[RxJava&RxAndroid] #tags:Android

TipsRxJava.java

//Turning Any Callback Into An Rx-observable
/**
**So, let's say you're using a library that does something amazing. Trouble is that you didn't write it and the author hasn't RX'd it yet. The call you need to use is asynchronous and returns the result by virtue of a callback.  How can we make it into an Observable?  Here's a way.
**/

doAmazingThing(int param, CallBack cb);

public interface CallBack {
  onGotResult(String value);
}
//So we create a wrapper method thusly:
public Observable<String> doAmazingThingObservable(int param) {
  return Observable.create(new Observable.OnSubscribe<String>() {

    @Override
    public void call(Subscriber<? super String> subscriber) {
      doAmazingThing(param, new CallBack() {

        @Override
        public void onGotResult(String result) {
          if (result == null) {
            if (!subscriber.isUnsubscribed()) {
              subscriber.onError(new SomeException());
            }
          } else {
            if (!subscriber.isUnsubscribed()) {
              subscriber.onNext(result);
              subscriber.onCompleted();
            }
          }
        }
      });
    }
  });
}