How to pass selected image from UIImagePicker to the UIViewController

Question

I've implemented a UIImagePicker into my app, but I'm struggling to pass the UIImage to the UIViewController that the picker was initiated from (see comment in code below)

The below code is an extension stored in Extensions/ImageUploader.swift

import UIKit
import Firebase

extension UIViewController: UIImagePickerControllerDelegate, UINavigationControllerDelegate{


    public func ImagePicker() {
        let picker = UIImagePickerController()
        picker.delegate = self
        picker.allowsEditing = true
        // mediaType is image only by default

        present(picker, animated: true, completion: nil)

    }


    public func imagePickerController(_ picker: UIImagePickerController, didFinishPickingMediaWithInfo info: [String : Any]) {

        var selectedImageFromPicker: UIImage?

        if let editedImage = info[UIImagePickerControllerEditedImage] as? UIImage {
            selectedImageFromPicker = editedImage
        }
        if let originalImage = info[UIImagePickerControllerOriginalImage] as? UIImage {
            selectedImageFromPicker = originalImage
        }

        picker.dismiss(animated: true, completion:{print("Image upload started")})// Closing the window before the upload, so upload can continue in background while user finishes the form

           // Here I want to pass the selectedImageFromPicker to the ViewController that initiated the imagePicker - how do I do that??


        })
        }
}

In the createActivityVC, I have this IBAction to get access to photo library and initiative the picker - self.imagePicker()

@IBAction func addPictureBtnWasPressed(_ sender: Any) {

    PHPhotoLibrary.requestAuthorization({(status:PHAuthorizationStatus) in
        switch(status) {

       case .notDetermined:

        // Access has not been determined.
        PHPhotoLibrary.requestAuthorization({ (newStatus) in

            if (newStatus == PHAuthorizationStatus.authorized) {
                // Access has been granted.

                self.imagePicker() 
            }

            else {

            }
        })
        break

    case .restricted:
        break

    case .denied:
        // Access has been denied.
        print("Acccess to photo denied")
        break

    case .authorized:
        // Access has been granted.
        print("Access to photo authorized")

         self.imagePicker()

         break


      }
   })
}

I want to pass the selectedImageFromPicker to viewController createActivityVC. How can this be done? I would prefer to not name the viewController specifically but rather make it so that it is dynamic so the imagePicker can be used across multiple ViewControllers if possible.

Answer 1

In your form, have you implemented a UIImageView? If it's the case, in your

public func imagePickerController(_ picker: UIImagePickerController, didFinishPickingMediaWithInfo info: [String : Any])

you can say:

myFormImageView.image = selectedImageFromPicker

and then when you submit your form you can upload the form info + the image data

UPDATE:

My approach by subclassing UIIMagePickerController

import UIKit

protocol ImagePickerDelegate {
    func imagePicked(image: UIImage)
}

class myPickerViewController: UIImagePickerController, UIImagePickerControllerDelegate, UINavigationControllerDelegate{

    var imagePickerDelegate:ImagePickerDelegate!

    override func viewDidLoad() {
        super.viewDidLoad()
        allowsEditing = true
        delegate = self
    }

    func imagePickerController(_ picker: UIImagePickerController, didFinishPickingMediaWithInfo info: [String : Any]) {
        let selectedImage = info[UIImagePickerControllerOriginalImage] as! UIImage
            imagePickerDelegate.imagePicked(image: selectedImage)
        dismiss(animated: true, completion: nil)
    }

}

class ViewController : UIViewController, ImagePickerDelegate {

    func imagePicked(image: UIImage) {
        imagePicked = image
    }


    var imagePicked:UIImage! {
        didSet {
            imageView.image = imagePicked
        }
    }

    let button: UIButton = {
       let button = UIButton()
        button.translatesAutoresizingMaskIntoConstraints = false
        button.setTitle("Select an image", for: .normal)
        button.backgroundColor = .red
        button.addTarget(self, action: #selector(handleImagePicker), for: .touchUpInside)
        return button
    }()

    let imageView: UIImageView = {
        let iv = UIImageView()
        iv.translatesAutoresizingMaskIntoConstraints = false
        iv.contentMode = .scaleAspectFill
        iv.layer.masksToBounds = true
        iv.layer.borderWidth = 2
        iv.layer.borderColor = UIColor.black.cgColor
        return iv
    }()

    override func viewDidLoad() {
        super.viewDidLoad()

        title = "Get image via Delegate"
        view.backgroundColor = .white

        view.addSubview(button)
        view.addSubview(imageView)

        button.topAnchor.constraint(equalTo: self.view.topAnchor, constant: 100).isActive = true
        button.heightAnchor.constraint(equalToConstant: 30).isActive = true
        button.widthAnchor.constraint(equalToConstant: 150).isActive = true
        button.centerXAnchor.constraint(equalTo: self.view.centerXAnchor).isActive = true

        imageView.topAnchor.constraint(equalTo: self.button.topAnchor, constant: 50).isActive = true
        imageView.leftAnchor.constraint(equalTo: self.view.leftAnchor, constant: 20).isActive = true
        imageView.rightAnchor.constraint(equalTo: self.view.rightAnchor, constant: -20).isActive = true
        imageView.bottomAnchor.constraint(equalTo: self.view.bottomAnchor, constant: -50).isActive = true

    }

    @objc func handleImagePicker() {
        let myPickerVC = myPickerViewController()
        myPickerVC.imagePickerDelegate = self

        self.present(myPickerVC, animated: true, completion: nil )
    }

}

You create a new project and paste the entire code it will works, I guess, like me. Hope it helps