LetSwift RxSwift 시작하기

letswift(16)
RxSwift 시작하기
최완복

class ViewController: UIViewController {
@IBOutlet weak var textField: UITextField!
@IBOutlet weak var button: UIButton!
@IBOutlet weak var passwordField: UITextField!
@IBOutlet weak var signInButton: UIButton!
override func viewDidLoad() {
super.viewDidLoad()
self.textField.rac_textSignal().subscribeNext { (x) -> Void in
println(x)
}
let textSignal = self.textField.rac_textSignal().map { (x) -> AnyObject! in
NSNumber(bool: ((x as? NSString) ?? "").rangeOfString("@").location != NSNotFound)
} //NSNumber (boolean)
let colorSignal = textSignal.map { x in
((x as? NSNumber)?.boolValue ?? false) ? UIColor.greenColor() : UIColor.redColor()
} // UICOlor
//textSignal ~> RAC(button, "enabled")
colorSignal ~> RAC(textField, "textColor")
let passwordSignal = self.passwordField.rac_textSignal().map { x in
NSNumber(bool: (x as? NSString ?? "").length > 4)
} //NSNumber
let formValidSignal = RACSignal.combineLatest([textSignal, passwordSignal]).map {
let tuple = $0 as! RACTuple
let bools = tuple.allObjects() as! [Bool]
return NSNumber(bool: bools[0] == true && bools[1] == true)
}
formValidSignal ~> RAC(signInButton, "enabled")
button.rac_command = RACCommand(enabled: textSignal, signalBlock: { (x) -> RACSignal! in
println("pressed")
return RACSignal.empty()
})
}
}

In computing, reactive programming is a programming
paradigm oriented around data ﬂows and the propagation of
change.
Reactive Programming

Functional reactive programming (FRP) is a programming
paradigm for reactive programming (asynchronous dataﬂow
programming) using the building blocks of functional
programming (e.g. map, reduce, ﬁlter).
Functional Reactive Programming

Functional Reactive Programming
functional programming data ﬂows propagation of change

Functional Programming
1 부터 10까지 더하는 문제
var sum = 0
for i in 1...10 {
sum += 1
}
print(sum)
Procedural way
print((1...10).reduce(0) { $0 + $1 })
Functional way

Data Flow
(1...10)
.filter {
$0 % 2 == 0 // 2, 4, 6, 8, 10
}
.map {
$0 * 10 // 20, 40, 60, 80, 100
}
.reduce(0) {
$0 + $1 // 300
}

Propagation of Change
(1...5)
.filter {
$0 % 2 == 0 // 2, 4
}
.map {
$0 * 10 // 20, 40
}
.reduce(0) {
$0 + $1 // 60
}

Propagation of Change
(1...5)
.filter {
$0 % 2 == 0 // 2, 4
}
.map {
$0 * 100 // 200, 400
}
.reduce(0) {
$0 + $1 // 600
}

ReactiveX
http://reactivex.io/

An API for asynchronous programming
with observable streams

단일 다수
동기 Try<T> Iterable<T>
비동기 Future<T> Observable<T>

Iterable(pull) Observable(push)
데이터받기 T next() onNext (T)
에러 발견 throws Exception onError(Exception)
완료 !hasNext() onCompleted()

Observable.create<String> { observer in
observer.onNext("🐶")
observer.onNext("🐱")
observer.onNext("👽")
observer.onCompleted()
}
.subscribe {
print($0)
}
>> “🐶”..”🐱”.."👽" >>

import RxSwift
.subscribe { (event) in
print(event)
}
.distinctUntilChanged()
🐶 🐱 👽🐱
🐱🐶 🐶
🐶
👽

["🐶", "🐱", "🐱", "🐶", "👽"].toObservable()
import RxSwift
print(event)
}
🐶 🐱 👽🐱
🐱🐶 🐶
🐶
👽

["🐶", "🐱", "🐱", "🐶", "👽"].toObservable()
import RxSwift
print(event)
}
🐶 🐱 👽🐱
🐱🐶 🐶
🐶
👽🐱
Next(🐶)
Next(🐱)
Next(🐱)
Next(🐶)
Next(👽)
Completed

["🐶", "🐱", "🐱", "🐶", "👽"].toObservable()
import RxSwift
print(event)
}
🐶 🐱 👽🐱
🐱🐶 🐶
🐶
👽
Next(🐶)
Next(🐱)
Next(🐶)
Next(👽)
Completed

["🐶", "🐱", "🐱", "🐶", "👽"].toObservable()
import RxSwift
print(event)
}
.addDisposableTo(disposeBag)
Disposable

DisposableDisposableDisposableDisposableDisposableDisposableDisposable

["🐶", "🐱", "🐱", "🐶", "👽"].toObservable()
import RxSwift
print(event)
}
.dispose()

Creating Observables
asObservable, create, deferred, empty, error, toObservable (array), interval, never, just, of, range, repeatElement, timer
Transforming Observables
buffer, flatMap, flatMapFirst, flatMapLatest, map, scan, window
Filtering Observables
debounce / throttle, distinctUntilChanged, elementAt, filter, sample, skip, take, takeLast, single
Combining Observables
merge, startWith, switchLatest, combineLatest, zip
Error Handling Operators
catch, retry, retryWhen
Observable Utility Operators
delaySubscription, do / doOnNext, observeOn / observeSingleOn, subscribe, subscribeOn, timeout, using, debug
Conditional and Boolean Operators
amb, skipWhile, skipUntil, takeUntil, takeWhile
Mathematical and Aggregate Operators
concat, reduce / aggregate, toArray
Connectable Observable Operators
multicast, publish, refCount, replay, shareReplay

let sequenceThatErrors = Observable<String>.create { observer in
observer.onNext("🍎")
observer.onNext("🍐")
observer.onNext("🍊")
if isGoingWrong {
observer.onError(Error.Test)
print("Error encountered")
count += 1
}
observer.onNext("🐶")
observer.onNext("🐱")
observer.onNext("🐭")
observer.onCompleted()
return NopDisposable.instance
}
————result————
🍎
🍐
🍊
Error encountered
sequenceThatErrors
.subscribeNext { print($0) }
🍊🍐🍎

import UIKit
import RxSwift
import RxCocoa
class EmailLoginViewController: UIViewController {
let disposeBag = DisposeBag()
@IBOutlet weak var emailTextField: UITextField!
@IBOutlet weak var passwordTextField: UITextField!
@IBOutlet weak var loginButton: UIButton!
…
@IBAction func onLogin(sender: UIButton) {
guard let email = emailTextField?.text,
password = passwordTextField?.text
else {
return
}
Router.EmailLogin(["email": email, "password": password]).request
.responseJSON { [weak self] response in
let json = JSON(response.result.value!)
let user = User(json: json)
}
}
// MARK: UIViewController implements
super.viewDidLoad()
}
}
Login
Validator

import UIKit
import RxSwift
import RxCocoa
…
@IBAction func onLogin(sender: UIButton) {
guard let email = emailTextField?.text,
password = passwordTextField?.text
else {
return
}
Router.EmailLogin(["email": email, "password": password]).request
let json = JSON(response.result.value!)
let user = User(json: json)
self?.succeedToLogin(user)
}
}
super.viewDidLoad()
}
}

1. 이메일형식을 체크
2. 패스워드는 6자리 이상
3. 이메일/패스워드가 비어있을때, 입력을 요구한다.

emailTextField.rx_text.asObservable()
import RxSwift
import RxCocoa
a@b.c
.subscribeNext { print($0) }
a
a@
a@b
a@b.
a@b.c

import RxSwift
import RxCocoa
.subscribeNext {
let isValid = $0.isEmail || $0.isEmpty
}

import RxSwift
import RxCocoa
.map { $0.isEmail || $0.isEmpty }
.subscribeNext {
print($0)
}

import RxSwift
import RxCocoa
.subscribeNext {
self.emailTextField.backgroundColor =
$0 ? UIColor.whiteColor() : UIColor.alertColor
}

passwordTextField.rx_text.asObservable()
import RxSwift
import RxCocoa
.map { !(1..<6 ~= $0.characters.count) }
.subscribeNext {
self.passwordTextField.backgroundColor =
$0 ? UIColor.whiteColor() : UIColor.alertColor
}

import RxSwift
import RxCocoa
.subscribeNext {
let buttonTitle = $0 ? "이메일을 입력하세요" : "로그인 하기"
self.loginButton?.setTitle(buttonTitle, forState: .Normal)
}
.map { $0.isEmpty }

import RxSwift
import RxCocoa
.subscribeNext {
let buttonTitle = $0 ? "패스워드를 입력하세요" : "로그인 하기"
self.loginButton?.setTitle(buttonTitle, forState: .Normal)
}
.map { $0.isEmpty }

let emailEmptyObservable = emailTextField.rx_text.asObservable()
.map { $0.isEmpty }
let passwordEmptyObservable = passwordTextField.rx_text.asObservable()
.map { $0.isEmpty }
a a@ a@b a@b.ca@b.
.map { $0.isEmpty }
true false false false falsefalse
“”

Observable
.combineLatest(emailEmptyObservable, passwordEmptyObservable) {
return ($0, $1)
}
true false false
false falsetrue
(true, true) (false, true) (false, true)
false
.combineLatest(email, pass) { return ($0, $1) }
(false, false) (false, false)(false, false)

let emailEmptyObservable = emailTextField.rx_text.asObservable()
.map { $0.isEmpty }
let passwordEmptyObservable = passwordTextField.rx_text.asObservable()
.map { $0.isEmpty }
Observable
return ($0, $1)
}
.subscribeNext { tuple in
let buttonTitle: String = {
switch tuple {
case (true, true): return "이메일/패스워드를 입력하세요"
case (true, _): return "이메일을 입력하세요"
case (_, true): return "패스워드를 입력하세요"
default: return "로그인 하기"
}
}()
self.registerButton?.setTitle(buttonTitle, forState: .Normal)
self.registerButton?.backgroundColor =
tuple.0 || tuple.1 ? UIColor.gray4AColor : UIColor.tintColor
}

import UIKit
import RxSwift
import RxCocoa
…
super.viewDidLoad()
addValidations()
}
func addValidations() {
…
}
}

func addValidations() {
let emailEmptyObservable = emailTextField.rx_text.asObservable().map { $0.isEmpty }
let passwordEmptyObservable = passwordTextField.rx_text.asObservable().map { $0.isEmpty }
Observable
return ($0, $1)
}
.subscribeNext { tuple in
let buttonTitle: String = {
switch tuple {
case (true, true): return "이메일/패스워드를 입력하세요"
case (true, _): return "이메일을 입력하세요"
case (_, true): return "패스워드를 입력하세요"
default: return "로그인 하기"
}
}()
self.registerButton?.setTitle(buttonTitle, forState: .Normal)
self.registerButton?.backgroundColor = tuple.0 || tuple.1 ? UIColor.gray4AColor : UIColor.tintColor
}
.subscribeNext {
self.emailTextField.backgroundColor = $0 ? UIColor.whiteColor() : UIColor.alertColor
}
.map { !(1..<6 ~= $0.characters.count) }
.subscribeNext {
self.passwordTextField.backgroundColor = $0 ? UIColor.whiteColor() : UIColor.alertColor
}
}

enum Router: URLRequestConvertible {
case Collection(Int)
var request: Alamofire.Request {
return HTTPManager.sharedHTTPManager.request(self)
}
var method: Alamofire.Method {
return .GET
}
var path: String {
switch self {
case .Collection(let id): return “/Collections/(id)"
}
}
var parameters: Parameter {
switch self {
case .Collection: return ["filter": ["include": ["images"]]]
}
}
// MARK: URLRequestConvertible
var URLRequest: NSMutableURLRequest {
let URL = NSURL(string: Router.baseURLString)!
let mutableURLRequest = NSMutableURLRequest(URL: URL.URLByAppendingPathComponent(path))
mutableURLRequest.HTTPMethod = method.rawValue
return Alamofire.ParameterEncoding.URL.encode(mutableURLRequest, parameters: parameters).0
}
}
}

let collections = Variable([Collection]())
Router.Collections(["filter": filterParameter]).request
.validate()
if let value = response.result.value {
let newData = Collection.array(JSON(value))
self?.collections.value = newData
return
}
}

extension Alamofire.Request {
func rx_validateSuccessfulResponse() -> Request {
……
}
public func rx_result<T: ResponseSerializerType>(
queue queue: dispatch_queue_t? = nil,
responseSerializer: T)
-> Observable<T.SerializedObject>
{
return Observable.create { [weak self] observer in
self?
.rx_validateSuccessfulResponse()
.response(queue: queue, responseSerializer: responseSerializer) { _response in
switch _response.result {
case .Success(let result):
if let _ = _response.response {
observer.on(.Next(result))
} else {
observer.on(.Error(NSError(domain: "Frip", code: -1, userInfo: nil)))
}
observer.on(.Completed)
case .Failure(let error):
observer.on(.Error(error as ErrorType))
}
}
return NopDisposable.instance
}
}
public func rx_JSON(options options: NSJSONReadingOptions = .AllowFragments)
-> Observable<AnyObject>
{
return rx_result(responseSerializer: Request.JSONResponseSerializer(options: options))
}
}

.response(queue: queue, responseSerializer: responseSerializer) { _response in
switch _response.result {
case .Success(let result):
if let _ = _response.response {
observer.on(.Next(result))
} else {
observer.on(.Error(NSError(domain: "Frip", code: -1, userInfo: nil)))
}
observer.on(.Completed)
case .Failure(let error):
observer.on(.Error(error as ErrorType))
}
}

.rx_JSON()
.retry(1)
.startWith([])
.catchErrorJustReturn([])
.bindTo(collections)

.rx_JSON()
.retry(1)
.startWith([])
.retry(1)

.rx_JSON()
.retry(1)
.startWith([])
.startWith([])
[ ] [Collection, …, Collection]

.rx_JSON()
.retry(1)
.startWith([])
[ ]

.rx_JSON()
.retry(1)
.startWith([])
[ ] […] […] […]

https://github.com/RxSwiftCommunity/RxAlamoﬁre
RxAlamoﬁre

https://github.com/RxSwiftCommunity
RxSwift Community

https://justhackem.wordpress.com/2015/03/19/rmvvm-architecture/
Reactive MVVM(Model-View-ViewModel) 모바일 응용프로그램 아키텍쳐
https://github.com/devxoul/RxTodo
RxTodo

References
ReactiveX.io
https://github.com/ReactiveX/RxSwift
http://www.introtorx.com/
http://mobicon.tistory.com/467
http://www.slideshare.net/sunhyouplee/functional-reactive-
programming-with-rxswift-62123571
http://www.slideshare.net/deview/1b4-39616041
http://www.slideshare.net/gmind7/springcamp2015-rxjava
http://www.slideshare.net/jongwookkim/ndc14-rx-functional-reactive-
programminghttps://justhackem.wordpress.com/2015/03/19/rmvvm-
architecture/
https://github.com/devxoul/RxTodo

LetSwift RxSwift 시작하기

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