kotlinlang #getting-started

when (textInputEditText.id) {
            R.id.editText_fullName -> {
                setState { copy(signUpData = signUpData.copy(fullName = textInputEditText.text.toString())) }
            }
            R.id.editText_username -> {
                setState { copy(signUpData = signUpData.copy(username = textInputEditText.text.toString())) }
            }
            R.id.editText_email -> {
                setState { copy(signUpData = signUpData.copy(email = textInputEditText.text.toString())) }
            }
            R.id.editText_password -> {
                setState { copy(signUpData = signUpData.copy(password = textInputEditText.text.toString())) }
            }
        }

Hullaballoonatic

05/20/2019, 6:53 PM

what are reasons to use enum classes instead of sealed class? so far, i know that: *enums are simpler syntax *enums have a (final😡) name property *enums have ordinals Are sealed classes more space and time costly? Should I avoid using them over enums if all i want is to define the name property myself?

itnoles

05/20/2019, 6:54 PM

Possible to use inline sealed class

davidasync

05/21/2019, 7:10 AM

Is there any http client library at kotlin that utilize netty ?

Marko Mitic

05/21/2019, 2:45 PM

Does anybody knows some ObservableList implementation on Kotlin (or java 😞)?

EnricCamarero

05/21/2019, 4:33 PM

Hi there! Anyone into kotlin multiplatform development? I’ve been working on Android so far and moving to more complex gradle builds is being a nightmare 🐿

scottiedog45

05/21/2019, 6:44 PM

What is the “+” doing here?

private val coroutineContext: CoroutineContext
        get() = parentJob + Dispatchers.Default

robnik

05/22/2019, 8:39 AM

Three ways to get a task:

tasks["foo"]

tasks.named("foo").get()

tasks.getByName("foo")

. I guess the first is extra in Kotlin, because the language allows the

[]

syntax for

get

, but is there a difference between the second and third?

scottiedog45

05/22/2019, 5:15 PM

What is “A” here?

fun <T : ViewModel, A> singleArgViewModelFactory(constructor: (A) -> T):
        (A) -> ViewModelProvider.NewInstanceFactory {
    return { arg: A ->
        object : ViewModelProvider.NewInstanceFactory() {
            @Suppress("UNCHECKED_CAST")
            override fun <V : ViewModel> create(modelClass: Class<V>): V {
                return constructor(arg) as V
            }
        }
    }
}

Florian

05/25/2019, 9:38 AM

Which vendor's JDK do people use?

Pepperbc

05/26/2019, 12:48 PM

In kotlin exposed, is there a way to get just the id from a lazily loaded relation? Just accessing it to get the id (which is on the main table and has already been fetched from the db) seems to trigger fetching the whole object.

otakusenpai

05/26/2019, 4:29 PM

hello, how do i use klaxon to send JSON data online?

ursus

05/26/2019, 10:20 PM

Hi, what is this error about?

Suspicious equality check: equals() is not implemented in Object

override fun areContentsTheSame(oldItemPosition: Int, newItemPosition: Int) =
        oldList[oldItemPosition] == newList[newItemPosition] <----------

Type of the list items is ChatItem, which is a sealed class

sealed class ChatItem

object ProgressBarItem : ChatItem()

data class ThreadHeaderItem(
    val commenterUsername: String,
    val commenterRealName: String?,
    val commenterImageUrl: String?,
    val commentedUsername: String,
    val commentedRealName: String?,
    val commentedTimestamp: LocalDateTime
) : ChatItem(), ThreadPart

data class AddCommentItem(val message: Message) : ChatItem(), ThreadPart
data class DateItem(val date: LocalDateTime) : ChatItem()

dave08

05/27/2019, 3:02 PM

Does return from Kotlin use lambda close the resource? Usually returning from a lambda is without a

return

, so am I returning from the outer function bypassing the

use

fun doSomething(): Boolean =
resource.use {
   if (condition) return false
}

Hullaballoonatic

05/27/2019, 6:21 PM

what is the best way to get

setA

to also

setB

when called, and

setB

to also

setA

when called, but not infinite loop them? One calls the other but doesn't allow itself to be called again.

Ruckus

05/28/2019, 6:37 PM

nums.indices.reversed()

👍 1

ursus

05/29/2019, 2:02 AM

not sure what you mean

Atendra Singh

05/29/2019, 2:05 AM

Admin please create a separate channel for Kotlin-Multiplatform

Slackbot

05/29/2019, 4:18 AM

This message was deleted.

jaspersmit

05/29/2019, 9:36 AM

is it possible to use elvis operator with multiple statements? like

val someValueNotNull = somethingReturningNull ?: { sttmt1 stmt2 stmt3 }

poohbar

05/29/2019, 12:35 PM

I would like the auto-formatter to help me keep the columns aligned 🤔

dave08

05/29/2019, 5:39 PM

What I wanted was to get the backing field created and initial value passed to the constructor all at once, one of the Kotlin conveniences that we got too used to, I guess...

Florian

05/30/2019, 10:17 AM

Kotlin bytecode is the same as Java bytecode, right?

👍 4

oday

05/30/2019, 4:04 PM

without resorting to comparing it with null

Hullaballoonatic

05/31/2019, 2:05 AM

can someone explain why implemented functions from an interface are not allowed to have default parameters? what use is an abstract method with a default parameter...

Florian

05/31/2019, 11:02 AM

naming convention for .kt files is PascalCase, right?

✔️ 2

:yes: 1

05/31/2019, 7:07 PM

Hello all, is there a way to do Partial<TypeName> like in TypeScript? I saw this question already asked on [stack overflow](https://stackoverflow.com/questions/50651879/kotlin-feature-like-typescript-partial) but its unanswered. My use case is having a

data class User(name: String, pass: String, email: String, etc...)

and then an update method which would take a Partial User so that you'd only have to supply a subset of the fields

fun update(user: Partial<User>): User {...}

. Should I just create a new type for this? Such as

data class PartialUser(name?: String = null, pass?: String = null, email: String = null, etc...)

Title

05/31/2019, 7:07 PM

data class User(name: String, pass: String, email: String, etc...)

and then an update method which would take a Partial User so that you'd only have to supply a subset of the fields

fun update(user: Partial<User>): User {...}

. Should I just create a new type for this? Such as

data class PartialUser(name?: String = null, pass?: String = null, email: String = null, etc...)

serebit

05/31/2019, 7:52 PM

You’ll have to create a second type, yes

👍 1

05/31/2019, 9:33 PM

Thanks, good to know what's possible/isn't possible. I ended up creating separate types for create/update in the end. I think its better than partial anyway because their accepted fields vary slightly.

Ian White

05/31/2019, 11:34 PM

I have a codegen that handles this. You add a

@PartialDataObjects(["Partial","Create","Update"])

annotation to a data object X and it will create

PartialX

CreateX

UpdateX

data objects for you. it’s not totally ready for public consumption but i’ve found it super handy for my own projects if you’re interested: https://github.com/stardogventures/stardao/tree/master/stardao-kotlin-partial

View count: 4