RXSWIFT REACTIVE PROGRAMMING WITH + =

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ABOUT YOU ▸Swift ▸Reactive programming

TRADITIONAL VS. REACTIVE A SIMPLE EXAMPLE IN IOS

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Reactive Programming is essentially about modeling asynchronous sequences What is Reactive Programming?

Reactive Programming is essentially about modeling asynchronous sequences

What is Reactive Programming? Reactive Programming is essentially about modeling asynchronous sequences So what is RxSwift? RxSwift implements patterns, types, and operators to create and work with Observable sequences

REACTIVE EXTENSIONS N ov. ‘09 Rx.N ET RxJS M ar. ‘10 RxJava M ar. ‘12 RxC pp N ov. ‘12 RxRuby D ec. ‘12 RxScala, RxC lojure, RxG roovy, RxJRuby Jan. ‘13 RxPY, RxPH P M ar. ‘13 RxKotlin O ct. ‘13 RxSw ift Feb. ‘15

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ABOUT RX ▸ Event-driven ▸ Asynchronous ▸ Functional ▸ Common patterns ▸ Observer ▸ Iterator ▸ Cross-platform

LIFECYCLE OF AN OBSERVABLE SEQUENCE ▸ Next 1 2 3

LIFECYCLE OF AN OBSERVABLE SEQUENCE ▸ Next tap tap tap

LIFECYCLE OF AN OBSERVABLE SEQUENCE ▸ Next ▸ Error 1 2 3

LIFECYCLE OF AN OBSERVABLE SEQUENCE ▸ Next ▸ Error ▸ Completed 1 2 3

LIFECYCLE OF AN OBSERVABLE SEQUENCE ▸ Next ▸ Error ▸ Completed ▸ dispose() / DisposeBag 1 2 3

RXSWIFT ▸RxSwift ▸RxCocoa ▸RxSwiftCommunity ▸ RxDataSources

SETUP ▸ Install ThisCouldBeUsButYouPlaying ▸ bit.ly/podsPlaygrounds ▸ gem install cocoapods-playgrounds ▸ Create RxSwiftPlayground ▸ pod playgrounds RxSwift

SETUP //: Please build the scheme 'RxSwiftPlayground' first import XCPlayground XCPlaygroundPage.currentPage.needsIndefiniteExecution = true import RxSwift func exampleOf(description: String, action: Void -> Void) { print("\n--- Example of:", description, "---") action() }

--- Example of: just --- Next(32) Completed CREATING & SUBSCRIBING exampleOf("just") { Observable.just(32) } .subscribe { } print($0)

--- Example of: just --- Next(32) Completed exampleOf("just") { Observable.just(32) .subscribe { element in print(element) } } CREATING & SUBSCRIBING

--- Example of: just --- 32 exampleOf("just") { _ = Observable.just(32) .subscribeNext { print($0) } } CREATING & SUBSCRIBING

--- Example of: of --- 1 2 3 4 5 CREATING & SUBSCRIBING exampleOf("of") { Observable.of(1, 2, 3, 4, 5) } .subscribeNext { print($0) } .dispose()

exampleOf("toObservable") { } --- Example of: toObservable --- 1 2 3 CREATING & SUBSCRIBING let disposeBag = DisposeBag() [1, 2, 3].toObservable() .subscribeNext { print($0) } .addDisposableTo(disposeBag)

CREATING & SUBSCRIBING let string = BehaviorSubject(value: "Hello") string.subscribe { print($0) } .addDisposableTo(disposeBag) exampleOf("BehaviorSubject") { let disposeBag = DisposeBag() } string.on(.Next("World!"))

CREATING & SUBSCRIBING let string = BehaviorSubject(value: "Hello") string.subscribe { print($0) } .addDisposableTo(disposeBag) string.onNext("World!") exampleOf("BehaviorSubject") { let disposeBag = DisposeBag() }

--- Example of: BehaviorSubject --- Next(Hello) Next(World!) CREATING & SUBSCRIBING let string = BehaviorSubject(value: "Hello") string.subscribe { print($0) } .addDisposableTo(disposeBag) string.onNext("World!") exampleOf("BehaviorSubject") { let disposeBag = DisposeBag() }

CREATING & SUBSCRIBING --- Example of: Variable --- Next(1) Next(12) Next(1234567) Completed number.value = 12 number.value = 1_234_567 exampleOf("Variable") { let disposeBag = DisposeBag() let number = Variable(1) number.asObservable() .subscribe { print($0) } .addDisposableTo(disposeBag) }

TRANSFORMING --- Example of: map --- 1 4 9 Observable.of(1, 2, 3) example("map") { let disposeBag = DisposeBag() } .map { $0 * $0 } .subscribeNext { print($0) } .addDisposableTo(disposeBag)

TRANSFORMING 1 1 2 4 3 9 map { $0 * $0 }

TRANSFORMING --- Example of: flatMap --- Scott Lori Eric exampleOf("flatMap") { let disposeBag = DisposeBag() } struct Person { var name: Variable } let scott = Person(name: Variable("Scott")) let lori = Person(name: Variable("Lori")) let person = Variable(scott) person.asObservable() .flatMap { $0.name.asObservable() } .subscribeNext { print($0) } .addDisposableTo(disposeBag) person.value = lori scott.name.value = "Eric"

TRANSFORMING --- Example of: flatMapLatest --- Scott Lori exampleOf("flatMapLatest") { let disposeBag = DisposeBag() struct Person { var name: Variable } let scott = Person(name: Variable("Scott")) let lori = Person(name: Variable("Lori")) let person = Variable(scott) person.asObservable() .flatMapLatest { $0.name.asObservable() } .subscribeNext { print($0) } .addDisposableTo(disposeBag) person.value = lori scott.name.value = "Eric" }

TRANSFORMING exampleOf("flatMapLatest") { let disposeBag = DisposeBag() struct Person { var name: Variable } let scott = Person(name: Variable("Scott")) let lori = Person(name: Variable("Lori")) let person = Variable(scott) person.asObservable() .debug("person") .flatMapLatest { $0.name.asObservable() } .subscribeNext { print($0) } .addDisposableTo(disposeBag) person.value = lori scott.name.value = "Eric" } --- Example of: flatMapLatest --- 2016-05-28 07:31:22.555: person -> subscribed 2016-05-28 07:31:22.556: person -> Event Next((Person #1)(nam...able)) Scott 2016-05-28 07:31:22.557: person -> Event Next((Person #1)(nam...able)) Lori 2016-05-28 07:31:22.560: person -> Event Completed 2016-05-28 07:31:22.560: person -> disposed

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

exampleOf("distinctUntilChanged") { let disposeBag = DisposeBag() let searchString = Variable("iOS") searchString.asObservable() .map { $0.lowercaseString } .distinctUntilChanged() .subscribeNext { print($0) } .addDisposableTo(disposeBag) searchString.value = "IOS" searchString.value = "Rx" searchString.value = "ios" } FILTERING --- Example of: distinctUntilChanged --- ios rx ios

exampleOf("combineLatest") { let disposeBag = DisposeBag() let number = PublishSubject() let string = PublishSubject() Observable.combineLatest(number, string) { "\($0) \($1)" } .subscribeNext { print($0) } .addDisposableTo(disposeBag) number.onNext(1) print("Nothing yet") string.onNext("A") number.onNext(2) string.onNext("B") string.onNext("C") } COMBINING --- Example of: combineLatest --- Nothing yet 1 A 2 A 2 B 2 C

exampleOf("takeWhile") { [1, 2, 3, 4, 5, 6, 5, 4, 3, 2, 1].toObservable() .takeWhile { $0 < 5 } .subscribeNext { print($0) } .dispose() } CONDITIONAL --- Example of: takeWhile --- 1 2 3 4

MATHEMATICAL --- Example of: _scan --- 11 13 16 20 25 exampleOf("scan") { Observable.of(1, 2, 3, 4, 5) .subscribeNext { print($0) } .dispose() } .scan(10, accumulator: +)

MATHEMATICAL --- Example of: _scan --- 11 13 16 20 25 exampleOf("scan") { Observable.of(1, 2, 3, 4, 5) .subscribeNext { print($0) } .dispose() } .scan(10) { $0 + $1 }

ERROR HANDLING --- Example of: error --- A exampleOf("error") { enum Error: ErrorType { case A } Observable.error(Error.A) .subscribeError { // Handle error print($0) } .dispose() }

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RXCOREDATA

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How do I get started with RxSwift? I’m glad you asked! !

LEARN RXSWIFT ▸This talk ▸RxSwift operators

RXSWIFT OPERATORS

LEARN RXSWIFT ▸This talk ▸RxSwift operators ▸RxCocoa ▸RxExample

RXSWIFT OPERATORS

RXSWIFT OPERATORS

LEARN RXSWIFT ▸This talk ▸RxSwift operators ▸RxCocoa ▸RxExample ▸RxCommunity

▸ github.com/ReactiveX/RxSwift ▸ reactivex.io ▸ rxmarbles.com ▸ slack.rxswift.org ▸ rx-marin.com ▸ as.ync.io ▸ github.com/scotteg/RxSwiftPlayer ▸ github.com/Artsy/eidolon ▸ lynda.com/Scott-Gardner/281956-1.html WANT MORE RXSWIFT?

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THANK YOU! Scott Gardner @scotteg scotteg.com as.ync.io bit.ly/scottOnLyndaDotCom