Is it possible to work with my CoreData model in the today extension in swift like in the original app? If yes, how can I create the NSManagedObjectContext?
I really have no clue, beside the group-identifier, but unfortunatly I don't know how to get the context..
In the past I created apps with the check at the beginning that I want to use CoreData and then I got the managedObjectContext via my AppDelegate.. But how can I do somethink like that in an extension? Apple doesn't offer information about that..
I edited this line in AppDelegate:
NSURL *storeURL = [[self applicationDocumentsDirectory] URLByAppendingPathComponent:#"HTWcampus.sqlite"];
to this (after including the group to both targets):
NSURL *storeURL = [[NSFileManager defaultManager] containerURLForSecurityApplicationGroupIdentifier:#"group.BenchR.TodayExtensionSharingDefaults"];
storeURL = [storeURL URLByAppendingPathComponent:#"HTWcampus.sqlite"];
NSLog(#"StoreURL2: %#", storeURL);
With that the existing database in my app was gone (what is great, because I think it worked to put the database in the shared segment).
But how can I create an instance of my context in the extension? And how can I access my NSManagedObject-subclasses?
In the extension I have this code so far:
var context: NSManagedObjectContext!
override func viewDidLoad() {
super.viewDidLoad()
var storeURL = NSFileManager.defaultManager().containerURLForSecurityApplicationGroupIdentifier("group.BenchR.TodayExtensionSharingDefaults")
storeURL = storeURL?.URLByAppendingPathComponent("HTWcampus.sqlite")
let modelURL = NSBundle.mainBundle().URLForResource("HTWcampus", withExtension: "momd")
let model = NSManagedObjectModel(contentsOfURL: modelURL)
let coordinator = NSPersistentStoreCoordinator(managedObjectModel: model)
coordinator.addPersistentStoreWithType(NSSQLiteStoreType, configuration: nil, URL: storeURL, options: nil, error: nil)
context = NSManagedObjectContext()
context.persistentStoreCoordinator = coordinator
}
Is this right? And if yes, how can I get my NSManagedObject-Subclasses in there? And do I have to add the momd-file to the extensions target? If yes, how can I do that?
What you really want is to access your persistent store (most likely a SQLite database).
In order to achieve that, you need to configure App Groups and make sure that your host app configures the Core Data stack using your shared container (so your store is accessible in extension as well).
Something like:
NSString *containerPath = [[NSFileManager defaultManager] containerURLForSecurityApplicationGroupIdentifier:YOUR_SECURITY_APP_GROUP].path;
NSString *sqlitePath = [NSString stringWithFormat:#"%#/%#", containerPath, #"database.sqlite"];
Then in your extension just create persistent store coordinator with managed object contexts using database in shared container.
You can share your model (.momd) and managed object subclasses with extension just by making sure they are included in extension target as well.
Edit:
To add your model and managed object subclasses:
Make sure you have your app and extension targets
Click on your model file, and select both targets under 'Target Membership' on right-hand panel
Repeat the same with all your managed object subclasses
Related
An update is requested, since this question has of course been answered for previous versions, the latest search result dated 12/16 generates irrelevant compatibility with previous iOS 9 and 10 projects.
The documentation of course says to select the Use Core Data checkbox when starting a new project, which I did not select, but now think iCloud + Core Data needs to be added to take my app to its next phase -> wherein something like NSFileCoordinator and NSFilePresenter is needed, since in my app UI users are presented with a number of TOPICS, each having three OPTIONS, regarding which users are to choose one option. For each topic the UI then displays the TOTAL NUMBER of users who have chosen each option and the PERCENTAGE of the total for each option.
Right now, the number of choices for each option and the percentage of the total are of course just calculated in my native app -> but actually need to be CALCULATED in something central like the cloud or most likely on a website…but then the website raises the simultaneous read/write problems that NSFileCoordinator and NSFilePresenter have already solved.
So if the iCloud + Core Data system can interject basic arithmetic calculations on the existing Ubiquitous Container numerical value totals - in the cloud upon receiving write numerical value commands from individual users - before sending out the new Ubiquitous Container numerical total and percent values - then I’d much appreciate advise on how fix the errors generated below in trying Create and Initialize the Core Data Stack. Otherwise guess I’ll have to scrape Xcode and go to a hybrid app like PhoneGap if that's the best one for the job.
