I'm currently facing an interesting issue. A customer is reporting back that my app is crashing on launch for them. I can see the crash logs (using AppCenter for crash management), and the reason the app is crashing seems to be in CoreData:
(Attaching text for seachability, and screenshot for readability):
libsystem_platform.dylib
_platform_memmove$VARIANT$Haswell
CoreData
-[_PFExternalReferenceData initForExternalLocation:safeguardLocation:data:protectionLevel:]
CoreData
-[NSSQLSavePlan _populateRow:fromObject:timestamp:inserted:shouldAddToRowCache:]
CoreData
-[NSSQLSavePlan _createRowsForSave]
CoreData
-[NSSQLSaveChangesRequestContext executePrologue]
CoreData
-[NSSQLCore dispatchRequest:withRetries:]
CoreData
-[NSSQLCore executeRequest:withContext:error:]
CoreData
-[NSPersistentStoreCoordinator executeRequest:withContext:error:]
CoreData
-[NSPersistentStoreCoordinator _routeHeavyweightBlock:]
CoreData
-[NSPersistentStoreCoordinator executeRequest:withContext:error:]
CoreData
-[NSManagedObjectContext save:]
I have never seen that crash before, it's the first time it is appearing since CoreData has been incorporated into the app (in 2016 or so). Any hints on what could possibly be happening? I am unable to provoke the crash on my end, thus debugging is quite interesting.
Core Data
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I'm working on an iOS app using SwiftUI and CoreData and am running into a problem that I cannot seem to figure out.
To provide a little bit of information of what I am trying to do:
I have two CoreData entities that have a One-To-Many relationship:
Tarantula - A tarantula may molt many times (To Many) and when deleted, all of the molts shold also be removed (Cascade)
Molt - A molt belongs to a single Tarantula (To One) and when
deleted, should have the reference removed from the Tarantula (Nullify)
I then have a view that lists all of the molts for a given Tarantula that allows adding and deleting molts. It looks like this:
struct MoltListView: View {
		private static let DATE_FORMATTER: DateFormatter = {
						let d = DateFormatter()
						d.dateFormat = "MMM d, y"
						return d
				}()
		
		@Environment(\.managedObjectContext) private var viewContext
		
		@ObservedObject private var tarantula: Tarantula
		@FetchRequest private var molts: FetchedResults<Molt>
		@State private var userMessage: String = ""
		@State private var displayMessage: Bool = false
		
		init(tarantula: Tarantula) {
				self.tarantula = tarantula
				self._molts = FetchRequest(entity: Molt.entity(),
																	 sortDescriptors: [NSSortDescriptor(keyPath: \Molt.date, ascending: false)],
																	 predicate: NSPredicate(format: "tarantula = %@", tarantula))
		}
		
		var body: some View {
				List {
						Section(header: Text("Summary")) {
								Text("\(molts.count) Molt\(molts.count == 1 ? "" : "s")")
						}
						Section(header: Text("Molts")) {
								NavigationLink(destination: MoltView(tarantula: tarantula, molt: Molt.newModel())) {
										Text("Add Molt").foregroundColor(.blue)
								}
								ForEach(molts, id: \.self) { molt in
										NavigationLink(destination: MoltView(tarantula: tarantula, molt: molt)) {
												Text(MoltListView.DATE_FORMATTER.string(from: molt.modelDate))
										}
								}
								.onDelete(perform: deleteItems)
						}
				}.alert(isPresented: $displayMessage) {
						Alert(title: Text("Save Failure"), message: Text(userMessage), dismissButton: .default(Text("Ok")))
				}
		}
		
		private func deleteItems(offsets: IndexSet) {
				withAnimation {
						offsets.map { molts[$0] }.forEach(viewContext.delete)
						do {
								try viewContext.save()
						} catch {
								viewContext.rollback()
								userMessage = "\(error): \(error.localizedDescription)"
								displayMessage.toggle()
						}
				}
		}
}
The error I am experiencing comes from whenever I try to delete a molt from the list view. The app instantly crashes and the error is:
Simultaneous accesses to 0x7f92efc61cb8, but modification requires exclusive access
Find the complete error here:
error - https://developer.apple.com/forums/content/attachment/6d74dcde-d82b-4024-ade0-5936d8926488
I have tried removing the animation block and have played around with removing different UI components/restructuring.
