Android use RxAndroid on Service - android

this below code work fine on my activity or fragments, but when i rotate my phone this method work again, how can i move that to service and get event on Ui?
private void getUserStories() {
mSubscriptions.add(mDataManager.getUserPosts(mUser)
.observeOn(AndroidSchedulers.mainThread())
.subscribeOn(mDataManager.getScheduler())
.subscribe(new Subscriber<Post>() {
#Override
public void onCompleted() { }
#Override
public void onError(Throwable e) {
hideLoadingViews();
Timber.e("There was a problem loading the user stories " + e);
DialogFactory.createSimpleOkErrorDialog(
getActivity(),
getString(R.string.error_stories)
).show();
}
#Override
public void onNext(Post story) {
hideLoadingViews();
mPostAdapter.addItem(story);
}
}));
}

Related

NetworkOnMainThreadException with .subscribeOn(Schedulers.newThread())

I am trying to fetch list from an api and display in recyclerview using Retrofit with RxJava.
I have used below code-
ApiInterface apiService =
ApiService.getClient().create(ApiInterface.class);
Observable<MoviesResponse> call = apiService.getTopRatedMovies(API_KEY);
call.subscribeOn(Schedulers.newThread())
.observeOn(AndroidSchedulers.mainThread())
.subscribe();
call.subscribe(new Observer<MoviesResponse>() {
#Override
public void onSubscribe(Disposable d) {
Toast.makeText(getApplicationContext(), d.toString(), Toast.LENGTH_LONG).show();
}
#Override
public void onNext(MoviesResponse moviesResponse) {
movies=moviesResponse;
moviesAdapter.notifyDataSetChanged();
}
#Override
public void onError(Throwable e) {
Toast.makeText(getApplicationContext(), e.toString(), Toast.LENGTH_LONG).show();
}
#Override
public void onComplete() {
Toast.makeText(getApplicationContext(), "complete", Toast.LENGTH_LONG).show();
}
});
Below two lines specify that the REST call will be made in a new thread . And when the call response returns, the onNext, onError, and onComplete methods are called on the mainThread.
.subscribeOn(Schedulers.newThread())
.observeOn(AndroidSchedulers.mainThread())
But I am getting NetworkOnMainThreadException which is thrown when an application attempts to perform a networking operation on its main thread.Why am i getting this exception and how can i resolve this?
That's because you are subscribing to the observable 2 times. You can remove subscribe method from here:
call.subscribeOn(Schedulers.newThread())
.observeOn(AndroidSchedulers.mainThread())
.subscribe();
So it will look like this:
ApiInterface apiService =
ApiService.getClient().create(ApiInterface.class);
call.subscribeOn(Schedulers.newThread())
.observeOn(AndroidSchedulers.mainThread())
.subscribe(new Observer<MoviesResponse>() {
#Override
public void onSubscribe(Disposable d) {
Toast.makeText(getApplicationContext(), d.toString(), Toast.LENGTH_LONG).show();
}
#Override
public void onNext(MoviesResponse moviesResponse) {
movies=moviesResponse;
moviesAdapter.notifyDataSetChanged();
}
#Override
public void onError(Throwable e) {
Toast.makeText(getApplicationContext(), e.toString(), Toast.LENGTH_LONG).show();
}
#Override
public void onComplete() {
Toast.makeText(getApplicationContext(), "complete", Toast.LENGTH_LONG).show();
}
});
You are subscribing twice, the second time to the unmodified call source. You should have something like this:
ApiInterface apiService =
ApiService.getClient().create(ApiInterface.class);
Observable<MoviesResponse> call = apiService.getTopRatedMovies(API_KEY);
call.subscribeOn(Schedulers.newThread())
.observeOn(AndroidSchedulers.mainThread())
.subscribe(new Observer<MoviesResponse>() {
#Override
public void onSubscribe(Disposable d) {
Toast.makeText(getApplicationContext(), d.toString(), Toast.LENGTH_LONG).show();
}
#Override
public void onNext(MoviesResponse moviesResponse) {
movies=moviesResponse;
moviesAdapter.notifyDataSetChanged();
}
#Override
public void onError(Throwable e) {
Toast.makeText(getApplicationContext(), e.toString(), Toast.LENGTH_LONG).show();
}
#Override
public void onComplete() {
Toast.makeText(getApplicationContext(), "complete", Toast.LENGTH_LONG).show();
}
});

In how place(activity/fragment/singleton) I must realise Observable from retrofit?

