Kotlin for the Masses

Kotlin for the Masses @SerjLtt

@SerjLtt Kotlin?

@SerjLtt Kotlin? class MyClass

@SerjLtt Kotlin? class MyClass(val valueProperty: String)

@SerjLtt Kotlin? class MyClass(var variableProperty: String)

@SerjLtt Kotlin? data class MyClass(val prop: String)

@SerjLtt Kotlin? data class MyClass(val prop: String) val myClass =
MyClass("something")

@SerjLtt Kotlin? data class MyClass(val prop: String) val myClass =
MyClass(“something") val myClass2 = MyClass(null)

@SerjLtt Kotlin? data class MyClass(val prop: String?)

@SerjLtt Kotlin? data class MyClass(val prop: String?) if (myClass.prop.isEmpty()) {
}

@SerjLtt Kotlin? data class MyClass(val prop: String?) if (myClass.prop.isEmpty()) {
// Compiler error }

@SerjLtt Kotlin? data class MyClass(val prop: String?) if (myClass.prop!!.isEmpty()) {
}

@SerjLtt Kotlin? data class MyClass(val prop: String?) myClass.prop?.let { if
(it.isEmpty()) { } }

@SerjLtt Kotlin? fun foo(): Unit { }

@SerjLtt Kotlin? fun foo() { }

@SerjLtt Kotlin? fun foo() { } fun bar(): String {
return "bar" }

@SerjLtt Kotlin? fun foo() { } fun bar() { return
"bar" }

@SerjLtt Kotlin? fun foo() { } fun bar() = "bar"

fun <T> Iterable<T>.tail() = drop(1)

fun <T> Iterable<T>.tail() = drop(1) fun <R> (() -> R).run(): R = invoke()

fun <T> Iterable<T>.tail() = drop(1) fun <R> (() -> R).run(): R = invoke() fun <R> fooBar(block: () -> R): R = block()

@SerjLtt Kotlin?

@SerjLtt Kotlin? • Typesafe

@SerjLtt Kotlin? • Typesafe • Nullsafe

@SerjLtt Kotlin? • Typesafe • Nullsafe • Modern & Concise

• Functional (?)

• Functional (?) • Interoperable (!)

• Functional (?) • Interoperable (!) • Allows for DSL creation

• Functional (?) • Interoperable (!) • Allows for DSL creation • Find more @ kotlinlang.org

@SerjLtt Why Kotlin?

@SerjLtt Why Kotlin? Pros

@SerjLtt Why Kotlin? Pros • Secure & Reliable

@SerjLtt Why Kotlin? Pros • Secure & Reliable • Huge
open source community

open source community • ∞ Tools

open source community • ∞ Tools • ∞ Libraries

open source community • ∞ Tools • ∞ Libraries Cons

open source community • ∞ Tools • ∞ Libraries Cons • Too verbose

open source community • ∞ Tools • ∞ Libraries Cons • Too verbose • Slow language evolution (*)

open source community • ∞ Tools • ∞ Libraries Cons • Too verbose • Slow language evolution (*) • Misconceptions that the platform is old (&| dying)

open source community • ∞ Tools • ∞ Libraries Cons • Too verbose • Slow language evolution (*) • Misconceptions that the platform is old (&| dying) • [Android] Stuck on Java 6/7

@SerjLtt Why Kotlin? Pros

@SerjLtt Why Kotlin? Pros • Relatively easy to learn

@SerjLtt Why Kotlin? Pros • Relatively easy to learn •
Run’s on every browser (*)

Run’s on every browser (*) • ∞ Frameworks (*)

Run’s on every browser (*) • ∞ Frameworks (*) Cons

Run’s on every browser (*) • ∞ Frameworks (*) Cons • Not type safe

Run’s on every browser (*) • ∞ Frameworks (*) Cons • Not type safe • Callback based (*)

Run’s on every browser (*) • ∞ Frameworks (*) Cons • Not type safe • Callback based (*) • Is being pushed beyond the browser

@SerjLtt Why Kotlin? And many others…

@SerjLtt Why Kotlin? Write once, run anywhere?

@SerjLtt Why Kotlin? Write once, run anywhere? and pray that
it will run.

@SerjLtt Why Kotlin? •Embraces the target platform

@SerjLtt Why Kotlin? •Embraces the target platform •Framework agnostic (*)

@SerjLtt Why Kotlin? •Embraces the target platform •Framework agnostic (*)
•Polylingual

@SerjLtt Project?

@SerjLtt Project? Android iOS Web Backend

@SerjLtt Project? Android

@SerjLtt Project? Android View

@SerjLtt Project? Android View ViewModel

@SerjLtt Project? Android View ViewModel Presenter

@SerjLtt Project? Android View ViewModel Presenter UseCase’s

@SerjLtt Project? Android View ViewModel Presenter UseCase’s Other

@SerjLtt Project? Web

@SerjLtt Project? Web View

@SerjLtt Project? Web View ViewModel

@SerjLtt Project? Web View ViewModel Backend?

