Delegate Isn't getting Created in Swift - ios

Question

I am working on a swift project involving delegates and protocols. I have two files that are working smoothly in this, however I am having an issue where the delegate keeps coming up nil in a different two files where I am doing the same thing as before with different names. It seems like the delegate isn't being set/created for some reason. See code below:
ItemDetailViewController
import UIKit
protocol ItemDetailViewControllerDelegate: class {
func itemDetailViewControllerDidCancel(controller: ItemDetailViewController)
func itemDetailViewController(controller: ItemDetailViewController, didFinishAddingItem item: ChecklistItem)
func itemDetailViewController(controller: ItemDetailViewController, didFinishEditingItem item: ChecklistItem)
}
class ItemDetailViewController: UITableViewController, UITextFieldDelegate {
**weak var delegate: ItemDetailViewControllerDelegate?**
#IBOutlet weak var doneBarButton: UIBarButtonItem!
#IBOutlet weak var textField: UITextField!
var itemToEdit: ChecklistItem?
#IBAction func cancel() {
delegate?.itemDetailViewControllerDidCancel(self)
}
#IBAction func done() {
if let item = itemToEdit {
item.text = textField.text!
delegate?.itemDetailViewController(self, didFinishEditingItem: item)
}
else {
let item = ChecklistItem()
item.text = textField.text!
delegate?.itemDetailViewController(self, didFinishAddingItem: item)
}
}
override func tableView(tableView: UITableView, willSelectRowAtIndexPath indexPath: NSIndexPath) -> NSIndexPath? {
return nil
}
override func viewWillAppear(animated: Bool) {
super.viewWillAppear(animated)
textField.becomeFirstResponder()
}
func textField(textField: UITextField, shouldChangeCharactersInRange range: NSRange, replacementString string: String) -> Bool {
let oldText: NSString = textField.text!
let newText: NSString = oldText.stringByReplacingCharactersInRange(range, withString: string)
doneBarButton.enabled = (newText.length > 0)
return true
}
override func viewDidLoad() {
super.viewDidLoad()
textField.delegate = self
if let item = itemToEdit {
title = "Edit Item"
textField.text = item.text
doneBarButton.enabled = true
}
}
}
ChecklistViewController
import UIKit
class ChecklistViewController: UITableViewController, ItemDetailViewControllerDelegate {
var checklist: Checklist!
override func viewDidLoad() {
super.viewDidLoad()
title = checklist.name
}
override func didReceiveMemoryWarning() {
super.didReceiveMemoryWarning()
}
override func tableView(tableView: UITableView, numberOfRowsInSection section: Int) -> Int {
return checklist.items.count
}
override func tableView(tableView: UITableView, didSelectRowAtIndexPath indexPath: NSIndexPath) {
let item = checklist.items[indexPath.row]
performSegueWithIdentifier("ShowMap", sender: item)
tableView.deselectRowAtIndexPath(indexPath, animated: true)
}
override func tableView(tableView: UITableView, cellForRowAtIndexPath indexPath: NSIndexPath) -> UITableViewCell {
let cell = tableView.dequeueReusableCellWithIdentifier("ChecklistItem", forIndexPath: indexPath)
let item = checklist.items[indexPath.row]
configureTextForCell(cell, withChecklistItem: item)
return cell
}
override func tableView(tableView: UITableView, commitEditingStyle editingStyle: UITableViewCellEditingStyle, forRowAtIndexPath indexPath: NSIndexPath) {
// 1
checklist.items.removeAtIndex(indexPath.row)
// 2
let indexPaths = [indexPath]
tableView.deleteRowsAtIndexPaths(indexPaths, withRowAnimation: .Automatic)
}
func configureTextForCell(cell: UITableViewCell,withChecklistItem item: ChecklistItem) {
let label = cell.viewWithTag(1000) as! UILabel
label.text = item.text
}
func itemDetailViewControllerDidCancel(controller: ItemDetailViewController) {
dismissViewControllerAnimated(true, completion: nil)
}
func itemDetailViewController(controller: ItemDetailViewController,didFinishEditingItem item: ChecklistItem) {
if let index = checklist.items.indexOf(item) { // indexOf needs to compare (test for equality) item to the items in the array
let indexPath = NSIndexPath(forRow: index, inSection: 0)
if let cell = tableView.cellForRowAtIndexPath(indexPath) {
configureTextForCell(cell, withChecklistItem: item)
}
}
dismissViewControllerAnimated(true, completion: nil)
}
func itemDetailViewController(controller: ItemDetailViewController, didFinishAddingItem item: ChecklistItem) {
let newRowIndex = checklist.items.count
checklist.items.append(item)
let indexPath = NSIndexPath(forRow: newRowIndex, inSection: 0)
let indexPaths = [indexPath]
tableView.insertRowsAtIndexPaths(indexPaths, withRowAnimation: .Automatic)
dismissViewControllerAnimated(true, completion: nil)
}
override func prepareForSegue(segue: UIStoryboardSegue,sender: AnyObject?) {
if segue.identifier == "AddItem" {
let navigationController = segue.destinationViewController
as! UINavigationController
let controller = navigationController.topViewController
as! ItemDetailViewController
controller.delegate = self
}
else if segue.identifier == "EditItem" {
let navigationController = segue.destinationViewController
as! UINavigationController
let controller = navigationController.topViewController
as! ItemDetailViewController
controller.delegate = self
if let indexPath = tableView.indexPathForCell(
sender as! UITableViewCell) {
controller.itemToEdit = checklist.items[indexPath.row]
}
}
}
}

Answer 1

Is it possible that your segue identifiers in ChecklistViewController:prepareForSegue are not correct, or are not setup correctly in the storyboard? If so the destination controller delegate would not get set.