Hello
I am developing an app with SwiftUI using CoreData and iCloudKit to sync data between platforms. The problem is that the iCloud background update is not being triggered when staying in the application. If I make changes on both systems, the changes are being pushed, however not visible on the other device. I need to reload the app, close the app and open again.
I already enabled iCloud capability, background notifications and push notifications.
This is my persistentContainer
var persistentContainer: NSPersistentCloudKitContainer = {
let container = NSPersistentCloudKitContainer(name: "Test7")
container.loadPersistentStores(completionHandler: {(StoreDescription, error) in
if let error = error as NSError? {
fatalError("Unresolved error \(error), \(error.userInfo)")
}
})
container.viewContext.automaticallyMergesChangesFromParent = true
container.viewContext.mergePolicy = NSMergeByPropertyStoreTrumpMergePolicy
return container
}()
func saveContext() {
let context = persistentContainer.viewContext
if context.hasChanges{
do {
try context.save()
} catch {
let nserror = error as NSError
fatalError("Unresolved error \(nserror), \(nserror.userInfo)")
}
}
}
This is my model
class ItemsModel: ObservableObject {
init() {
readData()
}
@Published var dataInputs: [Item] = []
let context = persistentContainer.viewContext
func readData(){
let request: NSFetchRequest<Item> = Item.fetchRequest()
do {
let results = try context.fetch(request)
self.dataInputs = results
} catch {
print(error.localizedDescription)
}
}
func addItem(todo: String, date: Date){
let entity = NSEntityDescription.insertNewObject(forEntityName: "Item", into: context) as! Item
entity.todo = todo
entity.date = date
do {
try context.save()
self.dataInputs.append(entity)
} catch {
print(error.localizedDescription)
}
}
func deleteItems(indexSet: IndexSet){
for index in indexSet{
do {
let obj = dataInputs[index]
context.delete(obj)
try context.save()
let index = dataInputs.firstIndex(of: obj)
dataInputs.remove(at: index!)
} catch {
print(error.localizedDescription)
}
}
}
}
and this is my view
struct ContentView: View {
@EnvironmentObject var items: ItemsModel
var body: some View {
NavigationView{
List {
ForEach(items.dataInputs) { item in
Text("Item at \(item.date!)")
}
.onDelete(perform: items.deleteItems)
}
.toolbar {
Button {
items.addItem(todo: "Hello", date: Date())
} label: {
Image(systemName: "plus")
}
}
}
}
}
Thank you
In CoreData, NSFetchRequest is used to perform a single fetch, whereas NSFetchedResultsController provides a continuous view of data matching your predicates. Furthermore, for SwiftUI, you should look at the property wrapper @FetchRequest, which in fact implements a NSFetchResultsController, and can be used instead of your ItemsModel class. Hope this helps.
