In my tableViewController I have the following. And I am trying to get delete an item to work.
var myData: Array<AnyObject> = []
override func tableView(tableView: UITableView, cellForRowAtIndexPath indexPath: NSIndexPath) -> UITableViewCell {
let cellID: NSString = "Cell"
var Cell: UITableViewCell = tableView.dequeueReusableCellWithIdentifier(cellID) as UITableViewCell
var data: NSManagedObject = myData[indexPath.row] as NSManagedObject
Cell.textLabel?.text = data.valueForKeyPath("Name") as? String
return Cell
}
Then to try and delete I have.
override func tableView(tableView: (UITableView!), commitEditingStyle editingStyle: UITableViewCellEditingStyle, forRowAtIndexPath indexPath: NSIndexPath) {
if editingStyle == .Delete {
let cellID: NSString = "Cell"
var Cell: UITableViewCell = tableView.dequeueReusableCellWithIdentifier(cellID) as UITableViewCell
var data: NSManagedObject = myData[indexPath.row] as NSManagedObject
data.delete(0)
// Delete the row from the data source
//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
}
}
Update on my coding issue with executing a delete of data in swift and coredata. This the code I ended up with that worked.
override func tableView(tableView: UITableView, commitEditingStyle editingStyle: UITableViewCellEditingStyle, forRowAtIndexPath indexPath: NSIndexPath) {
switch editingStyle {
case .Delete:
// remove the deleted item from the model
let appDel:AppDelegate = UIApplication.sharedApplication().delegate as AppDelegate
let context:NSManagedObjectContext = appDel.managedObjectContext!
context.deleteObject(myData[indexPath.row] as NSManagedObject)
myData.removeAtIndex(indexPath.row)
context.save(nil)
//tableView.reloadData()
// remove the deleted item from the `UITableView`
self.tableView.deleteRowsAtIndexPaths([indexPath], withRowAnimation: .Fade)
default:
return
}
}
EDIT Above for Swift 2.2 and Xcode 7.3.1
override func tableView(tableView: UITableView, commitEditingStyle editingStyle: UITableViewCellEditingStyle, forRowAtIndexPath indexPath: NSIndexPath) {
switch editingStyle {
case .Delete:
// remove the deleted item from the model
let appDel:AppDelegate = UIApplication.sharedApplication().delegate as! AppDelegate
let context:NSManagedObjectContext = appDel.managedObjectContext
context.deleteObject(myData[indexPath.row] )
myData.removeAtIndex(indexPath.row)
do {
try context.save()
} catch _ {
}
// remove the deleted item from the `UITableView`
self.tableView.deleteRowsAtIndexPaths([indexPath], withRowAnimation: .Fade)
default:
return
}
}
Also need was these two lines of code to be corrected.
var myData: Array<AnyObject> = []
let managedObjectContext = (UIApplication.sharedApplication().delegate as AppDelegate).managedObjectContext
Swift 3.0
Below is the code to delete item and to reload the data.
func tableView(_ tableView: UITableView, commit editingStyle: UITableViewCellEditingStyle, forRowAt indexPath: IndexPath) {
let noteEntity = "Note" //Entity Name
let managedContext = (UIApplication.shared.delegate as! AppDelegate).persistentContainer.viewContext
let note = notes[indexPath.row]
if editingStyle == .delete {
managedContext.delete(note)
do {
try managedContext.save()
} catch let error as NSError {
print("Error While Deleting Note: \(error.userInfo)")
}
}
//Code to Fetch New Data From The DB and Reload Table.
let fetchRequest = NSFetchRequest<NSFetchRequestResult>(entityName: noteEntity)
do {
notes = try managedContext.fetch(fetchRequest) as! [Note]
} catch let error as NSError {
print("Error While Fetching Data From DB: \(error.userInfo)")
}
noteTableView.reloadData()
}
To complete the answer from zisoft:
You need to save your context after deleting an object.
So the correct way would be:
// get your app managemenent context
let appDel:AppDelegate = (UIApplication.sharedApplication().delegate as AppDelegate)
let context = self.appDel.managedObjectContext!
