into instances of CKRecord that are stored in CloudKit. Youll need to ensure that you have set a unique bundle identifier at this point. More importantly, you have a foundation for adding more advanced CloudKit functionality. The CKFetchRecordsOperation operates on one or more records at a time. Asking for help, clarification, or responding to other answers. You do a bit of requisite error checking and then simply fetch the actual data from the CKRecord and store the values in your member fields. Rather than relying on individual notifications to give you detailed knowledge of what change an individual notification represents, you use a notification to simply indicate that something has changed, and then you can ask CloudKit whats changed since the last time you asked. and operate on the objects I share with them. New in iOS 15 is acceptShareInvitations(from:into:completion:). Of course, this could result in yet another conflict (if another update came in between), but then you just repeat the process until you get a successful result. Once set up, operations are passed to the CKDatabase object, where theyll be executed on a background thread. Naturally, this domain knowledge is reflected in the APIs we have built for NSPersistentCloudKitContainer. where my friends and I can share our photos with each other. Then, it sets the persistent store based on the scope. Let's look at that change in a bit more detail. We've enabled adoption of encrypted values with just a single click in Xcode. If I select the location attribute, I can see its configuration in the data model inspector on the right. CloudKit is built on top of Apples iCloud service. Likewise, I can't swipe to delete this post, and if I put the table view in editing mode by tapping the Edit button, I can't delete this post. For our purposes, a single view application containing a UITextView with the ViewController as its delegate will suffice. Heres Apples sample project on Synchronizing a Local Store to the Cloud. For your Note app, you can use the default container. Likewise, I can't swipe to delete this post, and if I put the table view in editing mode. Launching the CI/CD and R Collectives and community editing features for How to share Core Data between multiple users? You see a travel journal screen with an empty state message and a button. Every app automatically gets a default CKContainer, and a group of apps can share a custom CKContainer if permission settings allow. It rejects specific requests with enough error context in the response to allow each client to make a local, enlightened decision about how to resolve the conflict. For each participant, NSPersistentCloudKitContainer manages objects in two CloudKit databases, the .private and the .shared database. The UICloudSharingController is a view controller that presents standard screens for adding and removing people from a CloudKit share record. Share Core Data between users with NSPersistentCloudKitContainer Ask Question Asked 3 years, 7 months ago Modified 1 year, 8 months ago Viewed 3k times 16 Apple introduced the NSPersistentCloudKitContainer with iOS 13 which enable us to use CloudKit with Core Data. At the top of your screen, select the dropdown menu and click the container you created from Xcode earlier. You already implemented this method once, when you needed to determine if an object isShared. before deploying your schema to production. So that's how we use NSPersistentCloudKitContainer. by tapping the Edit button, I can't delete this post. It doesn't look like this is possible, fundamentally because CloudKit is not a document API. When a notification comes in that a record has changed, CloudKitNoteDatabase will do the heavy lifting of fetching the changes from CloudKit. CloudKit prefixes your entities with CD to distinguish them from traditional CloudKit records. Here, youll add the code to accept the share. Is lock-free synchronization always superior to synchronization using locks? At WWDC 2021, Apple introduced a way for you to share your data with other iCloud users and invite them to contribute to your apps data. It has a wide variety of actions I can take, including a number of ways to share. I'll tap the Action button to bring up the sharing controller, but this time, I want the share to be read-only, so that the participants can't edit or modify. Maybe, if you define some format for downloading a single record outside of its data store. At the moment, when you launch the app, entries in your journal all look the same. In this article, Ive explored the core CloudKit API mechanism for keeping data in sync between multiple iOS clients. In the window that comes up, enter your containers name. Add a destination. Owners create and share objects with a set of participants. At the top level is CKContainer, which encapsulates a set of related CloudKit data. In my brief demo, I showed an application that makes use of two CloudKit databases, the .private and the .shared database. To edit or update the caption or description, tap the destination cell to see the detail screen. Kodeco requires JavaScript. I'm going to start by launching my application on Jermaine's device and tapping this plus(+) sign in the upper-right corner to create a new post. Within a CKDatabase are CKRecordZones, and within zones CKRecords. If you have any questions or comments, please join the forum discussion below. and some of the permissions on the shared album. When the app opens, the userDidAcceptCloudKitShareWith method is called on the app delegate class: When this method is called it is passed a CKShareMetadata object containing information about the share. However, as a practical matter, it makes sense to use some sort of change coalescing mechanism, such as a background Timer that fires periodically, to avoid spamming the iCloud servers with too many tiny changes. Within this handler, the CKShare object must be created and saved as outlined in the previous section. It accepts the share and adds the necessary metadata into the sharedPersistentStore. CloudKit app require a few items to be enabled on the Capabilities Pane of the Xcode Target: iCloud (naturally), including the CloudKit checkbox, Push Notifications, and Background Modes (specifically, remote notifications). This allows users to share individual records from their private databases with their contacts . The SharingProvider has methods for binding. First, update your container type to