| import { mergeMap } from './mergeMap'; |
| /* tslint:enable:max-line-length */ |
| /** |
| * Projects each source value to an Observable which is merged in the output |
| * Observable, in a serialized fashion waiting for each one to complete before |
| * merging the next. |
| * |
| * <span class="informal">Maps each value to an Observable, then flattens all of |
| * these inner Observables using {@link concatAll}.</span> |
| * |
| * <img src="./img/concatMap.png" width="100%"> |
| * |
| * Returns an Observable that emits items based on applying a function that you |
| * supply to each item emitted by the source Observable, where that function |
| * returns an (so-called "inner") Observable. Each new inner Observable is |
| * concatenated with the previous inner Observable. |
| * |
| * __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: `concatMap` is equivalent to `mergeMap` 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.concatMap(ev => 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 concatMapTo} |
| * @see {@link exhaustMap} |
| * @see {@link mergeMap} |
| * @see {@link switchMap} |
| * |
| * @param {function(value: T, ?index: number): ObservableInput} project A function |
| * that, when applied to an item emitted by the source Observable, returns an |
| * 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 that emits the result of applying the |
| * projection function (and the optional `resultSelector`) to each item emitted |
| * by the source Observable and taking values from each projected inner |
| * Observable sequentially. |
| * @method concatMap |
| * @owner Observable |
| */ |
| export function concatMap(project, resultSelector) { |
| return mergeMap(project, resultSelector, 1); |
| } |
| //# sourceMappingURL=concatMap.js.map |
