DroidKaigi 2024 - You will 💜 Becoming a fullstack developer with your Android skills

Kotlin is much more than just a language; it is a complete ecosystem! From backend development to cross-platform front-end development, and even data science, it is everywhere. This is part of the DNA of Kotlin since its creation and grows exponentially especially with the latest Google IO and KotlinConf 2024.

This talk demonstrates how Android devs can easily become fullstack using their existing Kotlin skills. We will share three demos covering different stacks of development including exotic and funny ones. We will achieve all of this by keeping our favorite Jetpack libraries (such as navigation, Room and preferences datastore) and integrating new ones (such as Ktor client/server, DataFrame).

By the end of this presentation, you will be delighted to realize how easy and pleasant it is to kick-start development for other targets than Android. Indeed, in addition to iOS, desktop, web, backend, and data-science apps, even more app stacks are already in your reach.

https://2024.droidkaigi.jp/en/timetable/687445/

Transcript

1. Payments to grow your world You will Becoming a fullstack developer with your Android skills DroidKaigi 2024 - 1
2. - 2 Yassine Benabbas DevRel, Teacher Lille Android User Group @yostane in/benabbasyassine Ibrahim Gharbi DevRel, Teacher @__brah in/Ibrahim.gharbi Lille / France
3. What can we develop with Kotlin? - 3 Mobile Web Desktop Backend Data science ? …
4. Already 13th years and a promising future ! Ecosystem milestones Language & Web/Desktop support - Kotlin: JVM + JS targets - Kotlin in Android Studio - KMP beta1 Mobile & Backend in the ecosystem - Coroutines - Ktor client / server 1.0 - Kotlin 1st class on Android - Jetpack compose for Android - Apple platforms interop iOS & Kotlin multiplatform - Jetpack Compose 1.0 - Compose multiplatform 1.0 (Android/Desktop) - Compose multiplatform iOS - Kotlin DSL by Default for New Gradle Builds - K2 - KMP Wizard 2011 2017 2018 2020 2021 2024
5. Kotlin Multiplatform (KMP) - 5
6. - 6 Swift UI Shared UI with Compose Multiplatform UIKit widgets Android views Swing/AWT views WebUI Common library with Kotlin Multiplatform iOS specific Logic Android specific Logic Desktop specific Logic Web specific Logic iOS APIs Android APIs Desktop JVM/APIs WEB APIs ? Kotlin Multiplatform (KMP) ? Stable Stable Alpha Beta
7. KMP : Architecture (1/3) - 7
8. Keywords: Expect / Actual KMP : Architecture : specific platform code (2/3) specific code (UIKit) specific code (Android SDK) actual fun getPlatform(): String { "Android ${android.os.Build.VERSION.SDK_INT}" } actual fun getPlatform(): String { "iOS ${UIDevice.currentDevice.systemVersion}" } expect fun getPlatform(): String
9. Composants Status Official or 3rd party libraries Composables Navigation Ressources/i18n Helped with Jetpack compose docs Navigation library multiplatform (2024) Painter-ressource, font, string ressources (2024) ViewModel View model multiplatform (2024) KMP : Architecture (3/3) Database SQLDelight, Realm, Room Database (2024) User preferences KStore, Jetpack datastore-preferences, Multiplatform-Settings Network Jetbrain Ktor Client And also o Injection : Koin o Concurrent prg : kotlinx.coroutines o Business logic components (BLoC) : Decompose
10. Kotlin for Frontend (compose) - 10
11. - 11 Title 8:30 @composable MyComposableView(){ Box( contentAlignment = Alignment.Center, modifier = Modifier.fillMaxWidth().fillMaxHeight() ) { Card( shape = RoundedCornerShape(8.dp), modifier = Modifier.padding(10.dp), ) { Column(horizontalAlignment = Alignment.CenterHorizontally) { Text( text = "Quiz", fontSize = 30.sp, modifier = Modifier.padding(all = 10.dp) ) Text(modifier = Modifier.padding(all = 10.dp), text = "A simple Quiz to discovers KMP, KMM and compose.") Button( modifier = Modifier.padding(all = 10.dp), onClick = { } ) { Text("Start the Quiz")} }} } Start the Quiz Quizz A simple Quizz to discovers KMP, KMM and compose Declarative UI with Compose multiplatform Jetpack compose Skia and Skiko Behind compose multiplatform (https://github.com/JetBrains/skiko)
12. - 12 wrl.li/quizapp
13. - 13 DEMO TIME KMP + compose
14. - 14 https://wrl.li/kmpdemo
15. - 15 KMP: WishList Architecture o WASM stable support on compose for web o BDD multiplatform support ❑ Better SQLDelight driver instantiation, WASM support ❑ Room for Web, EXPOSED support o kotlinx.coroutines : better dispatchers multiplatform support Tooling o Concise build.gradle config with Ampere o Fleet improvements ( Run config, cache, previews ) o iOS ❑ xcodebuild gradle native plugin ❑ iOS support in IntelliJ ❑ Logging improvement on iOS
16. Kotlin for the backend - 16
17. Many choices JVM Pure Kotlin Kotlin/JS - WASM - 17
18. Case study https://kotlinlang.org/lp/server-side/case-studies - 18
19. - 19
20. - 20
21. Ktor server By JetBrains • State of art server framework • Free and open source • Powerful DSLs • Plugin support - 21
22. - 22 https://wrl.li/ktorserverdemo
23. Kotlin for the Data science - 23
24. Jupyter Notebook • markdown + executable code + its output => a single « .ipynb » file • Can be executed from webapps (Jupyter lab, Datalore, ...) and IDEs (VSCode, IntelliJ, ...) • Can be rendered by many tools such as GitHub • Kernels provide language support (there is a Kotlin Kernel ) - 24
25. Getting started with data analysis - 25 Kandy plotting library Dataframe: data manipulation
26. - 26
27. - 27
28. - 29 https://wrl.li/kandystats
29. - 30 https://wrl.li/kandystats
30. - 31 https://wrl.li/kotlindatasciencedemo
31. Notable and new language features - 32
32. Explicit Backing fields (Since Kotlin 2) github.com/Kotlin/KEEP/issues/278 - 33
33. github.com/Kotlin/KEEP/issues/278 - 34 Explicit Backing fields (Since Kotlin 2)
34. youtrack.jetbrains.com/issue/KT-43871 - 35 Collection litterals (in discussion)
35. Annd many more amazing features Explicit backing field Array Literals guards Infinite loop github.com/Kotlin/KEEP x.com/kotlin Multi-field value classes Context parameters Kotlin statics and static extensions HexFormat
36. Conclusion - 37
37. Fullstack Kotlin: is it time to onboard? - 38 ✓ Achieved milestones: KMP + Kotlin 2.0 ✓Comprehensive ecosystem ✓Mature backend frameworks ✓Android devs will be delighted to be open to other platforms ( web, back, data science)
38. Case studies | Kotlin Multiplatform Development Documentation https://www.jetbrains.com/help/kotlin-multiplatform-dev/case-studies.html https://blog.worldline.tech/2022/01/26/kotlin_multiplatform.html Joanvi Orenga Sergio Casero Hernández
39. - 40 Mobile Web Desktop Backend Data science Kotlin training KMP training
40. Contacts: Thanks for your attention! Any questions ? @__brah @yostane - 41