こんにちは。きんくまです。
RxSwiftを勉強中です。それで、いろいろと調べていたのですが、イマイチ全体像が見えてこない!
でこれは何なのか?と考えたら、一番の基本となるものが何なのかわからないことに気がつきました。
そんなとき、公式のリポジトリにあるPlaygroundを写経してみたところ、ベースとなるものがわかった気がしました。
で、もう少しいろいろと調べないといけないのですが、毎回「これって何するやつ?」というのを調べるのが面倒くさいです。
なので、このページにPlaygroundに乗っていたやつを1ページに全て書いてしまい、Cmd + f で検索できたら出力がすぐに確認できて便利だなーと思った、メモ記事になります。
コードは基本的にPlaygroundのままなのですが、公式のやつは絵文字ばっかりつかってて、見づらいので普通のアルファベットとかに直しています。
バージョン
1 2 | pod 'RxSwift', '~> 4.4.0' pod 'RxCocoa', '~> 4.4.0' |
Creating and Subscribing to Observables
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 192 193 194 195 196 197 198 199 200 201 202 203 204 205 206 207 208 209 210 211 212 213 214 215 216 217 218 219 220 221 222 223 224 225 226 227 228 229 230 231 232 233 234 235 236 237 238 239 240 241 242 243 244 245 246 247 248 249 250 251 252 253 254 255 256 257 258 259 260 261 262 263 264 265 266 267 268 269 270 271 | //以下のimportはこのクラスだけ載せていますが、以降は省略します import UIKit import RxSwift import RxCocoa class Playground_SubscribingToObservables { var disposeBag = DisposeBag() public init (){ } func neverSample(){ print( "never start === " ) let neverSequence = Observable< String >.never() neverSequence.subscribe { _ in print( "never" ) }.disposed(by: disposeBag) /* 何もイベントを発行しない */ } func emptySample(){ print( "empty start === " ) Observable< Int >.empty() .subscribe{ event in print( "event \(event)" ) }.disposed(by: disposeBag) /* completedだけemit empty start === event completed */ } func just(){ print( "just start ===" ) Observable< String >.just( "Hello world" ) .subscribe{ event in print( "subsc --" ) print( "event \(event.event)" ) print( "elem \(String(describing: event.element))" ) }.disposed(by: disposeBag) /* 1個のelementからObservableを作成 just start === subsc -- event next(Hello world) elem Optional("Hello world") subsc -- event completed elem nil */ } func ofSample(){ print( "of start ===" ) Observable< String >.of( "a" , "b" , "c" ) .subscribe(onNext:{ event in print( "onNext: \(event)" ) }, onCompleted: { print( "onCompleted" ) }).disposed(by: disposeBag) /* 引数のelementsからObservableを作成 of start === onNext: a onNext: b onNext: c onCompleted */ } func fromSample(){ print( "from start ===" ) Observable< String >.from([ "a" , "b" , "c" ]) .subscribe(onNext: { event in print( "on next: \(event)" ) }).disposed(by: disposeBag) /* 配列からObservableを作成 from start === on next: a on next: b on next: c */ } func createSample(){ print( "create start ===" ) let myjust = { (elem: String ) -> Observable< String > in return Observable.create { observer in observer.onNext(elem) observer.onCompleted() return Disposables.create() } } myjust( "hello world" ).subscribe { print($ 0 ) } .disposed(by: disposeBag) /* 独自のObservableを作成 create start === next(hello world) completed */ } func range(){ print( "start range ===" ) //2から4まで3つnextする Observable.range(start: 2 , count: 3 ) .subscribe{ print($ 0 )} .disposed(by: disposeBag) /* startからcount分のelementをemit start range === next(2) next(3) next(4) completed */ } func repeatElement(){ print( "start repeat elem ===" ) //5回 k が next Observable.repeatElement( "k" ) .take( 5 ) .subscribe { print($ 0 ) } .disposed(by: disposeBag ) /* 引数回elementをemit start repeat elem === next(k) next(k) next(k) next(k) next(k) completed */ } func generate(){ print( "generate start ===" ) Observable.generate( initialState: 5 , condition: { $ 0 < 15 }, iterate: { $ 0 + 3 } ).subscribe { print($ 0 ) } .disposed(by: disposeBag) /* 複雑な条件のObservableを生成 generate start === next(5) next(8) next(11) next(14) completed */ } func deferredSample(){ print( "deferred start ===" ) var count = 1 let mySeqence = Observable< String >.deferred { print( "Creating \(count)" ) count += 1 return Observable.create { observer in print( "Emitting..." ) observer.onNext( "foo" ) observer.onNext( "bar" ) observer.onNext( "baz" ) return Disposables.create() } } mySeqence .subscribe(onNext: { print($ 0 ) } ) .disposed(by: disposeBag) mySeqence .subscribe(onNext: { print($ 0 ) } ) .disposed(by: disposeBag) /* subscribeされるまで次のObservableを作らない。 subscribeされたら次のやつを作る deferred start === Creating 1 Emitting... foo bar baz Creating 2 Emitting... foo bar baz */ } func errorSample(){ print( "error ===" ) let info:[ String :Any] = [ "error_message" : "dayo" ] //Observable<String> の <String> を書かないとエラー Observable< String >.error(NSError(domain: "myerror domain" , code: 150 , userInfo:info)) .subscribe(onError:{ (error) in let error2 = error as NSError print(error2) }).disposed(by: disposeBag) /* itemはemitしなけれど、すぐにerrorを発行 error === Error Domain=myerror domain Code=150 "(null)" UserInfo={error_message=dayo} */ } func doOnSample(){ print( "do on ===" ) Observable< String >.from([ "dog" , "cat" , "baz" ]) . do (onNext: { print( "doOnNext:" , $ 0 ) }, onCompleted: { print( "doOnCompleted" ) }) .subscribe(onNext: { print($ 0 ) }) .disposed(by: disposeBag) /* emitするたびに、実行 do on === doOnNext: dog dog doOnNext: cat cat doOnNext: baz baz doOnCompleted */ } } |
Working with Subjects
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 | class Playground_subjects { public init (){} let disposeBag = DisposeBag() func publishSubject(){ print( "PublishSubject ===" ) let subject = PublishSubject< String >() subject .subscribe(onNext: { print( "id1 -> " , "onNext:" , $ 0 )}) .disposed(by: disposeBag) subject.onNext( "foo" ) subject.onNext( "bar" ) subject .subscribe(onNext: { print( "id2 -> " , "onNext:" , $ 0 ) }) .disposed(by: disposeBag) subject.onNext( "foo2" ) subject.onNext( "bar2" ) /* subscribeしたときは何もeventを出さない 次のnextから受け取る PublishSubject === id1 -> onNext: foo id1 -> onNext: bar id1 -> onNext: foo2 id2 -> onNext: foo2 id1 -> onNext: bar2 id2 -> onNext: bar2 */ } func replaySubject() { print( "ReplaySubject ===" ) let subject = ReplaySubject< String >.create(bufferSize: 1 ) subject .subscribe(onNext: { print( "id1 -> " , "onNext:" , $ 0 )}) .disposed(by: disposeBag) subject.onNext( "foo" ) subject.onNext( "bar" ) subject .subscribe(onNext: { print( "id2 -> " , "onNext:" , $ 0 ) }) .disposed(by: disposeBag) subject.onNext( "foo2" ) subject.onNext( "bar2" ) /* 初期化時のbufferSizeだけ subscribe したときに event が出る ReplaySubject === id1 -> onNext: foo id1 -> onNext: bar id2 -> onNext: bar id1 -> onNext: foo2 id2 -> onNext: foo2 id1 -> onNext: bar2 id2 -> onNext: bar2 */ } func behaviorSubject(){ print( "BehaviorSubject === " ) let subject = BehaviorSubject(value: "behavior initial value!!" ) subject .subscribe(onNext: { print( "id1 -> " , "onNext:" , $ 0 )}) .disposed(by: disposeBag) subject.onNext( "foo" ) subject.onNext( "bar" ) subject .subscribe(onNext: { print( "id2 -> " , "onNext:" , $ 0 ) }) .disposed(by: disposeBag) subject.onNext( "foo2" ) subject.onNext( "bar2" ) subject .subscribe(onNext: { print( "id3 -> " , "onNext:" , $ 0 )}) .disposed(by: disposeBag) subject.onNext( "foo3" ) subject.onNext( "bar3" ) /* subscribeした時点で最新のeventを受け取る BehaviorSubject === id1 -> onNext: behavior initial value!! id1 -> onNext: foo id1 -> onNext: bar id2 -> onNext: bar id1 -> onNext: foo2 id2 -> onNext: foo2 id1 -> onNext: bar2 id2 -> onNext: bar2 id3 -> onNext: bar2 id1 -> onNext: foo3 id2 -> onNext: foo3 id3 -> onNext: foo3 id1 -> onNext: bar3 id2 -> onNext: bar3 id3 -> onNext: bar3 */ } } |
