The final page I found is a blog from Andrew Bancroft. Your entitlements file will look something like: This next step deals with your .xcdatamodel file. If you don’t want to manually make your class, you can skip this step and go to the next section. If you select “Schema” in CloudKit dashboard, you can see that the Entity created in Core Data is automatically created on CloudKit! I would like to dive a little deeper into the comparison between Core Data and Realm. CloudKit Tutorial: Getting Started, CloudKit Tutorial: iCloud - Save Data in SwiftUI // In this iCloud Swift tutorial you will learn how Duration: 18:42 Posted: Oct 31, 2019 In the CloudKit dashboard, go back to Data, select Public Database and the type Establishment from the drop-down. I have worked with Core Data long time ago and left with a bad impression about the framework. Select the Use Core Data and Use CloudKit checkboxes. All of these changes go in our AppDelegate.swift file. Even better, CloudKit is free as long as you stay within a generous quota – you get 10GB of asset storage, 100MB of database storage, 2GB of data transfer, and 40 requests per second – and those are just the starting figures. Full disclosure: I am the developer of Ensembles, a Core Data sync framework that works with many different services, including CloudKit, Dropbox, WebDAV, and even peer-to-peer. There is also another important property you should set in the relationships. By creating a useful app for a small pizza restaurant, we will talk through all basic CRUD operations (Create, Read, Update, and Delete Data) used in Core Data. CloudKit Quick Start 03 Use CloudKit Dashboard to Manage Databases (SwiftUI iCloud CloudKit Chinese Document Manual Tutorial) You can use the CloudKit dashboard to perform many database management tasks. Without this, you cannot use CloudKit at all. When we use many NSSortDescriptor, they must be written in order of importance. You have to set a flag, then choose how you want to merge the data using a merge policy. For now, I’m going to follow the demo and use NSMergeByPropertyStoreTrumpMergePolicy. I'll give you an introduction throughout this post on how to start developing apps in SwiftUI using Core Data. Of course there are a thousand of things you'll learn after it. Migrations, for example. The main components of the Core Data Stack are: However, since iOS 10, we have another class that abstracts most of this complexity from us. Core Data can take care of your model layer, it can hold your entities, so you can ask Core Data for sorted, or filtered sets of entities that you need in some point of your app execution. You don't have to manually create anything. The next thing we need to do is setup the iCloud capability. Their code didn’t work right off the bat for me, but updating the NSPersistentStoreRemoteChange Observer in their code to use nil instead of container got this to work. The selector you pass in here will get called whenever a change from the cloud is saved to your device. Users expect it and expect it to work well, but it can be tricky to implement. In the list relationship, set the type as To One, because a Todo may only be included in a single list. I’ll just call my entity Entity and give it a single property name. I’ve seen a few different examples of what you need for this to work. Now we need to pull changes from the iCloud. I covered all the basic steps you need to keep in mind while starting a new project using Core Data in SwiftUI. It adds the Todo to the relationship. Without this, changes will not be pulled down from the iCloud to your phone. At the end of this, I want you to be able to setup a basic Core Data stack that automatically syncs to the cloud. Forums. Core Data & iCloud Auto Sync. Learn how to use Apple's CloudKit API to keep a user’s data … You also need to add the Background Modes capability and check the Remote Notifications option. You need to either have a personal account or a business account. https://forums.developer.apple.com/thread/120453, try container.initializeCloudKitSchema(options: []). The way the app was setup, it synchronization doesn’t happen very often. The rest of them are: You also need to set automaticallyMergesChangesFromParent to true. NSFetchRequest is a class that represents a query. It is an hour long and has no sound after the first 4 minutes. NSPersistentContainer, which holds all these classes and exposes a viewContext property which is a NSManagedObjectContext you can use to generate NSManagedObject entities, save, delete and update them. I followed everything up to the Manage Multiple Stores section. We strive for transparency and don't collect excess data. Learn. I found a similar quirkiness with sync not working correctly without backgrounding the app in my own development. The first thing you’ll have to do is setup a developer account on Apple’s website. If you didn’t initialize the project with CloudKit, you’ll need to update this manually. "An error ocurred while instantiating persistentContainer: "Failed loading persistent stores with error: "Failed to locate momd file for TodoListsSwiftUI", "Failed to load momd file for TodoListsSwiftUI", https://gumroad.com/l/practical-core-data, https://github.com/fmo91/TodoListsSwiftUI. Senior iOS Engineer and Mobile Chapter Lead at Parser Digital | ortizfernandomartin@gmail.com. Next, click on Query Records. The default behavior is to throw an error, but you can also have local or remote changes be the source of truth. SwiftUI and Core Data: The MVVM Way. The NSManagedObjectContext can be used for all the operations we need to do from the app that would impact in the persistent stores. Here is the code: So, that's it! Adding a new capability will create a new entitlements file and add the container to it. Once you log into your account, CloudKit will work in the simulator. If you'd like to unit test your Core Data implementation, you'll need to do some changes in our PersistenceProvider. Most of the important code is in