I get the following error when i try to unarchive a custom object
'cannot decode object of class (PhotoList) for key (root); the class may be defined in source code or a library that is not linked'
I currently have a version on the app store (v1.0, have issued an update via version TestFlight (v2.0) and this is where the error happens. The error doesn't happen on the same version builds via Xcode. Nothing has changed (that I can see!) that would have caused this.
Here is the code I have for archiving the object
let data = NSKeyedArchiver.archivedDataWithRootObject(VehicleList.instance)
NSUserDefaults.standardUserDefaults().setObject(data, forKey: "archiveName")
And here is the code I have for unarchiving the object
if let data = NSUserDefaults.standardUserDefaults().objectForKey("archiveName") as? NSData {
let photoList : PhotoList = NSKeyedUnarchiver.unarchiveObjectWithData(data) as! PhotoList
}
It turns out the issue was related to multiple targets. It seems when I duplicated targets, I swapped over the original target with another, so it was in fact a different target that couldn't unarchive the data.
So be careful when you create targets and make sure you don't mix them up! Hope this saves someone the amount of time it took me to figure this out!
I've already searched a lot but any answer fixed the problem.
I've created an app group, selected it on both app and today extension, they're linked to the same group now. I'm trying to load data from the app and display it on a table view on the today extension, the thing is that I'm getting a crash saying that my array is nil, and it cannot be nil. I don't know why tho, cause I'm putting the data into the array. Here is my code:
func handleData() {
let defaults = NSUserDefaults(suiteName: "MY APP GROUP HERE")
if let descriptionsArr = defaults?.valueForKey("descriptions") as? [String] {
descriptions = descriptionsArr
}
defaults?.synchronize()
}
So, I'm pretty sure the app group is spelled right, and the value key. What could it be that is making my array nil? Really need help!
Thanks.
This is a followup question to a question previously asked before.
didselectatrow updating multiple cells below reloaded tableview + counter
So after much reading and experimenting even after I accepted the guys answer I am still having the same issue. I am going to try a much different approach to it after reading around I found use of adding/removing the index path by having a Set <NSIndexPath>() var that I am constantly checking.
After much experimentation I finally got a working check on the Set <NSIndexPath> the problem is for some reason in xcode 7 when I try to create a second array to capture the integer values related to the set xcode freezes up on indexing. Which is altogether a different issue. How do I go about keeping track of not only the indexpath row but also the counter as well? My latest code to insert/remove indexpaths at row is:
if indexCount == 1 || indexCount == 2 {
CountIndex.insert(indexPath)
} else {
CountIndex.remove(indexPath)
}
My latest try was to try creating a dictionary that stores the indexpath + the Counter in a dictionary like so var cardCountindexCount = [NSIndexPath: Int]()
Then setting it in the func tableView(tableView: UITableView, didSelectRowAtIndexPath indexPath: NSIndexPath) { by cardCountindexCount = [indexPath: cardCount]. However I am lacking any experience on going about this approach as it is all experimental and it seems that what I get when I try to recall this is a similar problem. Instead of actually changing the text label in the didselectatrow I am now trying to change it in cellforrow method and creating a universal variable that can store the data changes.
I am willing to admit I am slightly out of my depths on this problem as I have only ever worked with simple tableviews prior. More guidance would be greatly appreciated!
The way I ended up fixing this was by setting the relationship in core data, then saving the quantity of the card in core data, and finally recalling the object relationship and quantity back into the func tableview willDisplayCell method showing the changes in text in that method.
Could anyone tell me what the way of storing a long text in a swift app is. Let's suppose I have an app that has a table view and when I chose a row I go to a new scene where I have a big page filled by text.
The question is where do I have to store the data of the table's row and the whole text? And how?
Do I have to make a model? Is it just one for both the table and the text? Or more than one. Is there any tutorial that explains this exact situation or close to it?
You could use Parse.com framework to retrieve data from a database. There is a lot of documentation on this.
In this link you can find a tutorial that will explain you how to load data from Parse and show it in your UITableView.