Combining Operators
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 | class Playground_Operators { let disposeBag = DisposeBag() func startWith() { print( "start with === " ) Observable.of( "foo" , "bar" , "baz" ) .startWith( "1" ) .startWith( "2" ) .startWith( "3" , "3-2" , "3-3" ) .subscribe(onNext: { print($ 0 ) }) .disposed(by: disposeBag) /* startWithのものの方が先にnextされる。 startWithは最初に書いたものの方が最後に出力される start with === 3 3-2 3-3 2 1 foo bar baz */ } func merge(){ print( "start merge ===" ) let subject1 = PublishSubject< String >() let subject2 = PublishSubject< String >() Observable.of(subject1, subject2) .merge() .subscribe(onNext: { print( "merged next:" , $ 0 )}) .disposed(by: disposeBag) // subject1.subscribe(onNext: { print("subject1 next:", $0)}) // .disposed(by: disposeBag) // // subject2.subscribe(onNext: { print("subject2 next:", $0)}) // .disposed(by: disposeBag) subject1.onNext( "foo" ) subject1.onNext( "bar" ) subject2.onNext( "foo2" ) subject2.onNext( "bar2" ) subject1.onNext( "foo3" ) subject2.onNext( "bar3" ) /* mergeされたものが1つのタイムラインにのっかって出てくる start merge === merged next: foo merged next: bar merged next: foo2 merged next: bar2 merged next: foo3 merged next: bar3 */ } func combineLatest(){ print( "combine latest === " ) let strSubject = PublishSubject< String >() let intSubject = PublishSubject< Int >() Observable.combineLatest(strSubject, intSubject){ strElem, intElem in "combine: \(strElem), \(intElem)" } .subscribe(onNext: { print($ 0 ) }) .disposed(by: disposeBag) strSubject.onNext( "foo" ) strSubject.onNext( "bar" ) intSubject.onNext( 1 ) intSubject.onNext( 2 ) strSubject.onNext( "baz" ) /* 個別にeventが出るのではなくて、同時に合わさったeventを発行する 各Observableが少なくとも1回はEventを発行しないと開始しない. 開始するときは、最新のものが使われる combine latest === combine: bar, 1 combine: bar, 2 combine: baz, 2 */ } func combineLatest2() { print( "combineLatest2 === " ) let ken = Observable.just( "Ken" ) let arr = Observable.from([ "foo" , "bar" , "baz" ]) let num = Observable.of( "1" , "2" , "3" , "4" ) Observable.combineLatest([ken, arr, num]) { "combined: \($0[0]), \($0[1]), \($0[2]))" }.subscribe({ print($ 0 ) }) .disposed(by: disposeBag) /* かなり特殊な例なんじゃないかな?使うことあるか? combineLatest2 === next(combined: Ken, foo, 1)) next(combined: Ken, bar, 1)) next(combined: Ken, bar, 2)) next(combined: Ken, baz, 2)) next(combined: Ken, baz, 3)) next(combined: Ken, baz, 4)) completed */ } func switchLatest() { print( "switchLatest === " ) let subject1 = BehaviorSubject(value: "foo" ) let subject2 = BehaviorSubject(value: "bar" ) let subjectsSubject = BehaviorSubject(value: subject1) subjectsSubject.asObservable() .switchLatest() .subscribe(onNext: { print($ 0 ) }) .disposed(by: disposeBag) subject1.onNext( "Mike" ) subject1.onNext( "Paul" ) subjectsSubject.onNext(subject2) subject1.onNext( "Nancy" ) subject2.onNext( "Cathy" ) subjectsSubject.onNext(subject1) //※1 /* event発行のものを途中で切り替えている 切り替え後はeventを発行しない。 しかし、また※1 で戻すとeventが流れる switchLatest === foo Mike Paul bar Cathy Nancy */ } } |
Transforming Operators
