I'd like all publishers to execute unless explicitly cancelled. I don't mind AnyCancellable going out of scope, however based on docs it automatically calls cancel on deinit which is undesired.
I've tried to use a cancellable bag, but AnyCancelable kept piling up even after the publisher fired a completion.
Should I manage the bag manually? I had impression that store(in: inout Set) was meant to be used for convenience of managing the cancellable instances, however all it does is push AnyCancellable into a set.
var cancelableSet = Set<AnyCancellable>()
func work(value: Int) -> AnyCancellable {
return Just(value)
.delay(for: .seconds(1), scheduler: DispatchQueue.global(qos: .default))
.map { $0 + 1 }
.sink(receiveValue: { (value) in
print("Got value: \(value)")
})
}
work(value: 1337).store(in: &cancelableSet)
DispatchQueue.main.asyncAfter(deadline: .now() + .seconds(5)) {
print("\(cancelableSet)")
}
What I came up with so far, which works fine but makes me wonder if something is missing in the Combine framework or it was not meant to be used in such fashion:
class DisposeBag {
private let lock = NSLock()
private var cancellableSet = Set<AnyCancellable>()
func store(_ cancellable: AnyCancellable) {
print("Store cancellable: \(cancellable)")
lock.lock()
cancellableSet.insert(cancellable)
lock.unlock()
}
func drop(_ cancellable: AnyCancellable) {
print("Drop cancellable: \(cancellable)")
lock.lock()
cancellableSet.remove(cancellable)
lock.unlock()
}
}
extension Publisher {
@discardableResult func autoDisposableSink(disposeBag: DisposeBag, receiveCompletion: @escaping ((Subscribers.Completion<Self.Failure>) -> Void), receiveValue: @escaping ((Self.Output) -> Void)) -> AnyCancellable {
var sharedCancellable: AnyCancellable?
let disposeSubscriber = {
if let sharedCancellable = sharedCancellable {
disposeBag.drop(sharedCancellable)
}
}
let cancellable = handleEvents(receiveCancel: {
disposeSubscriber()
}).sink(receiveCompletion: { (completion) in
receiveCompletion(completion)
disposeSubscriber()
}, receiveValue: receiveValue)
sharedCancellable = cancellable
disposeBag.store(cancellable)
return cancellable
}
}
