Rx入門

Reactive Extensions入門。社内勉強会用。

Transcript

1. ࡶͳ3FBDUJWF&YUFOTJPOT
   ೖ໳
   !SFJ@N
   4VQFSTIJQࣾ಺ษڧձ༻
   

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2. ࣗݾ঺հ
   w SFJ@N
   w 4VOOZDIBU࡞ͬͯ·͢
   w ͳΜ͔͍Ζ͍Ζ΍͖͚ͬͯͨ
   Ͳڈ೥͔Β"OESPJEͷਓ
   w J04΋࢝Ί͚ͨͲ9DPEFͱ༑
   ୡʹͳΓ͖Εͳ͍
   

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3. 3Yʹ͍ͭͯ
   w ΋ͱ΋ͱ͸೥ʹ/FUքͰੜ·ΕͨϥΠϒϥϦɻʢ$ͷ-*/2͕ݯྲྀʣ
   w /FUqJY͕͜ͷϥΠϒϥϦΛ+BWBʹҠ২ͨ͠3Y+BWBΛ࢝Ίɺ3Y+4ɺ3Y4XJGUɺ
   3Y"OESPJEͳͲ༷ʑͳݴޠɺϓϥοτϑΥʔϜʹ޿͕͍ͬͯΔɻ
   w 3FBDUͱ͔3FEVYͱ໊͔લ͕ࣅͯΔ͚Ͳ͋Μ·ؔ܎͸ͳ͍ɻ3FBDUJWF
   1SPHSBNJOHͱ͍͏͘͘Γʹ͓͍ͯ͸஥ؒɻ
   

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4. 3FBDUJWF1SPHSBNJOHͱ͍͏ύϥμΠϜ
   w "ͷηϧΛΠϯΫϦϝϯτ͢Δͱ#ɺ$ɺ"ͷ஋΋มԽ͢Δ
   w ී௨ʹखଓ͖తʹίʔυΛॻ͍ͯ͸࠶ݱͰ͖ͳ͍ɻ0CTFSWFSύλʔϯΛ࢖ͬͯ"ͷ஋Λ؂ࢹ͢Δ
   Α͏ͳίʔυΛॻ͘ඞཁ͕͋Δɻ
   w 3FBDUJWF1SPHSBNJOH͸ʮมԽ͢Δঢ়ଶʯͷؔ܎ੑΛॻ͍͍ͯ͘͜ͱͰঢ়ଶΛίϯτϩʔϧ͢Δ
   
   

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5. ࿩͸໭ͬͯ3Y
   w 3Y͸ঢ়ଶͷมԽΛ4USFBNͱͯ͠දݱ͢Δ
   w ొ৔͢Δͷ͸0CTFSWBCMFͱ0CTFSWFSΠϯλʔϑΣʔεɻ0CTFSWBCMF͸ྲྀΕͯ
   ͘Δσʔλɺ0CTFSWFS͸ྲྀΕͯ͘Δσʔλͷ؍ଌऀ
   w Ұ൪؆୯ͳϦετͷத਎Λ4USFBNʹม׵ͯ͠දࣔ͢Δྫʢ+BWBʣ
   -JTU*OUFHFSMJTU"SSBZTBT-JTU
   

   0CTFSWBCMFGSPN MJTU
   TVCTDSJCF 4ZTUFNPVUQSJOUMO
   

   
   
   
   

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6. 0QFSBUPSͰ஋ΛՃ޻͢Δ
   w ྲྀΕͯ͘ΔσʔλΛՃ޻͢Δྫʢ+BWBʣ
   w ΦϖϨʔλͷҰཡIUUQSFBDUJWFYJPEPDVNFOUBUJPOPQFSBUPSTIUNM
   List list = Arrays.asList(1, 2, 3, 4, 5, 6);

   Observable.from(list)

   .filter(v -> (v % 2) == 1)

   .map(v -> v * 2)

   .subscribe(System.out::println);
   2
   6
   10
   

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7. 0CTFSWBCMFΛ߹੒͢Δ
   Observable stream1 = Observable.from(Arrays.asList(1, 2, 3));

   Observable stream2 = Observable.from(Arrays.asList(10, 20, 30));

   Observable.concat(stream1, stream2).subscribe(System.out::println);
   1
   2
   3
   10
   20
   30
   Observable stream1 = Observable.from(Arrays.asList(1, 2, 3));

