How to read user contacts with ContactAccessButton

2024년 6월 21일About 4 min

How to read user contacts with ContactAccessButton 관련

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How to read user contacts with ContactAccessButton | SwiftUI by Example

How to read user contacts with ContactAccessButton

Updated for Xcode 16

New in iOS 18

SwiftUI has a dedicated ContactAccessButton for displaying and adding contacts in your app, along with a contactAccessPicker() modifier for adjusting access later on.

Important

You should use ContactAccessButton initially because it's a really smooth way of reading contacts at the point they are needed, then bring in contactAccessPicker() only if needed.

To get started, open the Info tab in your app's target and add the key "Privacy - Contacts Usage Description". You should set this to a string that explains why your app needs access to contacts, so that iOS can automatically show this message when a request is made.

When it comes to the code, you need to do three things:

Add an import for ContactsUI.
Place a ContactAccessButton with a query string and some kind of action to run when a contact is selected.
Create a function that's able to receive an array of contact identifiers and turn them into actual CNContact instances by using CNContactStore.

This works best when the user is actually searching for something, so that ContactAccessButton matches the same search query you are running elsewhere in your UI.

Here's a complete example to get you started:

struct ContentView: View {
    // We hold all our loaded contacts here
    @State private var allContacts = [CNContact]()

    // Whatever the user is currently looking for
    @State private var searchText = ""

    // Results from our existing contacts list
    var filteredContacts: [CNContact] {
        if searchText.isEmpty {
            allContacts
        } else {
            allContacts.filter {
                $0.givenName.localizedStandardContains(searchText)
                || $0.familyName.localizedStandardContains(searchText)
            }
        }
    }

    var body: some View {
        NavigationStack {
            VStack {
                List(filteredContacts) { contact in
                    Text("Say hello to \(contact.givenName)")
                }
                .searchable(text: $searchText)

                // This will automatically show a contact if one is matched, or a Search button otherwise
                ContactAccessButton(queryString: searchText) { results in
                    // Run fetchContacts(with:) when a contact is selected
                    fetchContacts(with: results)
                }
                .padding()
            }
        }
    }

    // Converts an array of contact identifiers into actual contacts
    func fetchContacts(with identifiers: [String]) {
        Task {
            // Prepare the Contacts system to return the names of matching people
            let keys = [CNContactFormatter.descriptorForRequiredKeys(for: .fullName)]
            let fetchRequest = CNContactFetchRequest(keysToFetch: keys)
            fetchRequest.predicate = CNContact.predicateForContacts(withIdentifiers: identifiers)

            // Store new contacts in this array
            var newContacts = [CNContact]()

            try CNContactStore().enumerateContacts(with: fetchRequest) { contact, _ in
                newContacts.append(contact)
            }

            // Load is completed, so add the new contacts to our existing array
            allContacts += newContacts
        }
    }
}

As you can see, most of the work happens in the fetchContacts(with:) method – ContactAccessButton wraps all the UI part, but actually loading the data is still a bit of a slog. It would be nice if Apple could simplify this a little so that ContactAccessButton could be given a list of keys to fetch, and send back CNContact objects pre-filled with that data.

Note

Once the user has clicked Add for a given contact, it's down to you to store that contact safely – they will not be shown for future search results.

Once you have your ContactAccessButton in place, you can customize it using standard SwiftUI modifiers such as font() and foregroundStyle(), alongside new modifiers such as contactAccessButtonCaption() and contactAccessButtonStyle().

For example, this displays a contact's email address below their name, and also uses indigo to tint user images when they don't have a photo attached:

ContactAccessButton(queryString: searchText) { results in
    fetchContacts(with: results)
}
.contactAccessButtonStyle(.init(imageColor: .indigo))
.contactAccessButtonCaption(.email)

As an alternative to ContactAccessButton, the contactAccessPicker() modifier lets us present a list of the user's contacts in a privacy-safe way – it's controlled by the system rather than us – so that the user can add or remove many contacts at once.

Important

This API reports back to you only the contacts that were new, which means it won't include contacts added previously or contacts that were removed. Apple hasn't given us a way to handle those removals, other than manually requesting all known contacts every time and seeing what comes back.

So, I would be careful using this API: yes, it's a great way to mass add or remove contacts, but you should be sure to validate the user's selection fully each time results are returned.

For example, this code queries the contacts store by merging the new identifiers will existing identifiers, so we can detect when the user has request a contact be removed:

struct ContentView: View {
    @State private var allContacts = [CNContact]()
    @State private var showingContactsPicker = false

    var body: some View {
        NavigationStack {
            List(allContacts) { contact in
                Text("Say hello to \(contact.givenName)")
            }
            .toolbar {
                Button("Select Contacts", systemImage: "person.crop.circle.badge.plus") {
                    showingContactsPicker.toggle()
                }
            }
            .contactAccessPicker(isPresented: $showingContactsPicker) { results in
                fetchContacts(with: results)
            }
        }
    }

    func fetchContacts(with newIdentifiers: [String]) {
        Task {
            // Create an array of all identifiers, old and new
            let existingIdentifiers = allContacts.map(\.identifier)
            let allIdentifiers = existingIdentifiers + newIdentifiers

            let keys = [CNContactFormatter.descriptorForRequiredKeys(for: .fullName)]
            let fetchRequest = CNContactFetchRequest(keysToFetch: keys)
            fetchRequest.predicate = CNContact.predicateForContacts(withIdentifiers: allIdentifiers)
            var newContacts = [CNContact]()

            try CNContactStore().enumerateContacts(with: fetchRequest) { contact, _ in
                newContacts.append(contact)
            }

            allContacts = newContacts
        }
    }
}