the CoreDataStack.swift file. This ends up looking like the following: While I have used Core Data for close to ten years, I don't have much experience with Realm. You can do this by going to your App settings, clicking on the +Capability button, and searching for iCloud. It works similar to Core Data, although it’s much simpler in practice – you can save any kind of Swift data you like, and CloudKit takes care of the rest. If I need all the Todo for a list, this is the fetch request I'd set: This is a bit more complex, since I'm adding a predicate. It will trigger the fetch request, and in case the underlying data storage changes, the fetch request will trigger again, making the view re-render. We're a place where coders share, stay up-to-date and grow their careers. They listen for NSPersistentStoreRemoteChange notifications in NotificationCenter. Follow. Here is the code: Now, imagine if you had to do some query depending on a parameter you send to the View using its init method. Core Data can store your data in a SQLite database, or it can have your data in-memory, or even synchronized with CloudKit. If you want more information about how to correctly use Core Data, I would highly recommend reading Donny Wals' Practical Core Data book https://gumroad.com/l/practical-core-data . First, we want to test each test independently, and start from a clean state for each test case, so we'll create an enum for each case: inMemory and persisted. Download the code (or copy it from this article), and you can compile it and see the actual app running. The second page I found was a step by step guide to setting up Core Data with CloudKit in Swift. So, as also shown in the images, create a list relationship in Todo with destination equal to TodoList and a todos relationship in TodoList with destination equal to Todo and the inverse equal to list. Mattia Righetti. Also, we're using two NSSortDescriptor. Really, it is not an ORM. The next step is to add an observer for NSPersistentStoreRemoteChange notifications. Apple provides a bunch of merge policies. In this article, I will show you how you can start using Core Data, and how you can enjoy using it most of the time. However, it seems that something changed. When you initialize a project with CloudKit, you’ll see some differences in the AppDelegate.swift file. CloudKit is a framework by Apple where developers can use to build app with iCloud integration to store data in a database or assets within containers. at least once but only once every time you reset your CloudKit development container or create a new container. There’s a lot I didn’t cover in this article (like more advanced merging techniques), but I hope that you learned something from this. In this tutorial, we're going to focus on integrating Core Data Cloud with CloudKit using NSPersistentCloudKitContainer to an existing expense tracker iOS & … SwiftUI – Hacking with Swift forums. Of course this is a brief introduction. Select a Single View template and check the Core Data and Cloudkit boxes on the next screen and choose SwiftUI as the User Interface. With this article, I would like to debunk a few misunderstandings about Core Data and point out some less obvious advantages of Core Data and Realm. The first thing I do when learning something new is check out what documentation already exists for it. I would like to know for sure! A laughably simple sample app for experimenting with SwiftUI and a CloudKit-backed CoreData store. A clean and intuitive way to handle Core Data entities in SwiftUI. Instead, I'm requesting all the TodoList that are in the store. The biggest change is that persistentContainer now returns a NSPersistentCloudKitContainer instead of a NSPersistentContainer. DEV Community – A constructive and inclusive social network for software developers. Since iOS 13 now supports Core Data auto sync with CloudKit, the project will take advantage of that. For Money Master, I was able to remove almost 1000 lines of my most complex code, and I have more reliable sync as a… Let's see the full example of the list of Todo: In this example, whenever the allLists property changes, the body will be recalculated. - jknlsn/SwiftUI-Core-Data-Test If you haven’t checked out his blog before, I highly recommend it. With Core Data + CloudKit, we're able to persist data locally as well as syncing the data to iCloud across all our Apple devices. Relationships may be To One or To Many. I haven’t been able to pin down exactly what creates this container, but I’m pretty sure they are created when you enter it in the config. Finally, i’ll make my Entity class. This isn’t necessarily an issue, but it’s annoying to see a ton of containers. In Todo, add title, creationDate and completed, as non-optional properties, as shown in the image: In TodoList, add title and creationDate, as non-optional properties, as shown in the image: There should be a relationship between Todo and TodoList, since a TodoList may have any number of Todo objects related to it. So far, so good. This means that Core Data (the local storage) Technical Apparel For Recreation To Get You Out There And Doing Things Daily. I found a youtube video on how to save and image with core data and swiftui. To create a new entity, you just instantiate the object for that entity sending the context to its constructor and then save the context. Core Data can store your data in a SQLite database, or it can have your data in-memory, or even synchronized with CloudKit. DEV Community © 2016 - 2021. This tells our persistent container to notify us when there are changes in the cloud that we don’t have. CloudKit Tutorial: iCloud - Save Data in SwiftUI // In this iCloud Swift tutorial you will learn how to use CloudKit in SwiftUI. Use the Core Data model editor to define your app’s entities and their properties, or construct your model in code. Github repo to some code: https://github.com/SchwiftyUI/OrderedList, If you want to help support this blog: https://www.patreon.com/SchwiftyUI. Core