Transformation using RxJava tutorial for beginners
Checkout the previous post here
Suppose I want to append my signature to the “Hello, world!” output. One possibility would be to change the
Observable.just("Hello, world! -Dan") .subscribe(s -> System.out.println(s));
This works if you have control over your
Observable, but there’s no guarantee that will be the case – what if you’re using someone else’s library? Another potential problem: what if I use my
Observable in multiple places but only sometimes want to add the signature?
How about we try modifying our
Observable.just("Hello, world!") .subscribe(s -> System.out.println(s + " -Dan"));
This answer is also unsatisfactory, but for different reasons: I want my
Subscribers to be as lightweight as possible because I might be running them on the main thread. On a more conceptual level,
Subscribers are supposed to be the thing that reacts, not the thing that mutates.
Wouldn’t it be cool if I could transform “Hello, world!” with some intermediary step?