Swift code. fatal error: unexpectedly found nil while unwrapping an Optional value - ios

Question

When I run my app I get an error message that says
fatal error: unexpectedly found nil while unwrapping an Optional value
MealViewController.swift
import UIKit
class MealViewController: UIViewController, UITextFieldDelegate, UINavigationControllerDelegate {
// MARK: Properties
#IBOutlet weak var nameTextField: UITextField!
#IBOutlet weak var saveButton: UIBarButtonItem!
/*
This value is either passed by `MealTableViewController` in `prepareForSegue(_:sender:)`
or constructed as part of adding a new meal.
*/
override func prepareForSegue(segue: UIStoryboardSegue, sender: AnyObject?) {
if saveButton === sender {
let weightInt: Int? = Int(weightInKilos.text!)
let dehydrationInt: Int? = Int(percentOfDehydration.text!)
let lossesInt: Int? = Int(ongoingLosses.text!)
let factorInt: Int? = Int(Factor.text!)
let name = nameTextField.text ?? ""
let wt = weightInt!
let dn = dehydrationInt!
let ol = lossesInt!
let fr = factorInt!
// Set the meal to be passed to MealListTableViewController after the unwind segue.
meal = Meal(name: name, wt: wt, dn: dn, ol: ol, fr: fr)
}
if calcButton === sender {
if weightInKilos.text == "" && percentOfDehydration.text == "" && ongoingLosses.text == "" && Factor.text == "" {
let alertController = UIAlertController(title: "Fields were left empty.", message:
"You left some fields blank! Please make sure that all fields are filled in before tapping 'Calculate'.", preferredStyle: UIAlertControllerStyle.Alert)
alertController.addAction(UIAlertAction(title: "Dismiss", style: UIAlertActionStyle.Default,handler: nil))
self.presentViewController(alertController, animated: true, completion: nil)
}
else {
let DestViewController: ftrViewController = segue.destinationViewController as! ftrViewController
let weightInt: Int? = Int(weightInKilos.text!)
let dehydrationInt: Int? = Int(percentOfDehydration.text!)
let lossesInt: Int? = Int(ongoingLosses.text!)
let factorInt: Int? = Int(Factor.text!)
let lrs24Int = (30 * weightInt! + 70) * factorInt! + weightInt! * dehydrationInt! * 10 + lossesInt!
let lrsPerHourint = lrs24Int / 24
DestViewController.lrsHr = "\(lrsPerHourint)"
DestViewController.lrs24Hrs = "\(lrs24Int)"
}
}
}
func textFieldShouldReturn(textField: UITextField) -> Bool {
textField.resignFirstResponder()
return true
}
var meal: Meal?
override func viewDidLoad() {
super.viewDidLoad()
// Handle the text field’s user input through delegate callbacks.
nameTextField.delegate = self
// Set up views if editing an existing Meal.
if let meal = meal {
navigationItem.title = meal.name
nameTextField.text = meal.name
var weightInt: Int? = Int(weightInKilos.text!)
var dehydrationInt: Int? = Int(percentOfDehydration.text!)
var lossesInt: Int? = Int(ongoingLosses.text!)
var factorInt: Int? = Int(Factor.text!)
weightInt = meal.wt
dehydrationInt = meal.dn
lossesInt = meal.ol
factorInt = meal.fr
weightInKilos.delegate = self
percentOfDehydration.delegate = self
ongoingLosses.delegate = self
Factor.delegate = self
calcButton.layer.cornerRadius = 4;
resetbutton.layer.cornerRadius = 4;
}
// Enable the Save button only if the text field has a valid Meal name.
checkValidMealName()
}
// MARK: UITextFieldDelegate
func textFieldDidEndEditing(textField: UITextField) {
checkValidMealName()
navigationItem.title = textField.text
}
func textFieldDidBeginEditing(textField: UITextField) {
// Disable the Save button while editing.
saveButton.enabled = false
}
func checkValidMealName() {
// Disable the Save button if the text field is empty.
let text = nameTextField.text ?? ""
saveButton.enabled = !text.isEmpty
}
// MARK: Navigation
#IBAction func cancel(sender: UIBarButtonItem) {
// Depending on style of presentation (modal or push presentation), this view controller needs to be dismissed in two different ways.
let isPresentingInAddMealMode = presentingViewController is UINavigationController
if isPresentingInAddMealMode {
dismissViewControllerAnimated(true, completion: nil)
} else {
navigationController!.popViewControllerAnimated(true)
}
}
// Calculation outlets & actions
#IBOutlet weak var resetbutton: UIButton!
