Does Kotlin needs a DI framework? Searching for the need of Dependecy Injection (DI) it became clear to me that not all languages are using DI Frameworks. For instance there is this particular article about Ruby (Ruby Talk about DI Frameworks) talking about DI and how Ruby doesn't need a DI Framework because of the flexibility and the intentions of the language. It states for example that instead of injecting...

@PostConstruct not called when using Kotlin BeanDefinitionDsl It seems that the @PostConstruct method is not called when a bean is added to the context using a Kotlin BeanDefinitionDsl. This happened to me in my own project but to create a simple way to reproduce it, here's what I did. I forked the Spring example of using the Kotlin DSL https://github.com/sdeleuze/spring-kotlin-functional I added a @PostConstruct to the UserHandler class. (More details...

How to initialize ToMany<> relation in kotlin @Entity data class EmailMessage ( @Id var id: Long = 0, var subject: String = "", var body: String = "", var attachments: ToMany? = null, ) for 'attachments', Is there a better way to do it without assigning null?

ojAlgo - Expressing Variables as Boundaries in Optimization? I've been playing around with ojAlgo and I've been pretty thrilled with it so far. I've worked through a few studies with it but I'm having trouble with this problem described in this article. I'm using Kotlin instead of Java, but that shouldn't cause any issues. I'm stuck trying to input an expression into my model but bounding on a variable rather than a literal numeric value....

Not supplying enough data to HAL, expected position I'm getting this error in Android Studio. I just want to print the text when I push the button. I get the below error, which appears every time I press the button. If I uncomment out the intent it works perfectly fine as well, but the more code I have the more the error changes. I am not actually sure this is the true error. I say this because I have an entire app (not this one) that uses retrofit and github api to search for repos. This button is the nexus for searching. If I hard code in a...

Sharing implementations of extension functions between Float and Double in Kotlin In our project, we have a handful of utility functions to extend Double and Float, such as toFixed (inspired by Javascript's Number.toFixed) fun Double.toFixed(digits: Int):String = java.lang.String.format("%.${digits}f", this) fun Float.toFixed(digits: Int):String = java.lang.String.format("%.${digits}f", this) As you can see, Double.toFixed and Float.toFixed have an identical implementation. Because there are several other, more complicated extension functions like this, improvements...

Kotlin StringRequest using Volley unable to resolve host I am trying to do with Kotlin something that was supposed to be easy, or at least it is with Java, a simple StringRequest using Volley. Everything looks quite ok, however for some reason the url is being cropped and the app is throwing Unable to resolve host error. Here is the code for the StringRequest val request = object : StringRequest(Request.Method.POST, "https://sampleServer.000webhostapp.com/phpFiles/upload.php", Response.Listener { response ->...

Passing lambda as argument in Kodein I am using Kodein for dependency injection on Android (in Kotlin, of course), but I am struggling with one aspect: I can't seem to pass a lambda as an argument to a factory. It compiles correctly but fails at runtime (something I though Kodein as meant to protect against). In my Application class, I do the following binding: class MyApplication : Application(), KodeinAware { override val kodein by Kodein.lazy { ... bind() with factory { func: () -> Unit ->...

How to get multi-dimenstional primitive array class in kotlin? Back in Java days I have been using gson to parse a json like this [[1.2, 4.1], [3.4,4.4]] into a java primitive multi-array double[][] The code looks like this (and works fine) : double[][] variable = new Gson().fromJson(json, double[][].class); Is there a way to get the double[][].class in kotlin ? Is double[][] variable; can be substitute in kotlin ?

AsyncTask without leaks This AsyncTask class should be static or leaks might occur Why my AsyncTask don't work? Call: PlacesTask(this).execute(...) Code: private class PlacesTask internal constructor(activity: MainActivity) : AsyncTask() { var data: String? = null private val mRef: WeakReference = WeakReference(activity) override fun doInBackground(vararg url: String): String? { try { data = MainActivity().downloadUrl(url[0]) } catch (e:...

Kotlin VerifyError: Uninitialized object exists on backward branch 90 I am using the Kotlin getting started guide to setup Kotlin for the first time on IntelliJ IDEA with the following configuration: IntelliJ IDEA 2017.2.5 Build #IC-172.4343.14, built on September 26, 2017 JRE: 1.8.0_152-release-915-b12 x86_64 JVM: OpenJDK 64-Bit Server VM by JetBrains s.r.o Mac OS X 10.11.6 I created an App.kt file in a new Kotlin project with the following code: fun...

How to serialize an object in kotlin How to serialize an object in kotlin? I don't know how to serialize an object in kotlin. How to serialize an object in kotlin? I don't know how to serialize an object in kotlin. How to serialize an object in kotlin? I don't know how to serialize an object in kotlin. How to serialize an object in kotlin? I don't know how to serialize an object in kotlin

Extending the Kotlin Data Class for use with JPA? Kotlin has a Data class that automatically implements equals and hashcode, but these are still not automatically usable in a JPA context. In order to remedy this I was wondering what it would take to extend the Data type in order to either assign a "Business Key" or an id property that is final and non updatable and is initialized with a UUID that serves as...

Dagger2 Injection compile error on ViewModel I'm using Dagger2 latest Android Injection model (with AndroidInjection class) in my application. Until now, everything was working fine, including ViewModelFactory injection, but I only had parameterless constructors on my ViewModels. While implementing new features, I've created a ViewModel extending AndroidViewModel (I need the context in that viewmodel). AndroidViewModel needs an Application as constructor parameter, so I've added it as injected parameter in the constructor of my...