NSPersistentCloudKitContainer. This is your Destination entity in Core Data. It is important to be aware that this fetch operation must be executed on the shared cloud database instance of the app instead of the recipients private database. Now I'm going to add a new post, give it a title, and tap Done. I also had to add logic to enable or disable editing controls, depending on the permissions assigned to the current user participant. Here I'm setting the isSharedBlock to call the contains method of the set I created. than the simple injection I used in the test. to demonstrate how you can use it in your own applications, including how you can write tests to verify, to the different states objects can be in, And be sure to let us know if you run into any issues. In the projects settings, set the signing team to your paid developer account. To dig deeper into CloudKit, I strongly recommend taking the time to view the various CloudKit presentations from each of the last few WWDCs and follow along with the examples they provide. Because there's no root record, NSPersistentCloudKitContainer also has to understand how the concepts of owners and participants apply to the entire record zone. We and our partners use data for Personalised ads and content, ad and content measurement, audience insights and product development. When you create a destination, the data is being persisted via Core Data locally in your app. On Apple platforms, there are a number of ways we can share the data our applications create. But first, a quick discussion of CloudKit Errors. CloudKit: For managing structured data and sharing data among users. Learn SwiftUI and take your iOS Development to the Next LevelSwiftUI Essentials iOS 16 Edition book is now available in Print ($39.99) and eBook ($29.99) editions. - Accepting a shared note will now move it to the top level of your notes folder - Fixed a bug where clicking on the month name on macOS shifted the calendar weeks - Improved website titles when pasting a web link in NotePlan - iCloud Drive sync is now hidden as a sync option for new users since Cloudkit provides a better sync experience Implicit in all of this is that CloudKit may not always be available. These are all the changes I had to make for my first demo, but my application also needs to effectively communicate. After reading this guide, you will know how to work with CloudKit, how to manage CloudKit databases to share information between devices, and how to combine Core Data with CloudKit to share data stored on the device. Toptal handpicks top iOS developers to suit yourneeds. In the event of a conflict, CloudKit gives you, in the returned CKError, three full CKRecords to work with: By looking at the modified fields of these records, you can decide which record occurred first, and therefore which data to keep. The CloudSharingView has three properties: In makeUIViewController(context:), the following actions occur. It is important to be aware that when a share recipient accepts a share they are actually receiving a reference to the original record in the owners private database. directly to specific call sites in my application. Select Private Database. persistentContainer calls this method. CloudKit supports both structured and bulk data. The app designer is always in the best position to define rules for these situations, which can include everything from context-aware automatic merging to user-directed resolution instructions. Under isShared(object:), add the following methods: These methods return a Boolean based on the objects permissions. NSPersistentCloudKitContainer turns those managed objects into instances of CKRecord that are stored in CloudKit. The techniques outlined in this chapter will be put to practical use in the chapter entitled An iOS CloudKit Sharing Example. So that's how we use NSPersistentCloudKitContainer to combine the .private and .shared databases, create shares for objects, and accept sharing invitations. fetchShares(matching objectIDs:) is new in iOS 15 and allows me to get the CKShare for a specific post. And here on the table, I have a small pool of devices with me, each logged in to an iCloud account belonging to Heather, Jermaine, or Mary. Last, open HomeView.swift and look for the swipeActions modifier. CloudKit sharing allows records stored within a private CloudKit database to be shared with other app users at the discretion of the record owner. we need to identify two crucial concepts for sharing. The first step is to create a method that prepares your shared data. to store the objects an application creates. He loves solving hard problems. Connect and share knowledge within a single location that is structured and easy to search. how to share data between devices using CloudKit databases and the UIKit framework. But this isn't how NSPersistentCloudKitContainer works. The solution is in CloudSharingController.swift. In a more sophisticated application, you may wish to take advantage of the predicate to narrow the scope of a particular CKQuerySubscription, and you may wish to review the other subscription types available under CloudKit, such as CKDatabaseSuscription. The prior version of the record you tried to save. Select Private Database. This means not only the owner but also the second user can modify the data shared with them. Go to the first device you created the share from, because you need to be the Owner to access the Share Options. Generally speaking, youll be working with an NSManagedObject from your view. This seems to be a good tool for that: https://github.com/usebutton/ios-deeplink-sdk Streaming is available in most browsers, and in the WWDC app. The first change I had to make was to tell NSPersistentCloudKitContainer to mirror the .shared CloudKit database to a new persistent store. Apps can support such use cases by moving user data to CloudKit and implementing a data sharing flow that includes features like share management and access control. Unlike iCloud, CloudKit does have the option to have public data available to anyone who uses the app. Next, add the following code below the // TODO: 3 comment: This code adds your shared NSPersistentStoreDescription to the container. On Jermaine's device now, I'll accept the new share. Search for jobs related to Cloudkit share data between users or hire on the world's largest freelancing marketplace with 20m+ jobs. For example, this user may have a private zone and a shared zone that