记录区共享是如何完成的？

Question

我的用例如下： 我的应用程序的每个用户都可以作为所有者创建一组项目。 这些项目是私有的，直到所有者邀请其他用户作为参与者共享所有项目。 参与者可以修改共享项目和/或添加其他项目。
因此，共享不是与单个项目相关，而是与所有者的所有项目相关。

我想使用 CoreData 和 CloudKit 进行 CoreData/CloudKit 镜像，并拥有私有和共享项目的本地副本。 据我了解，CoreData 和 CloudKit 将所有镜像项目放在私有数据库中的一个特殊区域“com.apple.coredata.cloudkit.zone”中。 所以，这个区域应该是共享的，即其中的所有项目。

在 WWDC 2021 视频„Build apps that share data through CloudKit and Core Data“ 中，据说NSPersistentCloudKitContainer 使用记录区域共享，而不是使用根记录的分层记录共享。 在the docs 到UICloudSharingController 中给出了如何使用rootRecord 共享记录的示例。 我认为这可以修改为使用共享记录区域。
shareRecord 例如可以改为使用

let shareRecord = CKShare(rootRecord: rootRecord)

与

let shareRecord = CKShare.init(recordZoneID:)  

但这是使用Apple进行镜像的记录区域的ID，即“com.apple.coredata.cloudkit.zone”吗？如果是这样，如果我只有区域名称，我如何获得它的CKRecordZone.ID？

Answer 1

现在我想出了如何做到这一点。也许它可以帮助其他人。

从点击分享按钮开始。
首先，检查 iCloud 私有数据库中是否已经存在 CKShare 记录。 根据它，UICloudSharingController 被初始化以便它创建它，或者它使用它。 如果它应该创建共享，则对其进行相应配置。

// See <https://developer.apple.com/documentation/uikit/uicloudsharingcontroller>
@IBAction func sharingButtonTapped(_ sender: UIBarButtonItem) {
    let barButtonItem = sender
    
    /*
     If no CKShare record has been stored yet in iCloud, it will be created below using UICloudSharingController initialized with a preparation handler.
     If it exists already, UICloudSharingController is initializes with the existing CKShare record.
     */
    getShareRecord { result in
        DispatchQueue.main.async {
            let cloudSharingController: UICloudSharingController!
            switch result {
            case .success(let ckShareRecord):
                if let shareRecord = ckShareRecord {
                    cloudSharingController = UICloudSharingController.init(share: shareRecord, container: CKContainer.default())
                } else {
                    cloudSharingController = UICloudSharingController { [weak self] (controller, completion: @escaping (CKShare?, CKContainer?, Error?) -> Void) in
                        guard let `self` = self else { return }
                        self.share(completion: completion)
                    }
                }
                cloudSharingController.delegate = self
                
                if let popover = cloudSharingController.popoverPresentationController {
                    popover.barButtonItem = barButtonItem
                }
                self.present(cloudSharingController, animated: true) {}
            case .failure(let error):
                fatalError("\(error)")
            }
        }
    }
}

// For sharing see https://developer.apple.com/documentation/cloudkit/shared_records
private func share(completion: @escaping (CKShare?, CKContainer?, Error?) -> Void) {
    if #available(iOS 15, *) {
        // iOS 15++
        let recordZoneID = CKRecordZone.ID(zoneName: "com.apple.coredata.cloudkit.zone", ownerName: CKCurrentUserDefaultName)
        let shareRecord = CKShare(recordZoneID: recordZoneID)
        
        // Configure the share so the system displays the shopping lists name and logo 
        // when the user initiates sharing or accepts an invitation to participate.
        CloudKitHelper.fullNameOfICloudAccount { result in
            var fullName: String!
            switch result {
            case .success(let name):
                fullName = name
            case .failure(let error):
                print("Could not read user name: \(error)")
                fullName = "Unknown user"
            }
            shareRecord[CKShare.SystemFieldKey.title] = String(format: NSLocalizedString("SHARING_LIST_OF_USER", comment:" "), fullName)
            let image = UIImage(named: kFileNameLogo)!.pngData()
            shareRecord[CKShare.SystemFieldKey.thumbnailImageData] = image
            // Include a custom UTI that describes the share's content.
            shareRecord[CKShare.SystemFieldKey.shareType] = "com.zeh4soft.ShopEasy.shoppingList"
            
            let recordsToSave = [shareRecord]
            let container = CKContainer.default()
            let privateDatabase = container.privateCloudDatabase
            let operation = CKModifyRecordsOperation(recordsToSave: recordsToSave, recordIDsToDelete: nil) 
            operation.perRecordProgressBlock = { (record, progress) in
                if progress < 1.0 {
                    print("CloudKit error: Could not save record completely")
                }
            }
            
            operation.modifyRecordsResultBlock = { result in
                switch result {
                case .success:
                    completion(shareRecord, container, nil)
                case .failure(let error):
                    completion(nil, nil, error)
                }
            }
            
            privateDatabase.add(operation)
        }
        
    } else {
        // iOS <15
        fatalError("Sharing is only available in iOS 15")
    }
}

func getShareRecord(completion: @escaping (Result<CKShare?, Error>) -> Void) {
    let query = CKQuery(recordType: "cloudkit.share", predicate: NSPredicate(value: true))
    privateDB.fetch(withQuery: query) { result in
        switch result {
        case .success(let returned): 
            // .success((matchResults: [CKRecord.ID : Result<CKRecord, Error>], queryCursor: CKQueryOperation.Cursor?))
            let matchResults = returned.0 // [CKRecord.ID : Result<CKRecord, Error>]
            switch matchResults.count {
            case 0:
                completion(.success(nil))
                return
            case 1:
                let recordResult = matchResults.values.first!
                switch recordResult {
                case .success(let ckRecord):
                    completion(.success(ckRecord as? CKShare))
                    return
                case .failure(let error):
                    completion(.failure(error))
                    return
                }
            default:
                fatalError("More than 1 CKShare record")
            }
        case .failure(let error):
            completion(.failure(error))
            return
        }
    }
}