The only way I have been able to prevent this error is to remove the delete rule on the Molt->Tarantula relationship from Nullify to No Action. However, this seems more like a hack to me instead of a fix.
Was hoping for some help on this issue.
When I add or delete data of my entity type I can see the updates (between the simulator and the phone) but when i edit I dont see the updates although table view is reloaded. The console says
Ignoring remote change notification because it didn't change any entities tracked by persistent history
When I rebuild the app for both device and simulator I see it reflecting the most current changes.
Any help?
Neerav
Can anyone tell me how to use Swift Data and Core Data with playground?
Hello, developers,
I'm experiencing UI lag in SwiftUI when updating Core Data or SwiftData entities in the background, noticeable during scrolling. This issue arises regardless of whether the updated entity is currently displayed. For instance, updating a "Song" entity with a new localURL from a background download and saving background context affects an unrelated "Artists" list view.
Scenario: The lag is most evident when completing background downloads and updating entity properties, causing a hitch in scrolling interactions when using SwiftUI @FetchRequest or @Query for displaying data.
Observations:
The issue occurs with both Core Data @FetchRequest and SwiftData @Query property wrappers.
It affects unrelated views, suggesting a broader issue with SwiftUI's handling of data updates during user interactions.
Seeking Community Insights:
Has anyone faced similar issues with SwiftUI and background data updates?
Any strategies for reducing this lag/hitch?
Insights into SwiftUI's data update and view re-rendering process in this context?
For a practical example, Apple's project on loading and displaying a large data feed demonstrates this issue. Try tapping the refresh button while scrolling to observe the lag.
Appreciate any advice or solutions!
Best Regards,
[Personal Information Edited by Moderator]
I have a CoreData entity with a transformable property data that stores an NSDictionary. All of the classes inside the dictionary conform to NSSecureCoding
I have been getting many instances of this warning :
'NSKeyedUnarchiveFromData' should not be used to for un-archiving and will be removed in a future release
In trying to clean up the warning and future-proof my app, but I am running into a lot of trouble.
My understanding is that using NSKeyedUnarchiveFromData as the transformer in my data properties attribute should work, since the top level class is a dictionary and all of the contents conform to NSSecureCoding.
However, my data dictionary is now coming back as NSConcreteMutableData so I cannot access the data in it.
I have also tried creating a custom value transformer with additional allowedTopLevelClasses, but that hasn't helped, and again, the topLevel type is an NSDictionary, which should be allowed.
Thank you for any guidance.
I'm experiencing an unresponsive UI since MacOS 14.0 and iOS 17.0 when calling record(for: ) or recordID(for:) on the instance of NSPersistentCloudKitContainer.
On MacOS, the UI freeze almost always happens when calling the function.
On iOS, it is necessary that the device (or simulator) does not have any network connection.
I would like to ask if anyone experienced the same problem. I have posted the problem twice to Apple via the Feedback app (once for iOS and once for MacOS). No reply yet on MacOS but on iOS Apple marked it as resolved because apparently no one but me has experienced this problem.
In the meantime, I have set up a minimum reproducible example app (MRE).:
https://github.com/DominikButz/NotesApp-Cloud-Kit-Record-UI-Freeze-
Anyone interested, please read the readme of the repository. It includes step by step instructions on how to reproduce the bug.
I can't rule out I have misunderstood the usage of CoreData and CloudKit - in that case please point me in the right direction.
The app I'm working on should also work offline (and on MacOS!) but it doesn't do so properly as long as this bug exists.
I'm exploring switching to SwiftData (which would mean no one using macOS 13 / iOS 16 can use my app...) but I would still need to access cloud kit records even with SwiftData and I fear the bug also exists in SwiftData.
