I am facing an issue where operations against the dataStack.mainContext are not effective; for example,

print(dataStack.mainContext.hasChanges) // true try! dataStack.mainContext.save() print(dataStack.mainContext.hasChanges) // false

However, when the application reloads, the changes have not been committed to disk (reloading the database programmatically "works", but application restart does not.)

Simply changing to performInNewBackgroundContext{} makes everything work.

What might be the cause?

Hello! Is it the way to create new context, that can be used in main thread in DATAStack? For example I have «Edit item» view, I load all data there in separate context and if user doesn’t click «Save» all changes in that separate context are reset.

I’ve found only way to create separate background context (newBackgroundContext), or create newDisposableMainContext, but it is detached from saving to disk, so I can’t merge changes in it to my default mainContext.

I'm not sure what's going on, but I've been blocked by this issue for >= 48 hours. It appears as if none of the insertions on any context are making it to the persistent store coordinator. I've tried everything from changing the mergePolicy, to manually observing contexts. For whatever reason, changes made in a background context, even after invoking persistWithCompletion, never update the main context, even after explicit fetches until the application is killed and restarted.

I've tweaked the DemoSwift.ViewController to demonstrate the issue:

import UIKit
import CoreData
import DATASource

class ViewController: UITableViewController {

    var dataStack: DATAStack

    var _backgroundContext: NSManagedObjectContext

    lazy var dataSource: DATASource = {
        let request: NSFetchRequest = NSFetchRequest(entityName: "User")
        request.sortDescriptors = [NSSortDescriptor(key: "name", ascending: true)]

        let dataSource = DATASource(tableView: self.tableView, cellIdentifier: "Cell", fetchRequest: request, mainContext: self.dataStack.mainContext, configuration: { cell, item, indexPath in
            if let name = item.valueForKey("name") as? String, createdDate = item.valueForKey("createdDate") as? NSDate, score = item.valueForKey("score") as? Int {
                cell.textLabel?.text =  name + " - " + String(score)
            }
        })

        return dataSource
    }()

    init(dataStack: DATAStack) {
        self.dataStack = dataStack
        self.dataStack.mainContext.stalenessInterval = 0.0
        self._backgroundContext = dataStack.newBackgroundContext("_Background Context")
        self._backgroundContext.stalenessInterval = 0.0

        super.init(style: .Plain)
    }

    required init?(coder aDecoder: NSCoder) {
        fatalError("init(coder:) has not been implemented")
    }

    override func viewDidLoad() {
        super.viewDidLoad()

        self.tableView.registerClass(UITableViewCell.self, forCellReuseIdentifier: "Cell")
        self.tableView.dataSource = self.dataSource

        let backgroundButton = UIBarButtonItem(title: "Background", style: .Done, target: self, action: #selector(ViewController.createBackground))
        let customBackgroundButton = UIBarButtonItem(title: "Custom", style: .Done, target: self, action: #selector(ViewController.createCustomBackground))
        self.navigationItem.rightBarButtonItems = [customBackgroundButton, backgroundButton]

        let mainButton = UIBarButtonItem(title: "Main", style: .Done, target: self, action: #selector(ViewController.createMain))
        let dropAllButton = UIBarButtonItem(title: "Edit Main Object", style: .Done, target: self, action: #selector(ViewController.editMainObject))
        self.navigationItem.leftBarButtonItems = [dropAllButton, mainButton]
    }

    func createBackground() {
        self.dataStack.performInNewBackgroundContext { backgroundContext in
            let entity = NSEntityDescription.entityForName("User", inManagedObjectContext: backgroundContext)!
            let object = NSManagedObject(entity: entity, insertIntoManagedObjectContext: backgroundContext)
            object.setValue("Background", forKey: "name")
            object.setValue(NSDate(), forKey: "createdDate")
            try! backgroundContext.save()
        }
    }

    func createCustomBackground() {
        let backgroundContext = dataStack.newBackgroundContext("Sync Context")

        backgroundContext.performBlock {
            let entity = NSEntityDescription.entityForName("User", inManagedObjectContext: backgroundContext)!
            let object = NSManagedObject(entity: entity, insertIntoManagedObjectContext: backgroundContext)
            object.setValue(backgroundContext.name, forKey: "name")
            object.setValue(NSDate(), forKey: "createdDate")
            try! backgroundContext.save()
        }
    }

    func createMain() {
        let entity = NSEntityDescription.entityForName("User", inManagedObjectContext: self.dataStack.mainContext)!
        let object = NSManagedObject(entity: entity, insertIntoManagedObjectContext: self.dataStack.mainContext)
        object.setValue("Main", forKey: "name")
        object.setValue(1, forKey: "score")
        object.setValue(NSDate(), forKey: "createdDate")
        //try! self.dataStack.mainContext.save()
        self.dataStack.persistWithCompletion()
    }

    func editMainObject() {
        self.dataStack.performInNewBackgroundContext { _backgroundContext in
            _backgroundContext.stalenessInterval = 0.0
        //_backgroundContext.performBlock {
            let fetchRequest = NSFetchRequest(entityName: "User")
            fetchRequest.predicate = NSPredicate(format: "%K contains[c] %@", "name", "Main")

            let backgroundUsers = try! _backgroundContext.executeFetchRequest(fetchRequest) as! [NSManagedObject]

            var i: Int32 = 0
            for user in backgroundUsers {
                i += 1
                let number = NSNumber(int: (123 * i))
                user.setValue(number, forKey: "score")
            }

            try! _backgroundContext.save()
        }
        //}
    }
}

In this example, pressing the "Main" button will create a new User with a score of 0. That User will not be modified by the editMainObject function when the "Edit Main Object" button is pressed.

If the app is killed and restarted, the "Edit Main Object" button will cause the objects to be modified and updated.

