CODEWITHSUNDEEP
androidkotlinrx-java2kotlin-android-extensions
Roberto Betancourt
Roberto Betancourt

Reputation: 2505

Android views are null after rotation when using Rx-Java

I'm accessing all of the views in a fragment with Kotlin Android Extensions, this views work as expected and can be accessed normally even after screen rotations.

The problem starts when i try to access the views inside an Rx-Java observable interval like this:

 var interval = Observable.interval(10, TimeUnit.SECONDS, Schedulers.io())
        .observeOn(AndroidSchedulers.mainThread())

interval.retry().subscribe { updateUi(); }

If i rotate the screen between intervals. The next time the updateUi() method is run as a part of the observable, the views inside it will be null and the application will crash with the following exception:

io.reactivex.exceptions.OnErrorNotImplementedException: text_view must not be null

But if i try to run the method outside the observable, everything will work correctly.

I know that accessing the views with findViewById() will retrieve the view correctly, but that defeats the purpuose of having the kotlin-android-extensions.

Upvotes: 1

Views: 581

Answers (1)

Boy
Boy

Reputation: 7487

On rotation, the screen is being set up again, so the old views are gone.

You have to unsubscribe the subscription (returned by subscribe() call) in the onStop().

Maybe you should try out ViewModel of the Android architectures. I've been using it lately and really liking it. This will take care of your issue too. https://medium.com/google-developers/viewmodels-a-simple-example-ed5ac416317e

Upvotes: 4

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