Book Image

Learning RxJava

By : Thomas Nield
Book Image

Learning RxJava

By: Thomas Nield

Overview of this book

RxJava is a library for composing asynchronous and event-based programs using Observable sequences for the JVM, allowing developers to build robust applications in less time. Learning RxJava addresses all the fundamentals of reactive programming to help readers write reactive code, as well as teach them an effective approach to designing and implementing reactive libraries and applications. Starting with a brief introduction to reactive programming concepts, there is an overview of Observables and Observers, the core components of RxJava, and how to combine different streams of data and events together. You will also learn simpler ways to achieve concurrency and remain highly performant, with no need for synchronization. Later on, we will leverage backpressure and other strategies to cope with rapidly-producing sources to prevent bottlenecks in your application. After covering custom operators, testing, and debugging, the book dives into hands-on examples using RxJava on Android as well as Kotlin.
Table of Contents (21 chapters)
Title Page
Credits
About the Author
Acknowledgements
About the Reviewers
www.PacktPub.com
Customer Feedback
Preface

Throttling


The buffer() and window() operators batch up emissions into collections or Observables based on a defined scope, which regularly consolidates rather than omits emissions.The throttle() operator, however, omits emissions when they occur rapidly. This is helpful when rapid emissions are assumed to be redundant or unwanted, such as a user clicking on a button repeatedly. For these situations, you can use the throttleLast(), throttleFirst(), and throttleWithTimeout() operators to only let the first or last element in a rapid sequence of emissions through. How you choose one of the many rapid emissions is determined by your choice of operator, parameters, and arguments.

For the examples in this section, we are going to work with this case: we have three Observable.interval() sources, the first emitting every 100 milliseconds, the second every 300 milliseconds, and the third every 2000 milliseconds. We only take 10 emissions from the first source, three from the second, and two from...