Hey guys, I want to run

debounce

on a flow from within a Composable. I get this warning Flow operator functions should not be invoked within composition . I am not using Viewmodels so can’t run the flow operator in the VM. Ideally I’d just want to call

debounce

on the

fullNameFlow

and trigger some changes in the composable. What’s the best way to go forward?

//This is inside a Composable
val fullNameFlow = MutableStateFlow("")
fullNameFlow.debounce(3000).mapLatest {
    Log.i(TAG,it)
    //Change Composable State
}

FormTextField(
    onValueChange = {
        fullNameFlow.value = it
    }
)

What is the best way to include a given class only in debug compiles? For example, a mock object for the purpose of

@Preview

?

Hi i have two long operation.. and i’d like launch in parallel…

customScope.launch{

action1()

action2()

i’d like launch in parallel and when 2 methods end your action i have to invoke a method

Hi 👋 , I hope that one of you can be of help to me with my current issue 🙏 I have created a BaseViewModel that two different ViewModels VM1 and VM2 extend in hopes of sharing data and some functions used in both places.

abstract class OnboardingBaseViewModel(
    private val postNotificationSchemeUseCase: PostNotificationSchemeUseCase,
    private val putUserPropertyUseCase: PutUserPropertyUseCase
) : ViewModel() {
    // Data that needs to be shared 
    val _customOptionItems = MutableLiveData<List<CustomOptionItem>>()
    val customOptionItems = _customOptionItems
}

Upon my init function in VM1 I want to access the data already set from VM2 however it's null. VM2 is created like this:

@HiltViewModel
class RemindersTimeViewModel @Inject constructor(
    postNotificationSchemeUseCase: PostNotificationSchemeUseCase,
    putUserPropertyUseCase: PutUserPropertyUseCase
) : OnboardingBaseViewModel(postNotificationSchemeUseCase, putUserPropertyUseCase)
{
init{
// this is null - but why?
val data = customOptionsItems.value
}
}

I inject the viewmodels into the fragments with Hilt like so:

private val viewModel: RemindersViewModel by activityViewModels()

This message was deleted.

iDenfy uses Jetpack Compose in our production SDK. We’ve created an article about using Jetpack Compose to make custom UI for clients. Read & spread the adoption! 🚀 https://medium.com/idenfy/fully-customizable-jetpack-compose-8c8abaf93137

hey guys why is this snippet givving an error in viewModel() section:

composable(route = Screen.GetQuote.route) { navBackStackEntry ->
            val factory = HiltViewModelFactory(LocalContext.current, navBackStackEntry)
            val viewModel: GetQuoteListViewModel = viewModel("GetQuoteListViewModel", factory)
//            val viewModel: GetQuoteListViewModel = viewModel()
            GetQuoteScreen(
                state = viewModel.state.value,
                onClickHome = {
                    navController.navigate("${Screen.Home.route}")
                },
            )
        }

Does it make huge difference between these two version ?

displayCardList.filter { it.targetGrades?.contains(userGrade) == true }.run {
    return this.toMutableList().also {
        it.add(
            AmbientCardInfo(
                id = System.currentTimeMillis().toString(),
                cardType = CardType.GREETING.value,
                targetGrades = String.EMPTY
            )
        )
    }
}

V/S

return displayCardList
      .filter { it.targetGrades?.contains(userGrade) == true }
      .toMutableList()
      .also { 
          it.add(
                            AmbientCardInfo(
                                id = System.currentTimeMillis().toString(),
                                cardType = CardType.GREETING.value,
                                targetGrades = String.EMPTY
                            )
                        )
       }

Hey 👋 I’m migrating from Gradle 6.x to 7.x and from Android Gradle Plugin 4.x to 7.x so I’m trying to configure Java 11 target in my Gradle setup (following this description). My setup involves using some helper functions in

buildSrc

directory so I’m skipping that part. In the end, what I’m calling (or at least I should be calling) is simply:

android {
    val javaVersion: JavaVersion = JavaVersion.VERSION_11

    compileOptions {
        sourceCompatibility = javaVersion
        targetCompatibility = javaVersion
    }

    kotlinOptions {
        jvmTarget = javaVersion.toString()
    }
}

Nevertheless, I’m still seeing a lot of build warnings:

'compileJava' task (current target is 11) and 'compileKotlin' task (current target is 1.8) jvm target compatibility should be set to the same Java version.

Does anyone have any idea if I’m doing something wrong?

