Defaults/Sources/Defaults/Observation+Combine.swift

250 lines
9.2 KiB
Swift

#if canImport(Combine)
import Foundation
import Combine
extension Defaults {
/**
Custom `Subscription` for `UserDefaults` key observation.
*/
@available(iOS 13.0, macOS 10.15, tvOS 13.0, watchOS 6.0, iOSApplicationExtension 13.0, macOSApplicationExtension 10.15, tvOSApplicationExtension 13.0, watchOSApplicationExtension 6.0, *)
final class DefaultsSubscription<SubscriberType: Subscriber>: Subscription where SubscriberType.Input == BaseChange {
private var subscriber: SubscriberType?
private var observation: UserDefaultsKeyObservation?
init(subscriber: SubscriberType, suite: UserDefaults, key: String, options: NSKeyValueObservingOptions) {
self.subscriber = subscriber
self.observation = UserDefaultsKeyObservation(
object: suite,
key: key,
callback: observationCallback(_:)
)
self.observation?.start(options: options)
}
func request(_ demand: Subscribers.Demand) {
// Nothing as we send events only when they occur.
}
func cancel() {
observation?.invalidate()
observation = nil
subscriber = nil
}
private func observationCallback(_ change: BaseChange) {
_ = subscriber?.receive(change)
}
}
/**
Custom Publisher, which is using DefaultsSubscription.
*/
@available(iOS 13.0, macOS 10.15, tvOS 13.0, watchOS 6.0, iOSApplicationExtension 13.0, macOSApplicationExtension 10.15, tvOSApplicationExtension 13.0, watchOSApplicationExtension 6.0, *)
struct DefaultsPublisher: Publisher {
typealias Output = BaseChange
typealias Failure = Never
private let suite: UserDefaults
private let key: String
private let options: NSKeyValueObservingOptions
init(suite: UserDefaults, key: String, options: NSKeyValueObservingOptions) {
self.suite = suite
self.key = key
self.options = options
}
func receive<S>(subscriber: S) where S : Subscriber, DefaultsPublisher.Failure == S.Failure, DefaultsPublisher.Output == S.Input {
let subscription = DefaultsSubscription(
subscriber: subscriber,
suite: suite,
key: key,
options: options
)
subscriber.receive(subscription: subscription)
}
}
/**
Returns a type-erased `Publisher` that publishes changes related to the given key.
```
extension Defaults.Keys {
static let isUnicornMode = Key<Bool>("isUnicornMode", default: false)
}
let publisher = Defaults.publisher(.isUnicornMode).map { $0.newValue }
let cancellable = publisher.sink { value in
print(value)
//=> false
}
```
*/
@available(iOS 13.0, macOS 10.15, tvOS 13.0, watchOS 6.0, iOSApplicationExtension 13.0, macOSApplicationExtension 10.15, tvOSApplicationExtension 13.0, watchOSApplicationExtension 6.0, *)
public static func publisher<Value: Codable>(
_ key: Defaults.Key<Value>,
options: NSKeyValueObservingOptions = [.initial, .old, .new]
) -> AnyPublisher<KeyChange<Value>, Never> {
let publisher = DefaultsPublisher(suite: key.suite, key: key.name, options: options)
.map { KeyChange<Value>(change: $0, defaultValue: key.defaultValue) }
return AnyPublisher(publisher)
}
/**
Returns a type-erased `Publisher` that publishes changes related to the given key.
*/
@available(iOS 13.0, macOS 10.15, tvOS 13.0, watchOS 6.0, iOSApplicationExtension 13.0, macOSApplicationExtension 10.15, tvOSApplicationExtension 13.0, watchOSApplicationExtension 6.0, *)
public static func publisher<Value: NSSecureCoding>(
_ key: Defaults.NSSecureCodingKey<Value>,
options: NSKeyValueObservingOptions = [.initial, .old, .new]
) -> AnyPublisher<NSSecureCodingKeyChange<Value>, Never> {
let publisher = DefaultsPublisher(suite: key.suite, key: key.name, options: options)
.map { NSSecureCodingKeyChange<Value>(change: $0, defaultValue: key.defaultValue) }
return AnyPublisher(publisher)
}
/**
Returns a type-erased `Publisher` that publishes changes related to the given optional key.
*/
@available(iOS 13.0, macOS 10.15, tvOS 13.0, watchOS 6.0, iOSApplicationExtension 13.0, macOSApplicationExtension 10.15, tvOSApplicationExtension 13.0, watchOSApplicationExtension 6.0, *)
public static func publisher<Value: Codable>(
_ key: Defaults.OptionalKey<Value>,
options: NSKeyValueObservingOptions = [.initial, .old, .new]
) -> AnyPublisher<OptionalKeyChange<Value>, Never> {
let publisher = DefaultsPublisher(suite: key.suite, key: key.name, options: options)
.map { OptionalKeyChange<Value>(change: $0) }
return AnyPublisher(publisher)
}
/**
Returns a type-erased `Publisher` that publishes changes related to the given optional key.
