【RxSwift】オペレーター

はじめに

オペレータの使い方まとめ。備忘録。

ToArray

let disposeBag = DisposeBag()
Observable.of(1,2,3,4).toArray().subscribe {
    print($0)
}.disposed(by: disposeBag)

// 出力
success([1, 2, 3, 4])

Map

let disposeBag = DisposeBag()
Observable.of(1,2,3,4).map({$0 * 2}).subscribe {
    print($0)
}.disposed(by: disposeBag)

// 出力
next(2)
next(4)
next(6)
next(8)
completed

FlatMap

let disposeBag = DisposeBag()

struct Subject {
    let like: BehaviorRelay<Bool>
}

let english = Subject(like: BehaviorRelay(value: true))
let math = Subject(like: BehaviorRelay(value: false))

let subject = PublishSubject<Subject>()

subject.asObservable()
    .flatMap { 
        $0.like.asObservable()
    }
    .subscribe {
        print($0)
    }
    .disposed(by: disposeBag)

subject.onNext(english)
english.like.accept(false)

subject.onNext(math)
english.like.accept(false)

// 出力
next(true)
next(false)
next(false)
next(false)

FlatMapLatest

let disposeBag = DisposeBag()

// 構造体
struct Subject {
    let like: BehaviorRelay<Bool>
}

let english = Subject(like: BehaviorRelay(value: true))
let math = Subject(like: BehaviorRelay(value: false))

let subject = PublishSubject<Subject>()

subject.asObservable()
    .flatMapLatest {
        $0.like.asObservable()
    }
    .subscribe {
        print($0)
    }
    .disposed(by: disposeBag)

subject.onNext(english)
english.like.accept(false)

subject.onNext(math)
english.like.accept(false)

// 出力
next(true)
next(false)
next(false)

終わりに

随時更新