Observations

A light-weight implementation of Observables, Including a trivial example project for iOS and 100% (but not exhaustive) test coverage.

Usage

To make an object observable, make it conform to the Observable protocol:

class ObservableViewController: UIViewController, Observable {
    enum Action {
        case button1Tapped
        case button2Tapped(message: String)
    }

    typealias Observation = Action

    var observer: Observer<Observation>?
	…
}

To create an observer for the observable:

observer = Observer<ObservableViewController.Action> { [weak self] (action) in
            guard let self = self else { return }

            switch action {
            case .button1Tapped:
                self.history.append("\(self.history.count + 1) Remote action on button 1")
            case .button2Tapped(let message):
                self.history.append("\(self.history.count + 1) " + message)
            }
        }

For more info, see this blog post.