SwiftUI and UICloudSharingController hate each other

Question

I have a project using SwiftUI that requires CloudKit sharing, but I\'m unable to get the UICloudSharingController to play nice in a SwiftUI environment.

Answer 1

I got this working -- initially, I wrapped the UICloudSharingController in a UIViewControllerRepresentable, much like the link you provided (I referenced that while building it), and simply adding it to a SwiftUI .sheet() view. This worked on the iPhone, but it failed on the iPad, because it requires you to set the popoverPresentationController?.sourceView, and I didn't have one, given that I triggered the sheet with a SwiftUI Button.

Going back to the drawing board, I rebuilt the button itself as a UIViewRepresentable, and was able to present the view using the rootViewController trick that SeungUn Ham suggested here. All works, on both iPhone and iPad - at least in the simulator.

My button:

struct UIKitCloudKitSharingButton: UIViewRepresentable {
    typealias UIViewType = UIButton

    @ObservedObject
    var toShare: ObjectToShare
    @State
    var share: CKShare?

    func makeUIView(context: UIViewRepresentableContext) -> UIButton {
        let button = UIButton()

        button.setImage(UIImage(systemName: "person.crop.circle.badge.plus"), for: .normal)
        button.addTarget(context.coordinator, action: #selector(context.coordinator.pressed(_:)), for: .touchUpInside)

        context.coordinator.button = button
        return button
    }

    func updateUIView(_ uiView: UIButton, context: UIViewRepresentableContext) {

    }

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

    class Coordinator: NSObject, UICloudSharingControllerDelegate {
        var button: UIButton?

        func cloudSharingController(_ csc: UICloudSharingController, failedToSaveShareWithError error: Error) {
            //Handle some errors here.
        }

        func itemTitle(for csc: UICloudSharingController) -> String? {
            return parent.toShare.name
        }

        var parent: UIKitCloudKitSharingButton

        init(_ parent: UIKitCloudKitSharingButton) {
            self.parent = parent
        }

        @objc func pressed(_ sender: UIButton) {
            //Pre-Create the CKShare record here, and assign to parent.share...

            let sharingController = UICloudSharingController(share: share, container: myContainer)

            sharingController.delegate = self
            sharingController.availablePermissions = [.allowReadWrite]
            if let button = self.button {
                sharingController.popoverPresentationController?.sourceView = button
            }

            UIApplication.shared.windows.first?.rootViewController?.present(sharingController, animated: true)
        }
    }
}