Created
April 7, 2016 16:14
-
-
Save freedom27/3bd0e83917570b4520d28e79d4554fa2 to your computer and use it in GitHub Desktop.
This file contains bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
protocol Disposable { | |
func dispose() | |
func addToDisposablesBag(bag: DisposablesBag) | |
} | |
extension Disposable { | |
func addToDisposablesBag(bag: DisposablesBag) { | |
bag.add(self) | |
} | |
} | |
class DisposablesBag { | |
private var disposables = [Disposable]() | |
func add(disposable: Disposable) { | |
disposables.append(disposable) | |
} | |
func disposeAll() { | |
disposables.forEach{$0.dispose()} | |
} | |
} | |
class Observation<T> { | |
typealias Observer = T->Void | |
let observer: Observer | |
weak var observed: Observable<T>? | |
init(observer: Observer, observed: Observable<T>) { | |
self.observer = observer | |
self.observed = observed | |
} | |
} | |
extension Observation: Disposable { | |
func dispose() { | |
observed?.unobserve(self) | |
} | |
} | |
extension Observation:Equatable { } | |
func ==<T>(lhs: Observation<T>, rhs: Observation<T>) -> Bool { | |
return lhs === rhs | |
} | |
class Observable<T> { | |
var value: T { | |
didSet { | |
observations.forEach{$0.observer(self.value)} | |
} | |
} | |
private var observations = [Observation<T>]() | |
init(value: T) { | |
self.value = value | |
} | |
func observe(observer: T->Void) -> Observation<T> { | |
let observation = Observation(observer: observer, observed: self) | |
observations.append(observation) | |
return observation | |
} | |
func unobserve(observation: Observation<T>) { | |
observations = observations.filter{$0 != observation} | |
} | |
} | |
let bag = DisposablesBag() | |
let s = Observable(value: "a string") | |
s.observe {(s: String) in | |
print(s) | |
}.addToDisposablesBag(bag) | |
s.value = "another string" | |
print(s.value) | |
s.value = "again" | |
bag.disposeAll() | |
s.value = "and again" |
Sign up for free
to join this conversation on GitHub.
Already have an account?
Sign in to comment