All About KotlinConf 2019

Transcript

1. All About KotlinConf 2019 Ivan Wu
2. Hello! I am Ivan Senior Engineer @ETtoday You can find me at ivan.wu@ettoday.net 2
3. What is KotlinConf? KotlinConf is a conference, providing deep-dive technical content on Kotlin. 3 Playlist: https://www.youtube.com/watch?v=Lv5WcWNIDrw&list=PLQ176FUIyIUY6SKGl3Cj9yeYibBuRr3Hl
4. Related Events Kotlin Everywhere ⦁ 30K people across 86+ countries KotlinConf global ⦁ 50+ places 4
6. 6 KotlinConf 2019 App https://github.com/JetBrains/kotlinconf-app
14. Codelabs 14
15. Topics ⦁ Mutliplatform ⦁ Kotlin/Native ⦁ Kotlin/JS ⦁ Ktor ⦁ Jetpack Compose 15 ⦁ Coroutines ⦁ Flow ⦁ New product ⦁ Space Space: https://www.jetbrains.com/space/
16. Kotlin 16 ⦁ New compiler ⦁ Fast, uniform, and pluggable Source: Opening Keynote - Andrey Breslav ⦁ Compiler plugins ⦁ Write something to extend or enhance functionality of Kotlin
17. Kotlin 17 fun interface Action { fun run() } fun runAction(a: Action) = a.run() runAction { println("Hello, KotlinConf!") } Source: Opening Keynote - Andrey Breslav https://youtrack.jetbrains.com/issue/KT-7770
18. What’s more? 18 ⦁ Library author’s mode ⦁ Explicit visibility ⦁ Explicit public types ⦁ Dokka ⦁ Doc generation tool ⦁ Run/Debug iOS Kotlin Apps in Android Studio Source: Opening Keynote - Andrey Breslav
19. Kotlin/Native 19 ⦁ Performance improvement ⦁ Support for tvOS and watchOS ⦁ Kotlin Locator (demo) Source: Opening Keynote - Andrey Breslav
20. Kotlin/JS 20 ⦁ Quick autoreload ⦁ Smaller JS binary size ⦁ ES modules ⦁ NPM dependencies Source: Opening Keynote - Andrey Breslav
21. Writing Better Kotlin 21 ⦁ Readability ⦁ Reusability ⦁ Maintainability ⦁ Intentionality Source: Putting down the Golden Hammer - Huyen Dao
22. Writing Better Kotlin ⦁ Type inference ⦁ Do not nest scope functions ⦁ Implicit parameter: `it` ⦁ Nullability ⦁ !! operator ⦁ Platform type: ! ⦁ Safe operator -> silently fail ⦁ Use !! if you are sure it’s not null 22 Source: Putting down the Golden Hammer - Huyen Dao
23. Jetpack Compose ⦁ Still in developer preview ⦁ In Compose, everything is function ⦁ Composable function ⦁ Composition over inheritance ⦁ Uppercase naming function (top-level) 23 Source: Compose Yourself: Designing A Kotlin First UI Toolkit @Composable fun Checkbox(...)
24. Jetpack Compose ⦁ Single source of truth 24 Source: Compose Yourself: Designing A Kotlin First UI Toolkit @Override public boolean performClick() { setChecked(!mChecked); final boolean handled = super.performClick(); ... }
25. Jetpack Compose ⦁ Single source of truth 25 Source: Compose Yourself: Designing A Kotlin First UI Toolkit @Composable fun Checkbox( checked: Boolean, onCheckedChange: ((Boolean) -> Unit)?, ... )
26. Jetpack Compose ⦁ Properties down, events up 26 Source: Compose Yourself: Designing A Kotlin First UI Toolkit @Composable fun SettingsScreen(settings: SettingsStore) { Row { Text("Very important setting") Checkbox( checked = settings.isVeryImportant, onCheckedChange = { settings.updateVeryImportant(it) } ) } }
27. Jetpack Compose ⦁ Parameter explosion ⦁ Slot API 27 Source: Compose Yourself: Designing A Kotlin First UI Toolkit @Composable fun Button( text: String, onClick: (() -> Unit)? = null, style: ButtonStyle = ContainedButtonStyle(), children: @Composable () -> Unit )
28. Jetpack Compose ⦁ Compose Implementation ⦁ The Compose Runtime, Demystified - Leland Richardson 28
29. “ Trust your intuition Empower your people Innovate Adapt and thrive Tell stories But most of all… 29 Source: The Shuttle Case - Stephen Carver Have fun!!
30. 30 Thanks! Have fun!