Why are my buttons preferences/parameters resetting when I change view? - ios

Question

I have this iOS application where the value from cells in a tableview is used to set the preferences/parameters on my UIButtons.
When the button is pressed I send with it the tag ID to the tableview, when the user press a cell it collects both text and image and return it (along with the tag ID) back to the main view.
This successfully changes the parameters on the button with the corresponding button tag ID, but when I now press a new button to do the same procedure it resets the first button changes (clears the image and text) and just applies changes to the new button that is pressed.
This is the main view controller class:
class ViewController: UIViewController {
var recievedItem: ChosenItem?
var imageToButton: UIImage?
#IBOutlet weak var button1: UIButton!
#IBOutlet weak var button2: UIButton!
#IBOutlet weak var button3: UIButton!
func AddNew() {
performSegueWithIdentifier("addNew", sender: nil)
}
#IBAction func loadItem(sender: UIButton!) {
performSegueWithIdentifier("itemList", sender: sender)
}
override func prepareForSegue(segue: UIStoryboardSegue, sender: AnyObject?) {
if(segue.identifier == "itemList"){
let tableViewController : TableViewController = segue.destinationViewController as! TableViewController
tableViewController.buttonTag = sender!.tag
}
}
#IBAction func play(sender: UIButton) {
print("Jeg har fått \(recievedItem!.chosenWord)")
}
override func viewDidLoad() {
super.viewDidLoad()
self.navigationController?.navigationBar.setBackgroundImage(UIImage(), forBarMetrics: .Default)
self.navigationController?.navigationBar.shadowImage = UIImage()
self.navigationController?.navigationBar.translucent = true
navigationItem.rightBarButtonItem = UIBarButtonItem(title: "Open", style: .Plain, target: self, action: "AddNew")
navigationItem.rightBarButtonItem = UIBarButtonItem(barButtonSystemItem: .Add, target: self, action: "AddNew")
if(recievedItem != nil){
imageToButton = UIImage(data: recievedItem!.chosenImage)
switch recievedItem!.chosenButton{
case 0:
button1.setBackgroundImage(imageToButton, forState: .Normal)
button1.setTitle(recievedItem!.chosenWord, forState: .Normal)
case 1:
button2.setBackgroundImage(imageToButton, forState: .Normal)
button2.setTitle(recievedItem!.chosenWord, forState: .Normal)
case 2:
button3.setBackgroundImage(imageToButton, forState: .Normal)
button3.setTitle(recievedItem!.chosenWord, forState: .Normal)
default:
print("No buttonTag recieved")
}
}
}
override func didReceiveMemoryWarning() {
super.didReceiveMemoryWarning()
// Dispose of any resources that can be recreated.
}
}
This is the tableview class:
class TableViewController: UITableViewController {
var words = [Words]()
var chosenItem: ChosenItem!
var buttonTag: Int!
override func viewDidLoad() {
super.viewDidLoad()
let appDel: AppDelegate = (UIApplication.sharedApplication().delegate as! AppDelegate)
let context: NSManagedObjectContext = appDel.managedObjectContext
let request = NSFetchRequest(entityName: "Words")
request.returnsObjectsAsFaults = false
do {
words = try context.executeFetchRequest(request) as! [Words]
} catch {
print("Unresolved error")
abort()
}
print("Her er også button tag \(buttonTag)")
}
override func didReceiveMemoryWarning() {
super.didReceiveMemoryWarning()
// Dispose of any resources that can be recreated.
}
override func tableView(tableView: UITableView, numberOfRowsInSection section: Int) -> Int {
return self.words.count
}
override func tableView(tableView: UITableView, cellForRowAtIndexPath indexPath: NSIndexPath) -> UITableViewCell {
let cell = self.tableView.dequeueReusableCellWithIdentifier("Cell", forIndexPath: indexPath)
let itemWord = self.words[indexPath.row]
cell.textLabel?.text = itemWord.word
cell.imageView?.image = UIImage(data: itemWord.image!)
return cell
}
override func tableView(tableView: UITableView, didSelectRowAtIndexPath indexPath: NSIndexPath) {
print(self.words[indexPath.row].word!)
chosenItem = ChosenItem()
chosenItem.chosenButton = buttonTag
chosenItem.chosenWord = self.words[indexPath.row].word!
chosenItem.chosenImage = self.words[indexPath.row].image!
performSegueWithIdentifier("backToMain", sender: chosenItem)
}
override func prepareForSegue(segue: UIStoryboardSegue, sender: AnyObject?) {
if(segue.identifier == "backToMain"){
let mainViewController : ViewController = segue.destinationViewController as! ViewController
let data = sender as! ChosenItem
mainViewController.recievedItem = data
}
}
}
This is the model class that holds the data:
class ChosenItem: NSObject {
var chosenButton: Int!
var chosenWord: String!
var chosenImage: NSData!
}

Answer 1

The problem is this line:
performSegueWithIdentifier("backToMain", sender: chosenItem)
That is not how you return from a pushed-or-presented view controller to the view controller that pushed-or-presented it! What you are doing is creating a completely new view controller, and that's why the chosen button is not set; it is a different view controller with a different chosen button, namely none because this view controller has just come into existence.
Not only will this mess things up with the chosen button, but eventually your app will crash because you are creating one view controller on top of another every time you go forward and back, and eventually you'll run out of memory.
The way to get back from a pushed view controller is popViewController. The way to get back from a presented view controller is dismissViewController.
If you know what you're doing, you can instead use a special non-segue segue called an unwind segue, but it doesn't sound like you're ready to do that.