Hence, referring to the Core Data Programming Guide:
https://developer.apple.com/library/content/documentation/Cocoa/Conceptual/CoreData/InitializingtheCoreDataStack.html#//apple_ref/doc/uid/TP40001075-CH4-SW1
and pasting in the following code in the beginning of my existing project, generates
Use of unresolved identifier ‘persistentContainer’… ‘managedObjectContext’
... errors. And the line
init(completionClosure: #escaping () -> ()) {
... generates
Initializers may only be declared within a type
import UIKit
import CoreData
class DataController: NSObject {
var managedObjectContext: NSManagedObjectContext
init(completionClosure: #escaping () -> ()) {
persistentContainer = NSPersistentContainer(name: "DataModel")
persistentContainer.loadPersistentStores() { (description, error) in
if let error = error {
fatalError("Failed to load Core Data stack: \(error)")
}
completionClosure()
}
}
}
init(completionClosure: #escaping () -> ()) {
//This resource is the same name as your xcdatamodeld contained in your project
guard let modelURL = Bundle.main.url(forResource: "DataModel", withExtension:"momd") else {
fatalError("Error loading model from bundle")
}
// The managed object model for the application. It is a fatal error for the application not to be able to find and load its model.
guard let mom = NSManagedObjectModel(contentsOf: modelURL) else {
fatalError("Error initializing mom from: \(modelURL)")
}
let psc = NSPersistentStoreCoordinator(managedObjectModel: mom)
managedObjectContext = NSManagedObjectContext(concurrencyType: NSManagedObjectContextConcurrencyType.mainQueueConcurrencyType)
managedObjectContext.persistentStoreCoordinator = psc
let queue = DispatchQueue.global(qos: DispatchQoS.QoSClass.background)
queue.async {
guard let docURL = FileManager.default.urls(for: .documentDirectory, in: .userDomainMask).last else {
fatalError("Unable to resolve document directory")
}
let storeURL = docURL.appendingPathComponent("DataModel.sqlite")
do {
try psc.addPersistentStore(ofType: NSSQLiteStoreType, configurationName: nil, at: storeURL, options: nil)
//The callback block is expected to complete the User Interface and therefore should be presented back on the main queue so that the user interface does not need to be concerned with which queue this call is coming from.
DispatchQueue.main.sync(execute: completionClosure)
} catch {
fatalError("Error migrating store: \(error)")
}
}
}
// followed by my existing working code:
class ViewController: UIViewController {
go to File > new file... select core Data under iOS and select Data Model
you'll still need some code which xcode auto generates whenever you select core data during project creation.
to get it, just create new project with core data option checked and copy all the code written under ** //Mark: - Core Data Stack** comment in AppDelegate.swift
and add
import CoreData
above
OPTIONAL
And don't forget to change the name of the app after copying the completion block for lazy var persistentContainer. Change the name of your app on this part *NSPersistentContainer(name: "SHOULD-BE-THE-NAME-OF-YOUR-APP") And managedObjectModel function of the code you just copied**
If you're lazy like me, here's all the code you need to copy from the new Core Data project... (why make everyone create a new project?). Change YOUR_APP_NAME_HERE
At the top of your AppDelegate.swift file:
import CoreData
At the bottom of AppDelegate.swift file, before the ending curly bracket:
// MARK: - Core Data stack
func applicationWillTerminate(_ application: UIApplication) {
// Called when the application is about to terminate. Save data if appropriate. See also applicationDidEnterBackground:.
// Saves changes in the application's managed object context before the application terminates.
self.saveContext()
}
lazy var persistentContainer: NSPersistentContainer = {
/*
The persistent container for the application. This implementation
creates and returns a container, having loaded the store for the
application to it. This property is optional since there are legitimate
error conditions that could cause the creation of the store to fail.
