StructStateViewModel

StructStateViewModel.swift

class StructStateViewModel {

    public let state: Observable<State>

    struct State {
        var id: String?
        var loading = false
        var image: UIImage?
        var empty: String?
        var error: String?
        var cancel = false
    }

    private let privateState = BehaviorRelay(value: State())
    private let disposeBag = DisposeBag()

    init() {
        self.state = privateState.observeOn(MainScheduler.instance)
    }

    public func load(_ id: String) {
        var state = privateState.value
        state.id = id
        state.loading = true
        state.error = nil
        state.image = nil
        state.empty = nil
        privateState.accept(state)
        getSomeData()
            .subscribe(onSuccess: { [weak self] (image) in
                state.loading = false
                if image.size.width == 0 {
                    state.empty = "Nothing to see here, move along."
                } else {
                    state.image = image
                }
                self?.privateState.accept(state)
            }, onError: { [weak self] (error) in
                state.error = error.localizedDescription
                self?.privateState.accept(state)
            })
            .disposed(by: disposeBag)
    }

    public func cancel() {
        var state = State()
        state.cancel = true
        privateState.accept(state)
    }

    private func getSomeData() -> Single<UIImage> {
        return Single.just(UIImage())
    }

}