavigationView {
List {
ForEach(sections) { section in
Section(header: Text(section.id.description)) {
ForEach(section) { todo in
TodoRowView(todo: todo)
.frame(maxWidth: .infinity)
.listRowSeparator(.hidden)
}
.onDelete { row in
deleteTodo(section: section.id.description, row: row)
}
}
}
}
func deleteTodo(section: String, row: IndexSet) {
// Need to delete from list and CoreData viewContex.
}
// My old way of deleting notes with a regular fetch Request
func deleteNote(at offsets: IndexSet) {
for index in offsets {
let todo = todos[index]
viewContext.delete(todo)
}
try? viewContext.save()
}

Answer 1

This is how you would use the link...
Add this to the TodoRowView(todo: todo)
.swipeActions(content: {
Button(role: .destructive, action: {
deleteTodo(todo: todo)
}, label: {
Image(systemName: "trash")
})
})
And you need this method in the View
public func deleteTodo(todo: Todo){
viewContext.delete(todo)
do{
try viewContext.save()
} catch{
print(error)
}
}
Or you can use your current setup that uses onDelete on the ForEach
.onDelete { indexSet in
deleteTodo(section: Array(section), offsets: indexSet)
}
That uses this method
func deleteTodo(section: [Todo], offsets: IndexSet) {
for index in offsets {
let todo = section[index]
viewContext.delete(todo)
}
try? viewContext.save()
}
And of course for any of this to work you need a working
#Environment(\.managedObjectContext) var viewContext
At the top of your file

Answer 2

I found this question when searching for a neat solution, couldn't find one so thought I'd share my attempt at deleting from a #SectionedFetchRequest.
var body: some View {
NavigationView {
List {
ForEach(sections) { section in
Section(section.id) {
ForEach(section) { todo in
TodoRowView(todo: todo)
.frame(maxWidth: .infinity)
.listRowSeparator(.hidden)
.onDelete { indexSet in
deleteTodos(section: section, indexSet: indexSet)
}
}
}
}
}
...
private func deleteTodos(section: SectionedFetchResults<String, Todo>.Section, offsets: IndexSet) {
withAnimation {
offsets.map { section[$0] }.forEach(viewContext.delete)
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)")
}
}
}