Black arrow is flow
Red arrow is dependency
This is one big function
I can create some single for each time taking task
public static Single<byte[]> processData(byte[] fileData))
public static Single<APIResponse> callAPI(String id, byte[] processedData)
public static Single<UploadResponse> uploadData(String url)
This is my attempt
I tried using flatMap's resultSelector as described here
Retrofit and RxJava: How to combine two requests and get access to both results?
private static Single<FinalResult> bigFunction(String id, int type, String jwt, byte[] fileData){
return processData(fileData).flatMap(new Function<byte[], SingleSource<APIResponse>>() {
@Override
public SingleSource<APIResponse> apply(byte[] processedData) throws Throwable {
return callAPI(id, processedData);
}
}, new BiFunction<byte[], APIResponse, UploadResponse>() {
@Override
public FinalResult apply(byte[] processData, APIResponse apiResponse) throws Throwable {
if (processData.size() > LIMIT){
uploadData(apiResponse.getUrl()); // I am stuck here how to return a FinalResult() after this uploadData() is complete
}else{
return new FinalResult(); // if no need to upload, done
}
}
});
}
If you don't need a result then you can ignoreElement()
to convert your flow into Completable
and use toSingleDefault(...)
function:
uploadData(apiResponse.getUrl())
.ignoreElement()
.toSingleDefault(new FinalResult());
In case you just need to convert the response into FinalResult
then you can use map(...)
:
uploadData(apiResponse.getUrl())
.map(uploadResponse -> new FinalResult(uploadResponse));
In case you have to utilize the result from uploadData(..)
with any external calls or whatever then flatMap()
is your choice:
uploadData(apiResponse.getUrl())
.flatMap(uploadResponse -> {
// do whatever you want with response
return Single.just(new FinalResult(uploadResponse));
});
UPDATE:
In your case it can be simplified:
return processData(fileData)
.flatMap(processedData -> {
Single<FinalResult> postProcessing;
if (processedData.length > LIMIT) {
postProcessing = uploadData(apiResponse.getUrl())
.map(response -> new FinalResult(response));
} else {
postProcessing = Single.just(new FinalResult());
}
return callAPI(id, processedData)
.ignoreElement()
.andThen(postProcessing);
});