Issue
After reading a lot of articles about MVVM and RxJava, I need to implement the simplest demo to catch the idea well without using DataBinding
But I got stuck in the way how the ViewModel will notify the View (Activity) with the list of data
My ViewModel contain fetchGitHub() which using RxJava in this way
io.reactivex.Observable<List<Repo>> reposReturnedObservable = githubClient.reposForUser(user);
reposReturnedObservable
.subscribeOn(Schedulers.newThread())
.observeOn(AndroidSchedulers.mainThread())
.subscribe(new Observer<List<Repo>>() {
@Override
public void onError(Throwable e) {
}
@Override
public void onComplete() {
}
@Override
public void onSubscribe(Disposable d) {
compositeDisposable.add(d);
}
@Override
public void onNext(List<Repo> repos) {
data = repos;
}
});
What is the missing lines here to update the view with the data
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
viewModel = new ViewModel();
viewModel.fetchGitHub("square");
}
Solution
fetchGitHub() should return an Observable, so that the Activity can subscribe to it.
ViewModel:
public class ViewModel {
public Observable<List<Repo>> fetchGitHub(String userName) {
return githubClient.reposForUser(user);
}
}
Activity:
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
TextView listSizeTextView = findViewById(R.id.listSizeTextView);
viewModel = new ViewModel();
viewModel.fetchGitHub("square")
.subscribeOn(Schedulers.io())
.observeOn(AndroidSchedulers.mainThread())
.subscribe(list -> listSizeTextView.setText("list size: " + list.size()));
}
Above example does not store the subscription to provide you with a simplified answer but in real practice, make sure to clear subscriptions like you did in your example.
Answered By - Sanlok Lee
Answer Checked By - Clifford M. (JavaFixing Volunteer)
