I am using Rxjava and Retrofit2.0 in my project, it looks like this:
Observable<List<A>> getAFromServer();
Observable<List<B>> getBFromServer(@Body A.a);
If I don't use reactive way, it will be like this:
List<A> listA = getAFromServer();
foreach(A a: listA){
getBFromServer(a.a)
}
So, my question is how to use Rxjava to achieve this and what operator to use?
With Rx you can finally stop thinking about "nesting" network requests.
If you think about it, you never really wanted to "nest" network requests, right? That was only how the code ended up looking because you had only AsyncTasks or other callbacks at your disposal.
With Rx you can finally write code that in its structure resembles what you actually want to, which is chain network requests: First do one thing, then do another.
getAFromServer()
.flatMap(new Func1<List<A>, Observable<A>>() {
@Override
public Observable<A> call(List<A> list) {
// the first flatMap is just a trick to "flatten" the Observable
return Observable.from(list);
}
})
.flatMap(new Func1<A, Observable<B>>() {
@Override
public Observable<A> call(A someA) {
return getBFromServer(someA.a);
}
})
.subscribe(...);
