Strange Async Code - ReaxtiveX
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ReactiveX is a library that makes asynchronous programming easier using the Observer pattern. It allows data streams to be transformed and filtered in a declarative manner. ReactiveX implementations exist for many languages and make it simple to work with asynchronous data streams. Key benefits include avoiding nested callbacks and consistent concepts across languages. Observables produce data that Observers subscribe to receive. Operators allow transforming and filtering streams through methods like map, filter, and flatMap.
Strange Async Code - ReaxtiveX
- 1. Strange Async Code or: How I Learned to Stop Worrying and Love ReactiveX MATT WILL - @MATTWILL09 -HTTP://DPLBLOG.COM/MATT DON’T PANIC LABS SOFTWARE ENGINEER / CODE WRANGLER
- 3. What is ReactiveX The Observer pattern done right What is the observer pattern? https://en.wikipedia.org/wiki/Observer_pattern "A software design pattern in which an object, called the subject, maintains a list of its dependents, called observers, and notifies them automatically of any state changes" https://msdn.microsoft.com/en-us/library/ee817669.aspx I had never heard of this paper which was published around the time I started writing code professionally, but it essentially boils it down to the event and delegate model used in .Net This means that we have all been using an observer pattern for a long time, just that no one really called it that.
- 4. What makes ReactiveX so great? ReactiveX is a combination of the best ideas from the Observer pattern, the Iterator pattern, and functional programming It makes it very easy to set up new event sources. You can easily chain operations to transform and filter the result sets Tapping into an observable to listen for events is easy to do.
- 5. Sounds great, but can I use it? Java: RxJava JavaScript: RxJS C#: Rx.NET C#(Unity): UniRx Scala: RxScala Clojure: RxClojure C++: RxCpp Lua: RxLua Ruby: Rx.rb Python: RxPY Go: RxGo Groovy: RxGroovy JRuby: RxJRuby Kotlin: RxKotlin Swift: RxSwift PHP: RxPHP Elixir: reaxive Dart: RxDart
- 6. It makes life simpler It is simpler because the code consuming the observable doesn't care how the observable is implemented. The consumer only knows that it interacts with the observable in an async manner. We don't have to code a bunch of callback functions that get nested deeply within each other. Each language has it's own implementation of ReactiveX that conforms to the language but the concepts are the same across all languages.
- 7. Terminology Observable - a source for data that is subscribed to Observer - one who subscribes to be notified when changes occur on an observer Subscriber - A specialized type of observer that has an unsubscribe method so it can tell the observable it doesn't care about events any more Single - an observable that will only emit one item onNext - Method that the observable calls to notify an observer that the next item is available onCompleted - Method that the observable calls to indicate that there will be no more items available on the stream onError - Method that the observable calls to indicate that an error has occurred while processing the stream. Hot observable - an observable that is always producing a stream of items, even if no observers exist. Observers will connect mid- stream and get values from that point Cold observable - an observable that will not begin producing items on a stream until an observer connects.
- 11. Utilities SubscribeOn - tells the observable which scheduler it should run on ObserveOn - tells the observer which scheduler is should run on Timeout
- 14. Demos
- 15. What are some other ways people are using ReactiveX Making mobile apps more Pulling data from a live database (e.g. Firebase) and feeding that data to screens The Angular team is working on the ability to hook up ReativeX into the validation pipeline so you can do async validation
- 16. Resources Learn more: ◦ http://reactivex.io ◦ http://rxmarbles.com ◦ http://introtorx.com Code ◦ https://github.com/mattwill09/NebraskaCode17 Slides ◦ https://www.slideshare.net/MatthewWill5/strange-async-code-reaxtivex Or ◦ https://goo.gl/p03ak9