Kotlin-Firebase-cannot use string read from database I have managed to read data from my firebase database but cant seem to re-use the String which has been read. my successful read is as per below. when i check the logcat for the Log.d("Brand") it actually shows the String as expected. brandchosenRef=FirebaseDatabase.getInstance().reference val brandsRef = brandchosenRef.child("CarList2").orderByChild("Car").equalTo(searchable_spinner_brand.selectedItem.toString()) val valueEventListener = object :...

How can I read a huge file JSON with kotlin? I'm trying to read a json file regarding my scheduling lessons at university, getting it from this link : http://diag.uniroma1.it/pannello/?q=export_json I tried to do it using https://developer.android.com/training/volley/simple which works for very simple json file as in <a...

How do I test methods with high order function parameter? I'm trying to test a method with a high order function as parameter. And facing this error: Argument(s) are different! Wanted: viewContractMock.showError( (fetchUserIdentity_showOptions_failed$2) Function0 ); -> at br.com.fastshop.ecommerce.ui.resetpassword.controller.RecoveryOptionsControllerTest.fetchUserIdentity_showOptions_failed(RecoveryOptionsControllerTest.kt:65) Actual invocation has different arguments: viewContractMock.showError( () Function0 ); -> at...

Problem with getting the real File Path from Intent.ACTION_GET_CONTENT i was trying to read from a text file so i used Intent.ACTION_GET_CONTENT to choose the file, but the problem is with the path of the chosen file, The Real path in the phone is "Download/ThisaTest.txt" but when i select the file i get a path like this: "/document/msf:26" and when i try to read from it the application crashes and logs say that file doesnt exist thats how i got the path btw... val filename = data.data?.path Log.d("dbg",filename)

What is the best way to clear up resources in Android? I am building an application just like Spotify using ExoPlayer. I am starting a player notification when the song starts playing and it should be getting played even when the app is put into the background. Therefore, I need to release the player and save the last played song when the user deliberately clears the app off from the Ram but onDestory() is not reliable as <a href="https://developer.android.com/reference/android/app/Activity.html#onDestroy()" rel="nofollow noreferrer">stated...

Login using retrofit strategy I hope all is well! I'm new to Android development (about 3 weeks). My instructor gave me a project that I have to log in, show the items inside. He provided me the APIs. He asks that I use MVVM and Retrofit. So I'm trying to do the login. The response of the login is: { "msg":"success", "userid":"2", "usertype":"tenant", "useremail":"abc@xyz.com", "appapikey":"28a013c206583bc57fc2cfa4e11dfa14" } When I do retrofit, all it does is to give me the response, not if my...

i have a problem with media player (android) iam doing an education app for kids i have a activity with all the alphabet and when you press any alphabet it make the sound of it using media player the problem is after a number of touches on the alphabet , it depends on the device , non of the alphabet make sound and all the buttons stop making sound at the begining i had one variable , and i would re assign it each time i tired declaring 28 variable , one for each letter and it didnt work please help :( please

Is it possible to get Ktor connector port at runtime? I'm using Ktor framework and curious how to get the actual port of my http connector at runtime. The thing is i need to use random port and put port=0 inside a connector. The app starts but i was unable to find actual port information using api. Is it possible to retrieve the actual port in runtime?

error: undefined reference to 'libiconv_close' in Ndk Android Studio Iam getting error on setting up my ndk for gstreamer library in android studio. Below is the error which iam getting-: cerbero.git/1.16/build/sources/android_universal/armv7/glib-2.56.1/_builddir/../glib/gconvert.c308 error: undefined reference to 'libiconv_close' My project level gradle is -:

buildscript {

repositories {

jcenter()

google()

}

dependencies {

classpath 'com.android.tools.buildG3.5.0'

} }

allprojects {

...

Pass the function to the dialogFragment someone know a different approach to pass the function to the DialogFragment than using callback ? This approach need to respect Android OS (killing components by system).

