RxJS Introduction

Transcript

1. RxJS introduction
2. Current state of UIs • Extremely complex • Full of async events, client/server communication • UIs are always composed based on a state • State is hard to reason about
3. Imperative programming
5. User action UI Responds User action ….. Uses imperative programming Uses imperative programming UI Responds time (s)
6. Caveats of IP • Isolates state from time • You don’t see the bigger picture • Mutable values
7. Is there a way … ?
8. Reactive programming
9. – Andre Staltz “Reactive programming is programming with asynchronous data streams.”
10. Streams • Sequence of ongoing events ordered in time • Cheap, ubiquitous • Allow you to react to new data • Think event busses, typical click events, etc.
11. But in RP …
13. Observable/Observer • Observables are push-based, observable sequences that can send data to anyone who is interested • Observers are entities who register an interest through a subscription to an Observable
14. Observers • Register via subscribe method • You get back a Disposable object (a handler for the subscription) • onNext, onError, onCompleted
15. Demo time with RxJS
16. When to use RxJS • Orchestrate event-based computations • Deal with async data • Complex UIs with lots of user interaction
17. Thank you! @r31gN_ https://github.com/r31gN/rxjs-demo-workshop