UIViewControllerRepresentable and CNContactPickerViewController

Question

Can't seem to create a UIViewControllerRepresentable that works with CNContactPickerViewController.

Using Xcode 11 beta 4, I've created number of other UIViewControllerRepresentable using other UIViewController and those have worked fine. I've tried changing the features of the CNContactPickerViewController and different implementations of the delegate.

import SwiftUI
import ContactsUI

// Minimal version
struct LookupContactVCR : UIViewControllerRepresentable {

    func makeUIViewController(context: Context) -> CNContactPickerViewController {
        let contactPickerVC = CNContactPickerViewController()
        contactPickerVC.delegate = context.coordinator
        return contactPickerVC
    }

    func makeCoordinator() -> Coordinator {
        return Coordinator()
    }

    func updateUIViewController(_ uiViewController: CNContactPickerViewController, context: Context) {}

    class Coordinator: NSObject {}
}

extension LookupContactVCR.Coordinator : CNContactPickerDelegate {

    func contactPicker(_ picker: CNContactPickerViewController, didSelect contact: CNContact) {
        print("Chose: \(contact.givenName)")
    }
}

#if DEBUG
struct LookupContact_Previews : PreviewProvider {
    static var previews: some View {
        LookupContactVCR()
    }
}
#endif

No error messages. But the screen is always white with nothing rendered.

Answer 1

First of all, please file a [Bug Report][1] for this issue. [1]: https://bugreport.apple.com

Secondly, there are 2 workarounds for this issue:

1. You can use ABPeoplePickerNavigationController which is deprecated but still works.
2. Create a UIViewController which presents CNContactPickerViewController on viewWillAppear and use this newly created view controller with SwiftUI.

1. ABPeoplePickerNavigationController

import SwiftUI
import AddressBookUI

struct PeoplePicker: UIViewControllerRepresentable {
    typealias UIViewControllerType = ABPeoplePickerNavigationController

    final class Coordinator: NSObject, ABPeoplePickerNavigationControllerDelegate, UINavigationControllerDelegate {
        func peoplePickerNavigationController(_ peoplePicker: ABPeoplePickerNavigationController, didSelectPerson person: ABRecord) {
            <#selected#>
        }
        
        func peoplePickerNavigationControllerDidCancel(_ peoplePicker: ABPeoplePickerNavigationController) {
            <#cancelled#>
        }
    }

    func makeCoordinator() -> Coordinator {
        return Coordinator()
    }

    func makeUIViewController(context: UIViewControllerRepresentableContext<PeoplePicker>) -> PeoplePicker.UIViewControllerType {
        let result = UIViewControllerType()
        result.delegate = context.coordinator
        return result
    }
    
    func updateUIViewController(_ uiViewController: PeoplePicker.UIViewControllerType, context: UIViewControllerRepresentableContext<PeoplePicker>) { }

}

2. CNContactPickerViewController

EmbeddedContactPickerViewController

import Foundation
import ContactsUI
import Contacts

protocol EmbeddedContactPickerViewControllerDelegate: AnyObject {
    func embeddedContactPickerViewControllerDidCancel(_ viewController: EmbeddedContactPickerViewController)
    func embeddedContactPickerViewController(_ viewController: EmbeddedContactPickerViewController, didSelect contact: CNContact)
}

class EmbeddedContactPickerViewController: UIViewController, CNContactPickerDelegate {
    weak var delegate: EmbeddedContactPickerViewControllerDelegate?
    
    override func viewWillAppear(_ animated: Bool) {
        super.viewWillAppear(animated)
        self.open(animated: animated)
    }
    
    private func open(animated: Bool) {
        let viewController = CNContactPickerViewController()
        viewController.delegate = self
        self.present(viewController, animated: false)
    }
    
    func contactPickerDidCancel(_ picker: CNContactPickerViewController) {
        self.dismiss(animated: false) {
            self.delegate?.embeddedContactPickerViewControllerDidCancel(self)
        }
    }
    
    func contactPicker(_ picker: CNContactPickerViewController, didSelect contact: CNContact) {
        self.dismiss(animated: false) {
            self.delegate?.embeddedContactPickerViewController(self, didSelect: contact)
        }
    }
    
}

EmbeddedContactPicker

import SwiftUI
import Contacts
import Combine

struct EmbeddedContactPicker: UIViewControllerRepresentable {
    typealias UIViewControllerType = EmbeddedContactPickerViewController
    
    final class Coordinator: NSObject, EmbeddedContactPickerViewControllerDelegate {
        func embeddedContactPickerViewController(_ viewController: EmbeddedContactPickerViewController, didSelect contact: CNContact) {
            <#selected#>
        }
        
        func embeddedContactPickerViewControllerDidCancel(_ viewController: EmbeddedContactPickerViewController) {
            <#cancelled#>
        }
    }

    func makeCoordinator() -> Coordinator {
        return Coordinator()
    }

    func makeUIViewController(context: UIViewControllerRepresentableContext<EmbeddedContactPicker>) -> EmbeddedContactPicker.UIViewControllerType {
        let result = EmbeddedContactPicker.UIViewControllerType()
        result.delegate = context.coordinator
        return result
    }
    
    func updateUIViewController(_ uiViewController: EmbeddedContactPicker.UIViewControllerType, context: UIViewControllerRepresentableContext<EmbeddedContactPicker>) { }

}