Type inference only works for extension function The following code works fine and the call to the foo.get() extension function returns the correct type BarImpl. open class Bar class BarImpl: Bar() class Foo inline fun Foo.get(): T { return SomeMap(this).get(T::class) } class Activity { lateinit var foo: Foo val vm = foo.get() } But when I try to move Foo.get() into the class the type inference fails class Foo { inline fun get(): T { return SomeMap(this).get(T::class) } } class Activity { lateinit...

Android can't serialize Kotlin lambda we can read lambda function are serialize by default (https://discuss.kotlinlang.org/t/are-closures-serializable/1620), but I getting error: java.lang.RuntimeException: Parcelable encountered IOException writing serializable object (name = com.example.dialogfragment.Arguments) my class Arguments: class Arguments(val function: ()-> Unit) : Serializable What is wrong with my lambda ?...

How do I retrieve display profiles using UID on a FirestoreRecycler Adapter using Kotlin? I am having difficulties retrieving the information correctly from Firebase Firestore for my Recycler Adapter. I am not sure what I might be doing wrong but I used a Document Reference to get the required field but now it seems to just copy the same thing over and over, I want it to display each created users profile and display it on my RecyclerAdapter but am not sure what I should do and have tried different methods but get a "No setter/field error" on my Model Class "Users". <a...

How to print multiple attrributes from a hashMap that is a property inside a toString override I am learning Kotlin and writing code to check my understanding. I'm trying to use a toString override to print the values of a hashMap that is a property of a class. I can't get it to work. Instead I get output like "kotlin.Unit() -> kotlin.Unit". Also, I don't understand why the values of the hashMap ARE printing out before the toString output. I don't know where that output is coming from. Please help me. Thanks. Below is my code and the output I'm getting. Code: package...

Kotlin - Making it mutable in foreach So I've come to learn that the it in my foreach loop is immutable - namely I get the error val cannot be reassigned. results.forEach{ val subGenreNames = subGenreNames(it.subGenres) it.subGenres = subGenreNames } However I want to be able to update its value after I pass it into my subGenreNames function. How can I achieve this? Thanks.

Spring Boot - Cacheable appears to be going into the method every time I'm using GraphQL and Spring Boot (along with data-mongodb). There's a specific query I make to Mongo that I would like to be cached so it isn't actually executed every time. I came across the cacheable feature of Spring and feel I have implemented as per the docs but it doesn't seem to work. I've added a breakpoint in the cacheable method - the first time I make the query I'd expect it to go in, but the second time I wouldn't. Is my understanding above correct, or is my configuration...

Android Studio - Kotlin - SQLite Database isn't changing the ID for one of the corresponding tables I'm trying to implement my first SQLite Database in an Android App regarding obtaining location coordinates to keep track of where the user has been. I'm trying to add information from my entry into two tables: a Location table that contains information of the places name, id, latitude, and longitude information & a CheckIn table that contains information of the places address, corresponding location_id to know which location it corresponds to, latitude, longitude, and time of check in. Now,...

Device Administrator Add screen not appear I'm following this kotlin example from google website to prompt user to grant Admin access right to my app, but for some reason, the screen does not appear. In OnActivityResult, the result is registered as cancelled. I don't know what I'm doing wrong but I appreciate if anyone could point me to the right direction : //this code resides in OnCreate method of current activity val...

Chip setoncheckedchangelistener String comparison return false Some Context : I'm filtering trip according to their date, those trips are on firebase, I have a method(getTripState) that compare the current date to the trip date and either return "Upcoming" or "Old Trips" depending on the case. The chips play the role as switch button with single selection enabled. I filter tripArray based on the chip text is equal to the date in the trip. Even if the String are exactly the...

Android Navigation library crash after sending data back I use Android Navigation library for fragment navigation and try pass data back from second fragment to first. Do it with the next code: findNavController().setGraph(R.navigation.nav_graph, bundle) findNavController().popBackStack() It works fine, but when I try to open the same screen after it, the next error occurred: java.lang.IllegalArgumentException: navigation destination com.leshchenko.test:id/openDetailsAction is unknown to this NavController Thanks.

