SwiftMVVM is an sample iOS App written in Swift using the MVVM architecture. To present all this, we’ll dive in to FriendTableViewViewModel & FriendTableViewController. RxSwift has been a hot topic in the community for a few years now, but somehow I’ve managed to avoid it. To present all this we’ll dive in to FriendTableViewViewModel & FriendTableViewController. A table view, which displays a list of tasks and a add new task screen. Here we have defined loadInProgress, cells as Variables. If not, leave a comment or message me on twitter and I’ll explain help you with that. In the viewDidLoad, we'll call the preparing functions: First, we’ll prepare the view model by binding all the values in the bindViewModel(). I might change it a bit if I wrote the code today. This is the variable that we’ll bind to present the loading hud (binding happens in the view controller side). Next, let’s check the bindViewModel() function: At first, we’ll bind the friendCells to tableview. I decided to try out RxSwift using by implementing a small project. Here is where we can configure the cells. Maybe I can help you with that? The types are normal cell, error and empty cell. Open source Github iOS client written in RxSwift and MVVM architecture. Thanks for reading and see you next time, my friend! Now that we have handled the data source and delegation of the tableView, all that is left is to make sure that this observable is disposed of using the disposeBag, when View is deallocated. Check the GitHub repo for more info. RxSwift also provides subscribe functions we can use for the different states. I do have quite a few things on my topic list so I can’t promise(Kit) you that I’ll do it any time soon.. Furthermore, Variable is guaranteed not to emit error so it makes things a bit simpler to handle on the view controller side. MVVM with RxSwift. RxSwift calls the closure that we have defined for each item. MVVM is a UI architectural pattern from Model-View-X family. Check the GitHub repo for more info. Here is an example I wrote just now to demonstrate how you can use RxSwift to do what you want. The MVC pattern breaks an application up into three components or layers, model, view, and controller. ask question asked 1 year, 8 … To destroy an Observable, we should always call dispose() to it. If you are familiar with RxSwift (and maybe you are if you work with MVVM) that home-made binding may seem unnecessary. In the viewDidLoad we’ll call the preparing functions: First, we’ll prepare the view model by binding all the values in the bindViewModel(). I say most since we should try to avoid the situation that view model turns into just another place that we dump all our code. After that we’ll call getFriends() from the appServerClient and subscribe to the observable it returns. Also if you liked the post, I hope you’ll share it with some of your friends, I’d really appreciate it! At the beginning of the class, we’ll notice the view model definition. We can directly define the blocks for different states, as we’ve done above. To destroy an Observable, we should always call dispose() to it. This is the variable that we'll use later on the view controller side to bind the cell value to the tableView. Furthermore, BehaviorRelay can’t terminate with an error or completed event. In error case, we’ll create a default UITableViewCell and set the provided error message as the textLabel?.text. I would like to show you some problems that I ran into using MVVM with RxSwift and some solutions that made my life easier. This is where we’ll also create the view model since this is the first view of the application. Now, let’s check the onShowError which is defined as a PublishSubject. This code is still based on the same sample app I used a MVVM template: a currency converter app. Here we don’t need to free any memory when the onCompleted or onDisposedis called, so we only handle the onNext and onError states. It would be very hard work to handle the disposing manually, so RxSwift equips us with the DisposeBag. Every time a request is sent to AppServerClient, it returns an Observable. AppServerClient is a component which does all the requests to the server. Element contains the enum value defined on the view model side and index is the index of the element. I really like the idea of forwarding events through different layers but the user interface stays sometimes a challenge. There is no need to use any other data binding technique (such as Bindable we were using in the How to use MVVM tutorial), or delegation since RxSwift does it all for us! So instead of always checking which event was emitted, we can directly define the blocks for different states, as we've done above. Observables in RxSwift change their state by emitting onNext, onError, onCompleted event. At the bottom of the code block you can see two variables that are defined as BehaviorRelay. PublishSubjectreceives information and then publishes it to the subscriber. . I wrote the app using MVVM without RxSwift 1,5 years ago. Using UITableView, showing a loading indicator and how to displaying an error to the user. BehaviourSubject works like PublishSubject but it also repeats the latest value to new subscribers. Next, let’s check the bindViewModel() function: At first, we’ll bind the friendCells to tableView.