44 lines
1.9 KiB
TypeScript
44 lines
1.9 KiB
TypeScript
import { Operator } from '../Operator';
|
|
import { Subscriber } from '../Subscriber';
|
|
import { OperatorFunction } from '../interfaces';
|
|
/**
|
|
* Applies a given `project` function to each value emitted by the source
|
|
* Observable, and emits the resulting values as an Observable.
|
|
*
|
|
* <span class="informal">Like [Array.prototype.map()](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Array/map),
|
|
* it passes each source value through a transformation function to get
|
|
* corresponding output values.</span>
|
|
*
|
|
* <img src="./img/map.png" width="100%">
|
|
*
|
|
* Similar to the well known `Array.prototype.map` function, this operator
|
|
* applies a projection to each value and emits that projection in the output
|
|
* Observable.
|
|
*
|
|
* @example <caption>Map every click to the clientX position of that click</caption>
|
|
* var clicks = Rx.Observable.fromEvent(document, 'click');
|
|
* var positions = clicks.map(ev => ev.clientX);
|
|
* positions.subscribe(x => console.log(x));
|
|
*
|
|
* @see {@link mapTo}
|
|
* @see {@link pluck}
|
|
*
|
|
* @param {function(value: T, index: number): R} project The function to apply
|
|
* to each `value` emitted by the source Observable. The `index` parameter is
|
|
* the number `i` for the i-th emission that has happened since the
|
|
* subscription, starting from the number `0`.
|
|
* @param {any} [thisArg] An optional argument to define what `this` is in the
|
|
* `project` function.
|
|
* @return {Observable<R>} An Observable that emits the values from the source
|
|
* Observable transformed by the given `project` function.
|
|
* @method map
|
|
* @owner Observable
|
|
*/
|
|
export declare function map<T, R>(project: (value: T, index: number) => R, thisArg?: any): OperatorFunction<T, R>;
|
|
export declare class MapOperator<T, R> implements Operator<T, R> {
|
|
private project;
|
|
private thisArg;
|
|
constructor(project: (value: T, index: number) => R, thisArg: any);
|
|
call(subscriber: Subscriber<R>, source: any): any;
|
|
}
|