@SerjLtt Project? Android iOS Web ViewModel Backend

@SerjLtt Project? Android iOS Web ViewModel Backend Presenter

@SerjLtt Project? Android iOS Web ViewModel Client (Shared) Interfaces Backend
Presenter

@SerjLtt Project? interface DataStore { fun data(): Data }

@SerjLtt Project? interface DataStore { fun data(): Data } class
AndroidDataStore(private val db: RoomDatabase) : DataStore { override fun data() = TODO() }

AndroidDataStore(private val db: RoomDatabase) : DataStore { override fun data() = TODO() } class IosDataStore(private val db: CoreData) : DataStore { override fun data() = TODO() }

AndroidDataStore(private val db: RoomDatabase) : DataStore { override fun data() = TODO() } class IosDataStore(private val db: CoreData) : DataStore { override fun data() = TODO() } import org.w3c.dom.Storage class WebDataStore(private val store: Storage): DataStore { override fun data() = TODO() }

@SerjLtt Project? Android iOS Web ViewModel Client (Shared) Interfaces Backend
Presenter

@SerjLtt Why Kotlin? Write once, run anywhere?

@SerjLtt Why Kotlin? Define once, implement where needed.

@SerjLtt Kotlin Multiplatform Support

@SerjLtt Kotlin Multiplatform Support •Added in Kotlin 1.2.0

@SerjLtt Kotlin Multiplatform Support •Added in Kotlin 1.2.0 •Works with
JVM/Android/JS

@SerjLtt Kotlin Multiplatform Support •Added in Kotlin 1.2.0 •Works with
JVM/Android/JS •Kotlin Native coming soon?

@SerjLtt Kotlin Multiplatform Support // common/build.gradle

@SerjLtt Kotlin Multiplatform Support // common/build.gradle apply plugin: 'kotlin-platform-common'

@SerjLtt Kotlin Multiplatform Support // common/build.gradle apply plugin: 'kotlin-platform-common' dependencies
{ compile "org.jetbrains.kotlin:kotlin-stdlib-common:${kotlin_version}" }

{ compile "org.jetbrains.kotlin:kotlin-stdlib-common:${kotlin_version}" } // jvm/build.gradle

{ compile "org.jetbrains.kotlin:kotlin-stdlib-common:${kotlin_version}" } // jvm/build.gradle apply plugin: 'kotlin-platform-jvm'

{ compile "org.jetbrains.kotlin:kotlin-stdlib-common:${kotlin_version}" } // jvm/build.gradle apply plugin: 'kotlin-platform-jvm' dependencies { compile "org.jetbrains.kotlin:kotlin-stdlib-jre8:${kotlin_version}" }

{ compile "org.jetbrains.kotlin:kotlin-stdlib-common:${kotlin_version}" } // jvm/build.gradle apply plugin: 'kotlin-platform-jvm' dependencies { expectedBy project(':common') compile "org.jetbrains.kotlin:kotlin-stdlib-jre8:${kotlin_version}" }

@SerjLtt Kotlin Multiplatform Support // common class Printer(message: String) {
fun print() }

@SerjLtt Kotlin Multiplatform Support // common expect class Printer(message: String)
{ fun print() }

{ fun print() } // jvm class Printer(private val message: String) { fun print() { println(message) } }

{ fun print() } // jvm actual class Printer actual constructor(private val message: String) { actual fun print() { println(message) } }

@SerjLtt Kotlin Multiplatform Support // common expect class Observable<T> {
}

@SerjLtt Kotlin Multiplatform Support // common expect abstract class Observable<T>
{ }

{ fun <R> map(f: Function<in T, out R>): Observable<R> }

{ fun <R> map(f: Function<in T, out R>): Observable<R> } expect interface Function<T, R> { fun apply(t: T): R }

{ fun <R> map(f: Function<in T, out R>): Observable<R> } expect interface Function<T, R> { fun apply(t: T): R } // jvm

{ fun <R> map(f: Function<in T, out R>): Observable<R> } expect interface Function<T, R> { fun apply(t: T): R } // jvm actual typealias Observable<T> = io.reactivex.Observable<T>

{ fun <R> map(f: Function<in T, out R>): Observable<R> } expect interface Function<T, R> { fun apply(t: T): R } // jvm actual typealias Observable<T> = io.reactivex.Observable<T> actual typealias Function<T, R> = io.reactivex.functions.Function<T, R>

@SerjLtt Should I try Kotlin?

@SerjLtt Should I try Kotlin? •Kotlin JVM (`kotlin`)

@SerjLtt Should I try Kotlin? •Kotlin JVM (`kotlin`) •Kotlin Js
(`kotlin-js`) - stable since 1.1.x

(`kotlin-js`) - stable since 1.1.x •Kotlin Android (`kotlin-android`) - backed by Google

(`kotlin-js`) - stable since 1.1.x •Kotlin Android (`kotlin-android`) - backed by Google •Gradle Script Kotlin

(`kotlin-js`) - stable since 1.1.x •Kotlin Android (`kotlin-android`) - backed by Google •Gradle Script Kotlin •Kotlin Native (*) - currently 0.4

@SerjLtt Final Thoughts

@SerjLtt Final Thoughts •One language for all platforms/teams/universes

@SerjLtt Final Thoughts •One language for all platforms/teams/universes •Better communication
between teams (*)

between teams (*) •No man in the middle, just you and your platform (*)

between teams (*) •No man in the middle, just you and your platform (*) •Shared code/vision/ideas

Thank you! @SerjLtt

Kotlin for the Masses

Kotlin for the Masses

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