Hi guys , I'm trying to do a complex task in my function using coroutines. My code looks bad and my app is slow. Here is my task: 1-get the new place item that is added from database. / 2.make it selected / 3. get the last other items from database / 4. make them unselected. is there a better way to this?

fun checkNewItemAdded(item: PlaceItem) {
    viewModelScope.launch {
        withContext(<http://Dispatchers.IO|Dispatchers.IO>) {
            val newItemAdded = async { getPlaceItem(item.id) }
            val placeItem = newItemAdded.await()
            placeItem?.let {
                    if (!it.isChecked) {
                    it.isChecked = true
                    val checkNewItem = async { update(it) }
                        checkNewItem.await()
                        val getAllPlaces = async { getPlaces() }
                        val places = getAllPlaces.await()
                        val runningTasks = places.map { place ->
                            async {
                                val singlePlaceItem = getPlaceItem(place.id)
                                place to singlePlaceItem
                            }
                        }
                        val responses = runningTasks.awaitAll()
                        responses.forEach { (place, response) ->
                            if (response != placeItem) {
                                places.find { it.id == place.id }?.isChecked = false
                                update(place)
                            }
                        }
             }
            }
       }
    }
}

Hi, I'm working on a simple Apollo Kotlin graphql and a bit of a beginner. I am just trying to get a request for my query but I keep getting 400 errors from Apollo. This is my code for FirstFragment.kt where I'm trying to execute the query in some way.

package com.example.animod
import android.os.Bundle
import android.util.Log
import androidx.fragment.app.Fragment
import android.view.LayoutInflater
import android.view.View
import android.view.ViewGroup
import androidx.lifecycle.lifecycleScope
import com.apollographql.apollo3.api.Optional
import com.example.aniMod.CharacterQuery
import com.example.animod.databinding.FragmentFirstBinding



/**
 * A simple [Fragment] subclass as the default destination in the navigation.
 */
class FirstFragment : Fragment() {

  var _binding: FragmentFirstBinding? = null

    // This property is only valid between onCreateView and
    // onDestroyView.
     val binding get() = _binding!!


    override fun onCreateView(
        inflater: LayoutInflater,
        container: ViewGroup?,
        savedInstanceState: Bundle?
    ): View {
        _binding = FragmentFirstBinding.inflate(inflater)
        return binding.root


    }


    override fun onViewCreated(view: View, savedInstanceState: Bundle?) {
        super.onViewCreated(view, savedInstanceState)

        lifecycleScope.launchWhenResumed {
            val response = apolloClient.query(CharacterQuery(search =  Optional.Present<String>(""))).execute()
            Log.d("Anime Character Picture", "Success ${response.data}")
        }
    }


}

And this is my PictureQuery.kt file

query Character($search: String) {
    person: Character(search: $search) {
        image {
            large
        }
    }
}

I appreciate any help . Thank you

Hey can someone explain what is the use of

@Retention(AnnotationRetention.BINARY)

What is

Retention

,

AnnotationRetention

and

BINARY

?

Hey guys, how do I get an expert in Kotlin and android development? I think I know enough to develop basic apps with basic features, now I want to get to the next level and really dive into complex programming. For example I would like to create my own photo editor app. I have the feeling that there are no resources to such things online. Or am I just too bad in Googling? How would go start this journey? Before I always learned with Blog Posts, YouTube Videos and Raywenderlich or Udemy Courses. But for such topics there are no resources _/

Hi all, so what are my options when it comes to disk-based LRU cache implementations? There is the old one (https://github.com/JakeWharton/DiskLruCache) from Jake (originally from Google apparently), written in Java, which is basically discontinued, then there is this one (https://github.com/solkin/disk-lru-cache) which looks promising at first, but has bad test coverage, and finally OkHttp comes with one (https://github.com/square/okhttp/blob/master/okhttp/src/jvmMain/kotlin/okhttp3/internal/cache/DiskLruCache.kt), clearly based on Jake’s / Google’s, but in Kotlin, with quite a few inner dependencies to things from OkHttp itself. Tried to extract the latter and ended up with 3000+ LOC including tests (without OkHttp’s

TaskRunner

setup, but

Coroutines

for cleanup handling), which made some tests fail and overall made me feel I was doing something wrong (don’t want to import so many LOC in my tree).

How can I run the println function in init and still use the delegate in the fragment?

Hi guys, I wrote simple code to passing any of type for navigate between screens.

object Transformer {
    private var transformerMap = mutableMapOf<String, Any>()

    fun put(key: String, t: Any) {
        transformerMap[key] = t
    }

    fun pull(key: String): Any {
        return transformerMap[key]!!
    }
}

The logic is simple, When you use the navigate function you have to put the parameters which you want to send Where you use the Composable function, you need to pull it and give it as a parameter. It is perfectly working. I am wondering that is this wrong way ?

is there any to convert name of a city to latitude and longitude ?

