Category "kotlin"

Kotlin: Equivalent of property wrappers from Swift

What is the equivalent property wrappers for Kotlin: @propertyWrapper struct Foo { var wrappedValue: String { get { return "Test

Custom parameter names with a bean for request parameters in Spring 5

I'm trying to use Spring 5 to have a custom bean for my request parameters. In theory this is easy, but I want to have the field names be different from the par

How can I convert a Long value to date time and convert current time to Long kotlin?

The Code A can convert a long value to date value, just like 2018.01.10 I hope to get Date + Time value , such as 2018.01.10 23:11, how can I do with Kotlin?

Fragment navigation and menu. How to remove latest fragment? Check description

I was incapable of finding an answer for the following context: Let's say we have a menu and a nav graph instanced in the main activity. We have 3 fragment: Hom

How to inject data class in android with dagger where data class parameter have no default value?

My data class like: data class Animal(var id:Int = 2) { } My Provides method in module class like: @Provides @Singleton fun provide():

Kotlin Multiplatform Project Unit Test Issue

Today I just updated my Android Studio to Android Studio 3.5.2 Build #AI-191.8026.42.35.5977832, built on October 31, 2019 JRE: 1.8.0_202-release-1483-b49-5587

Firestore returns empty list [duplicate]

I have 3 entries in my firestore database. I need to query the data and fetch it, then input it into an ArrayList. The problem is my query is

Cannot access 'java.lang.Object' which is a supertype of... Check your module classpath for missing or conflicting dependencies

I thought it would be fun and informative to learn more about static code analysis by implementing my own custom linter. I've been trying to declare the below d

Why use Arrow's Options instead of Kotlin nullable

I was having a look at the Arrow library found here. Why would ever want to use an Option type instead of Kotlin's built in nullables?

Filtering a recyclerview list using map or switchmap

I've been trying to figure this out for 2 days now - I just can't seem to get it to work! I'm using MVVM with a Repository pattern. Could someone tell me what I

Error receiving broadcast Intent when using SmsRetriever

When authenticating using Firebase Auth, I want to auto input the code that is received via SMS. I am able to receive SMS and go through auth process manually,

Adding function to foreground service lifecycle methods can create an issue? Is this best practise?

I created a timer app. So it's counting time basically and I'm saving the time to room when service close in OnDestroy scope. Is it best practise? Or is there a

How to Pass a List of Objects from activity A to activity B in Kotlin?

I have 2 Activities, I want to pass an arraylist of an Object and show it on a ListView Activity A: btnGuardar.setOnClickListener{ i

Compile the Kotlin android file through the command line compiler, show unresolved reference: synthetic

I used kotlin-android-extensions the kotlin code is simple import android.os.Bundle import android.widget.TextView import android.widget.Toast import kotlinx.an

Get Currency symbol of only one character (e.g $,₹, etc) (Locale doesn't matter) android kotlin

i have currency code (e.g. USD,INR,etc...). I want to get symbols of only one letter of those codes (e.g $,₹, etc). i have tried to find many solutions li

E/FirebaseInstanceId: Token retrieval failed: AUTHENTICATION_FAILED - what changed?

I'm not sure what's going on here, I pulled my recently updated repo and every time I open the app to debug it on an emulator I get E/FirebaseInstanceId: Token

KMM: Compilation failed: Unexpected IrType kind: KIND_NOT_SET

I'm trying to run tests in the shared library. Setup (versions should be the same for both machines - all are up to date as of today): Kotlin 1.6.21 (tried 1.6.

What does the suspend function mean in a Kotlin Coroutine?

I'm reading Kotlin Coroutine and know that it is based on suspend function. But what does suspend mean? Coroutine or function gets suspended? From https://kotli

How can I change CardViews background color based on user's option in Kotlin?

I have 2 fragment pages. The first of these pages is the page where the user is given options. The other page is the page that is displayed according to the opt

Is it possible to download the first 100 lines of a big file with millions of lines from S3?

I have multiple 100MB raw files with series of user activities in CSV format. I only want to download the first 100 lines of the files. The problem is that each