LiveData has no public method to modify its data. LiveData<User> getUser() { if (userMutableLiveData == null) { userMutableLiveData = new MutableLiveData<>(); } return userMutableLiveData } You can’t update its value like getUser().setValue(userObject) or getUser().postValue(userObject) So when you don’t want your data to be modified use LiveData If you want to modify your data later use … Read more
The documentation has this to say on the issue: If you aren’t using an item-keyed network API, you may be using page-keyed, or page-indexed. If this is the case, the paging library doesn’t know about the page key or index used in the BoundaryCallback, so you need to track it yourself. You can do this … Read more
Why I get this error? Lint is recommending that you use the lifecycle of the fragment’s views (viewLifecycleOwner) rather than the lifecycle of the fragment itself (this). Ian Lake and Jeremy Woods of Google go over the difference as part of this Android Developer Summit presentation, and Ibrahim Yilmaz covers the differences in this Medium … Read more
Update There are actually a few ways to resolve this issue. They are summarized nicely in the article LiveData with SnackBar, Navigation and other events (the SingleLiveEvent case). This is written by a fellow Googler who works with the Architecture Components team. TL;DR A more robust approach is to use an Event wrapper class, which … Read more
I don’t think there is any best practice as such recommended by android for this. I would suggest you to use the approach which uses cleaner & less boilerplate code. If you are using android data binding along with LiveData you can go with the following approach: Your POJO object would look something like this … Read more
It means that the extension in androidx is not needed anymore. Simply remove its import import androidx.lifecycle.observe. It will be actually deprecated in androidx. Read more reasoning there. EDIT: Please note the “issue” from Erik Hoogendoorn This change causes values from the observed LiveData object to be interpreted as nullable(since the converted lambda syntax is … Read more
MutableLiveData has been updated and now it has a constructor that accepts an initial value 🙂 From what I can see, the constructor is available starting from this version: implementation ‘androidx.lifecycle:lifecycle-extensions:2.1.0-alpha01′ It’s a shame they haven’t updated MediatorLiveData to reflect that, though. 2.1.0 is finally stable, so now you can actually see the new constructor … Read more
I can observe LiveData from multiple Fragments. Can I do this with Flow? If yes then how? Yes. You can do this with emit and collect. Think emit is similar to live data postValue and collect is similar to observe. Lets give an example. Repository // I just faked the weather forecast val weatherForecast = … Read more
I have introduced just one change in your code: noteViewModel = ViewModelProviders.of(this).get(NoteViewModel.class); instead of: noteViewModel = ViewModelProviders.of(getActivity()).get(NoteViewModel.class); in Fragment‘s onCreate(Bundle) methods. And now it works seamlessly. In your version you obtained a reference of NoteViewModel common to both Fragments (from Activity). ViewModel had Observer registered in previous Fragment, I think. Therefore LiveData kept reference to … Read more
At first we need to know what is the relation between MutableLivedata and MediatorLivedata to understand the difference between them. java.lang.Object ↳ android.arch.lifecycle.LiveData<T> ↳ android.arch.lifecycle.MutableLiveData<T> ↳ android.arch.lifecycle.MediatorLiveData<T> Now it is clear that MediatorLiveData is a subclass of MutableLiveData therefore MediatorLiveData can access each and every property of MutableLiveData as well as LiveData. Question no. 1 … Read more