// remove your object
context.del(data)
// save your changes
context.save(nil)
Note to check first if there are any delete rules (if you have any related objects)
Not sure what your question is but you have to delete the object from the NSManagedObjectContext instance. So in your commitEditingStyle function:
let moc = appDelegate.managedObjectContext // or something similar to get the managed object context
moc.delete(data) // your NSManagedObject
For Xcode 8 and Swift 3.0. If we need to DELETE all data from any Table than we should use the code:
LoadStorage Class file: it also support iOS 9 and iOS 10 above.
import UIKit
import CoreData
class localStorage: NSObject {
//MARK: - Up for iOS10 and above
@available(iOS 10.0, *)
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: "JJS_Connect")
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 () {
if #available(iOS 10.0, *) {
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)")
}
}
}
else {
}
}
//MARK: - Usp for iOS10 below
lazy var applicationDocumentsDirectory: NSURL = {
// The directory the application uses to store the Core Data store file. This code uses a directory named "com.razeware.HitList" in the application's documents Application Support directory.
let urls = FileManager.default.urls(for: .documentDirectory, in: .userDomainMask)
return urls[urls.count-1] as NSURL
}()
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 = Bundle.main.url(forResource: "JJS_Connect", withExtension: "momd")!
return NSManagedObjectModel(contentsOf: modelURL)!
}()
lazy var persistentStoreCoordinator: NSPersistentStoreCoordinator = {
// The persistent store coordinator for the application. This implementation creates and return 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.appendingPathComponent("JJS_Connect.sqlite")
var failureReason = "There was an error creating or loading the application's saved data."
do {
try coordinator.addPersistentStore(ofType: NSSQLiteStoreType, configurationName: nil, at: url, options: nil)
} catch {
// Report any error we got.
var dict = [String: AnyObject]()
dict[NSLocalizedDescriptionKey] = "Failed to initialize the application's saved data" as AnyObject?
dict[NSLocalizedFailureReasonErrorKey] = failureReason as AnyObject?
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: - Creating NSManagedObject for saving data into table
func getContext() -> NSManagedObjectContext {
if #available(iOS 10.0, *) {
let context = self.persistentContainer.viewContext
return context
}else{
let context = self.managedObjectContext
return context
}
}
}
Than Create DatabaseMaster class and make function:
//MARK: - DELETE OPERATION FROM DB
func deleteFromAddressMaster() -> Void{
let request: NSFetchRequest<Address_master>
if #available(iOS 10.0, OSX 10.12, *) {
request = Address_master.fetchRequest()
} else {
request = NSFetchRequest(entityName: "Address_master")
}
do {
let results = try localStr.getContext().fetch(request)
for address in results {
print(" Deleted... \(address.group_id)")
localStr.getContext().delete(address)
}
} catch let error {
print(error.localizedDescription)
}
}
Address_master is Subclass file name.
please define
let localStr = localStorage()
in DatabasMaster Class file.
None of the answers above helped me in the case that I'm using Core Data with a FetchedResultsController for a tableView. As such here is my implementation to handle deleting below. My example uses a simple example assuming you want to delete a picture from swiping left on a table and selecting the default delete option.
Swift 3 Solution for FetchedResultsController Implementaitons
First add this delegate method for the table view to allow editing when you swipe on the row.
func tableView(_ tableView: UITableView, commit editingStyle: UITableViewCellEditingStyle, forRowAt indexPath: IndexPath) {
if editingStyle == .delete {
print("editing style delete detected")
let context = DataController.sharedInstance().managedObjectContext
let picture = self.fetchedResultsController.object(at: indexPath) as Pictures
context.delete(picture)
//Actually remove picture from storage on the device.
let fileManager = FileManager.default
let imagefilepath = "\(AppDelegate.appDelegate.applicationDocumentsDirectory())/\(picture.filepath!)"
do {
try fileManager.removeItem(atPath: imagefilepath)
}
catch let error as NSError {
print("Ooops! Something went wrong while trying to delete picture file: \(error)")
}
//Save the context change.
AppDelegate.appDelegate.saveContext()
tableView.reloadData()//update changes
}
}
Once you've done this, make sure the fetchedResultsController has its delegate set to your controller and implement these methods.
func controller(_ controller: NSFetchedResultsController<NSFetchRequestResult>, didChange anObject: Any, at indexPath: IndexPath?, for type: NSFetchedResultsChangeType, newIndexPath: IndexPath?) {
switch(type){
case .insert:
break;
case .delete:
print("delete detected on FRC Delegate")
tableView.deleteRows(at: [indexPath!], with: .fade)
break;
case .update:
break;
case .move:
break;
}
}
The secret here is getting access to the object via the fetchedResultsController.object method
let picture = self.fetchedResultsController.object(at: indexPath) as Pictures
This way you can run
context.delete(picture)
which is smart about deleting NSManagedObjects.
