Updated Lessons from a KMP Developer's Toolkit

Transcript

1. BlrKotlin x BlrDroid Updated Lessons from a KMP Developer's Toolkit Subhrajyoti Sen Motive
2. Agenda • Shared Resources • Dependency Injection • Shared ViewModel • Flow • Build optimizations
3. Shared Resources icerockdev/moko-resources Can be used to share: • Strings • Color • SVG, PNG
4. Shared Resources
5. Shared Resources
6. Shared Resources
7. Shared Resources task("renameAndroidSharedResource") { outputs.upToDateWhen { false } doLast { copy { from("build/generated/moko/androidMain/res/values-fr") into("build/generated/moko/androidMain/res/values-fr-rCA") } delete("build/generated/moko/androidMain/res/values-fr") } dependsOn("generateMRandroidMain") }
8. Shared Resources task("renameIosSharedResource") { outputs.upToDateWhen { false } doLast { copy { from("build/generated/moko/iosMain/res/fr.lproj") into("build/generated/moko/iosMain/res/fr-CA.lproj") } delete("build/generated/moko/iosMain/res/fr.lproj") } dependsOn("generateMRiosMain") }
9. Shared Resources tasks.preBuild { if (tasks.findByName("generateMRiosMain") != null) { dependsOn("renameIosSharedResource") } if (tasks.findByName("generateMRandroidMain") != null) { dependsOn("renameAndroidSharedResource") } }
10. Shared Resources No Configuration Cache support till 0.24.0
11. Shared Resources No Configuration Cache support till 0.24.0 0.24.0 was released in June, 2024
12. Dependency Injection - Earlier
13. Dependency Injection - Earlier // commonMain open class ChatMessageChannelViewModelImpl( private val messageChannelManager: MessageChannelManagerInterface ) : SharedViewModel(), ChatMessageChannelViewModel
14. Dependency Injection - Earlier // commonMain open class ChatMessageChannelViewModelImpl( private val messageChannelManager: MessageChannelManagerInterface ) : SharedViewModel(), ChatMessageChannelViewModel // android @HiltViewModel class ChatMessageChannelViewModelWrapper @Inject constructor( private val messageChannelManager: MessageChannelManagerInterface, ) : ChatMessageChannelViewModelImpl( messageChannelManager )
15. Dependency Injection - Later // commonMain expect annotation class KMMViewModel // androidMain actual typealias KMMViewModel = HiltViewModel
16. Dependency Injection - Later @KMMViewModel class ChatMessageChannelViewModelImpl( private val messageChannelManager: MessageChannelManagerInterface ) : SharedViewModel(), ChatMessageChannelViewModel
17. Dependency Injection - Now
18. Dependency Injection - Now // commonMain expect class KoinStringsModule // androidMain @Module @ComponentScan actual class KoinStringsModule // iosMain @Module @ComponentScan actual class KoinStringsModule
19. Dependency Injection - Now @Module( includes = [ KoinStringsModule::class ] ) class KoinSharedModule { //.. }
20. Dependency Injection - Now @Module( includes = [ KoinSharedModule::class, ] ) @ComponentScan class KoinAppAndroidModule { //.. }
21. Dependency Injection - Now class MainApplication : Application() { override fun onCreate() { super.onCreate() startKoin { androidLogger() androidContext(this@MainApplication) modules(KoinAppAndroidModule().module) } } }
22. Dependency Injection - Now private fun getKClass(type: ObjCObject): KClass<*> { return when (type) { is ObjCProtocol -> getOriginalKotlinClass(type) is ObjCClass -> getOriginalKotlinClass(type) else -> null } ?: throw IllegalArgumentException("Unknown type: $type") }
23. Dependency Injection - Now fun <T : ObjCObject> get(type: ObjCObject): T { val koin = KoinPlatformTools.defaultContext().get() val kotlinClass = getKClass(type) return try { koin.get(kotlinClass) } catch (e: Throwable) { throw e.getRootCause() } }
24. Dependency Injection - Now import Foundation import shared public func kmmGet<T: AnyObject>() -> T { guard let object = DiKt.get(type: T.self) as? T else { fatalError("error in casting") } return object }
25. Dependency Injection - Now import Foundation import shared public func kmmGet<T: AnyObject>() -> T { guard let object = DiKt.get(type: T.self) as? T else { fatalError("error in casting") } return object }
26. Dependency Injection - Now @Suppress("unused") // Used on iOS fun start( netConnectivity: NetConnectivity, ) { val iosNativeModule = module { factory { netConnectivity } } startKoin { modules(iosNativeModule, KoinSharedModule().module) } }
27. Shared ViewModel
28. Shared ViewModel // commonMain expect abstract class SharedViewModel() { protected val sharedScope: CoroutineScope protected open fun onCleared() }
29. Shared ViewModel // androidMain actual abstract class SharedViewModel : ViewModel() { actual val sharedScope = CoroutineScope(SupervisorJob() + Dispatchers.Main) actual override fun onCleared() { super.onCleared() sharedScope.cancel() } }
30. Shared ViewModel // iosMain actual abstract class SharedViewModel { actual val sharedScope = CoroutineScope(SupervisorJob() + Dispatchers.Main) protected actual open fun onCleared() { sharedScope.cancel() } }
31. Current Flow Repository UseCase ViewModel Android iOS
32. Observable State
33. Observable State interface ChatViewModel { val uiState: KLiveData<ChatUIState> fun method1() fun asyncMethod2() }
34. KMPNativeCoroutines https://github.com/rickclephas/KMP-NativeCoroutines
35. Observable State interface CamerasViewModel { @NativeCoroutinesState val uiState: StateFlow<CamerasUiState> @NativeCoroutines val effect: SharedFlow<CamerasEffect> }
36. Observable State // CamerasViewModelNative.kt @ObjCName(name = "effect") public val CamerasViewModel.effectNative: NativeFlow<CamerasEffect> get() = effect.asNativeFlow(null) public val CamerasViewModel.effectReplayCache: List<CamerasEffect> get() = effect.replayCache
37. Observable State // CamerasViewModelNative.kt public val CamerasViewModel.uiStateFlow: NativeFlow<CamerasUiState> get() = uiState.asNativeFlow(null) @ObjCName(name = "uiState") public val CamerasViewModel.uiStateValue: CamerasUiState get() = uiState.value
38. Observable State extension CamerasViewModel { func uiStateObservable() -> Observable<CamerasUiState> { return createObservable(for: self.stateFlow) } func effectObservable() -> Observable<CamerasEffect> { return createObservable(for: self.effect) } }
39. Build Optimizations
40. Build Optimizations • We won’t want to run iOS tasks when running CI for Android • We won’t want to run Android tasks when running CI for iOS
41. Build Optimizations // build.gradle.kts kotlin { targets.configureEach { disableCompilationsIfNeeded(project) } } https://github.com/arkivanov/gradle-setup-plugin
42. Build Optimizations // Podfile def pod_KMM if %r{^true$}i.match ENV['USE_KMM_DEV'] pod 'KotlinMultiplatformModule', :path => '../path' else pod 'KotlinMultiplatformModule' end end
43. FAQ • moko-resources or multiplatform-resources? • SQLDelight or Room?
44. General Tips • Keep a close look on Xcode versions • Understand the generated code • Not everything needs to be KMP • Remember to use `internal` implementation definitions: ◦ constructors ◦ usecases ◦ repositories
45. Questions?
46. Thank You @iamsubhrajyoti