I need to make two requests for services and combine it results:
ServiceA() => [{"id":1,"name":"title"},{"id":1,"name":"title"}]
ServiceB(id) => {"field":"value","field1":"value"}
Currently, I have managed to combine the results, but I need to pass id as a parameter to the ServiceB and get access to the first result.
What I tried so far:
Retrofit repo = new Retrofit.Builder()
.baseUrl("https://api.themoviedb.org/3/genre/")
.addConverterFactory(GsonConverterFactory.create())
.addCallAdapterFactory(RxJavaCallAdapterFactory.create())
.build();
Observable<GenerosResponse> Genres = repo
.create(services.class)
.getAllGeneros("movie","list","da0d692f7f62a1dc687580f79dc1e6a0")
.subscribeOn(Schedulers.newThread())
.observeOn(AndroidSchedulers.mainThread());
Observable<ResponseMovies> Movies = repo
.create(services.class)
.getAllMovies("28","movies","da0d692f7f62a1dc687580f79dc1e6a0",12)
.subscribeOn(Schedulers.newThread())
.observeOn(AndroidSchedulers.mainThread());
Observable<CollectionsMovies> combined = Observable.zip(Genres, Movies, new Func2<GenerosResponse, ResponseMovies, CollectionsMovies>() {
@Override
public CollectionsMovies call(GenerosResponse generosResponse, ResponseMovies responseMovies) {
return new CollectionsMovies(generosResponse, responseMovies);
}
});
combined.
subscribeOn(Schedulers.newThread())
.observeOn(AndroidSchedulers.mainThread())
.subscribe(...);
Edit
Solution according to @Maxim Ostrovidov's answer:
private Observable<GenerosResponse> makeRequestToServiceA() {
return service.getAllGeneros("movie","list","da0d692f7f62a1dc687580f79dc1e6a0"); //some network call
}
private Observable<ResponseMovies> makeRequestToServiceB(Genre genre) {
return service.getAllMovies(genre.getId(),"movies","da0d692f7f62a1dc687580f79dc1e6a0","created_at.asc"); //some network call based on response from ServiceA
}
void doTheJob() {
makeRequestToServiceA()
.flatMap(userResponse -> Observable.just(userResponse.getGenres())) //get list from response
.flatMapIterable(baseDatas -> baseDatas)
.flatMap(new Func1<Genre, Observable<? extends ResponseMovies>>() {
@Override
public Observable<? extends ResponseMovies> call(Genre genre) {
return makeRequestToServiceB(genre);
}
}, new Func2<Genre, ResponseMovies, CollectionsMovies>() {
@Override
public CollectionsMovies call(Genre genre, ResponseMovies responseMovies) {
return new CollectionsMovies(genre,responseMovies);
}
}).
subscribeOn(Schedulers.newThread())
.observeOn(AndroidSchedulers.mainThread())
.subscribe(....);
}
As I understand - you need to make a request based on result of another request and combine both results. For that purpose you can use this flatMap operator variant: Observable.flatMap(Func1 collectionSelector, Func2 resultSelector)
Returns an Observable that emits the results of a specified function to the pair of values emitted by the source Observable and a specified collection Observable.
Simple example to point you how to rewrite your code:
private Observable<String> makeRequestToServiceA() {
return Observable.just("serviceA response"); //some network call
}
private Observable<String> makeRequestToServiceB(String serviceAResponse) {
return Observable.just("serviceB response"); //some network call based on response from ServiceA
}
private void doTheJob() {
makeRequestToServiceA()
.flatMap(new Func1<String, Observable<? extends String>>() {
@Override
public Observable<? extends String> call(String responseFromServiceA) {
//make second request based on response from ServiceA
return makeRequestToServiceB(responseFromServiceA);
}
}, new Func2<String, String, Observable<String>>() {
@Override
public Observable<String> call(String responseFromServiceA, String responseFromServiceB) {
//combine results
return Observable.just("here is combined result!");
}
})
//apply schedulers, subscribe etc
}
Using lambdas:
private void doTheJob() {
makeRequestToServiceA()
.flatMap(responseFromServiceA -> makeRequestToServiceB(responseFromServiceA),
(responseFromServiceA, responseFromServiceB) -> Observable.just("here is combined result!"))
//...
}