Simple Block-based wrapper around UIImagePickerController

MVPhotoPicker

import UIKit

class MVPhotoPicker: NSObject, UIImagePickerControllerDelegate, UINavigationControllerDelegate {

    // Class to hold strong reference to the currently presented photo picker controller
    private class PhotoPickerController {
        
        var currentPicker: MVPhotoPicker?
        
        static let sharedInstance = PhotoPickerController()
    }

    private var completion: (image: UIImage?) -> ()
    private var picker: UIImagePickerController
    
    // Will call completion block if the user has selected an image
    // Will not call completion block if user dismissed the screen
    class func choosePhoto(presentingVC: UIViewController, completion: (image: UIImage?) -> ()) {

        let picker = MVPhotoPicker(completion: completion)

        PhotoPickerController.sharedInstance.currentPicker = picker

        presentingVC.presentViewController(picker.picker, animated: true, completion: nil)
    }
    
    private init(completion: (image: UIImage?) -> ()) {
        self.completion = completion
        picker = UIImagePickerController()
        super.init()
        picker.sourceType = UIImagePickerControllerSourceType.PhotoLibrary
        picker.delegate = self
    }
    
    // MARK: UIImagePickerControllerDelegate
    func imagePickerController(picker: UIImagePickerController, didFinishPickingMediaWithInfo info: [String : AnyObject]) {
        
        PhotoPickerController.sharedInstance.currentPicker = nil
        
        var img = info[UIImagePickerControllerEditedImage] as? UIImage
        if img == nil {
            img = info[UIImagePickerControllerOriginalImage] as? UIImage
        }
        completion(image: img)
    }
}