*/
let container = NSPersistentContainer(name: "YOUR_APP_NAME_HERE")
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)")
}
})
return container
}()
// MARK: - Core Data Saving support
func saveContext () {
let context = persistentContainer.viewContext
if context.hasChanges {
do {
try context.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)")
}
}
}
I know this is answered, but I believe the actual problem is with Apple's Documentation. If you compare the Objective-C code to the Swift code, you will see that var managedObjectContext: NSManagedObjectContext is not actually defined. You should replace that line with var persistentContainer: NSPersistentContainer. This is the Objective-c interface
#interface MyDataController : NSObject
#property (strong, nonatomic, readonly) NSPersistentContainer *persistentContainer;
- (id)initWithCompletionBlock:(CallbackBlock)callback;
#end
So DataController.swift should be:
class DataController: NSObject {
// Delete this line var managedObjectContext: NSManagedObjectContext
var persistentContainer: NSPersistentContainer
init(completionClosure: #escaping () -> ()) {
persistentContainer = NSPersistentContainer(name: "DataModel")
persistentContainer.loadPersistentStores() { (description, error) in
if let error = error {
fatalError("Failed to load Core Data stack: \(error)")
}
completionClosure()
}
}
}
As for the rest of your code, it's not necessary Apple Docs.
Prior to iOS 10 and macOS 10.12, the creation of the Core Data stack was more involved
That section of code is showing you the old way.
Use the following code
lazy var persistantCoordinator :NSPersistentStoreCoordinator = {
let poc = NSPersistentStoreCoordinator(managedObjectModel:managedObjectModel)
let documentFolderUrl = FileManager.default.urls(for: .documentDirectory, in:.userDomainMask).last
let path = documentFolderUrl!.appendingPathComponent("Database.sqlite")
let options = [NSMigratePersistentStoresAutomaticallyOption: true,NSInferMappingModelAutomaticallyOption: true]
do{
try poc.addPersistentStore(ofType:NSSQLiteStoreType, configurationName: nil, at: path, options: options)
}catch{
print(error.localizedDescription)
}
return poc
}()
private lazy var managedObjectModel:NSManagedObjectModel = {
let url = Bundle.main.url(forResource:"Database", withExtension:"momd")
return NSManagedObjectModel(contentsOf:url!)!
}()
fileprivate lazy var managedObjectContext:NSManagedObjectContext = {
let moc = NSManagedObjectContext(concurrencyType: .mainQueueConcurrencyType)
moc.persistentStoreCoordinator = persistantCoordinator
return moc
}()
I need to Display and modify my data structure from both Apple Watch and iPhone.
The Database:
I am currently using a simple Realm Structure where I have an Object A and an Object B which can hold lots of A's.
So on iPhone the user can create a B and add A's and view of course all A's and B's.
I want the Apple watch to show all A's of the current B and give the users the chance to add new A's to their current B.
The way I have tried to do it:
I wanted to move the hole Realm file from iPhone to the watch or the other way. (That was a tip from the Internet)
iPhone Code:
override func viewDidLoad() {
super.viewDidLoad()
if WCSession.isSupported() { //makes sure it's not an iPad or iPod
let watchSession = WCSession.default()
watchSession.delegate = self
watchSession.activate()
transferRealmFile()
if watchSession.isWatchAppInstalled {
do {
try watchSession.updateApplicationContext(["foo": "bar"])
} catch let error as NSError {
print(error.description)
}
}
}
}
func transferRealmFile(){
if let path = Realm.Configuration().fileURL {
WCSession.default().transferFile(path, metadata: nil)
}
}
WathcKit Extension:
func session(_ session: WCSession, didReceive file: WCSessionFile) {
//set the recieved file to default Realm file
var config = Realm.Configuration()
let paths = FileManager.default.urls(for: .documentDirectory, in: .userDomainMask)
let documentsDirectory = paths[0]
let realmURL = documentsDirectory.appendingPathComponent("data.realm")
if FileManager.default.fileExists(atPath: realmURL.path){
try! FileManager.default.removeItem(at: realmURL)
}
try! FileManager.default.copyItem(at: file.fileURL, to: realmURL)
config.fileURL = realmURL
Realm.Configuration.defaultConfiguration = config
}
Then I call transferRealmFile() every time I write to Realm. This works but I can't solve this Problems:
Problems:
It doesn't work if only watchKit App is started.
Apple Watch to iPhone doesn't work the same way. (I think I need to change the didRecived code, but I don't know what)
Question:
Do you know who to solve this 2 Problems or do you maybe know a better way to handle the situation or will the way we interact between iPhone an Watch change in WathcOS 3?
With watchOS1 it was possible to use AppGroups to share resources (even your Realm database) between an iOS app and its Watch extension. However, Apple removed this in watchOS 2, so now the only way to share data between your iOS and watchOS apps is via WatchConnectivity. Have a look at this answer.