   Observable stream2 = Observable.from(Arrays.asList(10, 20, 30));

   Observable.zip(stream1, stream2, ((v1, v2) -> {

   return v1 + v2;

   })).subscribe(System.out::println);
   11
   22
   33
   

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8. ΠϕϯτΛ0CTFSWBCMFͱͯ͠ѻ͏
   w ͜͜·Ͱͷ಺༰͸-JTUΛ4USFBNͱͯ͠ѻ͚ͬͨͩ
   w ϢʔβʔͷΠϕϯτΛ0CTBSWBCMFͰྲྀ͢
   private Subscription subscription;

   @Override

   public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle
   savedInstanceState) {
   …
   // ͜͜ͰϘλϯΛ؂ࢹͯ͠ΠϕϯτΛྲྀ͢StreamΛ࡞Δ.
   subscription = RxView.clicks(view.findViewById(R.id.button)).map(v -> 1).subscribe(v -> {

   System.out.println("ԡ͞Εͯ " + v + "͕ྲྀΕ͖ͯͨΑ");

   });
   }
   @Override

   public void onDestroyView() {

   super.onDestroyView();

   subscription.unsubscribe(); // View͕ഁغ͞ΕΔλΠϛϯάͰStreamͷߪಡΛղআͯ͠؂ࢹΛղ͘

   subscription = null;

   }
   

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9. Ұ୴໭ͬͯ0CTFSWFSΠϯλʔϑΣʔεΛோΊΔ
   w 4USFBN͕ऴ୺ʹୡ͢ΔͱPO$PNQMFUFE͕૸ͬͯߪಡ͸VOTVCTDSJCF͞ΕΔ
   w 7JFXͷ৔߹͸ৗʹ؂ࢹ͞Ε͍ͯΔɺͭ·Γ4USFBN͸ແݶͰPO$PNQMFUFE͕૸Βͳ͍ͷͰࣗ෼ͰVOTVCTDSJCF͠ͳ͍ͱϦʔ
   Ϋ͢Δɻ
   public interface Observer {

   

   /**

   * Notifies the Observer that the {@link Observable} has finished sending push-based notifications.

   * 

   * The {@link Observable} will not call this method if it calls {@link #onError}.

   */

   void onCompleted();

   

   /**

   * Notifies the Observer that the {@link Observable} has experienced an error condition.

   * 

   * If the {@link Observable} calls this method, it will not thereafter call {@link #onNext} or

   * {@link #onCompleted}.

   * 

   * @param e

   * the exception encountered by the Observable

   */

   void onError(Throwable e);

   

   /**

   * Provides the Observer with a new item to observe.

   * 

   * The {@link Observable} may call this method 0 or more times.

   * 

   * The {@code Observable} will not call this method again after it calls either {@link #onCompleted} or

   * {@link #onError}.

   * 

   * @param t

   * the item emitted by the Observable

   */

   void onNext(T t);

   

   }
   

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11. ࠓ·Ͱग़͖ͯͨ࿩ΛԠ༻͢Δ
    w શ߲໨Λೖྗͨ͠ΒϘλϯΛ༗ޮʹ͢Δͱ͍͏αϯϓϧ
    

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12. private val subscriptions = CompositeSubscription()

    override fun onCreateView(inflater: LayoutInflater, container: ViewGroup?, savedInstanceState: Bundle?): View {

    

    val view = inflater.inflate(R.layout.fragment_rx_sample, container, false)

    

    // ֤ೖྗཝͷObservableΛऔಘ

    val observableName = RxTextView.textChanges(view.findViewById(R.id.edit_order_name) as AppCompatEditText)

    val observablePostalCode = RxTextView.textChanges(view.findViewById(R.id.edit_order_postal_code) as
    AppCompatEditText)

    val observableAddressFirst = RxTextView.textChanges(view.findViewById(R.id.edit_order_address_first) as
    AppCompatEditText)

    val observableAddressSecond = RxTextView.textChanges(view.findViewById(R.id.edit_order_address_second) as
    AppCompatEditText)

    

    // ButtonΛऔಘ

    val submitButton = view.findViewById(R.id.button_rx_submit) as AppCompatButton

    submitButton.isEnabled = false

    