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 | class Playground_TransformingOp { let disposeBag = DisposeBag() public init (){} func map() { print( "map ===" ) Observable.of( 1 , 2 , 3 ) .map { $ 0 * $ 0 } .subscribe(onNext: { print($ 0 )}) .disposed(by: disposeBag) /* map === 1 4 9 */ } struct Player { let score: BehaviorSubject< Int > init (score: Int ) { self .score = BehaviorSubject(value: score) } } func flatMap() { print( "flatmap and flatmapLatest === " ) let tom = Player(score: 80 ) let mike = Player(score: 90 ) let player = BehaviorSubject(value: tom) player // asObservableしなくてもSubjectはそのままsubscribeできた。 // これは以前のバージョンだとできなかったのかも //.asObservable() //.flatMap{ $0.score.asObservable() } .flatMap{ $ 0 .score } //.flatMapLatest{ $0.score } .subscribe(onNext: { print($ 0 ) }) .disposed(by: disposeBag) print( "tom next" ) tom.score.onNext( 85 ) print( "change player to mike" ) player.onNext(mike) print( "tom next" ) tom.score.onNext( 95 ) print( "mike next" ) mike.score.onNext( 100 ) print( "tom next" ) tom.score.onNext( 110 ) print( "change player to tom" ) player.onNext(tom) /* //playerがmikeを指した後もtomのeventが受け取られている flatmap === 80 tom next 85 change player to mike 90 tom next 95 mike next 100 tom next 110 change player to tom 110 //tomの値を変えても、playerがmikeを指した後はeventを受け取らない //95の値が出ていない flatmapLatest === 80 tom next 85 change player to mike 90 tom next mike next 100 tom next //ここでは出てない change player to tom //ここで変えたから出る 110 */ } func scan() { print( "scan ===" ) Observable.of( 1 , 3 , 7 , 15 ) .scan( 4 ) { aggregateValue, newValue in print( "scanned:" , aggregateValue, newValue) return aggregateValue + newValue } .subscribe(onNext: { print($ 0 ) }) .disposed(by: disposeBag) /* scan(1) のとき === scanned: 1 1 2 scanned: 2 3 5 scanned: 5 7 12 scanned: 12 15 27 scan(4) のとき === scanned: 4 1 5 scanned: 5 3 8 scanned: 8 7 15 scanned: 15 15 30 */ } } |
Filtering and Conditional Operators
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 192 193 194 195 196 197 198 199 200 201 202 203 204 205 206 207 208 209 210 211 212 213 214 215 216 217 218 219 220 221 222 223 224 225 226 227 228 229 230 231 232 233 234 235 236 237 238 239 240 241 242 243 244 245 246 247 248 249 250 251 252 253 254 255 256 257 258 259 260 261 262 263 264 265 266 267 268 | class Playground_FilteringConditionalOperators { let bag = DisposeBag() func filter() { print( "filter ===" ) Observable.of( "foo" , "bar" , "baz" , "bar2" , "foo2" , "baz2" , "foo3" , "baz3" , "bar3" ).filter{ $ 0 .contains( "foo" ) } .subscribe(onNext: { print($ 0 ) }) .disposed(by: bag) /* foo foo2 foo3 */ } func distinctUntilChanged() { print( "distinctUntilChanged ===" ) Observable.of( "foo" , "bar" , "bar" , "foo" , "foo" , "foo" , "baz" , "foo" ) .distinctUntilChanged() .subscribe(onNext: { print($ 0 ) }) .disposed(by: bag) /* 同じ値が続いたときは、最初のもの以外は無視。 新しいものが出たら、nextで出す foo bar foo baz foo */ } func elementAt() { print( "elementAt ===" ) Observable.of( "1" , "2" , "3" , "4" ) .elementAt( 2 ) .subscribe(onNext: { print($ 0 ) }) .disposed(by: bag) /* indexで返す elementAt === 3 */ } func single1() { print( "single1 ===" ) Observable.of( "a" , "b" , "c" ) .single() .subscribe(onNext: { print($ 0 ) }) .disposed(by: bag) /* 最初のelementをemit single1 === a */ } func single2_4() { print( "single2 ===" ) Observable.of( "foo" , "bar" , "baz" , "alpha" , "beta" , "gamma" ) .single { $ 0 == "alpha" } .subscribe { print($ 0 ) } .disposed(by: bag) /* 正常終了 single2 === next(alpha) completed */ print( "single3 ===" ) Observable.of( "foo" , "bar" , "baz" , "foo" , "bar" , "baz" ) .single { $ 0 == "bar" } .subscribe { print($ 0 ) } .disposed(by: bag) /* エラー。