I use retrofit2 in my project. I have interface:
public interface ProductService {
#POST("findProducts")
Observable<ProductsResponse> getProducts();
}
and service method:
public ProductService getProductService() {
return getService(ProductService.class);
}
After that I use this service in my fragment. When I click to button I call this method:
#Override
public void onClick(View view) {
if (view.getId() == R.id.button) {
RestApiFactory.getInstance().getProductService().getProducts()
.subscribeOn(Schedulers.io())
.observeOn(AndroidSchedulers.mainThread())
.subscribe(new ProductHandler());
}
}
and realise handler in this fragment:
private class ProductHandler implements Observer<ProductsResponse> {
#Override
public void onSubscribe(Disposable d) {
Log.d(TAG, "onSubscribe: start");
progressBar.setVisibility(View.VISIBLE);
}
#Override
public void onNext(ProductsResponse value) {
//save to DB in new Thread
}
#Override
public void onError(Throwable e) {
Log.d(TAG, "onError: "+ e.getMessage());
price.setVisibility(View.INVISIBLE);
progressBar.setVisibility(View.INVISIBLE);
}
#Override
public void onComplete() {
Log.d(TAG, "onComplete: finish");
price.setVisibility(View.INVISIBLE);
progressBar.setVisibility(View.INVISIBLE);
}
}
is it correct to implement ProductHandler implements Observer<ProductsResponse>'s methods
onSubscribe
onNext
onError
onComplete
in fragment?
I'm advised to move this in a singleton:
MySingleton.getInstanse().getData();
and move all to getData :
public void getData(){
RestApiFactory.getInstance().getProductService().getProducts()
.subscribeOn(Schedulers.io())
.observeOn(AndroidSchedulers.mainThread())
.subscribe(new Observer<ProductsResponse>() {
#Override
public void onSubscribe(Disposable d) {
//send broadcast and catch in Fragment
}
#Override
public void onNext(ProductsResponse productsResponse) {
//send broadcast and catch in Fragment
}
#Override
public void onError(Throwable e) {
//send broadcast and catch in Fragment
}
#Override
public void onComplete() {
//send broadcast and catch in Fragment
}
});
}
but I think this is nonsense. who will tell you how to use it (in what place) Observable from retrofit?
there is no need to implement Observer.You can just need to create an observer for the same.Let's see the example.
service.getProducts()
.subscribeOn(Schedulers.io())
.observeOn(AndroidSchedulers.mainThread())
.subscribe(mObserver);
}
the observer should look like and must be initialized in oncreate:
mObserver = new Observer<ProductsResponse>() {
#Override
public void onSubscribe(Disposable d) {
mDisposableList.add(d);
}
#Override
public void onNext(ProductsResponse value) {
#Override
public void onError(Throwable e) {
e.printStackTrace();
}
#Override
public void onComplete() {
}
};