    // ObservableΛcombineLatestʹ৯Θ֤߲ͯ͠໨ͷͲΕ͔ʹมߋ͕͋ͬͨ৔߹͸Stream͕ྲྀΕΔΑ͏ʹ͢Δ

    // Ҿ਺ͷ࠷ޙͷAction1ͰྲྀΕ͖ͯͨ஋ΛνΣοΫͯ͢͠΂ͯೖྗࡁͳΒtrueΛྲྀ͢

    subscriptions.add(Observable.combineLatest(observableName,

    observablePostalCode,

    observableAddressFirst,

    observableAddressSecond,

    { v1, v2, v3, v4 ->

    (0 < v1.length && 0 < v2.length && 0 < v3.length && 0 < v4.length)

    }).subscribe({ isValid ->

    // ྲྀΕ͖ͯͨStreamʹै͍Ϙλϯͷ༗ޮ/ແޮΛ੾Γସ͑Δ

    submitButton.isEnabled = isValid

    }))

    

    return view

    }

    

    override fun onDestroyView() {

    super.onDestroyView()

    subscriptions.unsubscribe()

    }
    w αϯϓϧίʔυ͸,PUMJO IUUQRJJUBDPNSFJNJUFNTBDCFCFDCGFDBD
    
    

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13. "1*ͷϨεϙϯε0CTFSWBCMFͱͯ͠ѻ͏
    w 3Y͸ඇಉظॲཧͱ૬ੑ͕͍͍ɻΞϓϦͰඇಉظͱ͍͑͹"1*ͷݺͼग़͠ɻ
    w "1*ΛݺΜͰͦͷϨεϙϯεΛ0CTFSWBCMFʹྲྀͯ͠ฦ͢ɻ
    w "1*΋TVCTDSJQUJPOͷ؅ཧ͸ͨ͠΄͏͕Α͍ɻ"1*ΛݺΜͰ݁ՌΛ7JFXʹදࣔ͢Δͱ͍͏Α͏ͳ͜ͱΛ͍ͯ͠Δ৔߹ɺ7JFX
    ͕ഁغ͞ΕΔλΠϛϯάͰVOTVCTDSJCF͠ͳ͍ͱ7JFXͷ/VMMࢀর͕ى͖Δʢ"1*ͷϦΫΤετதʹը໘͕ऴྃ͢ΔͳͲͯ͠
    7JFX͕ഁغ͞ΕΔέʔεʣՄೳੑ͕͋Δɻ
    w 0CTFSWBCMFͳͷͰ౰વɺ߹੒΍ม׵ͳͲͷPQFSBUPS͕࢖͑Δɻຊͷ"1*Λ౤͛ऴΘͬͨΒ࣍ʹߦ͘ɺΈ͍ͨͳॲཧ΋
    0CTFSWBCMFʹม׵ͯ͠ɺ[JQͰ߹੒ͯ͠TVCTDSJCF͢Ε͹؆୯ʹॻ͚Δɻ
    // ͜Ε͸Sunnychatͷྫ
    // getCanvas͸APIΛୟ͍ͯObservableΛฦ͢.
    subscriptions.add(canvasService.getCanvas(authToken, canvasIdentifier)

    .subscribeOn(Schedulers.newThread()) // ഑৴͸ผεϨουͰ

    .observeOn(AndroidSchedulers.mainThread()) // ߪಡ͸ϝΠϯεϨουͰ

    .subscribe({
    // ͪ͜Β͸onNext

    onGetCanvasSuccess(it)

    }, {
    // ͪ͜Β͸onErrorɻωοτϫʔΫΤϥʔ΍200Ҏ֎ͷϨεϙϯεͷ৔߹͸഑৴ଆͰonError͕ݺ͹ΕΔ

    onGetCanvasFailure(it, canvasIdentifier)

    }))
    

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14. ·ͱΊ
    w 3FBDUJWF&YUFOTJPOͷߟ͑ํͱجૅʹ͍ͭͯ঺հ͠·ͨ͠ɻ
    w ϑϩϯτΤϯυͷ։ൃ͸ઈ͑ͣมԽ͠ଓ͚Δঢ়ଶͱͷઓ͍ͳͷͰ3YΛ࢖͏͜ͱͰ͍͍ײ͡ʹί
    ϯτϩʔϧ͠·͠ΐ͏ɻ
    

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