該当条件が1つより多くマッチしているため single3 === next(bar) error(Sequence contains more than one element.) */ print( "single4 ===" ) /* エラー。該当条件のelmentが見つからない single4 === error(Sequence doesn't contain any elements.) */ Observable.of( "foo" , "bar" , "baz" , "alpha" , "beta" , "gamma" ) .single { $ 0 == "delta" } .subscribe { print($ 0 ) } .disposed(by: bag) } func take() { print( "take === " ) Observable.of( "a" , "b" , "c" , "d" , "e" ) .take( 3 ) .subscribe(onNext: { print($ 0 ) }) .disposed(by: bag) /* 最初からのn個を取る take === a b c */ } func takeLast() { print( "takeLast ===" ) Observable.of( "a" , "b" , "c" , "d" , "e" ) .takeLast( 3 ) .subscribe(onNext: { print($ 0 ) }) .disposed(by: bag) /* 後ろからn個を取る takeLast === c d e */ } func takeWhile() { print( "takeWhile ===" ) Observable.of( 1 , 2 , 3 , 4 , 5 , 6 ) .takeWhile { $ 0 < 4 } .subscribe(onNext: { print($ 0 ) }) .disposed(by: bag) /* 条件を満たしているものだけemit takeWhile === 1 2 3 */ } func takeUntil() { print( "takeUntil ===" ) let sourceSequence = PublishSubject< String >() let referenceSequence = PublishSubject< String >() sourceSequence .takeUntil(referenceSequence) .subscribe { print($ 0 ) } .disposed(by: bag) sourceSequence.onNext( "a" ) sourceSequence.onNext( "b" ) sourceSequence.onNext( "c" ) referenceSequence.onNext( "d" ) sourceSequence.onNext( "e" ) sourceSequence.onNext( "f" ) sourceSequence.onNext( "g" ) /* takeUntilの引数がemitするまでemitし続ける。 引数がemitすると止まる(completed) takeUntil === next(a) next(b) next(c) completed */ } func skip() { print( "skip ===" ) Observable.of( "a" , "b" , "c" , "d" , "e" , "f" ) .skip( 2 ) .subscribe(onNext: { print($ 0 ) }) .disposed(by: bag) /* skipで指定した個数分だけとばしてからemit開始 skip === c d e f */ } func skipWhile() { print( "skipWhile ===" ) Observable.of( 1 , 2 , 3 , 4 , 5 , 6 ) .skipWhile { $ 0 < 4 } .subscribe(onNext: { print($ 0 ) }) .disposed(by: bag) /* 該当条件まではemitしないが、該当条件の境界はemitする skipWhile === 4 5 6 */ } //skipWhileWithIndexはdeprecated! // func skipWhileWithIndex() { // print("skipWhileWithIndex ===") // // Observable.of("a", "b", "c", "d", "e") // .skipWhileWithIndex() // } func skipUntil() { print( "skipUntil ===" ) let sourceSequence = PublishSubject< String >() let referenceSequence = PublishSubject< String >() sourceSequence .skipUntil(referenceSequence) .subscribe(onNext: { print($ 0 ) }) .disposed(by: bag) sourceSequence.onNext( "a" ) sourceSequence.onNext( "b" ) sourceSequence.onNext( "c" ) referenceSequence.onNext( "d" ) sourceSequence.onNext( "e" ) sourceSequence.onNext( "f" ) sourceSequence.onNext( "g" ) /* skipUntilの引数がemitするまでは待機。emitしたら流す skipUntil === e f g */ } } |
Mathematical and Aggregate Operators
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 | class Playground_Math_AggregateOps { let bag = DisposeBag() func toArray() { print( "toArray ===" ) Observable.range(start: 1 , count: 10 ) .toArray() .subscribe(onNext: { print($ 0 ) }) .disposed(by: bag) /* sequenceをひとつの配列にまとめてemit toArray === [1, 2, 3, 4, 5, 6, 7, 8, 9, 10] */ } func reduce() { print( "reduce === " ) Observable.of( 20 , 300 , 4000 ) .reduce( 5 , accumulator: +) .subscribe(onNext: { print($ 0 ) }) .disposed(by: bag) /* 初期値とaccumulatorを使ってひとつの値に計算してからemit reduce === 4325 */ Observable.of( 2 , 3 ) .reduce( 5 , accumulator: *) .subscribe(onNext: { print($ 0 ) }) .disposed(by: bag) /* 30 */ } func concat() { print( "concat ===" ) let subject1 = BehaviorSubject(value: "1-a" ) let subject2 = BehaviorSubject(value: "1-b" ) let subjectsSubject = BehaviorSubject(value: subject1) subjectsSubject .concat() .subscribe { print($ 0 ) } .disposed(by: bag) subject1.onNext( "1-c" ) subject1.onNext( "1-d" ) subjectsSubject.onNext(subject2) subject2.onNext( "2-I would be ignored" ) subject2.onNext( "2-e" ) subject1.onCompleted() subject2.onNext( "2-f" ) /* 最初に指定したものがcompleteするまで待ってから次のものをemit concat === next(1-a) next(1-c) next(1-d) next(2-e) next(2-f) */ } } |