Thanks
In Core data public configuration, added new attribute to entities, new entities, but the changes are neither synchronized nor data is transferred to existing container schema in cloudkit.
private var _publicPersistentStore: NSPersistentStore?
var publicPersistentStore: NSPersistentStore {
return _publicPersistentStore!
}
private var _privatePersistentStore: NSPersistentStore?
var privatePersistentStore: NSPersistentStore {
return _privatePersistentStore!
}
private var _sharedPersistentStore: NSPersistentStore?
var sharedPersistentStore: NSPersistentStore {
return _sharedPersistentStore!
}
static let shared = PersistenceController()
static var preview: PersistenceController = {
let result = PersistenceController(inMemory: true)
let viewContext = result.container.viewContext
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)")
}
return result
}()
let container: NSPersistentCloudKitContainer
init(inMemory: Bool = false) {
container = NSPersistentCloudKitContainer(name: “GS”)
if inMemory {
container.persistentStoreDescriptions.first!.url = URL(fileURLWithPath: "/dev/null")
}
guard let defaultDescription = container.persistentStoreDescriptions.first else {
fatalError("###\(#function): failed to retrieve a persistent store description.")
}
let containerIdentifier = defaultDescription.cloudKitContainerOptions!.containerIdentifier
print(containerIdentifier)
print(defaultDescription.url as Any)
let url = defaultDescription.url?.deletingLastPathComponent()
print(url as Any)
// Public
let publicDescription = NSPersistentStoreDescription(url: url!.appendingPathComponent("public.sqlite"))
publicDescription.configuration = "Public"
print(publicDescription.url)
let publicOptions = NSPersistentCloudKitContainerOptions(containerIdentifier: containerIdentifier)
publicOptions.databaseScope = .public
publicDescription.cloudKitContainerOptions = publicOptions
publicDescription.setOption(true as NSNumber, forKey: NSPersistentHistoryTrackingKey)
publicDescription.setOption(true as NSNumber, forKey: NSPersistentStoreRemoteChangeNotificationPostOptionKey)
// Private
let privateDescription = NSPersistentStoreDescription(url: url!.appendingPathComponent("private.sqlite"))
privateDescription.configuration = "Private"
print(privateDescription.url)
let privateOptions = NSPersistentCloudKitContainerOptions(containerIdentifier: containerIdentifier)
privateOptions.databaseScope = .private
privateDescription.cloudKitContainerOptions = privateOptions
privateDescription.setOption(true as NSNumber, forKey: NSPersistentHistoryTrackingKey)
privateDescription.setOption(true as NSNumber, forKey: NSPersistentStoreRemoteChangeNotificationPostOptionKey)
// Shared
guard let sharedDescription = privateDescription.copy() as? NSPersistentStoreDescription else {
fatalError("#\(#function): Copying the private store description returned an unexpected value.")
}
sharedDescription.url = url!.appendingPathComponent("shared.sqlite")
print(sharedDescription.url)
sharedDescription.configuration = "Shared"
let sharedOptions = NSPersistentCloudKitContainerOptions(containerIdentifier: containerIdentifier)
sharedOptions.databaseScope = .shared
sharedDescription.cloudKitContainerOptions = sharedOptions
sharedDescription.setOption(true as NSNumber, forKey: NSPersistentHistoryTrackingKey)
sharedDescription.setOption(true as NSNumber, forKey: NSPersistentStoreRemoteChangeNotificationPostOptionKey)
container.persistentStoreDescriptions = [publicDescription, privateDescription, sharedDescription]
container.loadPersistentStores(completionHandler: { (storeDescription, error) in
if let error = error as NSError? {
// 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.
/*
Typical reasons for an error here include:
* The parent directory does not exist, cannot be created, or disallows writing.
* The persistent store is not accessible, due to permissions or data protection when the device is locked.
* The device is out of space.
* The store could not be migrated to the current model version.
Check the error message to determine what the actual problem was.