Data is not an ORM. A couple of webpages led me to an answer: https://developer.apple.com/documentation/coredata/mirroring_a_core_data_store_with_cloudkit/creating_a_core_data_model_for_cloudkit It's worth reading it if you'll use Core Data in a project. The Apple tutorials say you need to edit your configurations and check the Used with CloudKit box. Following along with this will create containers in your iCloud developer account. Todo - Core Data, App Themes, and Alternate App Icons iOS 14 and iOS 13 app; Honeymoon - iOS 14 and iOS 13 app; What kind of advanced topics will be covered: MVVM architecture, External REST APIs integration, Combine Framework, SwiftUI Animation, Advanced Core Data with CloudKit integration, App Clips, App Widgets, Test-driven app development, This way, we have the counterpart of the list relationship. I've never used it again (started using Realm short after it). So, you have created a Xcode project with Core Data, or you have initialized a new Core Data stack in an existing project. The app we'll be building will let us create many ToDo lists, complete, and delete them. I found that this allowed data to sync properly without having to background the app. Core Data with CloudKit framework should be at … If you didn’t initialize the project with CloudKit, you’ll need to update this manually. Really typical. Enter any other project details and click Next. Without entering in further details, I recommend setting the Delete Rule in the todos relationship as Cascade. Data stored in the iCloud will be synced between simulators and your real devices. Step 1: Setup Core Data with CloudKit. This post is an introduction on how to use CloudKit, and is by no means a comprehensive guide. In this video, Mohammad Azam will explain how to integrate Core Data with SwiftUI application. AppDelegate.swift. Once you add the iCloud capability, you need to check the CloudKit services box and create a new container. Once you set this up, you have to sign into Xcode with this this account. This container will eventually show up in https://icloud.developer.apple.com. To execute a request, you just call the method fetch in the managed object context: Updating an entity in CoreData is as simple as setting new values to its properties and then saving the context: For deleting an entity you call the method delete in the context and then save the context: In order to make the NSManagedObjectContext available from all the application, you need to inject it in the initial view for your app using the environment modifier, injecting the context for the \.managedObjectContext key, like this: Inside your views, you can set a property as a @FetchRequest, so you can add relate a property in your view to a request to Core Data. Tutorial: https://www.blckbirds.com/post/core-data-and-swiftui - Abdenasser/Core-Data-in-SwiftUI---Pizza-Restaurant-App Core Data is a graph-based optionally persisted model framework. See I'm not setting any predicate for this fetch request. From my testing, you just need a basic class like: At this point, we have an app that will upload data to the iCloud. Apple has 2 pages I found extremely helpful, and I found a nice blog about this. If the template you want to use doesn’t support Core Data, add Core Data to the project as described in Setting Up a Core Data Stack. These containers are not deletable. The .xcdatamodeld file is normally named after your project. I bought it and it has been worth the money spent. The NSPredicate takes a format, for which I send a keyPath referencing the list property. Note: TodoListView is just a helper component, it doesn't do anything related to Core Data itself. So in this case, it will sort the results using completed, and then using creationDate. I'm not sure if Core Data became much better (NSPersistenceContainer has been added after I stopped using Core Data), or if I leveled up as a developer. With SwiftUI, building an independent watch App has never become so much simple and fast! For all the operations you do in Core Data, I recommend creating classes that will take care of them. I had to re-open the app before synchronization occurred. Modern mobile application development requires a well thought-out plan for keeping user data in sync across various devices. Today we will learn how to use the Core Data framework with SwiftUI to store and manage persistent data. Specify a location for your project and click Create. The next thing you need to do is sign into your Apple account in the simulator. CloudKit is a good option for iOS-only apps that use a lot of data but don’t require a great deal of server-side logic. As simple as it sounds: To create a Todo for this TodoList, it is as simple as this: The only maybe weird part is the addToTodos method that we call on list. This app isn’t SwiftUI, but it answered a lot of questions for me. Not all project templates support Core Data. If you prefer to just go over the code and learn it the hard way, here is the Github repo: https://github.com/fmo91/TodoListsSwiftUI. His page was very helpful, but I noticed that some of the things he did didn’t seem to be necessary. I try to update the core data entity using the following code self.viewContext.performAndWait { editingGroup.icon = self.icon editingGroup.title = self.title editingGroup.isFavorite = With you every step of your journey. Setting up merging is pretty simple. And see how easier it is to create the stack: The only thing that should change between this code and your app's code is the name you send to the persistent container init. The first page links to an app Apple created using Core Data + CloudKit. The video is worth it and now I am able to save images with Core Data and SwifUI. That name is the name of the .xcdatamodeld file where you define your entities, and relationships. The Core Data Stack is composed of objects which interact between them to persist entities. Templates let you quickly answer FAQs or store snippets for re-use.