they own in their .private database. depending on whether or not they are the owner of those zones. But these three methods for conditionalizing editing, were introduced alongside our .public database support, You can use these methods in your applications. was to tell NSPersistentCloudKitContainer. If you've worked with sharing before, you're probably familiar with hierarchical sharing, where these records are associated with a root record called the share. Select recordName from the list and ensure the index type is Queryable. Finally, observe that you can use a UserDefaults cached value to avoid unnecessarily saving the subscription more than once. introduced in the "What's New in CloudKit" session. How did StorageTek STC 4305 use backing HDDs? Since this is a first example of using an operation, here are a couple of general observations: First, all CloudKit operations have custom completion closures (and many have intermediate closures, depending on the operation). In my .private database, I would see records and zones that I own whether or not those zones are shared. Build apps that share data through CloudKit and Core Data Learn how to easily build apps that share data between multiple iCloud users with NSPersistentCloudKitContainer. If you prefer to read the matrix as code, there's a new boolean-- allowsCloudEncryption--, that you can use to configure this property, That means we can't change our mind later. The only way to distinguish the private records versus shared records is to tap the detail and view the role in the participants list. I needed a way to ensure they all work correctly. I've already saved Heather and Mary in my address book, so they're easy to find. Returning to the sample application, I can see the data from the first demo is now displayed with some new user interface decorations to indicate that the post is shared. CloudKit organizes data via a hierarchy of classes: CKContainer, CKDatabase, CKRecordZone, and CKRecord. Depending on the context, you may wish to assign a higher qualityOfService and handle these situations yourself. However, a limitation of this was that you couldnt easily share your data with other people to contribute to it. Otherwise, use fetchShares(matching:) to see if you have objects matching the objectID in question. However, such conflicts can arise from other circumstances. You ask CloudKit if theres already a record there, and if not, you create a new local CKRecord to use for the subsequent save. Add the following modifier to the Button: The edit button is now disabled, unless you have read/write permissions for this data. It's been my pleasure to introduce just some of the changes we've made to NSPersistentCloudKitContainer to support sharing. There you go! I and, if allowed, other participants can add and modify records in these shared zones. Then, I set its CloudKit container options databaseScope property to .shared. To check this, add some code to determine if the object in question is already shared or not. and how to operate on records and objects. For iOS and macOS, Apple provides a robust toolkit, called CloudKit API, which allows developers targeting Apple platforms to solve this synchronization problem. What's important is that it's way more complicated than I can easily exercise every time I want to verify a change to the table view, and trying to do so would add a lot of friction to the development process. Using a single managed object context, my application can access data in both stores. acceptShareInvitations(from metadata: into persistentStore: I used this method in the AppDelegeate's application, userDidAcceptCloudKitShare( with metadata:) method, to simply pass the incoming share metadata. and a shared zone that they own in their .private database. In many cases, it can infer where records belong based on the relationship they have to other objects. Note that the same code will work for macOS clients as well, with slight adjustments for differences in how notifications work on that platform. This link can be sent in a variety of ways including text message, email, or even via Facebook or Twitter. Basic CloudKit Setup CloudKit organizes data via a hierarchy of classes: CKContainer, CKDatabase, CKRecordZone, and CKRecord. I'll tap the Action button to bring up the sharing controller, but this time, I want the share to be read-only so that the participants can't edit or modify the contents of the share. whether or not to convert the title of a post. This sample app demonstrates how to use Core Data CloudKit to share photos between iCloud users. You could solve this by creating a CKRecord that contains a CKAsset which is the file that you want to share. Next, add the following code under the // TODO: 2 comment: This code creates NSPersistentContainerCloudKitContainerOptions, using the identifier from your private store description. Then, I set the BlockBasedProvider as the provider for the view controller, completing the injection. We call them the owner and the participants. Synchronizing a Local Store to the Cloud. At the top level is CKContainer, which encapsulates a set of related CloudKit data. to show that the post is part of a share. Its intended for experienced iOS developers who are already familiar with Apples frameworks and with Swift. This is a cute trick in Swift that allows me to simply check if the provided objectID is in sharedObjectIDs. of shared objects without ever talking to the CloudKit server. Next, we'll take a deep dive into the mechanics of sharing. NSPersistentCloudKitContainer manages these zones and automatically assigns records to them. From the home screen, open Settings. To view the purposes they believe they have legitimate interest for, or to object to this data processing use the vendor list link below. Launch a simulator. create shares for objects, and accept sharing invitations. If I'm allowed to, I can add records that I own to any of those zones just as they can in the zones that I own. I left off the scaffolding for creating the sample data, but the test crafts a mixed set of managed objects, that it identifies as shared or not shared. This might not always be the best outcome for professional apps, but its not bad for a first rule and, for this purpose, serves to illustrate the mechanism by which CloudKit passes conflict information back to the client. In Core Data, we think of our objects in terms of NSManagedObject. Now, youll resolve this error.