I'm really not sure how to proceed, or if I'm doing something wrong.

When i run the DemoSwift app, then tap on bar button on the top left, new data being created. Then i quit the app (rebuild/force quit), the data disappear, althought all data from background is stored. Am i missing some thing? Or it is a bug?

Xcode 7.3 breaks the TestCheck. The last comment in this thread fix it (http://stackoverflow.com/questions/24688512/what-is-the-proper-way-to-detect-if-unit-tests-are-running-at-runtime-in-xcode)

First of all sorry for my bad Engish.

I have a project with DATAStack. A lot of users have a problem, when they set a new iPhone from iCloud backup. The data strored in CoreData doesn't exists on the new phone. Should I have to set something to "tell" Apple, that they should backup the sql file? Did you hear about similar issues?

Thanks for your help!

Let's assume core data entity structure like this:

Cart:
-> CartEntry - To-Many, Optional

CartEntry:
-> product -> To-One, Optional

There is CartEntry with product in my Cart - coreData seems to be ok. I'm fetching Cart and as a result I've got:

Cart:
-> entries: [
      {
              product: nil
      }
] 

However when I changed

Cart:
-> CartEntry - To-Many

Everything seems to be fine - fetch result got also products.

I’m using NSFetchedResultsController and DATAStack. My NSFetchedResultsController doesn’t update my table if I make any changes in another contexts.

I use dataStack.mainContext in my NSFetchedResultsController. If I do any updates from mainContext everything is okay. But if I write such code for example:

        dataStack.performInNewBackgroundContext({ (backgroundContext) in
            // Get again NSManagedObject in correct context, 
            // original self.task persists in main context
            let backTask = backgroundContext.objectWithID(self.task.objectID) as! CTask

            backTask.completed = true
            let _ = try? backgroundContext.save()
        })

NSFetchedResultsController doesn’t update cells. I will see updated data if I reload application or whole view for example.

There is no error in data saving (I’ve checked).

I’ve tried to check NSManagedObjectContextDidSaveNotification is received, but if I do .performFetch() after notification is received I again get old data in table.

I’ve created a ticket at Stackoverflow, I’ve got reply that backgroundContext doesn’t merge changes with mainContext.

I have quite a big sync process. After running it some times with different data I randomly get the following crash which doesn't happen when I get back to DataSTack version 4.3.0 and Sync version 1.6.5. Any Idea how to fix this?

Crashed: com.apple.main-thread 0 CoreFoundation 0x181c93070 -[**NSSetM addObject:] + 476 1 CoreFoundation 0x181c8db00 -[NSMutableSet unionSet:] + 776 2 CoreData 0x183ca895c -[NSManagedObjectContext _mergeChangesFromDidSaveDictionary:usingObjectIDs:] + 3144 3 CoreData 0x183ca8c20 -[NSManagedObjectContext mergeChangesFromContextDidSaveNotification:] + 500 4 DATAStack 0x10049e250 TPA__TFFC9DATAStack9DATAStack24backgroundContextDidSaveFzCSo14NSNotificationT_U_FT_T + 132 5 CoreData 0x183ca908c developerSubmittedBlockToNSManagedObjectContextPerform + 196 6 libdispatch.dylib 0x1817f547c _dispatch_client_callout + 16 7 libdispatch.dylib 0x1817fab84 _dispatch_main_queue_callback_4CF + 1844 8 CoreFoundation 0x181d60dd8 __CFRUNLOOP_IS_SERVICING_THE_MAIN_DISPATCH_QUEUE** + 12 9 CoreFoundation 0x181d5ec40 __CFRunLoopRun + 1628 10 CoreFoundation 0x181c88d10 CFRunLoopRunSpecific + 384 11 GraphicsServices 0x183570088 GSEventRunModal + 180 12 UIKit 0x186f55f70 UIApplicationMain + 204

Hi!

The method: performInNewBackgroundContext: is missing a parameter name in the completion block.

//The method is declared like this in the current bridging header:
[self.dataStack performInNewBackgroundContext:^(NSManagedObjectContext * _Nonnull) {
        <#code#>
    }];

//It should be declared like this:
[self.dataStack performInNewBackgroundContext:^(NSManagedObjectContext * _Nonnull backgroundContext) {
        <#code#>
    }];

When I run app in production I don't want the code to run "Is it UnitTest target" all the time. The solution would be co create a separate subclass for DATAStack, that would override those methods and do them in sync way.

Hi,

I try to install the library via Cocoapods (in a freshly created Objective-C demo project) and I got the error below:

[!] Unable to determine Swift version for the following pods:

• DATAStack does not specify a Swift version and none of the targets (DNP) integrating it have the SWIFT_VERSION attribute set. Please contact the author or set the SWIFT_VERSION attribute in at least one of the targets that integrate this pod.

Unfortunately couldn't install the library.

my Podfile line is below:

pod 'DATAStack', '~> 6'

Best

My data model is being created, but when I try to write to it I get a nilError, this happens with a background context and with a main thread context, is there anything specific I should be looking into? I just copied the example code

Delete requests produce nilError, write requests fail silently

Hi,

I am using a DataStack created as follows: self.dataStack = DATAStack(modelName: "money", isExcludedFromBackup: false)

This should then be included in iTunes/iCloud backups. I wanted to check this, so I downloaded iPhone Backup Extractor from here (https://www.iphonebackupextractor.com/blog/ios-data-recovery-apps-data-iphone-backups/), made a new iTunes backup and then checked the backup using this app. Although I can see the SQLite file (under com.myapp.title/Library/Application Support/myapp.sqlite), if I extract it and then open the SQLite file using a SQLite viewer, it doesn't contain any actual data from my app. It does contain the full database structure though.

Do you have any ideas what might be causing the data to be missing from the backup?

Thanks