Migrating from RxJava1 to RxJava2

I was looking at the example of an android app coded in MVP (link here). But now I want to recode the given RxJava1 code in the tutorial to an RxJava2 code. However, I am having trouble with it especially unSubscribe() and isUnSubscribed(). I tried to convert it and I will share my attempt.
RxJava1 Code:
public void doLogin(AuthCredentials credentials) {
cancelSubscription();
subscriber = new Subscriber<Account>() {
#Override public void onCompleted() {
if (isViewAttached()) {
getView().loginSuccessful();
}
}
#Override public void onError(Throwable e) {
if (isViewAttached()) {
getView().showError();
}
}
#Override public void onNext(Account account) {
eventBus.post(new LoginSuccessfulEvent(account));
}
};
// do login
accountManager.doLogin(credentials)
.subscribeOn(Schedulers.io())
.observeOn(AndroidSchedulers.mainThread())
.subscribe(subscriber);
}
private void cancelSubscription() {
if (subscriber != null && !subscriber.isUnsubscribed()) {
subscriber.unsubscribe();
}
}
This is my attempt on RxJava2 Code:
public void doLogin(AuthCredentials credentials) {
cancelSubscription();
subscriber = new Subscriber<Account>() {
#Override public void onSubscribe(Subscription s) {
// do login
accountManager.doLogin(credentials)
.subscribeOn(Schedulers.io())
.observeOn(AndroidSchedulers.mainThread())
.subscribe(subscriber);
}
#Override public void onCompleted() {
if (isViewAttached()) {
getView().loginSuccessful();
}
}
#Override public void onError(Throwable e) {
if (isViewAttached()) {
getView().showError();
}
}
#Override public void onNext(Account account) {
eventBus.post(new LoginSuccessfulEvent(account));
}
};
}
private void cancelSubscription() {
//isUnsubscribed and unsubscribe doesnt work anymore
}
I am fairly new to the concept of RxJava. If anyone can point out my mistakes and guide me that would be great. :)
I apologize for the late answer. Have been extremely busy. As stated by #akarnokd there have been made a lot of changes in RxJava2 as compared to RxJava1. For those who interested please look at this video.
As far as the above question is concerned, we can achieve the same by using DisposableObservables
Here is the answer to the above question. I have tested it and it works.
public void doLogin(AuthCredentials credentials) {
myDisposableObserver = new DisposableObserver<Account>() {
#Override
public void onNext(Account account) {
eventBus.post(new LoginSuccessfulEvent(account));
}
#Override
public void onError(Throwable e) {
if (isViewAttached()) {
getView().showError();
}
}
#Override
public void onComplete() {
if (isViewAttached()) {
getView().loginSuccessful();
}
}
};
// do login
accountManager.doLogin(credentials)
.subscribeOn(Schedulers.io())
.observeOn(AndroidSchedulers.mainThread())
.subscribe(subscriber);
}
}
private void cancelSubscriptionToMyPrescriptorManager() {
if (myDisposableObserver != null && !myDisposableObserver.isDisposed()) {
myDisposableObserver.dispose();
}
}

