Add iCloud syncing

CHANGELOG.md

@@ -1,4 +1,5 @@
 ### Next
+* Added support for iCloud syncing via `Defaults.syncKeys([])`. [@StevenMagdy](https://github.com/StevenMagdy)
 
 ### 5.3.0 (2021-02-24)
 * Renamed `OptionalType.empty` to `OptionalType.__swifty_empty`. Also removed the `OptionalType.wrapped` since it wasn't used in the framework anymore. Please note that this still shouldn't be something you rely on tho, we're gonna explore ways to remove the public `OptionalType` in a future releases. [@sunshinejr](https://github.com/sunshinejr)

Sources/Defaults+Syncing.swift

@@ -0,0 +1,49 @@
+//
+// SwiftyUserDefaults
+//
+// Copyright (c) 2015-present Radosław Pietruszewski, Łukasz Mróz
+//
+// Permission is hereby granted, free of charge, to any person obtaining a copy
+// of this software and associated documentation files (the "Software"), to deal
+// in the Software without restriction, including without limitation the rights
+// to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+// copies of the Software, and to permit persons to whom the Software is
+// furnished to do so, subject to the following conditions:
+//
+// The above copyright notice and this permission notice shall be included in all
+// copies or substantial portions of the Software.
+//
+// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+// IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+// FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+// AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+// LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+// OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+// SOFTWARE.
+//
+
+#if !os(Linux) && !os(watchOS)
+
+public extension DefaultsAdapter {
+
+    func startSyncing(for keyPaths: PartialKeyPath<KeyStore>...) {
+        let rawKeys = keyPaths.map { keyStore[keyPath: $0] }.compactMap { $0 as? RawKeyRepresentable }.map { $0._key }
+        syncer.syncedKeys.formUnion(rawKeys)
+    }
+
+    func stopSyncing(for keyPaths: PartialKeyPath<KeyStore>...) {
+        let rawKeys = keyPaths.map { keyStore[keyPath: $0] }.compactMap { $0 as? RawKeyRepresentable }.map { $0._key }
+        syncer.syncedKeys.subtract(rawKeys)
+    }
+
+    func forceSync() {
+        syncer.forceSync()
+    }
+
+    func stopSyncingAll() {
+        syncer.syncedKeys = []
+    }
+
+}
+
+#endif

Sources/Defaults.swift

@@ -34,6 +34,8 @@ import Foundation
 
 public var Defaults = DefaultsAdapter<DefaultsKeys>(defaults: .standard, keyStore: .init())
 
+// MARK: - UserDefaults
+
 public extension UserDefaults {
 
     /// Returns `true` if `key` exists
@@ -80,3 +82,32 @@ internal extension UserDefaults {
         }
     }
 }
+
+#if !os(Linux) && !os(watchOS)
+
+// MARK: - NSUbiquitousKeyValueStore
+
+public extension NSUbiquitousKeyValueStore {
+
+    /// Returns `true` if `key` exists
+    func hasKey<T>(_ key: DefaultsKey<T>) -> Bool {
+        return object(forKey: key._key) != nil
+    }
+
+    /// Removes value for `key`
+    func remove<T>(_ key: DefaultsKey<T>) {
+        removeObject(forKey: key._key)
+        synchronize()
+    }
+
+    /// Removes all keys and values from iCloud
+    /// Use with caution!
+    func removeAll() {
+        for (key, _) in dictionaryRepresentation {
+            removeObject(forKey: key)
+        }
+        synchronize()
+    }
+}
+
+#endif

Sources/DefaultsAdapter.swift

@@ -46,9 +46,23 @@ public struct DefaultsAdapter<KeyStore: DefaultsKeyStore> {
     public let defaults: UserDefaults
     public let keyStore: KeyStore
 
+    #if !os(Linux) && !os(watchOS)
+    internal let syncer: DefaultsSyncer
+
+    internal init(defaults: UserDefaults, keyStore: KeyStore, remoteStore: RemoteStore) {
+        self.defaults = defaults
+        self.keyStore = keyStore
+        self.syncer = DefaultsSyncer(defaults: defaults, remoteStore: remoteStore)
+    }
+    #endif
+
     public init(defaults: UserDefaults, keyStore: KeyStore) {
         self.defaults = defaults
         self.keyStore = keyStore
+
+        #if !os(Linux) && !os(watchOS)
+        self.syncer = DefaultsSyncer(defaults: defaults, remoteStore: NSUbiquitousKeyValueStore.default)
+        #endif
     }
 
     @available(*, unavailable)

Sources/DefaultsKey.swift

@@ -24,11 +24,15 @@
 
 import Foundation
 
+internal protocol RawKeyRepresentable {
+  var _key: String { get }
+}
+
 // MARK: - Static keys
 
 /// Specialize with value type
 /// and pass key name to the initializer to create a key.
-public struct DefaultsKey<ValueType: DefaultsSerializable> {
+public struct DefaultsKey<ValueType: DefaultsSerializable>: RawKeyRepresentable {
 
     public let _key: String
     public let defaultValue: ValueType.T?

