GithubSearchKMM

Github Repos Search - Kotlin Multiplatform Mobile using Jetpack Compose, SwiftUI, FlowRedux, Coroutines Flow, Dagger Hilt, Koin Dependency Injection, shared KMP ViewModel, Clean Architecture

Minimal Kotlin Multiplatform project with SwiftUI, Jetpack Compose.

• Android (Jetpack compose)
• iOS (SwiftUI)

Liked some of my work? Buy me a coffee (or more likely a beer)

Modern Development

• Kotlin Multiplatform
• Jetpack Compose
• Kotlin Coroutines & Flows
• Dagger Hilt
• SwiftUI
• Koin Dependency Injection
• FlowRedux State Management
• Shared KMP ViewModel
• Clean Architecture

Tech Stacks

• Functional & Reactive programming with Kotlin Coroutines with Flow
• Clean Architecture with MVI (Uni-directional data flow)
• Multiplatform ViewModel
• Multiplatform FlowRedux State Management
• Λrrow - Functional companion to Kotlin's Standard Library
  • Either
  • Monad Comprehensions
  • Option
  • parZip
• Dependency injection
  • iOS: Koin
  • Android: Dagger Hilt
• Declarative UI
  • iOS: SwiftUI
  • Android: Jetpack Compose
• Ktor client library for networking
• Kotlinx Serialization for JSON serialization/deserialization.
• Napier for Multiplatform Logging.
• FlowExt.
• MOKO KSwift is a gradle plugin for generation Swift-friendly API for Kotlin/Native framework.
• kotlinx.collections.immutable: immutable collection interfaces and implementation prototypes for Kotlin..
• Testing
  • Kotlin Test for running tests with Kotlin Multiplatform.
  • Turbine for KotlinX Coroutines Flows testing.
  • Mockative: mocking for Kotlin/Native and Kotlin Multiplatform using the Kotlin Symbol Processing API.
  • Kotlinx-Kover for Kotlin Multiplatform code coverage.

Screenshots

Android (Light theme)

Android (Dark theme)

iOS (Light theme)

iOS (Dark theme)

Overall Architecture

What is shared?

• domain: Domain models, UseCases, Repositories.
• presentation: ViewModels, ViewState, ViewSingleEvent, ViewAction.
• data: Repository Implementations, Remote Data Source, Local Data Source.
• utils: Utilities, Logging Library

Unidirectional data flow - FlowRedux

• My implementation. Credits: freeletics/FlowRedux
• See more docs and concepts at freeletics/RxRedux

public sealed interface FlowReduxStore<Action, State> {
  /**
   * The state of this store.
   */
  public val stateFlow: StateFlow<State>

  /**
   * @return false if cannot dispatch action (this store was closed).
   */
  public fun dispatch(action: Action): Boolean

  /**
   * Call this method to close this store.
   * A closed store will not accept any action anymore, thus state will not change anymore.
   * All [SideEffect]s will be cancelled.
   */
  public fun close()

  /**
   * After calling [close] method, this function will return true.
   *
   * @return true if this store was closed.
   */
  public fun isClosed(): Boolean
}

Multiplatform ViewModel

open class GithubSearchViewModel(
  searchRepoItemsUseCase: SearchRepoItemsUseCase,
  private val savedStateHandle: SavedStateHandle,
) : ViewModel() {
  private val effectsContainer = GithubSearchSideEffectsContainer(searchRepoItemsUseCase)

  private val store = viewModelScope.createFlowReduxStore(
    initialState = GithubSearchState.initial(),
    sideEffects = effectsContainer.sideEffects,
    reducer = Reducer(flip(GithubSearchAction::reduce))
      .withLogger(githubSearchFlowReduxLogger())
  )

  val termStateFlow: NonNullStateFlowWrapper<String> = savedStateHandle.getStateFlow(TERM_KEY, "").wrap()
  val stateFlow: NonNullStateFlowWrapper<GithubSearchState> = store.stateFlow.wrap()
  val eventFlow: NonNullFlowWrapper<GithubSearchSingleEvent> = effectsContainer.eventFlow.wrap()

  init {
    store.dispatch(InitialSearchAction(termStateFlow.value))
  }

  @MainThread
  fun dispatch(action: GithubSearchAction): Boolean {
    if (action is GithubSearchAction.Search) {
      savedStateHandle[TERM_KEY] = action.term
    }
    return store.dispatch(action)
  }

  companion object {
    private const val TERM_KEY = "com.hoc081098.github_search_kmm.presentation.GithubSearchViewModel.term"