How to initialize fields outside the constructor I have a data class that is used in Room. At the head of the class there are date fields in the form of a string _dateControl and _timeCreate. There are dateControl and timeCreate fields of type Long in the body of the class. When requesting data via Retrofit, the dateControl and timeCreate fields are initialized independently. But if I try to declare an instance of a class, then these fields(dateControl and timeCreate) are not initialized and equal to 0. Class @Entity class DetailNum(...

Coding standards for initializing views in android using Kotlin What is the official coding standard for declaring and initializing views in Android using Kotlin? If it is case by case bases what cases would you use what? I've seen these ways: //Kotlin extensions onCreate ... btn_xml_tag.setOnClickListener { ... } //More like java private lateinit var button : Button ... onCreate ... button = findViewById(R.id.button) button?.setOnClickListener{...} //Lazy private val button : Button by lazy { findViewById(R.id.button_view) as Button }...

Spring Boot and Mongo - Aggregation to match Id from another collection I've been using Spring Boot along with Mongo to run a query - which was pretty simply like this: val query = Query() query.with(Sort.by(options.sortDirection, options.sortBy)) query.limit(options.limit.toInt()).skip(options.skip.toLong()) val results = mongoTemplate.find(query, Series::class.java) However I now to handle a sceanrio, where from the above results I also get an array of genre ids. I need to look up this array of ids and find the matching documents from a second...

Post JSON Array to RetroFit 2 using Moshi I need to send my request parameters to the Retrofit 2 API call. My request packet should be sent as followed: REQUEST PACKET: { "msgLang": "EN", "recieverMsisdn": [ { "msisdn": "1234" }, { "msisdn": "5678" } ], "textmsg": "Hello World", "senderName": "333111222", "orderKey": "orderSent" } I am using kotlin and retrofit for the POST request as: val sendBulkSMSRequest = SendBulkSMSRequest(...

Cannot create Kotlin object in Java (Android) I have an Android app written in Java and I am trying to write a new feature in Kotlin. So I added a new Kotlin file and IntelliJ offered to setup the project for Kotlin. The issue is that when trying to create a Kotlin object in Java, compilation fails with error: cannot find symbol constructor MyObject() My Kotlin class: class MyClass() { fun hello(view: View) { } } In my app mocule: implementation "org.jetbrains.kotlinkotlin stdlib$kotlin_version" In my project...

Kotlin: How to map URL with Regex I want to map Slug URL with Regex URL mentioned below. Regex URL - /openPage/*/* Slug URL -/openPage/{category}/{subCategory} URL - /openPage/ABC/XYZ where after pattern matching, I should get like, category = ABC subCategory = XYZ Any help would be appreciated.

spring-boot-starter-web-services with kotlin data classes I am trying to implement this example using kotlin and kotlin data classes. My first trial was to use the generated java classes and that works as espected. Then I manually created kotlin data classes and added all the annotations I found on the java classes. But with these I get SOAP-ENV:Server unexpected element...

Does the Elvis operator in Kotlin call methods twice? In Kotlin, if I write: val result = costlyGetter() ?: "default" will costlyGetter be called twice? Otherwise, I will write this: val subresult = costlyGetter() val result = subresult ?: "default" but this is more verbose.

Create a XSD from kotlin classes I want to create a soap endpoint but have my kotlin data classes as single point of truth (I do not have an XSD to hand and I want to use spring which just supports contract-first) I hardly found anything about generating an xsd from java classes, just the other way around. Does someone have experience with how to generate an XSD from kotlin data classes in gradle? Many thanks

Why Extension Functions are not working on ArrayList&lt;ArrayList&lt;Double&gt;&gt; I am very new to Android development in Kotlin. I have an ArrayList consisting two ArrayLists of Double type. I want to discard/ slice everything after the first element inside the Big ArrayList. On coming across the properties described here on Kotlin's page, I found some functions like dropLast, take etc. However, they don't perform on implementation also there is...