rx-java Getting started with rx-java Understanding Marble Diagrams
Example
An Observable can be thought of as just a stream of events. When you define an Observable, you have three listeners: onNext, onComplete and onError. onNext will be called every time the observable acquires a new value. onComplete will be called if the parent Observable notifies that it finished producing any more values. onError is called if an exception is thrown any time during the execution of the Observable chain. To show operators in Rx, the marble diagram is used to display what happens with a particular operation. Below is an example of a simple Observable operator "Just."
Marble diagrams have a horizontal block that represents the operation being performed, a vertical bar to represent the completed event, a X to represent an error, and any other shape represents a value. With that in mind, we can see that "Just" will just take our value and do an onNext and then finish with onComplete. There are a lot more operations then just "Just." You can see all the operations that are part of the ReactiveX project and there implementations in RxJava at the ReativeX site. There are also interactive marble diagrams via RxMarbles site.
