CloudKit Samples: Sharing

Goals

This project demonstrates sharing CloudKit records across user accounts. It shows how to initiate a share from one user account, and accept the share and subsequently view shared data on another account.

Prerequisites

• A Mac with Xcode 13 (or later) installed is required to build and test this project.
• An active Apple Developer Program membership is needed to create a CloudKit container.

Setup Instructions

• Ensure the simulator or device you run the project on is signed in to an Apple ID account with iCloud enabled. This can be done in the Settings app.
• If you wish to run the app on a device, ensure the correct developer team is selected in the “Signing & Capabilities” tab of the Sharing app target, and a valid iCloud container is selected under the “iCloud” section.

Using Your Own iCloud Container

• Create a new iCloud container through Xcode’s “Signing & Capabilities” tab of the Sharing app target.
• Update the containerIdentifier property in Config.swift with your new iCloud container ID.

How it Works

User One: Initiating the Share

• On either a device or simulator with a signed-in iCloud account, User One creates a new Contact record through the UI with a name and phone number. The Contact is saved to the user’s private iCloud database with the addContact(name:phoneNumber:completionHandler) function in ViewModel.swift.

• After the Contacts list is refreshed, the newly added Contact will appear under the “Private” section of the UI.

• Tapping the share button on the Contact list entry creates a CKShare object and writes it to the database with the createShare(contact:completionHandler) function in ViewModel.swift. After the share is created, the CloudSharingView is displayed which wraps UICloudSharingController in a SwiftUI compatible view. This view allows the user to configure share options and send or copy the share link to share with User Two.

User Two: Accepting the Share Invitation

• On a separate device with a different signed-in iCloud account, User Two accepts the share by following the link provided by User One.

• The link initiates a prompt on the user’s device to accept the share, which launches the Sharing app and accepts the share through a database operation defined in SceneDelegate’s userDidAcceptCloudKitShareWith delegate callback.

• After the share is accepted and the UI is refreshed, the shared Contact will display in User Two’s Contacts list in the “Shared” section. fetchSharedContacts(completionHandler:) in ViewModel.swift shows how Contacts in shared database zones are fetched.

Note on Swift Concurrency

This project uses Swift concurrency APIs. A prior completionHandler-based implementation has been tagged pre-async.

Further Reading

• Sharing CloudKit Data with Other iCloud Users