Connectable Operators
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 | func delay( _ delay: Double , closure: @escaping () -> Void) -> DispatchSourceTimer { let timer = DispatchSource.makeTimerSource() timer.schedule(deadline: .now() + delay) timer.setEventHandler { closure() } //resume忘れるとエラーが出る!! timer.resume() return timer } class Playground_ConnectableOps { let bag = DisposeBag() var timer:DispatchSourceTimer? var timer2:DispatchSourceTimer? var timer3:DispatchSourceTimer? func withoutOperators() { print( "withoutOperators ===" ) let interval = Observable< Int >.interval( 1 , scheduler: MainScheduler.instance) _ = interval .subscribe(onNext: { print( "Subscription: 1, Event: \($0)" ) }) timer = delay( 3 ) { _ = interval .subscribe(onNext: { print( "Subscription: 2, Event: \($0)" ) }) } /* withoutOperators === Subscription: 1, Event: 0 Subscription: 1, Event: 1 Subscription: 1, Event: 2 Subscription: 1, Event: 3 Subscription: 2, Event: 0 Subscription: 1, Event: 4 Subscription: 2, Event: 1 Subscription: 1, Event: 5 Subscription: 2, Event: 2 Subscription: 1, Event: 6 Subscription: 2, Event: 3 */ } func samplePublish() { print( "pubish ===" ) let intSequence = Observable< Int >.interval( 1 , scheduler: MainScheduler.instance) .publish() _ = intSequence .subscribe(onNext: { print( "subscription 1:, Event: \($0)" )}) timer2 = delay( 2 ) { _ = intSequence .subscribe(onNext: { print( "Subscription 2:, Event \($0)" ) }) } timer = delay( 4 ) { _ = intSequence.connect() } timer3 = delay( 6 ) { _ = intSequence .subscribe(onNext: { print( "Subscription 3:, Event \($0)" )}) } /* 4秒後にconnect() されてからemit開始 pubish === subscription 1:, Event: 0 Subscription 2:, Event 0 subscription 1:, Event: 1 Subscription 2:, Event 1 Subscription 3:, Event 1 subscription 1:, Event: 2 Subscription 2:, Event 2 Subscription 3:, Event 2 subscription 1:, Event: 3 Subscription 2:, Event 3 Subscription 3:, Event 3 subscription 1:, Event: 4 Subscription 2:, Event 4 Subscription 3:, Event 4 */ } func replay() { print( "replay ===" ) let intSequence = Observable< Int >.interval( 1 , scheduler: MainScheduler.instance) .replay( 1 ) _ = intSequence .subscribe(onNext: { print( "subscription 1:, Event: \($0)" )}) timer = delay( 2 ) { _ = intSequence.connect() } timer2 = delay( 4 ) { _ = intSequence .subscribe(onNext: { print( "Subscription 2:, Event \($0)" ) }) } timer3 = delay( 6 ) { _ = intSequence .subscribe(onNext: { print( "Subscription 3:, Event \($0)" )}) } /* replay === subscription 1:, Event: 0 Subscription 2:, Event 0 subscription 1:, Event: 1 Subscription 2:, Event 1 subscription 1:, Event: 2 Subscription 2:, Event 2 Subscription 3:, Event 2 subscription 1:, Event: 3 Subscription 2:, Event 3 Subscription 3:, Event 3 */ } } |
Error Handling Operators
