A swift library that extends the swift-sharing library with support for iCloud key-value synchronization through NSUbiquitousKeyValueStore.
SharingCloud provides a simple and elegant way to sync shared data across multiple Apple devices using iCloud's key-value store. The library implements the SharedKey protocol from the swift-sharing library, enabling you to use the @Shared property wrapper with iCloud as a persistence strategy.
- Seamless iCloud Integration: Automatically sync data between iOS, macOS, watchOS, and tvOS devices
- Simple Property Wrapper Syntax: Use the familiar
@Sharedsyntax with the.iCloudKVstorage strategy - Comprehensive Type Support:
- Primitives: Bool, Int, Double, String
- Complex Types: URL, Data, Date
- Optional variants of all supported types
- RawRepresentable types using Int or String as raw values
- Automatic Change Detection: Observes iCloud changes and updates UI automatically
- Entitlement Checking: Checks for proper iCloud entitlements and triggers the warning by
reportIssue - Key Length Validation: Checks that the key is under the 64-byte limit and triggers the warning by
reportIssue
Add the following to your Package.swift file:
dependencies: [
.package(url: "https://github.com/KeithBird/sharing-cloud", from: "1.0.0")
]Then add the product to any target that needs it:
.product(name: "SharingCloud", package: "sharing-cloud")import SharingCloud
// In an ObservableObject or @Observable class
@Observable
class SettingsModel {
@ObservationIgnored
@Shared(.iCloudKV("userPreferences"))
var isDarkModeEnabled: Bool = false
@ObservationIgnored
@Shared(.iCloudKV("notificationsEnabled"))
var notificationsEnabled: Bool = true
@ObservationIgnored
@Shared(.iCloudKV("fontSize"))
var fontSize: Int = 14
}
// In a SwiftUI view
struct SettingsView: View {
@Shared(.iCloudKV("userPreferences")) private var isDarkModeEnabled: Bool = false
@Shared(.iCloudKV("notificationsEnabled")) private var notificationsEnabled: Bool = true
@Shared(.iCloudKV("fontSize")) private var fontSize: Int = 14
var body: some View {
Form {
Toggle("Dark Mode", isOn: $isDarkModeEnabled)
Toggle("Notifications", isOn: $notificationsEnabled)
Stepper("Font Size: \(fontSize)", value: $fontSize, in: 10...30)
}
}
}enum Theme: String, Sendable {
case light
case dark
case system
}
struct ThemeSettingsView: View {
@Shared(.iCloudKV("appTheme")) private var theme: Theme = .system
var body: some View {
Picker("Theme", selection: $theme) {
Text("Light").tag(Theme.light)
Text("Dark").tag(Theme.dark)
Text("System").tag(Theme.system)
}
}
}Storing a URL example:
@Shared(.iCloudKV("lastVisitedURL")) var lastURL: URL?More examples can be found in the swift-sharing documentation.
- In Xcode, select your target and navigate to "Signing & Capabilities"
- Add the iCloud capability
- Check "Key-value storage"
- Ensure your app has the proper entitlements:
com.apple.developer.ubiquity-kvstore-identifier
- Replace
$(CFBundleIdenfier)with your key-value store ID (i.e.$(TeamIdentifierPrefix)<your key-value_store ID>).
For more information, please see: Synchronizing App Preferences with iCloud
- NSUbiquitousKeyValueStore has a maximum total storage size of 1MB per user
- Each key-value pair is limited to 1MB in size
- Maximum of 1024 keys allowed
- Keys can't be larger than 64 bytes using UTF-8 encoding
- Synchronization is not immediate; iCloud syncs on its own schedule
- Use short, descriptive key names to stay under the 64-byte limit
- Store only small pieces of data like preferences and settings
- Do not store sensitive user information in iCloud key-value store
- Check for iCloud availability before assuming data will be synced
This library is available under the MIT license.