Sadly the WatchConnectivity framework requires the WCSession to be active on both devices for transferring data, so you can't really get around problem 1.
In my opinion it is a better solution to only communicate the changes between the two apps and not send the whole Realm file, since your Realm file can get quite big and hence sending it forward and backward can take a lot of time and resources, while just sending the changes should be way faster.
So, for the purposes of saving space and caching, I defined a Photo model in CoreData that has an attribute imageDataURL (a fileURL).
This data would be stored in the Documents directory. As such, I want to make sure I am cleaning up that data if the user deletes the Photo object.
My question is, where should I look to have a deleteDataAtImageURL(...) method?
I'm thinking it would be in the prepareForDeletion() method on NSManagedObject and I check if that object's context's parent is nil. This tells me that it is a context directly in contact with the Persistent Store.
This should work, unless of course the user resets the context and doesn't save it.
I can't imagine I'm the first one to want to do this, so any advice on this approach (or a better one!) would be appreciated!
I had a similar issue. Here's how I solved it by using a NotificationCenter observer for an action on my root saving context.
//done as part of a singleton class setup
NotificationCenter.default.addObserver(self, selector: #selector(SingletonClass.handleModelDataChange), name:NSNotification.Name.NSManagedObjectContextObjectsDidChange, object: yourRootSavingContext)
internal func handleModelDataChange(notification: NSNotification) {
//get documents directory
let documentsURL = FileManager().urls(for: .documentDirectory, in: .userDomainMask).first!
//get deleted items from dictionary
if let deleted = notification.userInfo?[NSDeletedObjectsKey] as? Set<NSManagedObject> , deleted.count > 0 {
for object in deleted{
//sort out your objects of interest, I cared about objects of a certain class
if ...{
do {
//delete filepath
try FileManager.default.removeItem(at: documentsURL.appendingPathComponent(myPathComponent, isDirectory: true))
//print("Deleted the folder \(documentsURL.URLByAppendingPathComponent(myPathComponent, isDirectory: true))")
}
catch {
//print("I tried :(")
print(error)
}
}
}
}
}
In the end the solution for me was to override prepareForDeletion and check if the the object's .managedObjectContext.parent property is nil. That tells me that it's connected to the PersistentStore, and there I can do the task I want to.
I don't know if this is best practices, but it is working.
I believe the above answer from sschale would also work although I didn't try it.
I am a newbie in Swift and iPhone apps. Recently I created a project with Tabbed Application. As I have already finished my project, the last step was to add core data to save my info. I decided to create a new Single View Application with core data and copy its core data functions from Single View Application AppDelegate to Tabbed Application AppDelegate.
Here is the code I copied (from Single View Application to Tabbed Application, AppDelegate.swift):
func applicationWillTerminate(application: UIApplication) {
// Called when the application is about to terminate. Save data if appropriate. See also applicationDidEnterBackground:.
// Saves changes in the application's managed object context before the application terminates.
self.saveContext()
}
// MARK: - Core Data stack
lazy var applicationDocumentsDirectory: NSURL = {
// The directory the application uses to store the Core Data store file. This code uses a directory named "com.Spookas.bandymas" in the application's documents Application Support directory.
let urls = NSFileManager.defaultManager().URLsForDirectory(.DocumentDirectory, inDomains: .UserDomainMask)
return urls[urls.count-1]
}()
lazy var managedObjectModel: NSManagedObjectModel = {
// The managed object model for the application. This property is not optional. It is a fatal error for the application not to be able to find and load its model.
let modelURL = NSBundle.mainBundle().URLForResource("Model", withExtension: "momd")!
return NSManagedObjectModel(contentsOfURL: modelURL)!
}()
lazy var persistentStoreCoordinator: NSPersistentStoreCoordinator = {
// The persistent store coordinator for the application. This implementation creates and returns a coordinator, having added the store for the application to it. This property is optional since there are legitimate error conditions that could cause the creation of the store to fail.
