If sectionNameKeyPath is not nil I cannot start my app - ios

Question

Whenever I try to run my application when my sectionNameKeyPath is not nil, it crashes with the error
* Terminating app due to uncaught exception 'NSRangeException', reason: '* -[__NSArray0 objectAtIndex:]: index 0 beyond bounds for empty NSArray'
but whenever I set that to nil it works and I add some data, quit the app, set the sectionNameKeyPath back to my Core Data attribute, it now works just fine! This is the 7th hour today I'm fighting with this bug and I just can't solve it. What is wrong in my code?
//
// ViewController.swift
// Expense Manager
//
// Created by Andrei Vataselu on 10/3/17.
// Copyright © 2017 Andrei Vataselu. All rights reserved.
//
import UIKit
import SideMenu
import CoreData
import SwipeCellKit
let green = UIColor(red:0.00, green:0.62, blue:0.45, alpha:1.0)
let red = UIColor(red:0.95, green:0.34, blue:0.34, alpha:1.0)
let appDelegate = UIApplication.shared.delegate as? AppDelegate
var userMoney : [UserMoney] = []
var managedObjectContext: NSManagedObjectContext? = appDelegate?.persistentContainer.viewContext
class ViewController: UIViewController, NSFetchedResultsControllerDelegate {
#IBOutlet weak var sumTextField: UITextField!
#IBOutlet weak var userBudgetLabel: UILabel!
#IBOutlet var tap: UITapGestureRecognizer!
#IBOutlet weak var topView: UIView!
#IBOutlet weak var plusButton: UIButton!
#IBOutlet weak var tableView: UITableView!
#IBOutlet weak var moreBtn: UIButton!
func userBudgetCount(_ section: Int) -> Int{
return fetchedResultsController.sections![section].numberOfObjects
}
func getUserBudgetAtIndexPath(indexPath : IndexPath) -> Budget {
return fetchedResultsController.object(at: indexPath) as Budget
}
override func viewDidLoad() {
super.viewDidLoad()
self.hideKeyboard()
tableView.delegate = self
tableView.dataSource = self
self.tableView.tableFooterView = UIView()
}
override func viewDidAppear(_ animated: Bool) {
super.viewWillAppear(animated)
fetchCoreDataObject()
}
func fetchCoreDataObject() {
self.fetch { (complete) in
if complete {
if userBudgetCount(0) >= 1 {
userBudgetLabel.text = replaceLabel(number: userMoney[userMoney.count - 1].userMoney)
tableView.isHidden = false
plusButton.isHidden = false
moreBtn.isHidden = false
} else {
tableView.isHidden = true
userBudgetLabel.text = "Bugetul tau"
plusButton.isHidden = true
moreBtn.isHidden = true
}
}
}
}
var fetchedResultsController: NSFetchedResultsController<Budget> {
if _fetchedResultsController != nil {
return _fetchedResultsController!
}
let fetchRequest = NSFetchRequest<Budget>(entityName: "Budget")
// Set the batch size to a suitable number.
fetchRequest.fetchBatchSize = 20
// Edit the sort key as appropriate.
let sortDescriptor = NSSortDescriptor(key: "dateSubmitted" , ascending: false)
fetchRequest.sortDescriptors = [sortDescriptor]
// Edit the section name key path and cache name if appropriate.
// nil for section name key path means "no sections".
let aFetchedResultsController = NSFetchedResultsController(fetchRequest: fetchRequest, managedObjectContext: managedObjectContext!, sectionNameKeyPath: "dateSection", cacheName: nil)
aFetchedResultsController.delegate = self
_fetchedResultsController = aFetchedResultsController
do {
try _fetchedResultsController!.performFetch()
} 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)")
}
return _fetchedResultsController!
}
var _fetchedResultsController: NSFetchedResultsController<Budget>? = nil
func controller(_ controller: NSFetchedResultsController<NSFetchRequestResult>, didChange anObject: Any, at indexPath: IndexPath?, for type: NSFetchedResultsChangeType, newIndexPath: IndexPath?) {
tableView.reloadData()
}
override func didReceiveMemoryWarning() {
super.didReceiveMemoryWarning()
// Dispose of any resources that can be recreated.
