Swift delegate beetween two VC without segue - swift

Question

I have 3 classes:
ChatLogControoller
GetImageFromLibraty(NSObject class)
ImagePreviewViewController
I want to press a clip from the first VC, then open the media library to pick an image. Then the selected image is passed to the third VC as a previewController. Then if I select 'done' I want to pass it to the first VC.
1st VC
class ChatLogControoller: UICollectionViewController, UICollectionViewDelegateFlowLayout, NSFetchedResultsControllerDelegate, UINavigationControllerDelegate, UIImagePickerControllerDelegate, DataSentDelegate {
func recievePhoto(data: UIImage) {
imageFromView = data
print("-------\(imageFromView = data)")
}
override func viewDidLoad() {
super.viewDidLoad()
let vc = ImagePreviewController()
self.vc.delegate = self
}
2nd class its just picker of image, so i pass image to 3rd VC and this image appears on imageView of 3rd VC successfully!
my 3rd VC
protocol DataSentDelegate {
func recievePhoto(data: UIImage)
}
class PreviewController: UIViewController, UIScrollViewDelegate {
var delegate : DataSentDelegate? = nil
var aImageView: UIImageView!
var aImage: UIImage!
override func viewDidLoad() {
super.viewDidLoad()
navigationItem.rightBarButtonItem = UIBarButtonItem(title: "Add", style: .plain, target: self, action: #selector(actionSend))
navigationItem.leftBarButtonItem = UIBarButtonItem(title: "Cancel", style: .plain, target: self, action: #selector(actionBack))
}
#objc func actionBack() {
dismiss(animated: false, completion: nil)
}
#objc func actionSend() {
let data = aImageView.image
delegate?.recievePhoto(data: data!)
dismiss(animated: true, completion: nil)
}

Answer 1

You need to create one more protocol in your SecondViewController to Pass that delegate from ThirdViewController to FirstViewController.
FirstViewController:
import UIKit
class ViewController: UIViewController, DataSentDelegate, dataSentDelegate {
#IBOutlet weak var imagefromThirdVC: UIImageView!
var thirdVCImage: UIImage!
override func viewDidLoad() {
super.viewDidLoad()
}
#IBAction func buttonTapped(_ sender: Any) {
let vc = storyboard?.instantiateViewController(withIdentifier: "ViewController2") as! ViewController2
vc.delegate = self
self.navigationController?.pushViewController(vc, animated: true)
}
func goToThirdVC() {
let vc = storyboard?.instantiateViewController(withIdentifier: "ViewController3") as! ViewController3
vc.delegate = self
self.navigationController?.pushViewController(vc, animated: true)
}
func recievePhoto(data: UIImage) {
thirdVCImage = data
imagefromThirdVC.image = thirdVCImage
}
}
SecondViewController:
import UIKit
protocol dataSentDelegate {
func goToThirdVC()
}
class ViewController2: UIViewController {
#IBOutlet weak var passingImage: UIImageView!
var delegate: dataSentDelegate? = nil
var images: UIImage!
override func viewDidLoad() {
super.viewDidLoad()
images = UIImage(named: "screen")
}
#IBAction func actionButton(_ sender: Any) {
self.delegate?.goToThirdVC()
}
}
ThirdViewController:
import UIKit
protocol DataSentDelegate {
func recievePhoto(data: UIImage)
}
class ViewController3: UIViewController {
var delegate: DataSentDelegate? = nil
#IBOutlet weak var passedImageView: UIImageView!
var passedImage: UIImage!
override func viewDidLoad() {
super.viewDidLoad()
passedImage = UIImage(named: "screen")
passedImageView.image = passedImage
}
#IBAction func action(_ sender: Any) {
let data = passedImageView.image
delegate?.recievePhoto(data: data!)
// delegate?.goToFirstVC()
guard let viewControllers = self.navigationController?.viewControllers else {
return
}
for firstViewController in viewControllers {
if firstViewController is ViewController {
self.navigationController?.popToViewController(firstViewController, animated: true)
break
}
}
}
}