How to allow user to pick the image with Swift?

Question

I am writing my first iOS application (iPhone only) with Swift. The main application view should allow user to choose the image from the photo gallery.

I\'ve found

Answer 1

Complete copy-paste working image picker for swift 4 based on @user3182143 answer:

import Foundation
import UIKit


class ImagePickerManager: NSObject, UIImagePickerControllerDelegate, UINavigationControllerDelegate {

    var picker = UIImagePickerController();
    var alert = UIAlertController(title: "Choose Image", message: nil, preferredStyle: .actionSheet)
    var viewController: UIViewController?
    var pickImageCallback : ((UIImage) -> ())?;
    
    override init(){
        super.init()
        let cameraAction = UIAlertAction(title: "Camera", style: .default){
            UIAlertAction in
            self.openCamera()
        }
        let galleryAction = UIAlertAction(title: "Gallery", style: .default){
            UIAlertAction in
            self.openGallery()
        }
        let cancelAction = UIAlertAction(title: "Cancel", style: .cancel){
            UIAlertAction in
        }

        // Add the actions
        picker.delegate = self
        alert.addAction(cameraAction)
        alert.addAction(galleryAction)
        alert.addAction(cancelAction)
    }

    func pickImage(_ viewController: UIViewController, _ callback: @escaping ((UIImage) -> ())) {
        pickImageCallback = callback;
        self.viewController = viewController;

        alert.popoverPresentationController?.sourceView = self.viewController!.view

        viewController.present(alert, animated: true, completion: nil)
    }
    func openCamera(){
        alert.dismiss(animated: true, completion: nil)
        if(UIImagePickerController .isSourceTypeAvailable(.camera)){
            picker.sourceType = .camera
            self.viewController!.present(picker, animated: true, completion: nil)
        } else {
            let alertWarning = UIAlertView(title:"Warning", message: "You don't have camera", delegate:nil, cancelButtonTitle:"OK", otherButtonTitles:"")
            alertWarning.show()
        }
    }
    func openGallery(){
        alert.dismiss(animated: true, completion: nil)
        picker.sourceType = .photoLibrary
        self.viewController!.present(picker, animated: true, completion: nil)
    }

    
    func imagePickerControllerDidCancel(_ picker: UIImagePickerController) {
        picker.dismiss(animated: true, completion: nil)
    }
    //for swift below 4.2
    //func imagePickerController(_ picker: UIImagePickerController, didFinishPickingMediaWithInfo info: [String : Any]) {
    //    picker.dismiss(animated: true, completion: nil)
    //    let image = info[UIImagePickerControllerOriginalImage] as! UIImage
    //    pickImageCallback?(image)
    //}
    
    // For Swift 4.2+
    func imagePickerController(_ picker: UIImagePickerController, didFinishPickingMediaWithInfo info: [UIImagePickerController.InfoKey : Any]) {
        picker.dismiss(animated: true, completion: nil)
        guard let image = info[.originalImage] as? UIImage else {
            fatalError("Expected a dictionary containing an image, but was provided the following: \(info)")
        }
        pickImageCallback?(image)
    }



    @objc func imagePickerController(_ picker: UIImagePickerController, pickedImage: UIImage?) {
    }

}

Call it from your viewcontroller like this:

    ImagePickerManager().pickImage(self){ image in
        //here is the image
    }

Also don't forget to include the following keys in your info.plist:

NSCameraUsageDescription
This app requires access to the camera.
NSPhotoLibraryUsageDescription
This app requires access to the photo library.