kotlinlang #rx

You can apply backpressure implicitly, though, even to Rx2 observable. The longer you take to process the observed items, the more you block the producer. So, if producer is just a loop, then it will be able to emit only as many items per second as observer is able to process.

05/04/2018, 2:25 PM

you create a callback which receives an emitter that you can pipe information into as it's given to you

zak.taccardi

05/07/2018, 9:33 PM

I think misusing Rx’s

onError()

to pass expected error information is one of the biggest mistakes people make https://medium.com/@ZakTaccardi/api-design-handling-exceptions-84a143e32232

ursus

05/07/2018, 11:57 PM

do you have opionion on that?

oday

05/08/2018, 11:07 AM

why does line 6 get called multiple times? https://pastebin.com/tz0gkZrg

Paul Woitaschek

05/11/2018, 8:33 AM

use the flatMap instead of the second map

😀 1

Daniel

05/16/2018, 6:25 AM

Hey guys, I am making a library for Android which would later be made available via maven. I want to make an optional library which can be added to the project and would work with the original main library to give

Rx support

as I do not want to increase the original library’s method count. This is similar to how you can add optional

Rx support

Retrofit

and Retrofit can work with

Rxjava

. I tried finding ways to do it but without results. Can anyone who has worked on it help me out on how to set it up? Maybe some code examples or websites on how to do it?

leosan

05/17/2018, 3:12 PM

object Main {

    val items = Observable.just("a")
    val test = items
            .repeatWhen { it.concatMap { Observable.timer(1, TimeUnit.SECONDS) } }
    val exec = CompositeDisposable()

    @JvmStatic
    fun main(args: Array<String>) {

        exec.add(test
                .subscribe {
                    print(it)
                })
        Thread.sleep(5000)
        exec.dispose()
        exec.add(test
                .subscribe {
                    print(it)
                })
        Thread.sleep(5000)

    }
}

Why after disposing the first time, it only subscribe once? The first time prints fine five times

but after the dispose it runs only once

memphis

05/22/2018, 12:29 PM

Hello guys 🙂 I hope someone can give me a hint .. I’m working on a simple weather app .. Once I get data from the API I want to store it using Realm and call a method to fetch data from the database. But the problem is that the method for fetching from db is called before the data are saved into Realm, so I get this : E/LandingViewModel: onError with :java.util.NoSuchElementException: List is empty.

05/25/2018, 1:43 PM

you should not be implementing a disposable with a lambda

Paul Woitaschek

05/28/2018, 6:23 PM

runBlocking @aeruhxi

arekolek

05/30/2018, 10:36 AM

What's worse, Intellij gives you an intention action to convert former to the latter, I filed an issue about this https://youtrack.jetbrains.net/issue/IDEA-192952

adams2

05/31/2018, 6:25 PM

anyone have opinions on using onDetachedFromWindow vs onStop to unsubscribe from a hot observable? onDetachedFromWindow looks like it gets used pretty often but it feels weird to me to have your app doing work when you might have pressed Home.

06/13/2018, 7:35 PM

.toObservable()

Jacob Applin

06/28/2018, 12:27 PM

Is there an active project to create an RxKotlin which can be used for multiplatform?

blakelee

06/28/2018, 9:03 PM

If I do

Observable.fromIterable(list).flatMap{ fetchItem(item) }

does every item get fetched in parallel?

ursus

06/30/2018, 12:19 AM

-- Also, is there a way to just reset a value of BehaviourRelay without emitting?

darkmoon_uk

07/11/2018, 11:10 AM

I say this in full understanding why Subjects are 'non-Rx' in many use cases... but as model fields... it actually seems really useful for achieving 'reactiveness' between otherwise loosely connected parts of an App. I just wondered if anyone had positive experience following this pattern, or it has been avoided either a) because it has identifiable downfalls or b) just because a 'subjects are bad' dogma (in which case that might bear challenging).

blakelee

07/19/2018, 10:45 PM

My weird case is when I do

var myVariable: Int = 0
    private set(value) {
      field = value
      BehaviorSubject.onNext(BehaviorSubject.value)
   }

toby

07/23/2018, 12:37 PM

Any help will be greatly appreciated

liminal

07/23/2018, 12:39 PM

@edwardwongtl but then userManager.getUser() will execute even if tokensManager emits error

arekolek

07/27/2018, 12:59 PM

something like this?

fun isReadyToGo(
    loginAnonymously: Single<TokenData>,
    saveTokenData: (TokenData) -> Completable,
    isLoggedIn: Single<Boolean>
): Completable {
    return isLoggedIn
        .filter { !it }
        .flatMapSingleElement { loginAnonymously }
        .flatMapCompletable(saveTokenData)
}

not sure if it's not harder to understand though 😛

ursus

07/28/2018, 12:02 AM

var obs = map { success(it) }
        if (idle != null) {
            obs = obs.endWith(idle())
        }
        return obs.doOnError(LOG::e)
                .onErrorReturn { t -> error(defaultErrorTransformer.throwableToType(t, customErrorTransformation)) }
                .observeOn(AndroidSchedulers.mainThread())
                .startWith(started())

👍 2

ubu

07/29/2018, 9:50 PM

Good evening everyone, is there a nice way to fetch paginated data from backend using retrofit and rxjava adapter? Recursion? Thanks.

ursus

07/29/2018, 10:35 PM

like what, multiple pages at once or via ui?

ubu

08/10/2018, 10:16 AM

@edwardwongtl, thanks. could you post the link to the docs?

ursus

08/24/2018, 3:10 PM

@Paul Woitaschek who then subscribes?

alexsullivan114

08/29/2018, 8:00 PM

Question for y'all: Is there an operator similar to

combineLatest

but that emits as soon as any of the combined streams have a value? Right now it appears that

combineLatest

will only emit once all of the streams have a value, and will then emit each time one of the streams is updated.

ubu

08/30/2018, 2:57 PM

@kioba, would it retry to getPlacePrediction for B?

ursus

09/01/2018, 2:56 AM

-- is calling functions

fooObservable()

a hungarian notation?

Title

ursus

09/01/2018, 2:56 AM

-- is calling functions

fooObservable()

a hungarian notation?

kioba

09/02/2018, 8:50 AM

not exactly, but the function user will see the return type so its really not necessary to mention it inside the function name.

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