RxJava cache intermediate results - reactive-programming

Question

I'm developing android client for kaltura video platform, and now I develop uploading video. This feature consists of the following steps:
create MediaEntry
params: name, description
create UploadToken
params: fileName, mediaEntryId(which received at step
1)
addContent - in other words bind MediaEntry to UploadToken
params: mediaEntryId(which received at step 1), uploadTokenId(which received at step 2)
uploadVideo params: uploadTokenId(which received at step 2), videoData
Here is my code using RxJava:
API.createMediaEntry(name, description)
.flatMap(mediaEntry -> {
mediaEntryId = mediaEntry.getId();
return API.createUploadToken(this.videoUri.getPath(), mediaEntry.getId());
})
.flatMap(uploadToken -> {
uploadTokenId = uploadToken.getId();
return API.addContent(mediaEntryId, uploadToken.getId());
})
.flatMap(mediaEntry -> API.uploadVideo(uploadTokenId, FileUtil.getTypedVideoFileFromUri(this.videoUri, UploadVideoActivity.this)))
.doOnError(throwable -> {
throwable.printStackTrace();
dismissProgressDialog();
})
.doOnNext(response -> {
})
.doOnCompleted(() -> {
dismissProgressDialog();
})
.subscribe();
Where API is Retrofit rest adapter.
As you can see from code, i need to save mediaEntryId at step 1, and uploadTokenId at step 2, to use them at step 3.
I want to undestand, is there a way to save mediaEntry from step 1 and uploadToken from step 2 to using them later, or may be there is some way to change my code, to exclude saving data into local variables?
Ideal solution for me looks like this:
API.createMediaEntry(name, description)
.doSomeThingWithMedaiEntry(mediaEntry -> mediaEntry)
.flatMap(mediaEntry -> API.createUploadToken(this.videoUri.getPath(), mediaEntry.getId()))
.doSomeThingWithUploadToken(token -> token)
.getMediaEntryAndUploadTokenSomehow((mediaEntry, uploadToken) -> API.addContent(mediaEntry.getId(), uploadToken.getId()))
.getUploadTokenSomehow(uploadToken -> API.uploadVideo(uploadToken.getId(), FileUtil.getTypedVideoFileFromUri(this.videoUri, UploadVideoActivity.this)))
.doOnError(throwable -> {
throwable.printStackTrace();
dismissProgressDialog();
})
.doOnNext(response -> {
})
.doOnCompleted(() -> {
dismissProgressDialog();
})
.subscribe();

Answer 1

Aside from using tuple, you can nest your Observables.
API.createMediaEntry(name, description)
.flatMap(createdMediaEntry -> API.createUploadToken(this.videoUri.getPath(), createdMediaEntry.getId())
.flatMap(uploadToken -> API.addContent(createdMediaEntry.getId(), uploadToken.getId())
.flatMap(addedMediaEntry -> API.uploadVideo(uploadToken.getId(), , , ))
)
)
...