Observe mutuableMapof in android

1

Hi,
Is it possible to observe a map list?
This is my map:

var map = mutableMapOf<Int, Long>()

I would like to notify to UI when the list gets any changes, is it possible?
My goal is to observe a map, so if there are others way to reach my objective, please let me know. Thanks

2

You can use rx to achieve that. Simplest things that I would do are:

  1. Create a subject. (PublishSubject)
  2. Modify your mutable Map/List somewhere
  3. Publish the result via onNext method on subject
  4. Observe the changes on UI via subscribe method from observable. If you’re on android, don’t forget to use .observeOn(AndroidSchedulers.mainThread()).

Tips: you can use [aSubject].hide() method to return an observable from a subject.

Good luck.

rxJava: GitHub - ReactiveX/RxJava: RxJava – Reactive Extensions for the JVM – a library for composing asynchronous and event-based programs using observable sequences for the Java VM.
rxKotlin: GitHub - ReactiveX/RxKotlin: RxJava bindings for Kotlin

3

There’s no way to observe a Kotlin Map. Like @ptdede suggests, your best bet is probably to put the map inside an observable object. For Android I’d suggest your UI observe a LiveData, and every time your code updates the map it should also call liveData.setValue(myMap).