Cannot subscript a value of type '[String : Any]' with an index of type 'UIImagePickerController.InfoKey'

I'm using Apple's Swift iOS Tutorial. Which is throwing an error,

> Cannot subscript a value of type '[String : Any]' with an index of type 'UIImagePickerController.InfoKey'

The function they defined is below.

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

    // The info dictionary may contain multiple representations of the image. You want to use the original.
    guard let selectedImage = info[UIImagePickerControllerOriginalImage] as? UIImage else {
        fatalError("Expected a dictionary containing an image, but was provided the following: \(info)")
    }

    // Set photoImageView to display the selected image.
    photoImageView.image = selectedImage

    // Dismiss the picker.
    dismiss(animated: true, completion: nil)
}

I'm using Xcode Version 10.0 beta 3, which includes Swift 4.2.

I'd like to understand how to traverse the docs to understand what might have changed or broken.

The signature of the method has changed in Swift 4.2

func imagePickerController(_ picker: UIImagePickerController, 
  didFinishPickingMediaWithInfo info: [UIImagePickerController.InfoKey : Any])

and you have to write

guard let selectedImage = info[.originalImage] as? UIImage else {
    fatalError("Expected a dictionary containing an image, but was provided the following: \(info)")
}

You can figure out such terminology changes yourself by reading the documentation or by commenting out the entire method, retype the first few characters and use code completion.

I'm following also the same tutorial, the updated code looks like this:

func imagePickerController(_ picker: UIImagePickerController, didFinishPickingMediaWithInfo info: [UIImagePickerController.InfoKey : Any]) {
    
    // The info dictionary may contain multiple representations of the image. You want to use the original.
    guard let selectedImage = info[.originalImage] as? UIImage else {
        fatalError("Expected a dictionary containing an image, but was provided the following: \(info)")
    }
    
    // Set photoImageView to display the selected image.
    photoImageView.image = selectedImage
    
    // Dismiss the picker.
    dismiss(animated: true, completion: nil)
}

Swift 5

In latest version of swift 4 or 5 the delegate method is given below, it should work

func imagePickerController(_ picker: UIImagePickerController, didFinishPickingMediaWithInfo info: [UIImagePickerController.InfoKey : Any]) {
    // Code here
}

And use,

guard let selectedImage = info[.editedImage] as? UIImage else {

}



func imagePickerController(_ picker: UIImagePickerController, didFinishPickingMediaWithInfo info: [UIImagePickerController.InfoKey : Any]) {
    guard let selectedImage = info[.editedImage] as? UIImage else {

    }
}

Use like this,

guard let selectedImage = info[UIImagePickerController.InfoKey.originalImage.rawValue] as? UIImage else {
        fatalError("Expected a dictionary containing an image, but was provided the following: \(info)")
}

In Swift 4 and 5 like so:

func imagePickerController(_ picker: UIImagePickerController, didFinishPickingMediaWithInfo info: [UIImagePickerController.InfoKey : Any]) {
    
    guard let selectedImage = info[.editedImage] as? UIImage else {
        fatalError("Expected a dictionary containing an image, but was provided the following: \(info)")
    }
    
    self.myImageView.image = selectedImage
    
    picker.dismiss(animated: true, completion: nil)
}

I am also following the tutorial. It is working after changing as below.

func imagePickerController(_ picker: UIImagePickerController, didFinishPickingMediaWithInfo info: [UIImagePickerController.InfoKey : Any]) {
    
    // The info dictionary may contain multiple representations of the image. You want to use the original.
    guard let selectedImage = info[.originalImage] as? UIImage
        else {
        fatalError("Expected a dictionary containing an image, but was provided the following: \(info)")
    }
    
    // Set photoImageView to display the selected image.
    photoImageView.image = selectedImage
    
    // Dismiss the picker.
    dismiss(animated: true, completion: nil)
}

I am using XCode 11 and Swift 5.

Method has been changed a little bit in Swift 4.2.

First initialise these two variables:

var imagePicker = UIImagePickerController()
var pickedImageProduct = UIImage()

extension yourViewController: UIImagePickerControllerDelegate,UINavigationControllerDelegate{
//create an IBAction to access Camera
    @IBAction func accessCameraBtn(_ sender: UIButton) {
        imagePicker.delegate = self
        imagePicker.sourceType = UIImagePickerController.SourceType.camera
        self.present(imagePicker, animated: true, completion: nil)
    }
//create an IBAction to access Gallery
    @IBAction func accessGalleryBtn(_ sender: UIButton) {
        imagePicker.delegate = self
        imagePicker.sourceType = UIImagePickerController.SourceType.photoLibrary
        self.present(imagePicker, animated: true, completion: nil)
    }
//Final step put this Delegate    
    func imagePickerController(_ picker: UIImagePickerController,
                               didFinishPickingMediaWithInfo info: [UIImagePickerController.InfoKey : Any]) {
        
        guard let selectedImage = info[.originalImage] as? UIImage else {
           Print("Error: \(info)")
        }
        
            pickedImageProduct = selectedImage
        
        dismiss(animated: true, completion: nil)
     }
    func imagePickerControllerDidCancel(_ picker: UIImagePickerController) {
        
        dismiss(animated: true, completion: nil)
    }
    
}

In Swift 4.2 you can write the function as:

    func photoLib()
    {
        //opens Photo Library, call the function in a @IBAction func
        let myPickerController = UIImagePickerController()
        myPickerController.delegate = self;
        myPickerController.sourceType = 
        UIImagePickerController.SourceType.photoLibrary
        myPickerController.allowsEditing = true
        present(myPickerController, animated: true)
    }


    func imagePickerController(_ picker: UIImagePickerController, 
    didFinishPickingMediaWithInfo info: [UIImagePickerController.InfoKey : Any]) {
    picker.dismiss(animated: true)
    
    guard let image = info[.editedImage] as? UIImage else {
        print("No image found")
        photoLabel.text = "Photo Not Found"
        return
    }
}