Hello guys, what are your favorite open source MVVM + Jetpack Compose projects? I currently try to look into different projects to find new smart ways to do things and to learn some new kotlin syntax

Hi guys, Can someone explain “Hilt and Dagger” to me? I seem to understand the event, but in my not fully enlightened mind, I specifically want to know where, why and when to use it. Thanks everyone in advance🙏

When is Kotlin 1.7 expected? May right?

Just a general question about MVVM: Where to put code for IO Operations? I know you shouldn’t put business logic in the UI layer but also no context in the VIewModel. So where to put for example a function to download a file to internal storage? I need the context for that and it also has nothing to do with UI.

Hi All, Need a little help with something I have been struggling since days. Lets say I have a Extension function

fun Any?.toJSONString(): String {
  return this?.let {
    try {
      val gson = GsonBuilder().setPrettyPrinting().create()
      gson.toJson(this)
    } catch (e: Exception) {
      "{}"
    }
  } ?: "{}"
}

And I have another Extension function that takes in Generic T and I want to parse/manipulate the result. For example being

fun <T : Any> Response<MyResponse<T>>.toStr(): String {
  return T.toJSONString()
}

I am getting this error

Type parameter 'T' cannot have or inherit a companion object, so it cannot be on the left hand side of dot

Please help me out. If anyone can explain the error itself. It will be great. I do not have indepth Kotlin know-hows.

Anyone know about any open source maps solution which works on AOSP without GMS?

Hey I need to parse the following date format

"2021-12-02T16:54:08.931Z"

I am using the pattern

"yyyy-MM-dd'T'HH:mm:ss.SSSZ"

in Simple Date Format. I am getting unparseble date error

Hello guys, how can i call functions in a certain sequence?. I need the result from the first two functions for the third one. In the first two functions there is networking, so they take "long time" and the third one is executing first 😞 . The attached photo is from the MainActivity. Thank you in advance!

Hi, is there way to simplify this kotlin statement, i don't like it taking multiple iterations

private fun List<PaymentTaxDiscountDetail.PaymentTaxDiscount>.getTotalTaxDiscount(): Double {

    var vatPlusDiscountTotal = sumByDouble {
        if (!it.taxType.startsWith(TaxType.WHT.name)) it.whtAmount else 0.0
    }

    val whtTotal = sumByDouble {
        if (it.taxType.startsWith(TaxType.WHT.name)) it.whtAmount else 0.0
    }
    return vatPlusDiscountTotal - whtTotal
}

Hey guys, I was trying to use on-demand feature of

ViewStub

and

OnInflateListener

to listen once the original layout is inflated. This is my

ViewStub

layout `fragment_navigation_viewstub`:

<?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="<http://schemas.android.com/apk/res/android>"
    android:layout_width="match_parent"
    android:layout_height="match_parent">

    <ViewStub
        android:id="@+id/fragmentNavigationViewStub"
        android:layout="@layout/fragment_navigation"
        android:layout_width="match_parent"
        android:inflatedId="@+id/items_list"
        android:layout_height="match_parent" />

</androidx.constraintlayout.widget.ConstraintLayout>

and this is my original layout `fragment_navigation`:

<?xml version="1.0" encoding="utf-8"?>
<androidx.recyclerview.widget.RecyclerView
    xmlns:android="<http://schemas.android.com/apk/res/android>"
    android:id="@+id/items_list"
    android:layout_width="match_parent"
    android:layout_height="match_parent"/>

and my listeneer inside the fragment:

private val binding by viewBinding { FragmentNavigationViewstubBinding.inflate(it) }

override fun onCreate(savedInstanceState: Bundle?) {
    super.onCreate(savedInstanceState)
    binding.fragmentNavigationViewStub.setOnInflateListener { _, view ->
        fragmentNavigation = FragmentNavigationBinding.bind(view)
    }
}

But I got this exception and looks like

setOnInflateListener

is not called

kotlin.UninitializedPropertyAccessException: lateinit property fragmentNavigation has not been initialized

How can I add this icon relative to the single character in jetpack compose?

Did anyone get issue with viewModelScope ?

viewModelScope.launch

work like a charm until I’m navigate to other screen => viewModel go to onClear() => Then I’m navigate back and try to call

viewModelScope.launch

but it didn’t anything. Any idea for this ?