Thanks for the reply.
I've been trying to get CKSyncEngine working with SwiftData. Since you don't any sample code, here's my code and some questions about it.
CKSyncEngineDelegate has a function called "handleEvent". In that function I handle the "fetchedRecordZoneChanges" event amongst other events. Here's my function to handle that event (it's basically copy paste from the sample app):
func handleFetchedRecordZoneChanges(_ event: CKSyncEngine.Event.FetchedRecordZoneChanges) {
guard let localContainer else { return }
let newContext = ModelContext(localContainer)
let localHabits = SwiftDataPersistence.fetch(FetchDescriptor<Habit>(), predicate: nil, sortBy: [], fetchLimit: nil, context: newContext)
for modification in event.modifications {
// The sync engine fetched a record, and we want to merge it into our local persistence.
let serverHabit = modification.record
let serverHabitID = serverHabit.recordID.recordName
// If we already have this object locally, let's merge the data from the server.
if let localHabit = localHabits.first(where: { habit in
habit.identifier == serverHabitID
}) {
localHabit.mergeFromServerData(serverHabit)
localHabit.setLastKnownRecordIfNewer(serverHabit)
}
// Otherwise, let's create a new local object.
else {
let newHabit = Habit(record: serverHabit)
newContext.insert(newHabit)
}
}
for deletion in event.deletions {
// TO DO
}
// If we had any changes, let's save to disk.
if !event.modifications.isEmpty || !event.deletions.isEmpty {
SwiftDataPersistence.save(newContext)
NotificationCenter.default.post(name: newContextDidSaveNotification, object: nil)
}
}
Last line of code: I'm sending a notification to my SwiftUI view (that shows habits) to fetch edited/new habits.
Here's my view code:
struct HabitsListView: View {
@State private var habits = [Habit]()
@Environment(\.modelContext) private var context
var body: some View {
LazyVStack(alignment: .leading, spacing: 8) {
ForEach(habits) { habit in
HabitRow(habit)
}
}
.onNewContextDidSave {
fetchHabits()
}
}
func fetchHabits() {
self.habits = SwiftDataPersistence.fetch(FetchDescriptor<Habit>(), predicate: nil, sortBy: [SortDescriptor(\Habit.name)], fetchLimit: nil, context: context)
}
}
This approach seems to work, but it's not ideal and I'm not sure it's a correct way to do it. It works with only 1 custom notification, but I ran into problems when I added more notifications - then the notifications stopped firing or the view didn't catch them.
But my main question at this moment is:
How to get @Query to update my habits list, so I don't have to manually fetch habits at every change.
I would like to use a view like this:
struct HabitsListView: View {
@Query private var habits: [Habit]
var body: some View {
LazyVStack(alignment: .leading, spacing: 8) {
ForEach(habits) { habit in
HabitRow(habit)
}
}
}
}
Thanks!
Martin
Topic:
App & System Services
SubTopic:
iCloud & Data
Tags: