This document provides an overview of RxSwift, including its supported programming languages, what it is, common misconceptions about it, how it handles asynchronous code, updating UI with Observables, operators like map and filter, traits like Single and Completable, testing, pros and cons of using it for development and business, and references for further information.

1. RxSwift

2. Languages
● 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

3. What is RxSwift
- Multi-platform API called Rx
- Asynchronous programming
- Event sequences
- Composable operators
- Сombination of the best ideas from the Observer
pattern, the Iterator pattern, and functional
programming

4. Misconceptions
- You must be a functional programming wizard
- It’s all or nothing
- It’s too slow for mobile development

5. Asynchronous code
show / hide
user input
select element
synchronization
network data
portrait / landscape
update storage
tap

6. Complexity of async code
- States, shared states
- Side effects
- Combining, transforming, filtering async operations

7. Asynchronous code
Controller
NotificationCenter
Other Controller
closure
DataSource
Delegate
GCD
switch queues

8. Observable
true false
Observable<Bool>
true false true
0 1 2 3 0
Observable<Int>

9. Lifecycle of observable
true false true false true
0 1 2 3

10. Observable
0 1 2 3 0
Observable<Int>

11. Observable
0 1 2 3 0
Observable<Int>
Observable<Int> Observer 2
Observer 3
Observer 1
0, 1, 2, 3, 0
0, 1, 2, 3, 0
0, 1, 2, 3, 0

12. Operators
Observable<GMSVisibleRegion>
debounce(0.3)
Output: value0, value1, value2
filter { $0.isValid }
Output: value2
map { $0.toAPIStringBbox }
Output: value2
flatMap { mapMarkersInBbox($0) }
Output: bbox
Output: [MapMarker]
Subscriber

13. Updating UI
C Cr
Observable<String>
Cry CrysCrys

14. Updating UI
C Cr
Observable<String>
Cry CrysCrys
testLabel.text = string

15. Updating UI
C Cr
Observable<String>
Cry CrysCrys
testLabel.text = string
string.bindTo(testLabel)

16. Updating UI
[Item]
Observable<[Item]>
Crys
dataSourceVar = items
tableView.reloadData()
items.bindTo(tableView)
JSON [Item]

17. Filtering

18. Combining

19. Transforming

20. RxSwift vs RxCocoa
RxSwift
map, debounce,
filter, etc.
RxPython
RxCocoa
bindTo, Driver,
UISearchBar.rx,
UISwitch.rx
UIKit / Cocoa
specific APIs
RxScala RxKotlin
Rx API

21. Demo!

22. Traits
RxSwift
- Single
- Completable
- Maybe
RxCocoa
- Driver
- ControlProperty / ControlEvent

23. Traits
Single
- Emits exactly one element, or an error
- Doesn't share side effects

24. Traits
Completable
- Emits zero elements
- Emit a completion event or an error
- Doesn't share side effects

25. Traits
Maybe
- Emits either a completed event, a single element or
an error
- Doesn't share side effects

26. RxCocoa specific Traits
Driver
- Can't error out
- Observe occurs on main scheduler
- Shares side effects
(shareReplayLatestWhileConnected)

27. RxCocoa specific Traits
ControlProperty / ControlEvent
- it never fails
- shareReplay(1) behavior
- complete sequence on control being deallocated
- it never errors out
- it delivers events on MainScheduler.instance

28. Tests

29. Tests

30. Pros. Development
- Asynchrony is simplified with Declarative Code

31. Pros. Development
- Asynchrony is simplified with Declarative Code
- Cleaner Code & Architectures

32. Pros. Development
- Asynchrony is simplified with Declarative Code
- Cleaner Code & Architectures
- Code testability (using MVVM)

33. Pros. Development
- Asynchrony is simplified with Declarative Code
- Cleaner Code & Architectures
- Code testability (using MVVM)
- Built-in solutions & Composable components

34. Pros. Development
- Asynchrony is simplified with Declarative Code
- Cleaner Code & Architectures
- Code testability (using MVVM)
- Built-in solutions & Composable components
- Time-tested multiplatform technology

35. Cons. Development
- Efforts to learn a framework

36. Cons. Development
- Efforts to learn a framework
- Possible leg-shots

37. Cons. Development
- Efforts to learn a framework
- Possible leg-shots
- XCode still fucks you up

38. Pros. Business
- Less bugs and risks – less time to deliver

39. Pros. Business
- Less bugs and risks – less time to deliver
- Easier to create a great UX

40. Pros. Business
- Less bugs and risks – less time to deliver
- Easier to create a great UX
- Multiplatform

41. Cons. Business
- Expenses of team training
- Harder to find a developer

42. References
- https://github.com/ReactiveX/RxSwift
- http://rxmarbles.com/
- RxMarbles iOS App
- http://community.rxswift.org/
- RxSwift operators mindmap

43. RxDataSource