53 lines
2.4 KiB
TypeScript
53 lines
2.4 KiB
TypeScript
import { Observable } from '../Observable';
|
|
import { UnaryFunction } from '../types';
|
|
/**
|
|
* Splits the source Observable into two, one with values that satisfy a
|
|
* predicate, and another with values that don't satisfy the predicate.
|
|
*
|
|
* <span class="informal">It's like {@link filter}, but returns two Observables:
|
|
* one like the output of {@link filter}, and the other with values that did not
|
|
* pass the condition.</span>
|
|
*
|
|
* 
|
|
*
|
|
* `partition` outputs an array with two Observables that partition the values
|
|
* from the source Observable through the given `predicate` function. The first
|
|
* Observable in that array emits source values for which the predicate argument
|
|
* returns true. The second Observable emits source values for which the
|
|
* predicate returns false. The first behaves like {@link filter} and the second
|
|
* behaves like {@link filter} with the predicate negated.
|
|
*
|
|
* ## Example
|
|
* Partition click events into those on DIV elements and those elsewhere
|
|
* ```ts
|
|
* import { fromEvent } from 'rxjs';
|
|
* import { partition } from 'rxjs/operators';
|
|
*
|
|
* const clicks = fromEvent(document, 'click');
|
|
* const parts = clicks.pipe(partition(ev => ev.target.tagName === 'DIV'));
|
|
* const clicksOnDivs = parts[0];
|
|
* const clicksElsewhere = parts[1];
|
|
* clicksOnDivs.subscribe(x => console.log('DIV clicked: ', x));
|
|
* clicksElsewhere.subscribe(x => console.log('Other clicked: ', x));
|
|
* ```
|
|
*
|
|
* @see {@link filter}
|
|
*
|
|
* @param {function(value: T, index: number): boolean} predicate A function that
|
|
* evaluates each value emitted by the source Observable. If it returns `true`,
|
|
* the value is emitted on the first Observable in the returned array, if
|
|
* `false` the value is emitted on the second Observable in the array. The
|
|
* `index` parameter is the number `i` for the i-th source emission that has
|
|
* happened since the subscription, starting from the number `0`.
|
|
* @param {any} [thisArg] An optional argument to determine the value of `this`
|
|
* in the `predicate` function.
|
|
* @return {[Observable<T>, Observable<T>]} An array with two Observables: one
|
|
* with values that passed the predicate, and another with values that did not
|
|
* pass the predicate.
|
|
* @method partition
|
|
* @owner Observable
|
|
*/
|
|
/**
|
|
* @deprecated use `partition` static creation function instead
|
|
*/
|
|
export declare function partition<T>(predicate: (value: T, index: number) => boolean, thisArg?: any): UnaryFunction<Observable<T>, [Observable<T>, Observable<T>]>;
|