mirror of
https://github.com/Novaloop-AG/element-x-ios.git
synced 2026-10-31 16:24:11 +00:00
Mauro
2d486ece33
* use observation in unit and preview tests instead of the async stream * use a parsing approach that is independent of the sourcery annotation * Fix observation deferred fulfillments not receiving the initial value Observation's observe only emits transitions, not the value present at subscription time. Drop the leading initial value from the affected transitionValues sequences and assert it directly with #expect instead. * improved docs
60 lines
2.3 KiB
Swift
60 lines
2.3 KiB
Swift
//
|
|
// Copyright 2025 Element Creations Ltd.
|
|
// Copyright 2025 New Vector Ltd.
|
|
//
|
|
// SPDX-License-Identifier: AGPL-3.0-only OR LicenseRef-Element-Commercial.
|
|
// Please see LICENSE files in the repository root for full details.
|
|
//
|
|
|
|
import Foundation
|
|
import Observation
|
|
import Synchronization
|
|
|
|
extension Observable {
|
|
/// A convenience wrapper around the `Observations` sequence (SE-0475).
|
|
///
|
|
/// - Parameter property: The key path to the property you would like to observe.
|
|
@available(iOS 26.0, *)
|
|
@MainActor func observe<Value: Sendable>(_ property: KeyPath<Self, Value>) -> Observations<Value, Never> {
|
|
Observations { self[keyPath: property] }
|
|
}
|
|
|
|
/// Creates an async stream for the specified property on this object.
|
|
///
|
|
/// iOS 18 fallback for ``observe(_:)``. Remove once the minimum deployment target reaches iOS 26.
|
|
///
|
|
/// - Parameter property: The key path to the property you would like to observe.
|
|
@available(iOS, deprecated: 26.0, message: "Use observe(_:) which is backed by the Observations sequence.")
|
|
@_disfavoredOverload
|
|
@MainActor func observe<Value: Sendable>(_ property: KeyPath<Self, Value>) -> AsyncStream<Value> {
|
|
let (stream, continuation) = AsyncStream<Value>.makeStream()
|
|
let (changeSignals, changeSignaller) = AsyncStream<Void>.makeStream()
|
|
|
|
// Read and yield the initial value synchronously at subscription time,
|
|
// otherwise observers miss changes made right after creating the stream.
|
|
let initialValue = withObservationTracking {
|
|
self[keyPath: property]
|
|
} onChange: {
|
|
changeSignaller.yield()
|
|
}
|
|
continuation.yield(initialValue)
|
|
|
|
let task = Task { @MainActor in
|
|
// The signal is sent on willSet, but as this task runs on the next main
|
|
// executor job the new value will have been set by the time we read it.
|
|
for await _ in changeSignals {
|
|
let value = withObservationTracking {
|
|
self[keyPath: property]
|
|
} onChange: {
|
|
changeSignaller.yield()
|
|
}
|
|
continuation.yield(value)
|
|
}
|
|
}
|
|
|
|
continuation.onTermination = { _ in task.cancel() }
|
|
|
|
return stream
|
|
}
|
|
}
|