*/
fatalError("Unresolved error \(error), \(error.userInfo)")
}
else {
if let cloudKitContainerOptions = storeDescription.cloudKitContainerOptions {
if #available(iOS 16.0, *) {
if .public == storeDescription.cloudKitContainerOptions?.databaseScope {
print("loaded public store")
// self._publicPersistentStore = container.persistentStoreCoordinator.persistentStore(for: storeDescription.url!)
} else if .private == storeDescription.cloudKitContainerOptions?.databaseScope {
print("loaded private store")
//self._privatePersistentStore = container.persistentStoreCoordinator.persistentStore(for: storeDescription.url!)
} else if .shared == storeDescription.cloudKitContainerOptions?.databaseScope {
print("loaded shared store")
//self._sharedPersistentStore = container.persistentStoreCoordinator.persistentStore(for: storeDescription.url!)
}
} else {
// Fallback on earlier versions
}
}
}
})
container.viewContext.automaticallyMergesChangesFromParent = true
container.viewContext.mergePolicy = NSMergeByPropertyStoreTrumpMergePolicy // external changes trumping in-memory changes.
}
func save() {
let context = container.viewContext
if context.hasChanges {
do {
try context.save()
} catch {
// Show some error here
print("save error")
}
}
}
}
Tried new container on cloudkit, problem persists. Working previously until I updated Xcode to 15.2 and iOs 16.2. Can you please tell me why coredata is not synchronized for public configuration.
We are facing a challenging memory issue during a Core Data heavy weight migration in our app.
Background: We store sizable data(~250kb/record) in a Core Data entity called "Email." We have roughly 20k records. We are loading the "Email" list using fetchedResultsController with batching. Recently, we split the another entity named "Profile" into "Profile" and "Address" entities, requiring a heavyweight migration.
The Problem: This migration consumes an exorbitant amount of memory, causing the OS to kill our app. Interestingly, the "Email" entity is causing the brunt of the memory usage, even though the actual migration code deals with the "Profile" entity to create "Address." If we remove the "sizable" data from "Email" and attempt for migration then the migration is successful.
My Questions: Is this memory consumption expected behavior? Why does the "Email" entity, seemingly unrelated to the actual migration, seem to be the main memory culprit?
How can I prevent the OS from terminating my app during migration? Are there strategies to optimize memory usage or mitigate memory pressure?
Also we are encountering a delay in loading the email list on the very first launch of app. Subsequent launches work comparatively faster. Is that related to storing bigger size data in Email entity?
We have an entity called "EMail" with attributes such as ID, From, To, Subject, Body.
Due to various reasons including performance for retrieval, impact on migration etc, we want to refactor this entity into two entities with a parent child relationship: "EMail": ID, From, To, Subject and "EMailBody": ID, Body.
Can this be done with an existing model? If so, will this still fall under lightweight migration?
Hello,
I’ve been struggling with Core Data lightweight migration since the iOS 17 launch.
I have a NSPersistentStoreCoordinator which I use the following options in it:
[NSMigratePersistentStoresAutomaticallyOption: true as AnyObject, NSInferMappingModelAutomaticallyOption: true as AnyObject, NSSQLitePragmasOption: ["journal_mode": "DELETE"] as AnyObject]
I don’t create new versions when I change my .xcdatamodel. However, lightweight migration worked normally until iOS 17.
And there is something else, the migration doesn’t fail for all users.
So, if I update my xcdatamodel from version 1 to 2, some users get the following error:
An error occurred during persistent store migration., reason: Failed to open the store, underlyingReason: The model used to open the store is incompatible with the one used to create the store
Last but not least, my NSPersistentStoreCoordinator’s MOM merges two other models. But these two other models did not have any changes since I started getting this issue.
I don’t think the issue is because we are adding new entities or properties in our xcdatamodel because if it were, it would be described in the error we are printing when trying to add the persistent store.
I wonder if something has changed in iOS 17 that is causing this issue, which was working normally before.
Also, what do you think I should do to fix this issue?
Versioning my xcdatamodel? Although I don’t see it as a requirement in Apple’s docs.
Removing the two other models from NSPersistentStoreCoordinator?
Something else?
