如何使用MVVM和RxSwift快速显示/隐藏progressHUD

Question

I'm beginning with MVVM in order to well separate logic code from the view. But I have some concern about where to put the progressHUD related code when tapping a button that makes a request.

Before, I used to do that:

//Before 
@IBAction func startRequestTapped() {
   SVProgressHUD.show()
    self.apiClient.requestObservable().subscribe(onError: { (error) in
        SVProgressHUD.hide()                    
    }, onCompleted: { 
        SVProgressHUD.hide()                                        
    })
}

But when I use mvvm, I do like that:

//In the viewModel
public var validateButtonDidTap = PublishSubject<Void>()
init() {
    validateButtonDidTap.flatMap { (_)
        return self.apiClient.requestObservable()
    }
}


   // In the viewController
viewDidLoad() {
    let tap = self.validateButton.rx.tap
    tap.bindTo(self.viewModel.validateButtonDidTap)
}

And amongst that, I don't know where to put the the ProgressHUD hide or show.

Answer 1

Mark answer is right, but I am going to guide you step by step.

Let's supose you're going to try signing in.

1. Copy ActivityIndicator.swift file in your project.

2. In the viewModel :

    //MARK: - Properties /// The http client private let apiClient: YourApiClient /// Clousure when button is tapped var didTappedButton: () -> Void = {} /// The user var user: Observable<User> /// Is signing process in progress let signingIn: Observable<Bool> = ActivityIndicator().asObservable() //MARK: - Initialization init(client: YourApiClient) { self.client = client self.didTappedButton = { [weak self] in self.user = self.apiClient .yourSignInRequest() .trackActivity(self.signingIn) .observeOn(MainScheduler.instance) } } 

3. Create an extension of SVProgressHUD: (I don't know SVProgressHUD library, but it would be something like this. Please fix it if needed)

    extension Reactive where Base: SVProgressHUD { /// Bindable sink for `show()`, `hide()` methods. public static var isAnimating: UIBindingObserver<Base, Bool> { return UIBindingObserver(UIElement: self.base) { progressHUD, isVisible in if isVisible { progressHUD.show() // or other show methods } else { progressHUD.dismiss() // or other hide methods } } } } 

4. In your viewController :

    @IBAction func startRequestTapped() { viewModel.didTappedButton() } override func viewDidLoad() { // ... viewModel.signingIn .bindTo(SVProgressHUD.rx.isAnimating) .addDisposableTo(disposeBag) } 

Answer 2

Accepted answer updated to Swift 4, RxSwift 4.0.0 and SVProgressHUD 2.2.2:

3- Extension:

extension Reactive where Base: SVProgressHUD {

   public static var isAnimating: Binder<Bool> {
      return Binder(UIApplication.shared) {progressHUD, isVisible in
         if isVisible {
            SVProgressHUD.show()
         } else {
            SVProgressHUD.dismiss()
         }
      }
   }

}

4- Controller:

viewModel.signingIn.asObservable().bind(to: SVProgressHUD.rx.isAnimating).disposed(by: disposeBag)

Answer 3

You could try using an ActivityIndicator .

See the example here: https://github.com/RxSwiftCommunity/RxSwiftUtilities