#IBOutlet weak var calcButton: UIButton!
#IBOutlet weak var weightInKilos: UITextField!
#IBOutlet weak var percentOfDehydration: UITextField!
#IBOutlet weak var ongoingLosses: UITextField!
#IBOutlet weak var Factor: UITextField!
#IBAction func resetButton(sender: AnyObject) {
if weightInKilos.text == "" && percentOfDehydration.text == "" && ongoingLosses.text == "" && Factor.text == "" {
let alertController = UIAlertController(title: "...", message:
"There is no information to reset. Nice try though!", preferredStyle: UIAlertControllerStyle.Alert)
alertController.addAction(UIAlertAction(title: "Dismiss", style: UIAlertActionStyle.Default,handler: nil))
self.presentViewController(alertController, animated: true, completion: nil)
}
else {
weightInKilos.text=""
percentOfDehydration.text=""
ongoingLosses.text=""
Factor.text=""
}
}
}
class ftrViewController: UIViewController, UITextFieldDelegate {
#IBOutlet weak var lrs24hours: UILabel!
#IBOutlet weak var lrsPerHour: UILabel!
var lrs24Hrs = String()
var lrsHr = String()
override func viewDidLoad() {
lrs24hours.text = lrs24Hrs
lrsPerHour.text = lrsHr
}
}
Meal.swift
import UIKit
class Meal: NSObject, NSCoding {
// MARK: Properties
var name: String
var wt: Int
var dn: Int
var ol: Int
var fr: Int
// MARK: Archiving Paths
static let DocumentsDirectory = NSFileManager().URLsForDirectory(.DocumentDirectory, inDomains: .UserDomainMask).first!
static let ArchiveURL = DocumentsDirectory.URLByAppendingPathComponent("meals")
// MARK: Types
struct PropertyKey {
static let nameKey = "name"
static let wtKey = "weight"
static let dnKey = "dehydration"
static let olKey = "ongoinglosses"
static let frKey = "factor"
}
// MARK: Initialization
init?(name: String, wt: Int, dn: Int, ol: Int, fr: Int) {
// Initialize stored properties.
self.name = name
self.wt = wt
self.dn = dn
self.ol = ol
self.fr = fr
super.init()
// Initialization should fail if there is no name or if the rating is negative.
if name.isEmpty {
return nil
}
}
// MARK: NSCoding
func encodeWithCoder(aCoder: NSCoder) {
aCoder.encodeObject(name, forKey: PropertyKey.nameKey)
aCoder.encodeObject(wt, forKey: PropertyKey.wtKey)
aCoder.encodeObject(dn, forKey: PropertyKey.dnKey)
aCoder.encodeObject(ol, forKey: PropertyKey.olKey)
aCoder.encodeObject(fr, forKey: PropertyKey.frKey)
}
required convenience init?(coder aDecoder: NSCoder) {
let name = aDecoder.decodeObjectForKey(PropertyKey.nameKey) as! String
let wt = aDecoder.decodeObjectForKey(PropertyKey.wtKey) as! Int
let dn = aDecoder.decodeObjectForKey(PropertyKey.dnKey) as! Int
let ol = aDecoder.decodeObjectForKey(PropertyKey.olKey) as! Int
let fr = aDecoder.decodeObjectForKey(PropertyKey.frKey) as! Int
// Must call designated initializer.
self.init(name: name, wt: wt, dn: dn, ol: ol, fr: fr)!
}
}
MealTableViewController.swift
import UIKit
class MealTableViewController: UITableViewController {
// MARK: Properties
var meals = [Meal]()
override func viewDidLoad() {
super.viewDidLoad()
// Use the edit button item provided by the table view controller.
navigationItem.leftBarButtonItem = editButtonItem()
// Load any saved meals, otherwise load sample data.
if let savedMeals = loadMeals() {
meals += savedMeals
} else {
}
}
override func didReceiveMemoryWarning() {
super.didReceiveMemoryWarning()
// Dispose of any resources that can be recreated.