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 | enum TestError: Error { case test } class Playground_ErrorHandling { let bag = DisposeBag() func catchErrorJustReturn() { print( "catchErrorJustReturn === " ) let sequence = PublishSubject< String >() sequence .catchErrorJustReturn( "a" ) .subscribe { print($ 0 ) } .disposed(by: bag) sequence.onNext( "b" ) sequence.onNext( "c" ) sequence.onNext( "d" ) sequence.onError(TestError.test) /* errorになったら catchErrorJustReturn の引数をemitして終了 catchErrorJustReturn === next(b) next(c) next(d) next(a) completed */ } func catchError() { print( "catchError ===" ) let sequence = PublishSubject< String >() let recoverySequence = PublishSubject< String >() sequence .catchError { print( "Error;" , $ 0 ) return recoverySequence } .subscribe { print($ 0 ) } .disposed(by: bag) sequence.onNext( "a" ) sequence.onNext( "b" ) sequence.onNext( "c" ) sequence.onError(TestError.test) recoverySequence.onNext( "recovery" ) /* errorになったらhandlerを実行する。もしreturnしたら そのsequenceをemitする catchError === next(a) next(b) next(c) Error; test next(recovery) */ } func retry() { print( "retry ===" ) var count = 1 let sequence = Observable< String >.create { observer in observer.onNext( "a" ) observer.onNext( "b" ) observer.onNext( "c" ) if count == 1 { observer.onError(TestError.test) print( "Error encountered" ) count += 1 } observer.onNext( "d" ) observer.onNext( "e" ) observer.onCompleted() return Disposables.create() } sequence .retry() .subscribe(onNext: { print($ 0 ) }) .disposed(by: bag) /* retry === a b c Error encountered a b c d e */ } func retry2(){ print( "retry2 ===" ) var count = 1 let sequence = Observable< String >.create { observer in observer.onNext( "a" ) observer.onNext( "b" ) observer.onNext( "c" ) if count < 3 { observer.onError(TestError.test) print( "Error encountered. count: \(count)" ) count += 1 } observer.onNext( "d" ) observer.onNext( "e" ) observer.onCompleted() return Disposables.create() } sequence .retry( 4 ) .subscribe(onNext: { print($ 0 ) }) .disposed(by: bag) /* retry2 === a b c Error encountered. count: 1 a b c Error encountered. count: 2 a b c d e */ } } |
Debugging Operators
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 | class Playground_DebuggingOperators { let bag = DisposeBag() func debug() { print( "debug ===" ) var count = 1 let sequence = Observable< String >.create { observer in observer.onNext( "a" ) observer.onNext( "b" ) observer.onNext( "c" ) if count < 5 { observer.onError(TestError.test) print( "Error encountered" ) count += 1 } observer.onNext( "d" ) observer.onNext( "e" ) observer.onCompleted() return Disposables.create() } sequence .retry( 1 ) .debug() .subscribe { print($ 0 ) } .disposed(by: bag) /* debug === 2019-01-29 19:26:00.410: Playground_DebuggingOperators.swift:41 (debug()) -> subscribed 2019-01-29 19:26:00.418: Playground_DebuggingOperators.swift:41 (debug()) -> Event next(a) next(a) 2019-01-29 19:26:00.418: Playground_DebuggingOperators.swift:41 (debug()) -> Event next(b) next(b) 2019-01-29 19:26:00.418: Playground_DebuggingOperators.swift:41 (debug()) -> Event next(c) next(c) Error encountered 2019-01-29 19:26:00.420: Playground_DebuggingOperators.swift:41 (debug()) -> Event error(test) error(test) 2019-01-29 19:26:00.421: Playground_DebuggingOperators.swift:41 (debug()) -> isDisposed */ } } |
おまけ Void
Observable<Void>って、どうやって値をemitするのかと思ったら Void() ってやればよいみたい
1 2 3 4 5 6 7 8 9 10 11 12 | let sequence = Observable<Void>.create{ observer in observer.onNext(Void()) observer.onCompleted() return Disposables.create() } let bag = DisposeBag() sequence.subscribe{ print($ 0 ) }.disposed(by: bag) /* next(()) completed */ |
■ 自作iPhoneアプリ 好評発売中!
・フォルメモ - シンプルなフォルダつきメモ帳
・ジッピー電卓 - 消費税や割引もサクサク計算!
■ LINEスタンプ作りました!
毎日使える。とぼけたウサギ