64 lines
2.9 KiB
JavaScript
64 lines
2.9 KiB
JavaScript
|
"use strict";
|
||
|
|
var concatMap_1 = require('./concatMap');
|
||
|
|
/* tslint:enable:max-line-length */
|
||
|
|
/**
|
||
|
|
* Projects each source value to the same Observable which is merged multiple
|
||
|
|
* times in a serialized fashion on the output Observable.
|
||
|
|
*
|
||
|
|
* <span class="informal">It's like {@link concatMap}, but maps each value
|
||
|
|
* always to the same inner Observable.</span>
|
||
|
|
*
|
||
|
|
* <img src="./img/concatMapTo.png" width="100%">
|
||
|
|
*
|
||
|
|
* Maps each source value to the given Observable `innerObservable` regardless
|
||
|
|
* of the source value, and then flattens those resulting Observables into one
|
||
|
|
* single Observable, which is the output Observable. Each new `innerObservable`
|
||
|
|
* instance emitted on the output Observable is concatenated with the previous
|
||
|
|
* `innerObservable` instance.
|
||
|
|
*
|
||
|
|
* __Warning:__ if source values arrive endlessly and faster than their
|
||
|
|
* corresponding inner Observables can complete, it will result in memory issues
|
||
|
|
* as inner Observables amass in an unbounded buffer waiting for their turn to
|
||
|
|
* be subscribed to.
|
||
|
|
*
|
||
|
|
* Note: `concatMapTo` is equivalent to `mergeMapTo` with concurrency parameter
|
||
|
|
* set to `1`.
|
||
|
|
*
|
||
|
|
* @example <caption>For each click event, tick every second from 0 to 3, with no concurrency</caption>
|
||
|
|
* var clicks = Rx.Observable.fromEvent(document, 'click');
|
||
|
|
* var result = clicks.concatMapTo(Rx.Observable.interval(1000).take(4));
|
||
|
|
* result.subscribe(x => console.log(x));
|
||
|
|
*
|
||
|
|
* // Results in the following:
|
||
|
|
* // (results are not concurrent)
|
||
|
|
* // For every click on the "document" it will emit values 0 to 3 spaced
|
||
|
|
* // on a 1000ms interval
|
||
|
|
* // one click = 1000ms-> 0 -1000ms-> 1 -1000ms-> 2 -1000ms-> 3
|
||
|
|
*
|
||
|
|
* @see {@link concat}
|
||
|
|
* @see {@link concatAll}
|
||
|
|
* @see {@link concatMap}
|
||
|
|
* @see {@link mergeMapTo}
|
||
|
|
* @see {@link switchMapTo}
|
||
|
|
*
|
||
|
|
* @param {ObservableInput} innerObservable An Observable to replace each value from
|
||
|
|
* the source Observable.
|
||
|
|
* @param {function(outerValue: T, innerValue: I, outerIndex: number, innerIndex: number): any} [resultSelector]
|
||
|
|
* A function to produce the value on the output Observable based on the values
|
||
|
|
* and the indices of the source (outer) emission and the inner Observable
|
||
|
|
* emission. The arguments passed to this function are:
|
||
|
|
* - `outerValue`: the value that came from the source
|
||
|
|
* - `innerValue`: the value that came from the projected Observable
|
||
|
|
* - `outerIndex`: the "index" of the value that came from the source
|
||
|
|
* - `innerIndex`: the "index" of the value from the projected Observable
|
||
|
|
* @return {Observable} An observable of values merged together by joining the
|
||
|
|
* passed observable with itself, one after the other, for each value emitted
|
||
|
|
* from the source.
|
||
|
|
* @method concatMapTo
|
||
|
|
* @owner Observable
|
||
|
|
*/
|
||
|
|
function concatMapTo(innerObservable, resultSelector) {
|
||
|
|
return concatMap_1.concatMap(function () { return innerObservable; }, resultSelector);
|
||
|
|
}
|
||
|
|
exports.concatMapTo = concatMapTo;
|
||
|
|
//# sourceMappingURL=concatMapTo.js.map
|