RxJava2 - How to know when all concatMapSingle operations finished on iterating Observable

Question

I have the method below:

private fun bindUploadPhotos(uploadPhotoCommands: List<UploadPhotoCommand>): Disposable {
    return Observable.fromIterable(uploadPhotoCommands)
            .concatMapSingle { param ->
                requestUploadPhoto.getSingle(param)
            }
            .doFinally {
                onAllPhotosUploaded()
            }
            .subscribeOn(Schedulers.io())
            .observeOn(AndroidSchedulers.mainThread())
            .subscribe {
                onPhotoUploaded()
            }
}   

I upload photos sequentially. I expect doFinally to execute after all photos are uploaded successfully. However, it executes immediately.

I am not a RxJava2 master, so I gladly take your different approaches to achieve my purpose.

Answer 1

onComplete called when all your photos uploaded. so call onAllPhotosUploaded there

private fun bindUploadPhotos(uploadPhotoCommands: List<UploadPhotoCommand>): Disposable {
    return Observable.fromIterable(uploadPhotoCommands)
            .flatMapSingle { param ->
                requestUploadPhoto.getSingle(param)
            }.subscribeOn(Schedulers.io())
            .observeOn(AndroidSchedulers.mainThread())
            .subscribe ({onPhotoUploaded},{},{onAllPhotosUploaded()})
}