MvvmForIOS-Swift

MvvmForIOS is a framework for using Mvvm pattern on iOS.

It's fully written in Swift 4.x and have some tools for respecting the mvvm pattern.

Content of the framework :

• A structure View/ViewModel/Model
• A navigation service where we manage the navigation between viewModel
• A service locator for IoC capabilities

Compatibility

• Swift 4
• iOS 8

Binding issue ?

MvvmForIOS-Swift doesn't have a binding tool.

Currently, I advise to use Bond (https://github.com/DeclarativeHub/Bond)

This framework is specialized for binding content between view and viewModel

Also, you can use KVO but it's not fully compatible with Swift.

How to install MvvmForIOS-Swift

• import

import MvvmForIOSSwift

How to use it

There is a sample who explain how to implement the Framework in Swift project without binding stuff

Service Locator

There is a service locator which can be used for IoC.

//interface
protocol IDataServices : class {
    var name:String! { get }
    func openApplicationSetting() -> Bool
}

class DataServices: IDataServices {
    // ...implement protocol
}

//save
MvvmServiceLocator.register(service: DataServices() as IDataServices)
//get
let service:IDataServices! = MvvmServiceLocator.resolve()
let result = service.openApplicationSetting()

Navigation

Important

The navigations is based on components trought INavigationService .

* Presenter

When calling for navigation to another view, the presenter is called, it's a class which implement the protocol IMvvmPresenter.

/**
* A presenter is use when the app asked for navigate to another view
*/
public protocol IMvvmPresenter {
/**
* Init of the presenter
*/
init(window: UIWindow)
/**
* The current navigation controller
*/
var navigationController: UIViewController { get }

/**
* Called when asking to navigate to another view
*/
func show<T: IMvvmBaseViewModel>(request: MvvmRequest<T>)
/**
* Called when asking closing a view
*/
func close<T: IMvvmBaseViewModel>(viewModel: T)
}

* Container

The container is used before calling the presenter, it retrieve the wanted view by the viewmodel type

/**
* Used for getting the view
*/
public protocol IMvvmContainer {
init()
/**
* From the viewModel, retrieve the wanted view
*/
func getView<T: IMvvmBaseViewModel>(viewModel: T.Type) -> UIViewController
}

The Framework embedded a basic presenter and container but you can replace them when you setup the framework.

public init(window: UIWindow, presenter: IMvvmPresenter.Type = MvvmBasicPresenter.self, container: IMvvmContainer.Type = MvvmBasicContainer.self)

• The default container :

All navigation between Views are made in the ViewModels, it requires some specifics naming between the View + (Storyboard) and the corresponding ViewModel.

For the ViewModel testViewModel, the View must be named testView and the storyboard must be named test.

The navigation won't work if you do not respect this rule.

• Specify the stroyboard name :

You can specify the storyboard name with IMvvmFromStoryBoardAttribute (see FirstView)

• Without storyboard :

You can also navigate without storyboard but must follow this rule :

For the ViewModel testViewModel, the View must be named testView.

So how to navigate?

In the ViewModel just call :

//Show
self.navigation.showViewModel(viewModelToShow: AnotherViewModel.self)
or 
self.navigation.showViewModel(viewModelToShow: AnotherViewModel.self, onCompletion:nil, withParameters:[SOMEDATA])

//Inside AnotherViewModel 
override func startViewModel(parameters: Any? [SOMEDATA]) {
        
}
//Close
self.navigation.closeViewModel(viewModelToClose: self, onCompletion: { () -> (Void) in
    NSLog("AnotherViewModel closed")
})

INavigationService Interface

INavigationService have a lot of methods for navigating, with completion, parameters ...

public protocol IMvvmNavigationService {
    var baseNavigation: UIViewController { get }

    func showViewModel<T: IMvvmBaseViewModel>(viewModelToShow: T.Type)
    func showViewModel<T: IMvvmBaseViewModel>(viewModelToShow: T.Type,
    onCompletion:(() -> Void)?)
    func showViewModel<T: IMvvmBaseViewModel>(viewModelToShow: T.Type,
    onCompletion:(() -> Void)?,
    withParameters: Any?)

    func closeViewModel<T: IMvvmBaseViewModel>(viewModelToClose: T, onCompletion:(() -> Void)?)
    func closeViewModel<T: IMvvmBaseViewModel>(viewModelToClose: T)

    func resolveViewModel<T: IMvvmBaseViewModel>(viewModelToGet: T.Type) -> T
    func associateViewControllersWithViewModels<T: IMvvmBaseViewModel>(viewModels: [T.Type]) -> [UIViewController]?
}