CODEWITHSUNDEEP
iosswiftcore-data
UKDataGeek
UKDataGeek

Reputation: 6892

Unable to get CoreData to delete objects

I have a very simple class that I am using to try learn core image based on master detail view template. The data is saving ok when I add a new item. but when I delete it the context says that there is nothing to change.

Any ideas on how to correctly get it to save the updated object class to coreimage after I delete an event.

Here are the class variables: 

import UIKit
import CoreData

class MasterViewController: UITableViewController {

    var objects: [Event]!

Here are the methods that handle the adding and deleting from the Tableview: 

 func insertNewObject(sender: AnyObject) { //Triggered by add button in top menu
    objects.insert(Event(context: sharedContext), atIndex: 0)
    let indexPath = NSIndexPath(forRow: 0, inSection: 0)
    self.tableView.insertRowsAtIndexPaths([indexPath], withRowAnimation: .Automatic)

    CoreDataStackManager.sharedInstance().saveContext()
}

//Delete method is done via editing: 
override func tableView(tableView: UITableView, commitEditingStyle editingStyle: UITableViewCellEditingStyle, forRowAtIndexPath indexPath: NSIndexPath) {
    if editingStyle == .Delete {
        objects.removeAtIndex(indexPath.row)
        CoreDataStackManager.sharedInstance().saveContext() // This doesn't result in CoreData thinking that the main object has changed
        println(objects.count)
        tableView.deleteRowsAtIndexPaths([indexPath], withRowAnimation: .Fade)

    } else if editingStyle == .Insert {
        // Create a new instance of the appropriate class, insert it into the array, and add a new row to the table view.
    }
}

The Event model is done as an NSManaged Object: 

    import Foundation
import CoreData

@objc(Event)

class Event : NSManagedObject {

@NSManaged var timeStamp: NSDate

override init(entity: NSEntityDescription, insertIntoManagedObjectContext context: NSManagedObjectContext?) {
    super.init(entity: entity, insertIntoManagedObjectContext: context)
}

init(context: NSManagedObjectContext) {
    let entity = NSEntityDescription.entityForName("Event", inManagedObjectContext: context)!
    super.init(entity: entity, insertIntoManagedObjectContext: context)

    timeStamp = NSDate()
}

}

Any help would be welcome.

Upvotes: 0

Views: 118

Answers (1)

Martin R
Martin R

Reputation: 539765

You delete the object from your objects array, but not from the managed object context. You'll have to add

 sharedContext.deleteObject(objects[indexPath.row])

(If you were using a NSFetchedResultsController as a table view data source then this would be the only necessary action, since the table view would then be updated automatically from the fetched results controller delegate methods.)

Upvotes: 2

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