1 | import { MonoTypeOperatorFunction } from '../types';
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2 | /**
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3 | * Make a {@link ConnectableObservable} behave like a ordinary observable and automates the way
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4 | * you can connect to it.
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5 | *
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6 | * Internally it counts the subscriptions to the observable and subscribes (only once) to the source if
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7 | * the number of subscriptions is larger than 0. If the number of subscriptions is smaller than 1, it
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8 | * unsubscribes from the source. This way you can make sure that everything before the *published*
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9 | * refCount has only a single subscription independently of the number of subscribers to the target
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10 | * observable.
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11 | *
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12 | * Note that using the {@link share} operator is exactly the same as using the *publish* operator
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13 | * (making the observable hot) and the *refCount* operator in a sequence.
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14 | *
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15 | * ![](refCount.png)
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16 | *
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17 | * ## Example
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18 | *
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19 | * In the following example there are two intervals turned into connectable observables
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20 | * by using the *publish* operator. The first one uses the *refCount* operator, the
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21 | * second one does not use it. You will notice that a connectable observable does nothing
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22 | * until you call its connect function.
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23 | *
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24 | * ```ts
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25 | * import { interval } from 'rxjs';
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26 | * import { tap, publish, refCount } from 'rxjs/operators';
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27 | *
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28 | * // Turn the interval observable into a ConnectableObservable (hot)
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29 | * const refCountInterval = interval(400).pipe(
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30 | * tap((num) => console.log(`refCount ${num}`)),
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31 | * publish(),
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32 | * refCount()
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33 | * );
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34 | *
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35 | * const publishedInterval = interval(400).pipe(
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36 | * tap((num) => console.log(`publish ${num}`)),
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37 | * publish()
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38 | * );
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39 | *
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40 | * refCountInterval.subscribe();
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41 | * refCountInterval.subscribe();
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42 | * // 'refCount 0' -----> 'refCount 1' -----> etc
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43 | * // All subscriptions will receive the same value and the tap (and
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44 | * // every other operator) before the publish operator will be executed
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45 | * // only once per event independently of the number of subscriptions.
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46 | *
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47 | * publishedInterval.subscribe();
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48 | * // Nothing happens until you call .connect() on the observable.
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49 | * ```
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50 | *
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51 | * @see {@link ConnectableObservable}
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52 | * @see {@link share}
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53 | * @see {@link publish}
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54 | */
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55 | export declare function refCount<T>(): MonoTypeOperatorFunction<T>;
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