Is there a xml library to make the operation of xml easy in Kotlin? I know I can use anko-sqlite library in Kotlin, it make the operation of SQLite easy. Is there a xml library to make the operation of xml easy in Kotlin?

Kotlin funKTionale Disjunction Apologies for the seemingly basic question, I'm not terribly experienced with neither Kotlin nor funKTionale. I'm calling an API that returns a data class ReservationDetailsResponse ( val reservations: List?, val errorDetails: ErrorDetails? ) I'd like write a wrapper function that returns a Disjunction //in case response has reservations but reading the source and test it's not immediately obvious to me how to do achieve this simple thing.

How to start with Kotlin? Recently I read that google announced Kotlin is going to be official language for android development. I had gone through Kotlin official site [https://kotlinlang.org/docs/tutorials/]. But found they didn't put so much tutorials on their official site. I checked the book prices but it slightly costly. I didn't found any online books to read about it. If you guys know how to get start with Kotlin please let me...

How to interpret and translate kotlin code to java? I have been trying to translate this Kotlin code to Java since the project is in Java. I am translating by looking into Kotlin syntax. However, there are still others that I am having a hard time understanding. <a href="https://github.com/airbnb/lottie-android/blob/master/LottieSample/src/main/kotlin/com/airbnb/lottie/samples/AppIntroActivity.kt" rel="nofollow...

Kotlin setOnclickListener Back in java I used to write only return for a void method... But kotlin doesn't seem to allow just return, instead it uses return@methodname? Can someone explain what this is and how does it add value? bAddLine.setOnClickListener { val selectedSeries = getSelectedSeries() if (selectedSeries.isEmpty()) { Toast.makeText(this, getString(R.string.toast_channel_mandatory), Toast.LENGTH_LONG).show() return@setOnClickListener }...

Kotlin: Access nested enum class from java I'm trying to access a data class with embedded enum from java data class MyStatus( val status: Status ) { enum class Status{ OK, ERROR } } Seems that Status is invisible if I use it from Java. Is there any way to achieve this ?

My inputs are not being recognised So I have these 3 pickers val pickerHours = numberPickerHours as NumberPicker val pickerMinutes = numberPicker as NumberPicker val pickerSeconds = numberPickerSeconds as NumberPicker I created a Listener to get their value, but my validation is "working" to the point where it assumes the values didn't change. So it doesn't matter what value I choose on my pickers, it is not doing anything Any ideas? var timerString = "" var timerString1 = "" var timerString2 = ""...

How to clone or copy a list in kotlin How to copy list in kotlin... I'm using val selectedSeries = mutableListOf() selectedSeries.addAll(series) Is there a easier way?

start Intent with contact as vCard in string How is possible to start a new contact Intent with vCard stored as a string? Is possible set a raw vCard instead of URI in some way? A sort of: intent.setDataAndType(vcardAsString,"text/x-vcard")

How to change a member field with Kotlin reflection? I'm porting a class from Java to Kotlin. This class declares hundreds of objects. Each object has a name property which is identical with the declared variable name of the object. Java reflection allows to use the declared name via reflection to set the object member name. Just saves one parameter in hundreds of constructors. I try to do the same in Kotlin but can't figure out how to do the property setting. Here is some simplified test code: package myPackage import...

Private constructor in Kotlin In Java it's possible to hide a class' main constructor by making it private and then accessing it via a public static method inside that class: public final class Foo { /* Public static method */ public static final Foo constructorA() { // do stuff return new Foo(someData); } private final Data someData; /* Main constructor */ private Foo(final Data someData) { Objects.requireNonNull(someData); this.someData = someData; }...

ToMany&amp;lt;&amp;gt; deleting wrong entity after resorting im using recyclerview and a ToMany list in my project. i have drag and swipe options for each viewholder but for some reason manipulating the order in ToMany will break db updates. inorder to keep track of order my items have position var for example: my list is item1 pos 0 item2 pos 1 item3 pos 2 and i will swap item 2 and 3 and afterward will try to remove any of the items after removing it from db another item from the list will get targetId 0 (i couldnt figure out if theres any...

Is kotlin both functional and procedural? Apart from object oriented can it support procedural and functional programming styles?

Error:Execution failed for task ':app:kaptDebugKotlin' I'm new to using Kotlin and trying to set it up with Dagger2, I've seen some few examples but none of them seem to work for me. I keep getting this Error:Execution failed for task 'appkaptDebugKotlin'. Internal compiler error. See log for more details I have my build.gradle (Module: app) apply plugin: 'com.android.application' apply plugin: 'kotlin-android' apply plugin: 'kotlin-kapt' apply plugin: 'kotlin-android-extensions' android { compileSdkVersion 25...

Kotlin unresolved reference :add after converting from Java code I had java code which looked like this: public static Map createMultimap(@NonNull Collection values, @NonNull TransformFunction transformFunction) { Map tmpMap = new HashMap(); for (VALUE value : values) { if (value != null) { KEY key = transformFunction.transform(value); List valuesList = tmpMap.get(key); if (valuesList == null) { valuesList = new ArrayList(); tmpMap.put(key, valuesList); }...

How to use Before in Kotlin tests? I have found different examples for writing Kotlin Cucumber Tests. From the people creating Cucumber I found this nice looking example: package cucumber.runtime.kotlin.test; import cucumber.api.DataTable import cucumber.api.Scenario import cucumber.api.java8.En import org.junit.Assert.* var lastInstance : LambdaStepdefs? =...