CloudKit

CloudKit

Sync app data across devices using iCloud with CloudKit containers, records, and queries.

Setup & Container

Enable iCloud and CloudKit capability, then use a container and database.

Syntax:

• let container = CKContainer.default()
• let db = container.privateCloudDatabase

import CloudKit

let container = CKContainer.default()
let db = container.privateCloudDatabase

import SwiftUI

struct ContentView: View {
  var body: some View {
    Text("CloudKit Setup")
      .padding()
  }
}

import SwiftUI

@main
struct MyApp: App {
  var body: some Scene {
    WindowGroup { ContentView() }
  }
}

This prepares a handle to the user's private database.

Save a Record

Create a CKRecord with fields and save it to the database.

Syntax:

• let rec = CKRecord(recordType: "Type")
• db.save(rec) { ... }

import CloudKit

func addNote(title: String, body: String, completion: @escaping (Result) -> Void) {
  let rec = CKRecord(recordType: "Note")
  rec["title"] = title as CKRecordValue
  rec["body"] = body as CKRecordValue
  CKContainer.default().privateCloudDatabase.save(rec) { saved, err in
    if let saved = saved { completion(.success(saved)) } else { completion(.failure(err!)) }
  }
}

import SwiftUI

struct ContentView: View {
  var body: some View {
    Text("CloudKit Save Example")
      .padding()
  }
}

import SwiftUI

@main
struct MyApp: App {
  var body: some Scene {
    WindowGroup { ContentView() }
  }
}

This example writes a simple Note record into the private database.

Query Records

Fetch records matching a predicate using CKQuery.

Syntax:

• CKQuery(recordType:predicate:)
• db.perform(query, inZoneWith:)

import CloudKit

func loadNotes(completion: @escaping (Result<[CKRecord], Error>) -> Void) {
  let predicate = NSPredicate(value: true)
  let query = CKQuery(recordType: "Note", predicate: predicate)
  CKContainer.default().privateCloudDatabase.perform(query, inZoneWith: nil) { records, err in
    if let records = records { completion(.success(records)) } else { completion(.failure(err!)) }
  }
}

import SwiftUI

struct ContentView: View {
  var body: some View {
    Text("CloudKit Query Example")
      .padding()
  }
}

import SwiftUI

@main
struct MyApp: App {
  var body: some Scene {
    WindowGroup { ContentView() }
  }
}

This example loads all Note records. In production, prefer cursors or operations for large result sets.