How to asynchronous update image in custom CNContactViewController - ios

Question

My app has a local database of contacts not stored in the internal contact store (users can however choose to add the contacts to the internal contact store)
I'm using the CNContactViewController to show the details of the contacts - but the image is not (always) stored in the database and has to be loaded (asynchronous) on each request.
A minimalized version of the ContactModel class:
class ContactModel {
var id: String
var givenName: String?
var thumbnail: Data?
init?(_ identifier: String?, givenName: String? = nil)
{
if ((identifier ?? "").isEmpty) {
return nil
}
self.id = identifier
}
func toMutableContact() -> CNMutableContact
{
let contact = CNMutableContact()
contact.contactType = .person
contact.givenName = givenName
if let thumbnail = thumbnail {
contact.imageData = thumbnail
}
return contact
}
}
The following code shows the contact details and gets the thumbnail from an online service
func showContact(_ model : ContactModel)
{
// Create a 'CNMutableContact' from the 'ContactModel' object
let contact : CNMutableContact = model.toMutableContact()
let store = CNContactStore()
let cvc = CNContactViewController(forUnknownContact: contact)
cvc.delegate = self
cvc.contactStore = CNContactStore()
cvc.allowsEditing = false
self.navigationController?.pushViewController(cvc, animated: true)
var hasThumbnail: Bool = false
if let _ = model.thumbnail {
hasThumbnail = true
}
if !hasThumbnail {
// Get the thumbnail from the online service
getThumbnail(id: model.id) { (data, error) in
// Everything above works as expected!
// This does not work either
contact.givenName = "XXX"
if let data = data {
// How can I update the image ?
print("imageDataAvailable (before): \(contact.imageDataAvailable)") // returns: false
contact.imageData = data
print("imageDataAvailable (after): \(contact.imageDataAvailable)") // returns: true
}
}
}
}
I'm not going to save the contact to the internal contact store - just using the CNContactViewController to view the details.
If the image is set in the ContactModel then the image is shown perfectly - but if any values are changed afterwards then the view is not updated.
(The user can choose not to save the thumbnails to the local database due to space consumption)

Answer 1

You can't do that. The contact displayed by the CNContactViewController is an immutable contact with no connection to the CNMutableContact you created at the outset (it's a copy).