It is often the case that offline devices can add duplicate entities that needs to be merged when CloudKit syncs. Consider user-created tags. A user might create a Note, and then tag it with a newly created tag “Family.” On a separate offline device, they might create another note, and create another tag also called ”Family.” On device sync, both duplicate ”Family” tags would need to be identified as duplicates based on their name property, merged to a single entity, and their original relationships consolidated to the single merged Tag. And this needs to happen before the CloudKit sync data is presented to the UI in the main context.
With Core Data we have the mechanism to consume relevant store changes described here.
These tools allow us to listen for remote change, then process them appropriately (e.g. remove / merge duplicates) and then merge the changes into the app’s main context. This perfectly solves the problem described in the first paragraph above. Apple provides code using this mechanism for deduplicating tags in a sample app.
Is there a mechanism to solve this deduplication problem using SwiftData technology without implementing and maintaining a parallel Core Data stack?
As the title says, our app has begun running into a strange issue every time a user upgrades their iPhone to the latest iOS versions. It started in 17.2.1 and looks like it made a resurgence in 17.3. Post update the user's FullText Searches against the local sqlite db run egregiously slow. Fully re-installing the app and re-downloading all content seems to correct the issue, after which their searches come back in less than 500 ms tops. When the bug occurs searches can take upwards of 15 secs in some cases to complete... What makes no sense is why all of a sudden this is happening in 17.2.1 >=
Our app uses an old school approach (historic code we never removed) to create a local sqlite database from scratch on first app install in the user's device contentDir. this .db file is instantiated on each app load using the following:
private func sqliteOpenDB(url: URL) -> OpaquePointer? {
var db: OpaquePointer?
if sqlite3_open_v2(url.path, &db, SQLITE_OPEN_CREATE | SQLITE_OPEN_READWRITE | SQLITE_OPEN_FULLMUTEX, nil) == SQLITE_OK {
LoggingUtil.log(msg: "\(ContentFilestore.TAG): database file opened successfully")
// You must enable foreign key constraints every time the db connects otherwise they're off by default and cascade deletes/fk's won't work
sqlite3_exec(db, "PRAGMA foreign_keys = ON;", nil, nil, nil)
} else {
LoggingUtil.log(msg: "\(ContentFilestore.TAG) Error: unabled to open the database file")
}
return db;
}
Prior to iOA 17.2.1 we've never had an issue with this when a user's device upgraded the OS. Now this process continues to work without throwing an error or warning of any kind, but their FTS search db slows to a crawl. It also seems to be completely isolated to the FTS virtual table as well. The actual tables run just fine.
My question is did something major change in iOS 17.2.1 >= that I'm missing that would be causing virtual tables to lose their indexing or have some kind of issue that would cause this problem?
Is there a way to share CoreData data containing complex relationships easily by file? And also to create them easily after receiving the file?
The application runs on a secure iPad without iCloud, so CloudKit is not an option.
I'd really like to keep the file principle, so that data can be shared via Airdrop, e-mail, file transfer, etc.
The ideal would be :
data = myNSManagedObject.toJSON()
file = createFile(data)
share file
receive file
data = file.data.decodeJSON()
myNSManagedObjectContext.add(data)
All this without having to browse all the objects to create them individually
Thx
In our app, there is a scenario where we write and delete approximately 100MB of files to the iCloud server at once using NSPersistentCloudkItContainer(CoreData). While write, read, and delete operations are immediately reflected in the local database, there is a noticeable delay when accessing the CloudKit Database dashboard.
Here is the testing approach we have tried:
Data Insert Test
Prepare around 100MB of data.
Write the data to CoreData on device A.
When launching the app on device B, it takes about 5 minutes for the data to be fully synchronized.
Data Deletion Test
Remove all the added data on device A (immediately reflected in local storage.)
After performing step 1, leaving device A idle takes about 3 minutes for the deletion to be reflected on device B.
if the app is deleted on device A after step 1, deletion information does not reach device B. Upon reinstalling the app on device A, the deleted data reappears on device B (synchronized data).