    /**
     * Used by non-Android platforms.
     */
    fun create(searchRepoItemsUseCase: SearchRepoItemsUseCase): GithubSearchViewModel =
      GithubSearchViewModel(searchRepoItemsUseCase, SavedStateHandle())
  }
}

Platform ViewModel

Android

Extends GithubSearchViewModel to use Dagger Constructor Injection.

@HiltViewModel
class DaggerGithubSearchViewModel @Inject constructor(
  searchRepoItemsUseCase: SearchRepoItemsUseCase,
  savedStateHandle: SavedStateHandle,
) : GithubSearchViewModel(searchRepoItemsUseCase, savedStateHandle)

iOS

Conform to ObservableObject and use @Published property wrapper.

import Foundation
import Combine
import shared
import sharedSwift

@MainActor
class IOSGithubSearchViewModel: ObservableObject {
  private let vm: GithubSearchViewModel

  @Published private(set) var state: GithubSearchState
  @Published private(set) var term: String = ""
  let eventPublisher: AnyPublisher<GithubSearchSingleEventKs, Never>

  init(vm: GithubSearchViewModel) {
    self.vm = vm

    self.eventPublisher = vm.eventFlow.asNonNullPublisher()
      .assertNoFailure()
      .map(GithubSearchSingleEventKs.init)
      .eraseToAnyPublisher()

    self.state = vm.stateFlow.value
    vm.stateFlow.subscribe(
      scope: vm.viewModelScope,
      onValue: { [weak self] in self?.state = $0 }
    )

    self.vm
      .termStateFlow
      .asNonNullPublisher(NSString.self)
      .assertNoFailure()
      .map { $0 as String }
      .assign(to: &$term)
  }

  @discardableResult
  func dispatch(action: GithubSearchAction) -> Bool {
    self.vm.dispatch(action: action)
  }

  deinit {
    Napier.d("\(self)::deinit")
    vm.clear()
  }
}

Download APK

• Download latest debug APK here

Building & Develop

• Android Studio Chipmunk | 2021.2.1 (note: Java 11 is now the minimum version required).

• XCode 13.2 or later (due to use of new Swift 5.5 concurrency APIs).

• Clone project: git clone https://github.com/hoc081098/GithubSearchKMM.git

• Android: open project by Android Studio and run as usual.

• iOS

  # Cd to root project directory
  cd GithubSearchKMM
  
  # Setup
  sh scripts/run_ios.sh

  There's a Build Phase script that will do the magic. 🧞
  Cmd + B to build
  Cmd + R to run.

  When you see any error like this:

  ./GithubSearchKMM/iosApp/iosApp/ContentView.swift:4:8: No such module 'sharedSwift'
  

  You can run the following commands (must select Read from disk inside Xcode):

  # go to iosApp directory
  cd iosApp
  
  # install pods
  pod install

  Then, you can build and run inside Xcode as usual.

LOC

--------------------------------------------------------------------------------
 Language             Files        Lines        Blank      Comment         Code
--------------------------------------------------------------------------------
 Kotlin                 105         7647          936          439         6272
 JSON                     7         3938            0            0         3938
 Swift                   16          903          118          102          683
 Markdown                 1          294           54            0          240
 Bourne Shell             2          250           28          116          106
 Batch                    1           92           21            0           71
 XML                      6           69            6            0           63
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 Total                  138        13193         1163          657        11373
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