}
#IBAction func initialAddButtonPressed(_ sender: Any) {
if sumTextField.text != "" {
self.saveMoney(userMoney: (sumTextField.text! as NSString).doubleValue, completion: { (complete) in
})
self.save(sumText: sumTextField.text! , dataDescription: "Buget initial", dataColor: green) {
complete in
if complete {
tableView.isHidden = false
}
}
userBudgetLabel.text = "\(sumTextField.text!) RON"
self.fetchCoreDataObject()
tableView.reloadData()
} else {
sumInvalidAlert()
}
self.dismissKeyboard()
sumTextField.text = ""
}
#IBAction func plusButtonPressed(_ sender: Any) {
let plusController = UIAlertController(title: nil, message: nil, preferredStyle: .actionSheet)
let addBudgetAction = UIAlertAction(title: "Adauga buget", style: .default) {
(action) -> Void in
guard let createAddBudgetVC = self.storyboard?.instantiateViewController(withIdentifier: "AddBudgetVC") else { return }
self.presentViewController(createAddBudgetVC)
}
let addExpenseAction = UIAlertAction(title: "Adauga plata", style: .default) {
(action) -> Void in
guard let createAddExpenseVC = self.storyboard?.instantiateViewController(withIdentifier: "AddExpenseVC") else { return }
self.presentViewController(createAddExpenseVC)
}
let cancelAction = UIAlertAction(title: "Anuleaza", style: .cancel, handler: nil)
plusController.addAction(addBudgetAction)
plusController.addAction(addExpenseAction)
plusController.addAction(cancelAction)
present(plusController, animated: true, completion: nil)
}
#IBAction func moreButtonPressed(_ sender: Any) {
}
}
extension ViewController {
func fetch(completion: (_ complete: Bool) -> ()){
guard let managedContext = appDelegate?.persistentContainer.viewContext else { return }
let fetchMoneyRequest = NSFetchRequest<UserMoney>(entityName: "UserMoney")
do{
userMoney = try managedContext.fetch(fetchMoneyRequest)
print("success")
completion(true)
} catch {
debugPrint("Could not fetch \(error.localizedDescription)")
completion(false)
}
}
func removeCell(atIndexPath indexPath: IndexPath){
guard let managedContext = appDelegate?.persistentContainer.viewContext else { return }
do {
try managedContext.save()
debugPrint("removeCell CONTEXT SAVED")
} catch {
debugPrint("removeCell CONTEXT NOT SAVED \(error.localizedDescription)")
}
}
func cancelCell(color: UIColor, atIndexPath indexPath: IndexPath){
guard let managedContext = appDelegate?.persistentContainer.viewContext else { return }
if color.description == green.description {
// scade buget
userMoney[userMoney.count - 1].userMoney -= (getUserBudgetAtIndexPath(indexPath: indexPath).dataSum! as NSString).doubleValue
} else {
userMoney[userMoney.count - 1].userMoney += (getUserBudgetAtIndexPath(indexPath: indexPath).dataSum! as NSString).doubleValue
}
do {
try managedContext.save()
} catch {
print("cancelCell Managed Context Saving ERROR: \(error.localizedDescription)")
}
}
}
extension ViewController: UITableViewDelegate, UITableViewDataSource,SwipeTableViewCellDelegate {
func tableView(_ tableView: UITableView, editActionsForRowAt indexPath: IndexPath, for orientation: SwipeActionsOrientation) -> [SwipeAction]? {
guard orientation == .right else {
let cancelAction = SwipeAction(style: .default, title: "Anuleaza"){
(action, indexPath)
in
self.cancelCell(color: self.getUserBudgetAtIndexPath(indexPath: indexPath).dataColor as! UIColor, atIndexPath: indexPath)
self.removeCell(atIndexPath: indexPath)
self.fetchCoreDataObject()
tableView.deleteRows(at: [indexPath], with: .automatic)
}
cancelAction.backgroundColor = UIColor(red:0.16, green:0.63, blue:0.74, alpha:1.0)
return [cancelAction]
}
let deleteAction = SwipeAction(style: .destructive, title: "Sterge") { (action, indexPath) in
self.removeCell(atIndexPath: indexPath)
self.fetchCoreDataObject()
tableView.deleteRows(at: [indexPath], with: .automatic)
}
deleteAction.backgroundColor = red
return [deleteAction]
}
func numberOfSections(in tableView: UITableView) -> Int {
if let sections = fetchedResultsController.sections {
return sections.count
}
return 0
}
func tableView(_ tableView: UITableView, cellForRowAt indexPath: IndexPath) -> UITableViewCell {
guard let cell = tableView.dequeueReusableCell(withIdentifier: "expenseCell") as? ExpenseCell else { return UITableViewCell() }
print("indexPathRow: \(indexPath.row) | indexPathSection: \(indexPath.section)")
let budget = fetchedResultsController.object(at: indexPath) as Budget
cell.delegate = self
cell.configureCell(budget: budget)
return cell
}
func tableView(_ tableView: UITableView, canEditRowAt indexPath: IndexPath) -> Bool {
return true
}
func tableView(_ tableView: UITableView, editingStyleForRowAt indexPath: IndexPath) -> UITableViewCellEditingStyle {
return UITableViewCellEditingStyle.none
}
func tableView(_ tableView: UITableView, numberOfRowsInSection section: Int) -> Int {
if let sections = fetchedResultsController.sections {
let currentSection = sections[section]
return currentSection.numberOfObjects
}
return 0
}
func tableView(_ tableView: UITableView, titleForHeaderInSection section: Int) -> String? {
if let sections = fetchedResultsController.sections {
let currentSections = sections[section]
return currentSections.name
}
return nil
}
}