// Create the coordinator and store
let coordinator = NSPersistentStoreCoordinator(managedObjectModel: self.managedObjectModel)
let url = self.applicationDocumentsDirectory.URLByAppendingPathComponent("SingleViewCoreData.sqlite")
var failureReason = "There was an error creating or loading the application's saved data."
do {
try coordinator.addPersistentStoreWithType(NSSQLiteStoreType, configuration: nil, URL: url, options: nil)
} catch {
// Report any error we got.
var dict = [String: AnyObject]()
dict[NSLocalizedDescriptionKey] = "Failed to initialize the application's saved data"
dict[NSLocalizedFailureReasonErrorKey] = failureReason
dict[NSUnderlyingErrorKey] = error as NSError
let wrappedError = NSError(domain: "YOUR_ERROR_DOMAIN", code: 9999, userInfo: dict)
// Replace this with code to handle the error appropriately.
// abort() 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.
NSLog("Unresolved error \(wrappedError), \(wrappedError.userInfo)")
abort()
}
return coordinator
}()
lazy var managedObjectContext: NSManagedObjectContext = {
// Returns the managed object context for the application (which is already bound to the persistent store coordinator for the application.) This property is optional since there are legitimate error conditions that could cause the creation of the context to fail.
let coordinator = self.persistentStoreCoordinator
var managedObjectContext = NSManagedObjectContext(concurrencyType: .MainQueueConcurrencyType)
managedObjectContext.persistentStoreCoordinator = coordinator
return managedObjectContext
}()
// MARK: - Core Data Saving support
func saveContext () {
if managedObjectContext.hasChanges {
do {
try managedObjectContext.save()
} catch {
// Replace this implementation with code to handle the error appropriately.
// abort() 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
NSLog("Unresolved error \(nserror), \(nserror.userInfo)")
abort()
}
}
}
There are no errors in the code when I write it; however, when I start an application and do any methods that should save the data, I get this error:
2016-06-15 10:55:19.182 Taupyk![1387:32488] CoreData: Failed to load
NSManagedObjectModel with URL
'file:///Users/MyMac/Library/Developer/CoreSimulator/Devices/029E41C4-9E00-474A-BBA1-410D1211D39F/data/Containers/Bundle/Application/FE7605D7-A2F3-449E-8961-F0B33FCB4D15/Taupyk!.app/Model.momd/'
fatal error: unexpectedly found nil while unwrapping an Optional value
It then points into these lines of code:
lazy var managedObjectModel: NSManagedObjectModel = {
// The managed object model for the application. This property is not optional. It is a fatal error for the application not to be able to find and load its model.
let modelURL = NSBundle.mainBundle().URLForResource("Model", withExtension: "momd")!
return NSManagedObjectModel(contentsOfURL: modelURL)!
}()
It says something about Thread 1: EXC_BAD_INSTRUCTION(code=EXC_1386_INVOP, subcode=0x0)
I have also copied data model from the single view app project and renamed it into "Model", yet it still throws an error
I saw there were other people like me, however, they were able to resolve the issue whereas I can not and don't understand why it is not working even though I have done the same thing
Thanks for your help in advance
You are missing the actual CoreData database.
Add a new file to your project
select CoreData
Select Data Model
Call your data model "Model" (to match your source code)
Note, you will see this in your single view project as well.
Select new file to your project.
2.core Data -> Data model->click next button - >click create button.
your project model Add Entity and entity name.
I've been trying to unit test an iOS project which uses Core Data. I'm using the usual Core Data stack which is generated by Xcode. The line failing is the following:
lazy var applicationDocumentsDirectory: NSURL = {
let urls = NSFileManager.defaultManager().URLsForDirectory(.DocumentDirectory, inDomains: .UserDomainMask)
return urls[urls.count-1] as NSURL
}()
On my mac it returns: file:///Users/juliantejera/Library/Developer/CoreSimulator/Devices/{UNIQUE ID}/data/Containers/Data/Application/{UNIQUE ID}/Documents/
On travis: file:///var/empty/Documents/
Therefore my NSManagedObjectContext cannot be created and my app crashes. Any solutions?
After a week I was finally able to solve my problem by using a NSInMemoryStoreType for the NSPersistentStoreCoordinator whilst running unit tests.
var isRunningUnitTests = NSClassFromString("XCTest") != nil
var storeType = isRunningUnitTests ? NSInMemoryStoreType : NSSQLiteStoreType
In my case the problem was a combination of Kiwi and Realm:
I was initializing an object in the context block of the test spec, which in turn forced a Realm DB to be initialized. Not sure what exactly causes this weird action, but since then I take it as a rule of thumb to initialize variables in the beforeAll block.