Kotlin Multi-platform(?)

1. Multiplatform Kotlin(?) Kotlin Developers Meetup
2. About Me • Matthew Vern / Panini • Twitter: @callipan Github: panpanini • Mercari, Inc • Android Engineer (US) • kotlin@kawaii.com
3. About Me • Matthew Vern / Panini • Twitter: @callipan Github: panpanini • Mercari, Inc • Android Engineer (US) • kotlin@kawaii.com • React Native Engineer??
4. React Native • Build native mobile apps using JavaScript and React • “Write Once, Run Anywhere” • Works both on Android & iOS • Hot reload • Interfaces with native Kotlin/Swift code
5. React Native @ Mercari US • Used in Profile & Chat screens • Great for simple screens • Easy feature parity between platforms • But...
6. I wanna write Kotlin
7. Kotlin.js • Transpiles Kotlin to JavaScript • Kotlin-react https://github.com/JetBrains/create-react-kotlin-app • • Kotlin-React-Native?
8. Kotlin React Native • Create Kotlin JS project inside ReactNative project • Link React Native JS to Kotlin JS output
9. Kotlin React Native • Create wrapper for React Native JS • @JsModule • external
10. Kotlin React Native • React has a lot of ceremony to create components • Abstract as much away with DSL • Makes UI code much cleaner
11. Kotlin React Native • React has a lot of ceremony to create components • Abstract as much away with DSL • Makes UI code much cleaner
12. Hot Reload • “Keep the app running and to inject new versions of the files that you edited at runtime” • Kotlin has to be compiled though...
13. Gradle Continuous Build https://blog.gradle.org/introducing-continuous- build • “As of 2.5, Gradle supports continuous build execution, which will automatically re-execute builds when changes are detected to its inputs.” • Anytime a file is changed, gradle will rerun the task • Hot reload!
14. Summary • We can write React Native in Kotlin! • Supports Hot Reloading • Kotlin DSL makes building UI easy • Can run same code on Android & iOS
15. Summary • The Kotlin we write is 90% JavaScript.. • dynamic • Lots of boilerplate code • Very little documentation • Lets just use Kotlin multiplatform instead