Sources/DefaultsSyncer.swift

@@ -0,0 +1,114 @@
+//
+// SwiftyUserDefaults
+//
+// Copyright (c) 2015-present Radosław Pietruszewski, Łukasz Mróz
+//
+// Permission is hereby granted, free of charge, to any person obtaining a copy
+// of this software and associated documentation files (the "Software"), to deal
+// in the Software without restriction, including without limitation the rights
+// to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+// copies of the Software, and to permit persons to whom the Software is
+// furnished to do so, subject to the following conditions:
+//
+// The above copyright notice and this permission notice shall be included in all
+// copies or substantial portions of the Software.
+//
+// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+// IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+// FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+// AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+// LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+// OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+// SOFTWARE.
+//
+#if !os(Linux) && !os(watchOS)
+
+import Foundation
+
+internal protocol RemoteStore {
+    var dictionaryRepresentation: [String: Any] { get }
+
+    func object(forKey defaultName: String) -> Any?
+    func set(_ anObject: Any?, forKey aKey: String)
+    @discardableResult func synchronize() -> Bool
+}
+
+extension NSUbiquitousKeyValueStore: RemoteStore {
+}
+
+internal class DefaultsSyncer {
+
+    private let defaults: UserDefaults
+    private let remoteStore: RemoteStore
+
+    var syncedKeys = Set<String>()
+
+    init(defaults: UserDefaults, remoteStore: RemoteStore) {
+        self.defaults = defaults
+        self.remoteStore = remoteStore
+
+        NotificationCenter.default.addSafeObserver(self,
+                                                   selector: #selector(iCloudDefaultsDidUpdate),
+                                                   name: NSUbiquitousKeyValueStore.didChangeExternallyNotification)
+        NotificationCenter.default.addSafeObserver(self,
+                                                   selector: #selector(localDefaultsDidUpdate),
+                                                   name: UserDefaults.didChangeNotification)
+    }
+
+    internal func forceSync() {
+        iCloudDefaultsDidUpdate()
+        localDefaultsDidUpdate()
+    }
+
+    @objc
+    private func iCloudDefaultsDidUpdate() {
+        guard !syncedKeys.isEmpty else { return }
+
+        // HouseKeeping
+        NotificationCenter.default.removeObserver(self,
+                                                  name: UserDefaults.didChangeNotification,
+                                                  object: nil)
+        defer {
+            NotificationCenter.default.addSafeObserver(self,
+                                                       selector: #selector(localDefaultsDidUpdate),
+                                                       name: UserDefaults.didChangeNotification)
+        }
+
+        // Implementation
+        let allICloudKeys = Set(remoteStore.dictionaryRepresentation.keys)
+        let updatedSyncedKeys = allICloudKeys.filter { syncedKeys.contains($0) }
+        updatedSyncedKeys.forEach { key in
+            let iCloudValue = remoteStore.object(forKey: key)
+            defaults.set(iCloudValue, forKey: key)
+        }
+    }
+
+    @objc
+    private func localDefaultsDidUpdate() {
+        guard !syncedKeys.isEmpty else { return }
+        syncedKeys.forEach { key in
+            let localValue = defaults.object(forKey: key)
+            remoteStore.set(localValue, forKey: key)
+        }
+        // request upload to ICloud
+        remoteStore.synchronize()
+    }
+
+    deinit {
+        NotificationCenter.default.removeObserver(self,
+                                                  name: UserDefaults.didChangeNotification,
+                                                  object: nil)
+        NotificationCenter.default.removeObserver(self,
+                                                  name: NSUbiquitousKeyValueStore.didChangeExternallyNotification,
+                                                  object: nil)
+    }
+}
+
+private extension NotificationCenter {
+    func addSafeObserver(_ observer: Any, selector aSelector: Selector, name aName: NSNotification.Name, object anObject: Any? = nil) {
+        removeObserver(observer, name: aName, object: anObject)
+        addObserver(observer, selector: aSelector, name: aName, object: anObject)
+    }
+}
+
+#endif

SwiftyUserDefaults.xcodeproj/project.pbxproj

@@ -28,6 +28,8 @@
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@@ -69,6 +71,8 @@
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@@ -131,6 +135,8 @@
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@@ -165,7 +171,9 @@
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