*/
@available(iOS 13.0, macOS 10.15, tvOS 13.0, watchOS 6.0, iOSApplicationExtension 13.0, macOSApplicationExtension 10.15, tvOSApplicationExtension 13.0, watchOSApplicationExtension 6.0, *)
public static func publisher<Value: NSSecureCoding>(
_ key: Defaults.NSSecureCodingOptionalKey<Value>,
options: NSKeyValueObservingOptions = [.initial, .old, .new]
) -> AnyPublisher<NSSecureCodingOptionalKeyChange<Value>, Never> {
let publisher = DefaultsPublisher(suite: key.suite, key: key.name, options: options)
.map { NSSecureCodingOptionalKeyChange<Value>(change: $0) }
return AnyPublisher(publisher)
}
/**
Publisher for multiple `Key<T>` observation, but without specific information about changes.
*/
@available(iOS 13.0, macOS 10.15, tvOS 13.0, watchOS 6.0, iOSApplicationExtension 13.0, macOSApplicationExtension 10.15, tvOSApplicationExtension 13.0, watchOSApplicationExtension 6.0, *)
public static func publisher<Value: Codable>(
keys: Defaults.Key<Value>...,
options: NSKeyValueObservingOptions = [.initial, .old, .new]
) -> AnyPublisher<Void, Never> {
let initial = Empty<Void, Never>(completeImmediately: false).eraseToAnyPublisher()
let combinedPublisher =
keys.map { key in
return Defaults.publisher(key, options: options)
.map { _ in () }
.eraseToAnyPublisher()
}.reduce(initial) { (combined, keyPublisher) in
combined.merge(with: keyPublisher).eraseToAnyPublisher()
}
return combinedPublisher
}
/**
Publisher for multiple `OptionalKey<T>` observation, but without specific information about changes.
*/
@available(iOS 13.0, macOS 10.15, tvOS 13.0, watchOS 6.0, iOSApplicationExtension 13.0, macOSApplicationExtension 10.15, tvOSApplicationExtension 13.0, watchOSApplicationExtension 6.0, *)
public static func publisher<Value: Codable>(
keys: Defaults.OptionalKey<Value>...,
options: NSKeyValueObservingOptions = [.initial, .old, .new]
) -> AnyPublisher<Void, Never> {
let initial = Empty<Void, Never>(completeImmediately: false).eraseToAnyPublisher()
let combinedPublisher =
keys.map { key in
return Defaults.publisher(key, options: options)
.map { _ in () }
.eraseToAnyPublisher()
}.reduce(initial) { (combined, keyPublisher) in
combined.merge(with: keyPublisher).eraseToAnyPublisher()
}
return combinedPublisher
}
/**
Publisher for multiple `NSSecureCodingKey<T>` observation, but without specific information about changes.
*/
@available(iOS 13.0, macOS 10.15, tvOS 13.0, watchOS 6.0, iOSApplicationExtension 13.0, macOSApplicationExtension 10.15, tvOSApplicationExtension 13.0, watchOSApplicationExtension 6.0, *)
public static func publisher<Value: NSSecureCoding>(
keys: Defaults.NSSecureCodingKey<Value>...,
options: NSKeyValueObservingOptions = [.initial, .old, .new]
) -> AnyPublisher<Void, Never> {
let initial = Empty<Void, Never>(completeImmediately: false).eraseToAnyPublisher()
let combinedPublisher =
keys.map { key in
return Defaults.publisher(key, options: options)
.map { _ in () }
.eraseToAnyPublisher()
}.reduce(initial) { (combined, keyPublisher) in
combined.merge(with: keyPublisher).eraseToAnyPublisher()
}
return combinedPublisher
}
/**
Publisher for multiple `NSSecureCodingOptionalKey<T>` observation, but without specific information about changes.
*/
@available(iOS 13.0, macOS 10.15, tvOS 13.0, watchOS 6.0, iOSApplicationExtension 13.0, macOSApplicationExtension 10.15, tvOSApplicationExtension 13.0, watchOSApplicationExtension 6.0, *)
public static func publisher<Value: NSSecureCoding>(
keys: Defaults.NSSecureCodingOptionalKey<Value>...,
options: NSKeyValueObservingOptions = [.initial, .old, .new]
) -> AnyPublisher<Void, Never> {
let initial = Empty<Void, Never>(completeImmediately: false).eraseToAnyPublisher()
let combinedPublisher =
keys.map { key in
return Defaults.publisher(key, options: options)
.map { _ in () }
.eraseToAnyPublisher()
}.reduce(initial) { (combined, keyPublisher) in
combined.merge(with: keyPublisher).eraseToAnyPublisher()
}
return combinedPublisher
}
/**
Convenience `Publisher` for all `UserDefaults` key change events. A wrapper around the `UserDefaults.didChangeNotification`.
- Parameter initialEvent: Trigger an initial event immediately.
*/
@available(iOS 13.0, macOS 10.15, tvOS 13.0, watchOS 6.0, iOSApplicationExtension 13.0, macOSApplicationExtension 10.15, tvOSApplicationExtension 13.0, watchOSApplicationExtension 6.0, *)
public static func publisherAll(initialEvent: Bool = true) -> AnyPublisher<Void, Never> {
let publisher =
NotificationCenter.default.publisher(for: UserDefaults.didChangeNotification)
.map { _ in () }
if initialEvent {
return publisher
.prepend(())
.eraseToAnyPublisher()
} else {
return publisher
.eraseToAnyPublisher()
}
}
}
#endif