The ongoing occurrence of these issues has raised several questions regarding cloud synchronization and synchronization speed:
Is the synchronization speed of the Testflight app the same as the one received from the AppStore?
Are there traffic limitations per account or device?
Despite different perceived speeds for each account or device, is there any factor influencing synchronization speed other than network conditions?
I'm trying to setup a filter option for some core data records, but I'm not seeing the expected results.
Essentially, what I want is to have multiple sections. Within each section it would be an OR query, and an AND between each section. I've tried setting it up as below.
func getBasicFilter() -> NSPredicate? {
var predicatesBagsLeft : [NSPredicate] = []
var predicatesDrillType : [NSPredicate] = []
var andPredicates : [NSPredicate] = []
print("Filter List")
print(filters)
// Bags Left
if let show = filters["showFullLeft"] {
if show {
print("Predicates : Show Full")
let predicate = NSPredicate(format: "ANY projectColours.fullLeft > 0")
predicatesBagsLeft.append(predicate)
}
}
if let show = filters["showPartialLeft"] {
if show {
print("Predicates : Show Partial")
let predicate = NSPredicate(format: "ANY projectColours.partialLeft > 0")
predicatesBagsLeft.append(predicate)
}
}
// Drill Types
if let show = filters["showSquareOnly"] {
if show {
print("Predicates : Show Square Only")
let predicate = NSPredicate(format: "ANY projectColours.project.drillType = %@", "Square")
predicatesDrillType.append(predicate)
}
}
// Drill Manufacturers - TO DO
// Combine Predicates
if predicatesBagsLeft.count > 0 {
let predicatesForBagsLeft = NSCompoundPredicate(type: .or, subpredicates: predicatesBagsLeft)
andPredicates.append(predicatesForBagsLeft)
}
if predicatesDrillType.count > 0 {
let predicatesForDrillType = NSCompoundPredicate(type: .or, subpredicates: predicatesDrillType)
andPredicates.append(predicatesForDrillType)
}
if andPredicates.count > 0 {
let predicates = NSCompoundPredicate(type: .and, subpredicates: andPredicates)
return predicates
}
return nil
}
It does filter, but doesn't seem to be applying both correctly. I'm testing with a filter of showFullLeft & showSquareOnly, so it should show only squares which have a a fullest > 0
I'm getting 7 results back, but one of them is unwanted. It is square, but it has 0 for both full & partial
When I look at the query core data is using it looks correct
CoreData: sql: SELECT t0.ZMANU, COUNT (DISTINCT t0.Z_PK) FROM ZCOLOUR t0 JOIN ZPROJECTCOLOUR t1 ON t0.Z_PK = t1.ZCOLOUR JOIN ZPROJECTCOLOUR t2 ON t0.Z_PK = t2.ZCOLOUR JOIN ZPROJECT t3 ON t2.ZPROJECT = t3.Z_PK WHERE ( t1.ZFULLLEFT > ? AND t3.ZDRILLTYPE = ?) GROUP BY t0.ZMANU ORDER BY t0.ZMANU
CoreData: details: SQLite bind[0] = 0
CoreData: details: SQLite bind[1] = "Square"
What is the recommended architecture for a CoreData+CloudKit iOS App that has a large public database?
Assume the public database contains 10,000+ Locations from which a User would select a few as favorites. Totally impractical to mirror the locations such that they appear in the App's CoreData having been synced from the .public CloudKit database. Presumably one uses the CloudKit API to query the .public database and display some subset of locations for the User to select? (The selected locations can then be stored in the Users .private (or perhaps .shared) database.)
How does one configure CoreData + CloudKit for this scenario? Is there another approach?
Hello
I have a CoreData PersistenceController and would like to convert it to a SwiftData container. Before converting the whole app to use SwiftData I wanted to know if my conversion is right and preserves old data (in iCloud and local).
