How to Effectively get a list of database children (ordered and limited according to a child) for a Leaderboard System My goal is to effectively get a list of children (ordered* and indexed**) with the lowest number of data transfer. * ordered: ordered by points for each user / database child ** indexed: 2 or less ranks behind/after the current user [A specific child] (further elaborated below) My database structure is as follows:- I basically want to get the first 3 users ordered by points (simple):- val usersRef =...

How to do Union Query using Jetbrains Exposed I am facing problem when trying to do union query. I have multiple database tables (sharded tables). I have a list of all the table names. I want to do a union query on all the tables by looping through the list and creating a union query. Code example: fun main() { val tables = listOf("table_1", "table_2", "table_3") var finalQuery: Query? = null; for (table in tables) { var query = Model.selectAll(); if(finalQuery == null){ finalQuery = query;...

Using CsvMapper in Kotlin to parse huge CSV file I'm having a CSV file generated as a report by the server. The CSV file is having more than 1 lakh lines of text. I'm reading the file in Kotlin using CsvMapper, but I'm ending up with IOException. Here's the code that I'm implemented: //Declare the mapper object private var csvMapper = CsvMapper().registerModule(KotlinModule()) //Generate Iterator inline fun getIterator(fileName: String): MappingIterator? { csvMapper.disable(JsonParser.Feature.AUTO_CLOSE_SOURCE)...

can i use post with retrofit but i don't put any url on @POST I want to post a url likes "https://blog.banned.top:2054" without any subpath, how can i do? When I run code like this: //interface @Multipart @POST("") fun updateProfile( @Part("tile_mode") fullName : Int, @Part("raw_image") image : RequestBody, ) : Call val retrofit = Retrofit.Builder() .baseUrl("https://blog.banned.top:2054") .addConverterFactory(GsonConverterFactory.create())...

how to use dialog to close the parent fragment? I am developing an app that asks the user to type task's name, description....,but when the user intends to leave the edit page without saving the task I need to pop up a dialog to confirm leaving, so if he clicked abandon changes he must return to the home page of the app otherwise he will stay at the same page. I have problem with this, when the user clicks abandon changes the dialog dismisses and he stays at the edit page. MainActivity.kt package muhabalafandi.example.tasktimer import...

Downloading file once item is conusumed using in app purchase | kotlin/java How I can implement the downloading a file once in app purchase item consumed? Any logic or help? I try to building a logic when buy a something digital goods using in app purchase file/item will be downloading...

Documenting properties in KDoc I see much code, which uses the tag @property to document properties: /** * Some Class * * @property p Some property */ class C { val p = 42 } But I prefer to document properties where the are defined: /** Some Class */ class C { /** Some property */ val p = 42 } Are the two ways equivalent?

I want to learn android development with kotlin I want to learn android development with kotlin. I watched this kotlin tutorial - and I want to get started with android now. My goal within 2 weeks - I can be able to build simple applications like calculator apps, notes, voting, quiz, etc. In like 5 weeks I should be able to build applications like - e-commerce, an app like Instagram, WhatsApp, Uber,...

How to link reusable ExtendedFloatingActionButton with reusable Scaffold Expected result: Reusable ExtendedFloatingActionButton should expand or collapse within a reusable Scaffold when I scroll. Current result: ExtendedFloatingActionButton does not expand or collapse when I scroll the list in my Scaffold I followed this tutorial, but it was not created with reusability in mind. The part I'm...

NavigationController does not open new fragment if it already associated with bottom navigation I have a fragment in bottom navigation when try to launch new fragment with same id using navigation controller instead of launching new fragment it redirects me to bottom navigation tab. here is my code And code to navigate. findNavController().navigate(R.id.action_to_baseFragment)

BigDecimal serialization with unknown scale and precision I am trying to serialize a data class using Avro4k. @Serializable class Aggregator( @ScalePrecision(10, 10) @Serializable(with = BigDecimalSerializer::class) val value: BigDecimal ) The problem is that I don't know the scale and precision of the BigDecimal beforehand, and I get rounding errors if they are not big enough. How to solve this without using huge numbers? I am concerned doing that might affect the size / performance.

LiveData in an Android RecyclerView not updating as expected I am trying to create a very simple RecyclerView in Android containing LiveData retrieved from Room DB. Each item in the Recycler has a clickListener set, which navigates to a fragment containing the particular item's details. Besided the onClick, it also contains two buttons, for adding to favourites and for deleting. Both actions are handled by a ViewModel. ViewModel for fragment containing recycler:...

Recorder only records 9 seconds in android 12 using mediaRecorder I have an application which records calls , it works fine so far and it does record the calls , the issue is about the duration that the mediaRecorder records which is roughly 9 seconds in android 12 , when i try on android 11 and downwards , it works pretty fine , i'm not sure why it does not record the whole call in android 12 , any reason why ?? Thank you for the help in advance . This is receiver where i start recording the call class PhoneCallReceiver : BroadcastReceiver() {...

Step Step Register Screens I want to clone an application. The registration process of the application is done step by step. He does not know why this is done and what the advantages are. What is the best method of moving data between these screens? How do I set up this build?

How to convert List<List<List<Int>>> into Bitmap object in Android Kotlin? I have a data class (generated using JSON to Kotlin Data Class plugin) below that is used to parse json data from an object detection server. The server returns the "images" in multidimensional array. I am wondering how can I convert this JSON data in format that can be displayed in my ImageView in Kotlin. Your answers...