}
// MARK: - Table view data source
override func numberOfSectionsInTableView(tableView: UITableView) -> Int {
return 1
}
override func tableView(tableView: UITableView, numberOfRowsInSection section: Int) -> Int {
return meals.count
}
override func tableView(tableView: UITableView, cellForRowAtIndexPath indexPath: NSIndexPath) -> UITableViewCell {
// Table view cells are reused and should be dequeued using a cell identifier.
let cellIdentifier = "MealTableViewCell"
let cell = tableView.dequeueReusableCellWithIdentifier(cellIdentifier, forIndexPath: indexPath) as! MealTableViewCell
// Fetches the appropriate meal for the data source layout.
let meal = meals[indexPath.row]
cell.nameLabel.text = meal.name
return cell
}
// Override to support conditional editing of the table view.
override func tableView(tableView: UITableView, canEditRowAtIndexPath indexPath: NSIndexPath) -> Bool {
// Return false if you do not want the specified item to be editable.
return true
}
// Override to support editing the table view.
override func tableView(tableView: UITableView, commitEditingStyle editingStyle: UITableViewCellEditingStyle, forRowAtIndexPath indexPath: NSIndexPath) {
if editingStyle == .Delete {
// Delete the row from the data source
meals.removeAtIndex(indexPath.row)
saveMeals()
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
}
}
/*
// Override to support rearranging the table view.
override func tableView(tableView: UITableView, moveRowAtIndexPath fromIndexPath: NSIndexPath, toIndexPath: NSIndexPath) {
}
*/
/*
// Override to support conditional rearranging of the table view.
override func tableView(tableView: UITableView, canMoveRowAtIndexPath indexPath: NSIndexPath) -> Bool {
// Return false if you do not want the item to be re-orderable.
return true
}
*/
// MARK: - Navigation
// In a storyboard-based application, you will often want to do a little preparation before navigation
override func prepareForSegue(segue: UIStoryboardSegue, sender: AnyObject?) {
if segue.identifier == "ShowDetail" {
let mealDetailViewController = segue.destinationViewController as! MealViewController
// Get the cell that generated this segue.
if let selectedMealCell = sender as? MealTableViewCell {
let indexPath = tableView.indexPathForCell(selectedMealCell)!
let selectedMeal = meals[indexPath.row]
mealDetailViewController.meal = selectedMeal
}
}
else if segue.identifier == "AddItem" {
print("Adding new meal.")
}
}
#IBAction func unwindToMealList(sender: UIStoryboardSegue) {
if let sourceViewController = sender.sourceViewController as? MealViewController, meal = sourceViewController.meal {
if let selectedIndexPath = tableView.indexPathForSelectedRow {
// Update an existing meal.
meals[selectedIndexPath.row] = meal
tableView.reloadRowsAtIndexPaths([selectedIndexPath], withRowAnimation: .None)
} else {
// Add a new meal.
let newIndexPath = NSIndexPath(forRow: meals.count, inSection: 0)
meals.append(meal)
tableView.insertRowsAtIndexPaths([newIndexPath], withRowAnimation: .Bottom)
}
// Save the meals.
saveMeals()
}
}
// MARK: NSCoding
func saveMeals() {
let isSuccessfulSave = NSKeyedArchiver.archiveRootObject(meals, toFile: Meal.ArchiveURL.path!)
if !isSuccessfulSave {
print("Failed to save meals...")
}
}
func loadMeals() -> [Meal]? {
return NSKeyedUnarchiver.unarchiveObjectWithFile(Meal.ArchiveURL.path!) as! [Meal]
}
}
MealTableViewCell.swift
import UIKit
class MealTableViewCell: UITableViewCell {
// MARK: Properties
#IBOutlet weak var nameLabel: UILabel!
override func awakeFromNib() {
super.awakeFromNib()
// Initialization code
}
override func setSelected(selected: Bool, animated: Bool) {
super.setSelected(selected, animated: animated)
// Configure the view for the selected state
}
}

Answer 1

try this convenience required init?(coder aDecoder: NSCoder) method
convenience required init?(coder aDecoder: NSCoder) {
if let name = aDecoder.decodeObjectForKey(PropertyKey.nameKey) as? String,
wt = aDecoder.decodeObjectForKey(PropertyKey.wtKey) as? Int,
dn = aDecoder.decodeObjectForKey(PropertyKey.dnKey) as? Int,
ol = aDecoder.decodeObjectForKey(PropertyKey.olKey) as? Int,
fr = aDecoder.decodeObjectForKey(PropertyKey.frKey) as? Int {
// Must call designated initializer.
self.init(name: name, wt: wt, dn: dn, ol: ol, fr: fr)
} else {
return nil
}
}