Here is the code:
PersistenceController:
import CoreData
import SwiftUI
import Combine
#if os(iOS) || os(macOS) || os(watchOS)
import WidgetKit
#endif
struct PersistenceController {
static let shared = PersistenceController()
let container: NSPersistentCloudKitContainer
init() {
let fileContainer = URL.storeURL(for: "group.Water-Alert-App", databaseName: "CoreData")
container = NSPersistentCloudKitContainer(name: "CoreData")
let defaultDirectoryURL = NSPersistentContainer.defaultDirectoryURL()
let localStoreURL = defaultDirectoryURL.appendingPathComponent("Local.sqlite")
let localStoreDescription = NSPersistentStoreDescription(url: localStoreURL)
localStoreDescription.configuration = "Local"
// Create a store description for a CloudKit-backed local store
let cloudStoreDescription = NSPersistentStoreDescription(url: fileContainer)
cloudStoreDescription.configuration = "Cloud"
// Set the container options on the cloud store
cloudStoreDescription.cloudKitContainerOptions = NSPersistentCloudKitContainerOptions(containerIdentifier: "iCloud.namel")
cloudStoreDescription.setOption(true as NSNumber, forKey: NSPersistentHistoryTrackingKey)
cloudStoreDescription.setOption(true as NSNumber, forKey: NSPersistentStoreRemoteChangeNotificationPostOptionKey)
container.persistentStoreDescriptions = [cloudStoreDescription, localStoreDescription]
container.loadPersistentStores{ (storeDescription, error) in
if let error = error as NSError? {
fatalError("Unresolved error \(error), \(error.userInfo)")
}
}
container.viewContext.automaticallyMergesChangesFromParent = true
container.viewContext.mergePolicy = NSMergeByPropertyStoreTrumpMergePolicy
}
func save() {
if container.viewContext.hasChanges {
do {
try container.viewContext.save()
} catch {
print("COULD NOT SAVE WITH CORE DATA")
}
}
}
}
ModelContainer:
var container: ModelContainer? = {
let fileContainer = URL.storeURL(for: "group.Water-Alert-App", databaseName: "CoreData")
let defaultDirectoryURL = NSPersistentContainer.defaultDirectoryURL()
let localSchema = Schema([Reminder.self])
let cloudSchema = Schema([Goal.self, WaterData.self, Container.self])
let localConfiguration = ModelConfiguration("Local", schema: localSchema, url: defaultDirectoryURL.appendingPathComponent("Local.sqlite"))
let cloudConfiguration = ModelConfiguration("Cloud", schema: cloudSchema, url: fileContainer, cloudKitDatabase: .private("iCloud.Water-Alert-App-Offical"))
let container = try! ModelContainer(for: Reminder.self, Goal.self, WaterData.self, Container.self, configurations: localConfiguration, cloudConfiguration)
return container
}()
Thank you!
Dear:
Use core data to store super long strings. After storage, the strings are incomplete.
Xcode tips：
CoreData: debug: PostSaveMaintenance: fileSize 30409752 greater than prune threshold
CoreData: annotation: PostSaveMaintenance: wal_checkpoint(TRUNCATE)
help me?
Have an app that has a half dozen models. We created a new app version with a new model that has an additional property on one entity.
The options for the persistent store:
do {
let options = [
NSMigratePersistentStoresAutomaticallyOption: NSNumber(value: true),
NSInferMappingModelAutomaticallyOption: NSNumber(value: true)
]
let _ = try persistentStoreCoordinator.addPersistentStore(ofType: NSSQLiteStoreType, configurationName: nil, at: storeURL, options: options)
} catch {
try? FileManager.default.removeItem(at: storeURL) //Erase old sqlite
// Make new persistent store for future saves
let _ = try? persistentStoreCoordinator.addPersistentStore(ofType: NSSQLiteStoreType, configurationName: nil, at: storeURL, options: nil)
}
Launch this with data from a previous version. A breakpoint in the catch block never triggers so the migration must have worked.
Since I'm in development, what happens if I run a different branch that doesn't have the new model? I assume the catch block is going to trigger—but it doesn't!
Why doesn't it trigger? Does Core Data essentially ignore the new entity property, so all is well?
I was just surprised ...