onNext() onError() callbacks not executing on second subscribtion android

I've an Observable something like this:
#GET("endpoint")
Observable<Something> getSomething();
and Subscriber like this
Subscriber<Something> somethingSubscriber = new Subscriber<Something>() {
public void onCompleted() {
}
public void onError(Throwable e) {
//handle exceptions
}
public void onNext() {
//do something
}
In my OnClickListener associated with a button, i make a subscription
getSomething()
.subscribeOn(Schedulers.newThread())
.observeOn(AndroidSchedulers.mainThread())
.subscribe(somethingSubscriber);
If i don't have an internet connection, onError is called and i do some exception handling. when I press the button again (assume i want to retry), the callback methods do not get called.
I want that onNext / onError callbacks get called everytime I press the button.
There is extention for RxJava. It has a lot of "cool tools", but for handling retrofit errors you can use ResponseOrError class.
So in you case it would looks like:
final PublishSubject<Object> clickSubject = PublishSubject.create();
final Observable<ResponseOrError<Something>> responseOrErrorObservable = clickSubject
.flatMap(new Func1<Object, Observable<ResponseOrError<Something>>>() {
#Override
public Observable<ResponseOrError<Something>> call(Object o) {
return getSomething()
.subscribeOn(Schedulers.newThread())
.observeOn(AndroidSchedulers.mainThread())
.compose(ResponseOrError.<Something>toResponseOrErrorObservable());
}
})
.replay(1)
.refCount();
final Observable<Throwable> error = responseOrErrorObservable
.compose(ResponseOrError.<Something>onlyError())
.subscribe(new Action1<Segment>() {
#Override
public void call(Throwable throwable) {
// what to do on error, some toast or what ever yu need
}
});
final Observable<UserInfoResponse> success = responseOrErrorObservable
.compose(ResponseOrError.<Something>onlySuccess())
.subscribe(new Action1<Something>() {
#Override
public void call(Something some) {
// code what to do on success
}
});
And now, into onClick you just need to put clickSubject.onNext(null)
.replay(1).refCount(); needed because there are 2 Observables that uses responseOrErrorObservable, so without it retrofit request will "happens" two times.
You are reusing the same Subscriber. Once you get the onError or a result (so it completes) the subscriber is unsubscribed. Try to pass every time a new subscriber.
use this code
button.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View view) {
getSomething()
.subscribeOn(Schedulers.newThread())
.observeOn(AndroidSchedulers.mainThread())
.subscribe(new Action1<Something>() {
#Override
public void call(Something something) {
//do something
}
},
new Action1<Throwable>() {
#Override
public void call(Throwable throwable) {
//handle exceptions
}
},
new Action0() {
#Override
public void call() {
}
});
}
});
Addition
or
replace this
Subscriber<Something> somethingSubscriber = new Subscriber<Something>() {
public void onCompleted() {
}
public void onError(Throwable e) {
//handle exceptions
}
public void onNext() {
//do something
}
};
to
Subscriber<String> somethingSubscriber = new Subscriber<String>() {
#Override
public void onCompleted() {
}
#Override
public void onError(Throwable e) {
}
#Override
public void onNext(String s) {
}
};
In my Case onNext() and onError() methods are not getting called because of my model class wrong parsing, I was taking a double object as Integer so NumberFormatException was thrown and nothing was happening after getting the result from retrofit.

RxAndroid crashes the app although doOnError is implemented

I have the following code. It's basically an attempt to send all data from a specific SQLite table to DynamoDB:
Observable.create(new Observable.OnSubscribe<Area>() {
#Override
public void call(Subscriber<? super Area> subscriber) {
try {
for (Area item : areaDao.listAll()) {
subscriber.onNext(item);
}
subscriber.onCompleted();
} catch (Exception e) {
subscriber.onError(e);
}
}
}).flatMap(new Func1<Area, Observable<Area>>() {
#Override
public Observable<Area> call(Area area) {
dynamoDBMapper.save(area);
return Observable.just(area);
}
}).observeOn(
AndroidSchedulers.mainThread()
).doOnError(new Action1<Throwable>() {
#Override
public void call(Throwable throwable) {
Log.w("AreaHandler", "Could not upload area", throwable);
}
}).doOnCompleted(new Action0() {
#Override
public void call() {
Toast.makeText(ctx, R.string.toast_upload_successful, Toast.LENGTH_SHORT).show();
}
}).subscribeOn(
Schedulers.io()
).subscribe(new Action1<Area>() {
#Override
public void call(Area area) {
areaDao.delete(area.getId());
}
});
I'm trying to run it on an emulator with disabled Internet connectivity, and what happens is that the Dynamo client does a couple of (failed) retries, then an exception is thrown and it crashes the app. From what I read in the docs, the exception should be swallowed by doOnError instead of being let out to the wild and killing the process.
What am I missing?
You are grabbing the error in the wrong place. doOnError is for side effects. It does not handle the error.
Option 1. Pass in two Action1
Observable.just(1, 2, 3)
.subscribe(
new Action1<Integer>() {
#Override
public void call(Integer integer) {
System.out.println(integer);
}
},
new Action1<Throwable>() {
#Override
public void call(Throwable throwable) {
System.err.print(throwable);
}
});
Option 2: Pass in an Observer
Observable.just(1, 2, 3)
.subscribe(new Observer<Integer>() {
#Override
public void onCompleted() {
}
#Override
public void onError(Throwable throwable) {
System.err.print(throwable);
}
#Override
public void onNext(Integer integer) {
System.out.println(integer);
}
});

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