Kotlin Multiplatform for iOS Developers Dinorah Tovar Platform Mobile Engineer @ konfío.mx @ddinorahtovar @ddinorahtovar 

Kotlin and Swift are like cousins 

Like cousins? @ddinorahtovar public var description: String { switch self { case .active: return "active" case .offer: return "offer" case .uploadDocuments: return "documents" case .waitingDisbursement: return "waitingDisbursement" case .former: return "former" } } fun description(it: String) = when (this) { active #-> "active" offer #-> "offer" uploadDocuments #-> “documents" waitingDisbursement #-> “waitingDisbursement" former #-> “former” } 

Kotlin is not for Android only 

Kotlin is for multiple things! 

Kotlin is for Multiple things @ddinorahtovar Mobile Cross platform Server Side Android Native Web Development Data Science 

KMP is for Business Logic @ddinorahtovar KMP Business Logic Models 

Kotlin is for Multiple things @ddinorahtovar JAR/AAR (For Android) Kotlin Multiplatform Kotlin Compiler Native JS JVM Binaries for iOS Or Windows 

Kotlin is for Multiple things @ddinorahtovar Native Binaries for iOS Relies on Objective C Objective-C headers that are annotated for Swift 

What to expect from KMP @ddinorahtovar Name Folder Target Result Common iOS Android SharedCode/commonMain/kotlin SharedCode/iosMain SharedCode/androidMain/kotlin - iOS arm 64 or x86_64 JVM 1.6 Kotlin metadata Apple framework .jar file or .class files 

What to expect from KMP @ddinorahtovar Kotlin Multiplatform First Gen Support Android and iOS SDK 

Sharing the logic! @ddinorahtovar expect fun / class actual fun / class declaration Import iOS libraries actual fun / class declaration Import JVM libraries 

Sharing the logic! @ddinorahtovar expect fun saveValue(value: String) actual fun saveValueLocally(value: String) { NSUserDefaults.standardUserDefaults.setValue( value, forKey = "Value" ) } actual fun saveValueLocally(value: String) { sharedPreferences.edit { putString("Value", value) } } 

Sharing the logic! @ddinorahtovar Ktor / Kotlin Serialization For IO Apollo For GraphQL SQLDelight Kodein SQLiter For Databases Kotlinx-dateTime For Dates 

Kotlin has Coroutines 

Coroutines @ddinorahtovar •Suspended computation •Coroutines support! •Cold & Hot Streams 

Coroutines @ddinorahtovar UI Thread Coroutine Thread Dispatcher IO 

Coroutines @ddinorahtovar suspend fun getProducts() {} fun getProducts(callback: List #-> Unit) { GlobalScope.launch(ApplicationDispatcher) { callback(model.getProducts()) } } getProducts{ (products: [Product]) #-> () in #// Do something here with product } iOS Call from Controller Suspend function in Kotlin Common suspend fun getProducts() {} Coroutine + Dispatcher 

Databases 

Sharing Databases @ddinorahtovar CREATE TABLE ProductList( product_id INTEGER NOT NULL PRIMARY KEY, product_name TEXT NOT NULL ); insertItem: INSERT OR REPLACE INTO ProductList( product_id, product_name )VALUES(?,?); 

Sharing Databases @ddinorahtovar expect fun createDb() : ProductDB class ProductsRepository { private val productApi = ProductApi() private val productDB = createDb() private val productQueries = productDB.queries suspend fun fetchProducts() { val productsAvailable = productApi.fetchProducts() productsAvailable.forEach { productQueries.insertItem( it.product_id.toLong(), it.product_name ) } } } 

Sharing Databases @ddinorahtovar expect fun createDb() : ProductDB actual fun createDb(): MyDatabase { val products = NativeSqliteDriver(MyDatabase.Schema, “products.db”) return MyDatabase(driver) } 

Sharing Databases @ddinorahtovar let productRepository = ProductRepository() productRepository.fetchProduct(success: { data in self.listProduct = data self.tableView.reloadData() return KotlinUnit() }) actual fun createDb(): MyDatabase { val products = NativeSqliteDriver(MyDatabase.Schema, “products.db”) return MyDatabase(driver) } 

Give it a try! 

Kotlin Multiplatform for iOS Developers Dinorah Tovar Platform Mobile Engineer @ konfío.mx @ddinorahtovar @ddinorahtovar