Meet the new Photos picker

2:27 - PHPickerConfiguration

import PhotosUI

var configuration = PHPickerConfiguration()

// “unlimited” selection by specifying 0, default is 1
configuration.selectionLimit = 0

// Only show images (including Live Photos)
configuration.filter = .images
// Uncomment next line for other example: Only show videos or Live Photos (for their video complement), but no images
// configuration.filter = .any(of: [.videos, .livePhotos])

3:07 - PHPickerViewController

import UIKit
import PhotosUI

class SingleSelectionPickerViewController: UIViewController, PHPickerViewControllerDelegate {
    @IBAction func presentPicker(_ sender: Any) {
        var configuration = PHPickerConfiguration()
        // Only wants images
        configuration.filter = .images
        
        let picker = PHPickerViewController(configuration: configuration)
        picker.delegate = self
        
        // The client is responsible for presentation and dismissal
        present(picker, animated: true)
    }
    
    func picker(_ picker: PHPickerViewController, didFinishPicking results: [PHPickerResult]) {
        // The client is responsible for presentation and dismissal
        picker.dismiss(animated: true)
        
        // Get the first item provider from the results, the configuration only allowed one image to be selected
        let itemProvider = results.first?.itemProvider
        
        if let itemProvider = itemProvider, itemProvider.canLoadObject(ofClass: UIImage.self) {
            itemProvider.loadObject(ofClass: UIImage.self) { (image, error) in
                // TODO: Do something with the image or handle the error
            }
        } else {
            // TODO: Handle empty results or item provider not being able load UIImage
        }
    }
}

5:19 - Demo - Single Selection

import UIKit
import PhotosUI

class ViewController: UIViewController {
    
    @IBOutlet weak var imageView: UIImageView!
    
    @IBAction func presentPicker(_ sender: Any) {
        var configuration = PHPickerConfiguration()
        configuration.filter = .images
        
        let picker = PHPickerViewController(configuration: configuration)
        picker.delegate = self
        present(picker, animated: true)
    }
    
}

extension ViewController: PHPickerViewControllerDelegate {
    
    func picker(_ picker: PHPickerViewController, didFinishPicking results: [PHPickerResult]) {
        dismiss(animated: true)
        
        if let itemProvider = results.first?.itemProvider, itemProvider.canLoadObject(ofClass: UIImage.self) {
            let previousImage = imageView.image
            itemProvider.loadObject(ofClass: UIImage.self) { [weak self] image, error in
                DispatchQueue.main.async {
                    guard let self = self, let image = image as? UIImage, self.imageView.image == previousImage else { return }
                    self.imageView.image = image
                }
            }
        }
    }
    
}

7:34 - Demo - Multiple Selection

import UIKit
import PhotosUI

class ViewController: UIViewController {
    
    @IBOutlet weak var imageView: UIImageView!
    
    var itemProviders: [NSItemProvider] = []
    var iterator: IndexingIterator<[NSItemProvider]>?
    
    @IBAction func presentPicker(_ sender: Any) {
        var configuration = PHPickerConfiguration()
        configuration.filter = .images
        configuration.selectionLimit = 0
        
        let picker = PHPickerViewController(configuration: configuration)
        picker.delegate = self
        present(picker, animated: true)
    }
    
    func displayNextImage() {
        if let itemProvider = iterator?.next(), itemProvider.canLoadObject(ofClass: UIImage.self) {
            let previousImage = imageView.image
            itemProvider.loadObject(ofClass: UIImage.self) { [weak self] image, error in
                DispatchQueue.main.async {
                    guard let self = self, let image = image as? UIImage, self.imageView.image == previousImage else { return }
                    self.imageView.image = image
                }
            }
        }
    }
    
    override func touchesEnded(_ touches: Set<UITouch>, with event: UIEvent?) {
        displayNextImage()
    }
    
}

extension ViewController: PHPickerViewControllerDelegate {
    
    func picker(_ picker: PHPickerViewController, didFinishPicking results: [PHPickerResult]) {
        dismiss(animated: true)
        
        itemProviders = results.map(\.itemProvider)
        iterator = itemProviders.makeIterator()
        displayNextImage()
    }
    
}

11:13 - Using PHPicker with PhotoKit

import UIKit
import PhotosUI

class PhotoKitPickerViewController: UIViewController, PHPickerViewControllerDelegate {
    @IBAction func presentPicker(_ sender: Any) {
        let photoLibrary = PHPhotoLibrary.shared()
        let configuration = PHPickerConfiguration(photoLibrary: photoLibrary)
        let picker = PHPickerViewController(configuration: configuration)
        picker.delegate = self
        present(picker, animated: true)
    }
    
    func picker(_ picker: PHPickerViewController, didFinishPicking results: [PHPickerResult]) {
        picker.dismiss(animated: true)
        
        let identifiers = results.compactMap(\.assetIdentifier)
        let fetchResult = PHAsset.fetchAssets(withLocalIdentifiers: identifiers, options: nil)
        
        // TODO: Do something with the fetch result if you have Photos Library access
    }
}