How to implement autocomplete with RxBinding, RxJava, and Retrofit

Question

I'm new to RxJava, and there are a lot of examples and answers out there, but I'm having trouble piecing together something that addresses all of my concerns.

The code below seems to be working except that I occasionally get results out of order. So I think I need to introduce a switchMap, but I'm not sure exactly where, and I wonder if I haven't already made things unnecessarily complicated, like is it odd to subscribe to the RxBinding and separately subscribe to the network call?

view.autocompleteText() is an RxBinding. I want to get text from that, call the retrofit service, and update the view with results, with all the bells and whistles like showing/hiding spinner, and error handling for the network call that won't kill the whole thing and make my textbox unresponsive.

private void handleAutocompleteText() {
    mCompositeDisposable.add(view.autocompleteText()
        .debounce(400, TimeUnit.MILLISECONDS)
        .filter(s -> s.length() >= resources.getAutocompleteThreshold())
        .observeOn(threads.main())
        .doOnNext(s -> view.setProgressVisible(true))
        .subscribe(s -> {
            mCompositeDisposable.add(mAutocompleteService.query(s.toString())
                .subscribeOn(threads.io())
                .observeOn(threads.main()).toObservable()
                .retry(3)
                .doOnNext(response -> {
                    if (response.getStatus() != 200)
                        throw new RuntimeException("Server error " + response.getStatus());
                })
                .map(response -> response.getData())
                .subscribe(items -> {
                    view.setProgressVisible(false);
                    view.updateList(items);
                }, error -> {
                    view.setProgressVisible(false);
                    view.showMessage(resources.getListError());
                }));
            }, error -> {
                view.setProgressVisible(false);
                view.showMessage(resources.getListError());
            }
        )
    );
}

Is there a better way to do this, and where can I introduce a switchMap to discard any inflight searches and only update the view with results of the last one? And if the answer is drastically different, I'd really appreciate a walkthrough.

Thanks in advance!!

Answer 1

I am not sure this is you want. But it might give you hints and solutions. Let's see the code. The switchMap gets parameter from view and changes observable to resrofit observable . And then it returns response from API call . After all of that you can receive the response and use the response.

If the code doesn't work let me know.

mCompositeDisposable.add(
        view
                .autocompleteText()
                .debounce(400, TimeUnit.MILLISECONDS)
                .filter({ s -> s.length() >= resources.getAutocompleteThreshold() })
                .observeOn(threads.main())
                .doOnNext({ s -> view.setProgressVisible(true) })
                .map({ s -> s.toString())}
                .switchMap({ text -> mAutocompleteService.query(text))}
                .subscribeOn(threads.io())
                .observeOn(threads.main())
                .retry(3)
                .doOnNext({ response ->
                    if (response.getStatus() !== 200)
                        throw RuntimeException("Server error " + response.getStatus())
                })
                .map({ response -> response.getData() })
                .subscribe({ items ->
                    view.setProgressVisible(false)
                    view.updateList(items)
                }, { error ->
                    view.setProgressVisible(false)
                    view.showMessage(resources.getListError())
                })
)