Kaluga SwiftUI Tools

Tools for generating classes to easily link Kaluga projects to SwiftUI. Since Kotlin Multiplatform does not support Swift implementations, Kaluga does not offer full SwiftUI support. Instead some bridging classes are required to use Kaluga properly.

Kaluga projects do not directly import Kaluga into the Swift project however, instead exposing dependencies though a project specific shared library. Therefore, no proper Swift Framework can be offered to developers.

This library aims to resolve this issue by providing coding templates that generated Swift classes directly in the SwiftUI project. These classes are generated using Sourcery.

Installation

Make sure latest version of Sourcery is installed on your machine.

• Checkout this project as a submodule to your project
• Copy template-kaluga.sourcery.yml into the iOS folder of your shared code project and rename it to kaluga.sourcery.yml
• Open kaluga.sourcery.yml and change:
  • $XCODE_PROJECT_NAME to the name of your xcodeproj file
  • $TARGET_NAME to the name of the target in your project
  • $PATH_TO_SUBMODULE to the path of the submodule
  • $SHARED_FRAMEWORK_NAME to the name of the Kaluga-based Shared Framework
  • Configure features (see below)

Manually

• Run sourcery --config kaluga.sourcery.yml
• If the partial sheet feature was enabled, add https://github.com/AndreaMiotto/PartialSheet.git as a Swift Package Dependency to your project.
• Import the files in ./KalugaSwiftUI into your Xcode project.

Automatic

• Add Sourcery as pods into your project (Optional)
• Add new Run Build Phase: $PODS_ROOT/Sourcery/bin/sourcery --config kaluga.sourcery.yml
• Uncomment link section inside kaluga.sourcery.yml

Note code generation should go after multiplatform framework dependency

Features

To enable or disable certain Kaluga features, update their corresponding settings in the kaluga.sourcery.yml file. All features are enabled by default.

• includeResources: Set to true when Kaluga.resources is exported.
• includeAlerts: Set to true when Kaluga.alerts is exported.
• includeHud: Set to true when Kaluga.hud is exported.
• includeDatePicker: Set to true when Kaluga.date-picker is exported.
• includeKeyboard: Set to true when Kaluga.keyboard is exported. If your Minimum target version is lower than 15 you won't be able to use the SwiftUI extension. In case your project targets a version < 15, use the UIKit implementation instead.
• includePartialSheet: Set to true when using PartialSheet navigation.

Usage

ViewModels

Kaluga ViewModels require a lifecycle to be maintained. This can be automated by wrapping the ViewModel in a LifecycleViewModel. Use the wrappers body method to then display the viewModel in a lifecycle aware state.

struct SomeView: View {

    private let viewModel: LifecycleViewModel<SomeViewModel>

    init(_ someViewModel: SomeViewModel) {
        viewModel = LifecycleViewModel(viewModel: someViewModel)
    }

    var body: some View {
        viewModel.lifecycleView { viewModel in
            // Render View
            Text(viewModel.title)
        }
    }
}

Alerts, HUD and DatePicker.

If Kaluga.alerts, Kaluga.hud, and Kaluga.date-picker have been enabled, provide a ContainerView to the LifecycleViewModel to automatically add support for displaying alerts, huds, and date-pickers to the View.

The types of builders to support in a container can be provided on initialization.

let container = ContainerView(.alertBuilder, .hudBuilder, .datePickerBuilder)
let alertBuilder = container.alertBuilder
let hudBuilder = container.hudBuilder
let datePickerBuilder = container.datePickerBuilder
let wrapper = ViewModelWrapperView(container: container, viewModel: viewModel)

Observables and Subjects

This library provides functionality for using Kaluga Observables and Subjects in SwiftUI views. Observables can be mapped to an Observable or UninitializedObservable and Subjects to Subject or UninitializedSubject classes. These classes require a mapping, though convenience default mappings and typealiases are included in this library.

To use the value of an observable:

struct SomeView: View {

    @ObservedObject private var someString: StringObservable

    init(_ viewModel: SomeViewModel) {
        someString = StringObservable(
            viewModel.someStringObservable,
            defaultValue: "DefaultValueString",
            animated: true // Animate value changes
        )
    }

    var body: some View {
        Text(someString.value)
    }
}

Default Observables:

• ListObservable
• Object(Uninitialized)Observable
• Color(Uninitialized)Observable
• String(Uninitialized)Observable
• Bool(Uninitialized)Observable
• Int(Uninitialized)Observable
• Float(Uninitialized)Observable
• Double(Uninitialized)Observable

Default Subjects:

• String(Uninitialized)Subject
• Bool(Uninitialized)Subject
• Int(Uninitialized)Subject
• Float(Uninitialized)Subject
• Double(Uninitialized)Subject

Navigation

State-driven navigation

Suppose you have navigation state (simplified) in shared code:

class HomeRoutingNavigator {

    sealed class RoutingState(open val route: String) {
        object Root : RoutingState("Root")
        object LogIn : RoutingState("LogIn")
        object Profile : RoutingState("Profile")
    }

    val routingState = MutableStateFlow<RoutingState>(RoutingState.Root)
}

And view model holding this state:

class SomeViewModel : BaseLifecycleViewModel() {

    private val navigator = HomeRoutingNavigator()

    val isLogInScreenVisible = navigator.routingState
        .mapLatest { it is HomeRoutingNavigator.RoutingState.LogIn }
        .toInitializedObservable(false, coroutineScope)
}

To show LogInView in SwiftUI using navigation state:

struct HomeView: View {

    private let viewModel: LifecycleViewModel<HomeViewModel>
    @ObservedObject private var isLogInScreenVisible: BoolObservable

    init(_ homeViewModel: HomeViewModel) {
        viewModel = LifecycleViewModel(viewModel: homeViewModel)
        isLogInScreenVisible = BoolObservable(homeViewModel.isLogInScreenVisible, animated: true)
    }

    var body: some View {
        viewModel.lifecycleView { viewModel in
            Group {
                // Home View Layout
                Text(viewModel.staticTitle)
            }
            .navigation(state: ObservableRoutingState(isLogInScreenVisible), type: .fullscreen) {
                LogInView()
            }
        }
    }
}

View display types:

• Fullscreen (using fullScreenCover)
• Replace (fully replaced view)
• Cover (partly covered view)
• Sheet (using sheet)
• Push (using NavigationView)