Abstract types are not supported when deserialising session data I use kmongo with the kotlinx serialization library and the Id implementation implementation("org.litote.kmongokmongo id serialization4.8.0") // This is the dependency for the id implementation I declared my ktor deserialiser like that install(ContentNegotiation) { json(Json { prettyPrint = true serializersModule = IdKotlinXSerializationModule }) } And then my session logic: install(Sessions) { cookie("user_session_id") {...

Flow.stateIn() not receiving new value from it's source I tried to combine several SharedFlow into one StateFlow using stateIn. But my StateFlow seems not updating after I emit new value to it's SharedFlow source. I found out that the problem is from how I used stateIn. Here is the simplified code I am using (you can run it from kotlin playground). import kotlinx.coroutines.runBlocking import kotlinx.coroutines.GlobalScope import kotlinx.coroutines.flow.MutableSharedFlow import...

Best way to handle Null values Moshi-Kotlin/Retrofit I'm using an API to get some recipes for my Application using Retrofit and Moshi. Everything works fine when the values received are not null. A soon as I receive something that is null my whole app stops saying - Missing value was null. I found this solution on the Web- object NULL_TO_EMPTY_STRING_ADAPTER { @FromJson fun fromJson(reader: JsonReader): String { if (reader.peek() != JsonReader.Token.NULL) { return reader.nextString() } reader.nextNull() return "" } }...

ByteBuddy loaded class is slower than expected I'm using ByteBuddy to implement hasComponent(KClass): Boolean and findComponentOrNull(KClass): T? for child classes of an Entity interface. I've got it working, but it's around half the speed compared to a manual implementation. Here's some simple benchmark results (codegen benchmark doesn't include the time it takes to generate the bytecode) Benchmark Mode Cnt Score Error Units...

Springboot add test file in the same folder of tested class I'm looking to place the testing suite of a class in the same folder of the class because I don't like the approach of having a complete directory for the tests but I'm not sure if that is possible with springboot. Something like this: MyModule | ----src | ------kotlin | ------myPackage | ----------MyClass.kt |...

Why the vertical TextView taking different spaces -android- I have a TextView inside CardView. after rotation (-90 or 270), each textView had different space from ImageView The result is like this: () XML: I tried to put the TextView inside LinearLayout but the output is the same. if there any solution (using just XML) please tell me. i found this on stackoverflow : <a...

How do I solve the problem of thread on Kotlin HTTP Request Error I am trying to send a HTTP Request for my app to our local server in my senior project. However, I am getting a weird error that does not crash the application but also does not send my request (The server is running on my local pc). I am sharing all related materials about request that I wrote such as manifest, dependency and, function etc. Can anyone please help me how to solve this problem? I tried running my function in different thread other than main because I got...

How to access generic parameter's companion object in Kotlin Say that I have interfaces IEntity and IEntityFactory and a class Person. Imagine that I also have additional implementations of IEntity with their own unique properties, similar to Person. I require that Person implements the properties of IEntity and the "static" methods of IEntityFactory on its companion object. I wish there were a way to enforce this, but there does not seem to be. interface IEntityFactory { // a string like "entity.person" used for identifying object types across the...

Artefacts when implementing expandable items in RecyclerView I'm trying to make a simple RecyclerView with expandable items using Kotlin. Basically a list of bins which expand out to show descriptions of what should go in them. I tried to follow the Android Studio Recycler View example as closely as possible. The problem is when I expand each item, some artefacts would show. <a href="https://i.stack.imgur.com/K8Qyw.png" rel="nofollow noreferrer">Expanded...

Step Step Register Screen I want to make a step-by-step registration screen like in different applications. I want to get values such as email, password, name on different screens. How can I do that ?

Android deeplinks aren't being registered, browser loading URL I'm trying to have my android app open any urls that are at ex. mysite.com/users/12345 with an activity called LinksActivity, then (for now) just log everything in the intent. Instead when I send the test URL via android studio or open the URL in the browser it just loads the 404 for that page. I have added the .well-known/assetlinks.json file to my site, and I'm not certain I got the SHA keys right, but I don't think that's the issue since when I change the URL to some URL nobody owns, it...

RecyclerView only showing last item in JSON array Based on the logs I added in, the request is receiving all the data correctly, and the issues lies somewhere in displaying the list in the recycler list. It just prints out the last item in the your server pets array and prints its according to the length of the database array. My leaderboard seems to only been showing the last entry into the database and repeating it for the pets array length. I would like to show the entire database items in each slot. Also, I am not sure why petPhoto is...

Build Issue After Upgradingt to Android Studio Dolphin | 2021.3.1 Patch 1 | Navigation Directions I updated my IDE to Android Studio Dolphin | 2021.3.1 Patch 1 and I am getting build error. I don't now why. But they seems only related with navigation-directions from Navigation. here is the screen shots I couldn't find the solution for this on the internet so any help would be great, thanks.

Convert Json to data class kotlin Im a newcomer into android development world. Im using retrofit and coroutines. Trying convert the next json object into a data class. ` { "name": { "common": "Peru", "official": "Republic of Peru", "nativeName": { "aym": { "official": "Piruw Suyu", "common": "Piruw" }, "que": { "official": "Piruw Ripuwlika", "common":...

System Bottom Navigation Bar overlapping my views I went into a problem, when using Samsung phones (android 12), system Nav bar is overlapping my views as follows Here is my style.xml file @color/colorPrimary @android:color/transparent @color/colorAccent true true false false @drawable/shape_splash I also tried fitsSystemWindows property to set to true, but it did't...