SwiftUI 2020 + CloudKit + Core Data ZenJournal prototype: https://thezenjournal.com

App.swift

import SwiftUI
import CoreData

let appTransactionAuthorName = "app"

@main
struct ZenJournalApp: App {

    var body: some Scene {
        WindowGroup {
            NavigationWrapper()
                .environment(\.managedObjectContext, persistentContainer.viewContext)
        }
    }
    
    var persistentContainer: NSPersistentCloudKitContainer = {
            
        let container = NSPersistentCloudKitContainer(name: "ZenModel")
        
        // Enable history tracking and remote notifications
        guard let description = container.persistentStoreDescriptions.first else {
            fatalError("###\(#function): Failed to retrieve a persistent store description.")
        }
        description.setOption(true as NSNumber, forKey: NSPersistentHistoryTrackingKey)
        description.setOption(true as NSNumber, forKey: NSPersistentStoreRemoteChangeNotificationPostOptionKey)
        let id = "iCloud.com.idealistspace.zenjournal"
        let options = NSPersistentCloudKitContainerOptions(containerIdentifier: id)
        description.cloudKitContainerOptions = options

        container.loadPersistentStores(completionHandler: { (storeDescription, error) in
            if let error = error as NSError? {
                fatalError("Unresolved error \(error), \(error.userInfo)")
            }
        })
        
//        do {
//              // Uncomment to do a dry run and print the CK records it'll make
////            try container.initializeCloudKitSchema(options: [.dryRun, .printSchema])
//            // Uncomment to initialize your schema
//            try container.initializeCloudKitSchema()
//        } catch {
//            print("Unable to initialize CloudKit schema: \(error.localizedDescription)")
//        }
        
        container.viewContext.mergePolicy = NSMergeByPropertyObjectTrumpMergePolicy
        container.viewContext.transactionAuthor = appTransactionAuthorName
        
        // Pin the viewContext to the current generation token and set it to keep itself up to date with local changes.
        container.viewContext.automaticallyMergesChangesFromParent = true
        do {
            try container.viewContext.setQueryGenerationFrom(.current)
        } catch {
            fatalError("###\(#function): Failed to pin viewContext to the current generation:\(error)")
        }

        return container
    }()
}

NavigationWrapper.swift

import SwiftUI

struct NavigationWrapper: View {
    @Environment(\.managedObjectContext) var managedObjectContext
    
    @FetchRequest(fetchRequest: ZenLog.allLogsFetchRequest()) var allLogs: FetchedResults<ZenLog>

    var body: some View {
        VStack{
            TimelineView(logs: self.allLogs)
        }
    }
}

ZenLog.swift

import Foundation
import CoreData
class ZenLog: NSManagedObject, Identifiable {
    @NSManaged var text: String?
    @NSManaged var createdAt: Date?
}

extension ZenLog {
    // ❇️ The @FetchRequest property wrapper in the ContentView will call this function
    static func allLogsFetchRequest() -> NSFetchRequest<ZenLog> {
        let request: NSFetchRequest<ZenLog> = ZenLog.fetchRequest() as! NSFetchRequest<ZenLog>
        
        // ❇️ The @FetchRequest property wrapper in the ContentView requires a sort descriptor
        request.sortDescriptors = [NSSortDescriptor(key: "createdAt", ascending: true)]
          
        return request
    }
}