Medium article: SLC part 1 - BaseViewModel

BaseViewModel.swift

import RxSwift
import RxCocoa

class BaseViewModel<NavigationStep, FromView, Output>: ViewModelType {
    let bag = DisposeBag()
    // Small type wrapping a RxSwift PublishSubject, that we notify about navigation, passing
    // a contextual `NavigationStep` which typically is an enum, modelling all possible
    // outgoing navigation steps we can take from this scene.
    let navigator = Stepper<NavigationStep>()

    // MARK: - Methods to Override
    func transform(input: Input) -> Output { abstract }
}

extension BaseViewModel {
    struct Input: InputType {
        let fromController: ControllerInput
        let fromView: FromView

        init(fromView: FromView, fromController: ControllerInput) {
            self.fromView = fromView
            self.fromController = fromController
        }
    }
}


struct ControllerInput {

    let viewDidLoad: Driver<Void>

    // `Bool` representing argument `animated`
    let viewWillAppear: Driver<Bool>
    let viewDidAppear: Driver<Bool>

    let leftBarButtonTrigger: Driver<Void>
    let rightBarButtonTrigger: Driver<Void>
}