Extra Info Related to my Implementation (Only read below if you are needing more details)
---------------------------------------------------------------------------
Picture+CoreDataProperties.swift
import Foundation
import CoreData
extension Pictures {
@nonobjc public class func fetchRequest() -> NSFetchRequest<Pictures> {
return NSFetchRequest<Pictures>(entityName: "Pictures");
}
@NSManaged public var date: NSDate?
@NSManaged public var desc: String?
@NSManaged public var filepath: String?
@NSManaged public var type: String?
@NSManaged public var workorder: Workorders?
}
Pictures+CoreDataClass.swift
import Foundation
import CoreData
public class Pictures: NSManagedObject {
}
The file below is my coreData stack handler.
DataController.swift
import UIKit
import CoreData
class DataController: NSObject {
var managedObjectContext: NSManagedObjectContext
static var dataController: DataController!
override init() {
// This resource is the same name as your xcdatamodeld contained in your project.
guard let modelURL = Bundle.main.url(forResource: "WorkOrders", 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: .mainQueueConcurrencyType)
managedObjectContext.persistentStoreCoordinator = psc
let urls = FileManager.default.urls(for: .documentDirectory, in: .userDomainMask)
let docURL = urls[urls.endIndex-1]
/* The directory the application uses to store the Core Data store file.
This code uses a file named "DataModel.sqlite" in the application's documents directory.
*/
let storeURL = docURL.appendingPathComponent("WorkOrders.sqlite")
do {
let options = [NSSQLitePragmasOption: ["journal_mode": "DELETE"]]
try psc.addPersistentStore(ofType: NSSQLiteStoreType, configurationName: nil, at: storeURL, options: options)
} catch {
fatalError("Error migrating store: \(error)")
}
}
class func sharedInstance() -> DataController {
if (dataController != nil) {
return dataController
}
dataController = DataController()
return dataController
}
}
This is where my save method is for saving the context.
AppDelegate.swift
import UIKit
import CoreData
@UIApplicationMain
class AppDelegate: UIResponder, UIApplicationDelegate {
var window: UIWindow?
static var appDelegate: AppDelegate!
/// Returns application documents directory path
///
/// - returns: application documents directory path string
func applicationDocumentsDirectory() -> String {
let paths = NSSearchPathForDirectoriesInDomains(.documentDirectory, .userDomainMask, true)
print(paths[0])
return paths[0]
}
func application(_ application: UIApplication, didFinishLaunchingWithOptions launchOptions: [UIApplicationLaunchOptionsKey: Any]?) -> Bool {
//Override point for customization after application launch.
AppDelegate.appDelegate = self
_ = applicationDocumentsDirectory();
return true
}
func applicationWillResignActive(_ application: UIApplication) {
// Sent when the application is about to move from active to inactive state. This can occur for certain types of temporary interruptions (such as an incoming phone call or SMS message) or when the user quits the application and it begins the transition to the background state.
// Use this method to pause ongoing tasks, disable timers, and invalidate graphics rendering callbacks. Games should use this method to pause the game.
}
func applicationDidEnterBackground(_ application: UIApplication) {
// Use this method to release shared resources, save user data, invalidate timers, and store enough application state information to restore your application to its current state in case it is terminated later.
// If your application supports background execution, this method is called instead of applicationWillTerminate: when the user quits.
}
func applicationWillEnterForeground(_ application: UIApplication) {
// Called as part of the transition from the background to the active state; here you can undo many of the changes made on entering the background.
}
func applicationDidBecomeActive(_ application: UIApplication) {
// Restart any tasks that were paused (or not yet started) while the application was inactive. If the application was previously in the background, optionally refresh the user interface.
}
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 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: "WorkOrders")
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 = DataController.sharedInstance().managedObjectContext
context.mergePolicy = NSMergeByPropertyObjectTrumpMergePolicy
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)")
}
}
}
}
let entityDescription =
NSEntityDescription.entity(forEntityName: "Contacts",
in: managedObjectContext)
let request: NSFetchRequest<Contacts> = Contacts.fetchRequest()
request.entity = entityDescription
if let result = try? managedObjectContext.fetch(request) {
for object in result {
do {
try managedObjectContext.delete(object)
txtName?.text = ""
txtAddress?.text = ""
txtPhone?.text = ""
Status?.text = "Contact Deleted"
txtName?.text = ""
}
catch let error {
Status?.text = error.localizedDescription
}
}
}
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