Value is not passed after prepareforsegue. Swift

Question

VC that fires perform segue. It has a backgroundImage with a userImage and a collectionView with images in cells.

import UIKit

class EmojiCollectionVC:  {

    @IBOutlet weak var backgroundImage: UIImageView!
    @IBOutlet weak var emojiCollection: UICollectionView!

    var userImage: UIImage!

    override func viewDidLoad() {
        super.viewDidLoad()

        backgroundImage.image = userImage
    }

    @IBAction func dismiss(_ sender: Any) {

         dismiss(animated: false, completion: nil)
    }

    func collectionView(_ collectionView: UICollectionView, didSelectItemAt indexPath: IndexPath) {

        let cell = collectionView.cellForItem(at: indexPath) as! EmojiCollectionCell
        let chosenEmoji = cell.emojiView.image
        performSegue(withIdentifier: "backToEmojiVC", sender: chosenEmoji)
    }

    override func prepare(for segue: UIStoryboardSegue, sender: Any?) {
        if segue.identifier == "backToEmojiVC"{

        if let destinationVC = segue.destination as? EmojiVC {
            if let emoji = sender as? UIImage {
                destinationVC.emojiImage = emoji

                let data = UIImagePNGRepresentation(userImage)
                print("Zhenya: 1 - \(data)")
                destinationVC.imageData = data
                print("Zhenya: 5 - \(destinationVC.imageData)")
            }
        }
    }
    }
}

userImage has an image in it that is displayed. After pressing the cell, image from it (chosenEmoji) should be passed to EmojiVC, to its emojiImage.

Both prints "Zhenya: 1" and "Zhenya: 5" in prepare for segue print desired value.

The destination VC:

class EmojiVC: UIViewController {

    @IBOutlet weak var mainImg: UIImageView!
    @IBOutlet weak var emojiImageView: UIImageView!

    var imageData: Data!
    var imageItself: UIImage!
    var emojiImage: UIImage!

    override func viewDidLoad() {
        super.viewDidLoad()

        print("Zhenya:3 - \(imageData)")
        print("Zhenya:4 - \(emojiImage)")

    }

    override func viewDidAppear(_ animated: Bool) {
        print("Zhenya:3 - \(imageData)")
        print("Zhenya:4 - \(emojiImage)")

        if imageData != nil {
            print("Zhenya:2 - \(imageData)")
            let img = UIImage(data: imageData)
            mainImg.image = img
        } else if imageItself != nil {
            mainImg.image = imageItself
        }

        if emojiImage != nil {
            print("Zhenya: \(emojiImage)")
            emojiImageView.image = emojiImage
        }

    }

    @IBAction func addEmoji(_ sender: Any) {
        let img = mainImg.image
        performSegue(withIdentifier: "EmojiCollectionVC", sender: img)

    }
}

Both prints Zhenya: 3 and Zhenya: 4 print nil. Data that was set in prepare for segue wasn't passed to them. Segue backToEmojiVC is performed, but data isn't passed. I did check - if there are any other segues with same identifiers.

I suspect, that value gets destroyed somewhere or somehow when destination VC appears. Or both imageData and emojiImage are re-initialized with nil values.

What might be the problem?

Answer 1

Went through the code step by step. Copy pasted names of segues instead of typing them. Shit started to work.