assignWeakly

Publisher+Extensions.swift

public extension Publisher where Failure == Never {
    /// Assigns each element from a Publisher to a property on an object **and holds that objet weakly**.
    ///
    /// `Combine`'s  `assign` holds `object` with a strong reference, causing memory leaks on most use cases. Problem discussion and code origin [here](https://forums.swift.org/t/does-assign-to-produce-memory-leaks/29546/11)
    ///
    /// - Parameters:
    ///   - keyPath: The key path of the property to assign.
    ///   - object: The object on which to assign the value.
    /// - Returns: A cancellable instance; used when you end assignment of the received value. Deallocation of the result will tear down the subscription stream.
    func assignWeakly<Root: AnyObject>(to keyPath: ReferenceWritableKeyPath<Root, Output>, on object: Root) -> AnyCancellable {
        sink { [weak object] in
            object?[keyPath: keyPath] = $0
        }
    }
}