Storing Local (in-memory store):
For storing without a internet connection you could use Core Data Stack with NSInMemoryStoreType as storeType. This tutorial will give you a nice idea on how it works.
You can declare a model like it follows:
struct CoreDataModel {
let name: String
let bundle: NSBundle
init(name: String, bundle: NSBundle)
// other properties & methods
}
And then manage it with:
let model = CoreDataModel(name: "MyModel", bundle: myBundle)
let stack = CoreDataStack(model: model,
storeType: NSInMemoryStoreType,
concurrencyType: .MainQueueConcurrencyType)
// Use context
stack.managedObjectContext
I had a project that was working fine. It had "Core Data" checked, and had the data model all set up. I only started adding a couple entities and properties tonight. When I try to run my app now, it won't even load. It just crashes on me.
Here's the error:
'NSInvalidArgumentException', reason: 'executeFetchRequest:error: A fetch request must have an entity.'
I'm really scared because I don't have a backup of this and if I can't get it working I don't know what I'll do. :)
Thanks in advance!
EDIT:
I got fed up with my data, so I just copied a new blank xcdatamodel to my project and I'm going to start fresh. Thanks for the help!
My issue is I didn't use the same name for Entity and Class. Trivial solution to fix it is by giving them the same name.
If you are using MagicalRecored with Swift:
Make sure you use #objc directive in the Swift NSManagedObject subclass to make the class accessible to Objective-C code from the MagicalRecord library
#objc(MyEntity)
class MyEntity: NSManagedObject {
#NSManaged var myAttribute: Int16
}
After searching all over for a solution, what fixed it for me was doing a Clean/Build in Xcode.
Product->Clean, Product->Build, then try running it.
It seemed as if my data got corrupted, so I deleted my data model and the database in the iPhone simulator, and started fresh.
I had the same error.
For me, it is because I have added a new Model Version, but I did not set it as "Current Version". Careless me! To fix, select the xcdatamodel, click Design > Data Model > Set Current Version. The xcdatamodel file will then have a green tick.
Hopes that helps.
Also, make sure that your .xcdatamodeld file is in the "Copy Bundle Resources" phase of your Build Phases.
Here's what fixed it for me:
As I was converting to Swift 3, Xcode was giving me an error when declaring a new NSFetchRequest, saying that it needed a type. After adding the type, I did what anyone else would have assumed; if the request is typed, why specify an entity name? So, I removed it.
It actually was my mistake.
Swift 2.2:
let request = NSFetchRequest(entityName: "MyEntity")
When I first converted to Swift 3:
let request = NSFetchRequest<MyEntity>()
That was giving me an error. I ended up with this:
let request = NSFetchRequest<MyEntity>(entityName: "MyEntity")
And everything works fine. Personally, I'm not sure why it needs to have an entity name specified, if you're typing the request. Maybe they'll update that at some point (I hope)
i found this solution in the apple develper forum and it was exactly my problem!
the solutions is that the context must be defined inside the struct App.
not in the environment parameter
import SwiftUI
#main
struct CoreDataDemoApp: App {
private let context = CoreDataStack.context.
var body: some Scene {
WindowGroup {
ContentView()
.environment(\.managedObjectContext, context)
}
}
}
Check if,
the entity is present in the xcdatamodel file.
entity name used are same.
If you are using Swift 3 and Core Data's new stack syntax:
var persistentContainer: NSPersistentContainer = {
let container = NSPersistentContainer(name: "MyAppModel")
container.loadPersistentStores(completionHandler: {
(storeDescription, error) in
if let error = error as NSError? {
fatalError("Unresolved error \(error), \(error.userInfo)")
} else {
print(storeDescription)
}
})
return container
}()
Then you should be using this fetch syntax:
let request: NSFetchRequest<Client> = Client.fetchRequest()
I had this error on the first fetch after app launches when using different variations:
let request: NSFetchRequest<NSFetchRequestResult> = Client.fetchRequest()
let request = NSFetchRequest<NSFetchRequestResult>(entityName: "Client")
I did stumble across the same precise error upon taking my first steps into Core Data (and iOS 11 and Swift 4). I started off a book (sixth edition meant to target Swift 4 but presumably including some legacy stuff).
