ReSwift / Unidirectional State Flow - Programming Without Paradox

Transcript

1. Unidirectional State Flow in Swift programming without paradox ! @KarlBowden " @MezzanineAU # karlbowden.com/reswift-prezzo @karlbowden
2. WHAT? @karlbowden
3. What is Unidirectional State Flow Principles of state flow: • State only travels in one direction • State is immutable • State is modified by pure functions Source: redux.js.org/docs/introduction/ThreePrinciples.html @karlbowden
4. What is State state, noun • the particular condition that someone or something is in at a specific time. • at a specific time @karlbowden
5. What is an Application? Application: A set of instructions for interacting with a stream of states through time @karlbowden
6. What is the problem? Maintainability • State (sources) in your View • State (streams) in your View Controller • STATE IN ALL THE THINGS @karlbowden
7. It's already been solved • MVVM FTW • MVVM != State over Time @karlbowden
8. FRP FTW RxSwift, ReactiveCocoa, ReactiveKit, PromiseKit, [Name] {Kit,Swift}... @karlbowden
9. Why ReSwift? @karlbowden
10. Not just never gets. Never have, never hasn't, Never have had hasn't. @karlbowden
11. @karlbowden
12. DON'T CROSS THE STREAMS @karlbowden
13. Manages State Through Time FRP + Unidirectional State Flow + Swift = ReSwift • Store • State • Actions • Dispatch • Subscription • Reducers @karlbowden
14. DIAGRAMS! @karlbowden
15. @karlbowden
16. How does this fit into an application? Each application component is divided into: • Input and Output ~ State and Actions • Side effects ~ pushed to the edges • into Action Creators, Middleware and Services • State mutation: performed by Reducers @karlbowden
17. Input & Output / ViewModel Components @karlbowden
18. Composable @karlbowden
19. This sounds messy ! and over complicated Karl! Why are you even still talking? ! My application handles state just fine because I'm a ! @karlbowden
20. HERE BE DRAGONS ! Not applicable to every application First, try building your application without ReSwift Will a simple DIY store implementation suffice? @karlbowden
21. Protocol overview @karlbowden
22. @karlbowden
23. When is ReSwift a good fit? • Applications where portions of state are used or changed in multiple components. • Ie, Battleships. One set of rules. Multiple different views of the same state. Multiple inputs. • Side effect handling • Dealing with one or more API's • External sources of actions • Push API's & WebSockets @karlbowden
24. NOPES? • Simple applications that can already be reasoned about and tested • Large state. Ie, don't store images in the state tree, just use references • High performance gesture interactions • Don't create unthrottled actions for every touch event @karlbowden
25. Common pitfalls • Reducers need to be fast • Avoid sorting arrays • Reducer should not cause side effects • I've got 99 problems, but globals ain't one of them • Globals / Singletons / Shared Instances still cause Coupling • Use coordinator + presenters @karlbowden
26. HERE BE DRAGONS ⚔ OF AWESOME! • Routing • ReSwift-Router • Featherweight Router • Devtools / time travel • ReSwift-Recorder • Code injection • Injection4Xcode • KZPlayground @karlbowden
27. Charter by Matthew Palmer Swift mailing list client for iOS Available in the App Store Open source by default, h/t Artsy github.com/matthewpalmer/Charter @karlbowden
28. ϝαμϢϷϫίϤϷ RIDE By Fablic, Inc "Bike Flea Market App - RIDE" @karlbowden
29. Be excellent to each other ReduxKit + Swift-Flow => ReSwift @karlbowden
30. YOU CAN HALP! Join the discussion. Quick wins: Documentation. Know Japanese? Other implementations: Delta by Jake Craige at thoughtbot SwiftFlux by Kenichi Yonekawa @karlbowden
31. Resources: github.com/ReSwift/ReSwift ReSwift documentation Benjamin Encz: Unidirectional Data Flow in Swift / Realm presentation Redux Dan Abramov: Getting Started with Redux on Egghead Special Thank You to: Aleksander Rendtslev - @ARendtslev Benjamin Encz - @benjaminencz @karlbowden
32. Alternative titles Big in Japan Make state great again Hot State Time Machine Big Trouble in Little Gallifrey ALL YOUR STATE ARE BELONG TO US @karlbowden