As suggested in the book my code was:
let fetchRequest = NSFetchRequest<ReminderData>()
let entity = ReminderData.entity()
fetchRequest.entity = entity
do {
let rows = try managedObjectContext.fetch(fetchRequest)
} catch {
fatalError("Unresolved error")
}
It turned out that all I got from ReminderData.entity() is nil. Not sure if I did something wrong when setting up the data model or ... Apple's docs say that NSManagedObject.entity() must not be overwritten?
Long story short, the Codegen file ReminderData+CoreDataProperties.swift did include the solution:
#nonobjc public class func fetchRequest() -> NSFetchRequest<ReminderData> {
return NSFetchRequest<ReminderData>(entityName: "ReminderDB")
}
which was all I had to use to end-up with a proper NSFetchRequest, no fiddling with the NSEntityDescription, problem gone!
let fetchRequest = NSFetchRequest<ReminderData>(entityName: "ReminderDB")
do {
let rows = try managedObjectContext.fetch(fetchRequest)
} catch {
fatalError("Unresolved error")
}
I built clean, and that didn't fix it. Then I deleted the app, and that didn't fix it. Then I built clean and deleted the app AT THE SAME TIME, and that fixed it.
Just add the same problem. I copied all my entities. Deleted the data model, recreated an empty one and pasted the entities back into the new data model. Solved my issue.
First I downloaded the app's data through the Organizer (to see what was happening) and noticed that it offered me to save it under a previous project name. This puzzled me. So I exited XCode 4.6.1, deleted the app (and its data) from my iPhone, and came back.
This time I got an error saying Cannot create an NSPersistentStoreCoordinator with a nil model. So I looked into the AppDelegate.m file and changed the URLForResource in the - (NSPersistentStoreCoordinator *) persistentStoreCoodinator method. It was set to the name of my app, and I changed it to 'Model' so as to match the name of my Model.xcdatamodeld.
It's working now.
This happened to me when I was fetching from the wrong database. My application has 3 sqlite databases, and of course 3 ManagedObjectContext instances. Well I was submitting the wrong ManagedObjectContext to a method asking it to query a table that didn't exist in the ManagedObjectContext I submitted. After using the correct ManagedObjectContext, all was good.
I think the original question/problem, and also the issue that most of these answers fixes (just in different ways) is just a real simple one:
Anytime you modify your core data (like adding an entity as you mention), you either have to delete all existing data (if you haven't published your app yet), or add a new version to your model.
Just thought I would post this answer, even though this is an older question, because this answer seems pretty obvious and so far hasn't been discussed in any of the questions or comments I read above.
You can also use setter method from CoraData ... Just do something like this...
On your CustomCoreDataManager.m
import "ObjectiveRecord.h"
call init method like this
(instancetype)init {
self = [super init];
if (self) {
[[CoreDataManager sharedManager] setModelName:#"YourModelName"];
}
return self; }
Hope this helps to someone...
Maybe you are trying to load a Database from a different/the wrong bundle?
For instance from or within a Framework?
I had this issue and solved it by loading the DB from the bundle of the related Framework. And then it all worked fine!!
Swift 4 + MagicalRecord:
let frameworkBundle = Bundle(for: AClassFromTheFramework.self)
let managedObjectModel = NSManagedObjectModel.mergedModel(from: [frameworkBundle])
MagicalRecord.setShouldAutoCreateManagedObjectModel(false)
NSManagedObjectModel.mr_setDefaultManagedObjectModel(managedObjectModel)
MagicalRecord.setupCoreDataStack(withAutoMigratingSqliteStoreNamed: "db.sqlite")
And voila !
I faced same issue, actually i was calling MyEnty instead of MyEntity so please re-check what names you have given to your entities and call the same and also check whether you are calling same attributes that you have defined like name
In my case, it was because this dropdown was not set to "Current Product Module" in the Data Model Inspector in Xcode (13.4.1):
Once I set that, it stopped crashing.
Hope this helps!