12345678910111213141516171819202122232425262728293031323334353637383940414243444546474849505152535455565758596061626364656667686970717273747576 |
- /** PURE_IMPORTS_START .._operators_groupBy PURE_IMPORTS_END */
- import { groupBy as higherOrder, GroupedObservable } from '../operators/groupBy';
- export { GroupedObservable };
- /* tslint:enable:max-line-length */
- /**
- * Groups the items emitted by an Observable according to a specified criterion,
- * and emits these grouped items as `GroupedObservables`, one
- * {@link GroupedObservable} per group.
- *
- * <img src="./img/groupBy.png" width="100%">
- *
- * @example <caption>Group objects by id and return as array</caption>
- * Observable.of<Obj>({id: 1, name: 'aze1'},
- * {id: 2, name: 'sf2'},
- * {id: 2, name: 'dg2'},
- * {id: 1, name: 'erg1'},
- * {id: 1, name: 'df1'},
- * {id: 2, name: 'sfqfb2'},
- * {id: 3, name: 'qfs3'},
- * {id: 2, name: 'qsgqsfg2'}
- * )
- * .groupBy(p => p.id)
- * .flatMap( (group$) => group$.reduce((acc, cur) => [...acc, cur], []))
- * .subscribe(p => console.log(p));
- *
- * // displays:
- * // [ { id: 1, name: 'aze1' },
- * // { id: 1, name: 'erg1' },
- * // { id: 1, name: 'df1' } ]
- * //
- * // [ { id: 2, name: 'sf2' },
- * // { id: 2, name: 'dg2' },
- * // { id: 2, name: 'sfqfb2' },
- * // { id: 2, name: 'qsgqsfg2' } ]
- * //
- * // [ { id: 3, name: 'qfs3' } ]
- *
- * @example <caption>Pivot data on the id field</caption>
- * Observable.of<Obj>({id: 1, name: 'aze1'},
- * {id: 2, name: 'sf2'},
- * {id: 2, name: 'dg2'},
- * {id: 1, name: 'erg1'},
- * {id: 1, name: 'df1'},
- * {id: 2, name: 'sfqfb2'},
- * {id: 3, name: 'qfs1'},
- * {id: 2, name: 'qsgqsfg2'}
- * )
- * .groupBy(p => p.id, p => p.name)
- * .flatMap( (group$) => group$.reduce((acc, cur) => [...acc, cur], ["" + group$.key]))
- * .map(arr => ({'id': parseInt(arr[0]), 'values': arr.slice(1)}))
- * .subscribe(p => console.log(p));
- *
- * // displays:
- * // { id: 1, values: [ 'aze1', 'erg1', 'df1' ] }
- * // { id: 2, values: [ 'sf2', 'dg2', 'sfqfb2', 'qsgqsfg2' ] }
- * // { id: 3, values: [ 'qfs1' ] }
- *
- * @param {function(value: T): K} keySelector A function that extracts the key
- * for each item.
- * @param {function(value: T): R} [elementSelector] A function that extracts the
- * return element for each item.
- * @param {function(grouped: GroupedObservable<K,R>): Observable<any>} [durationSelector]
- * A function that returns an Observable to determine how long each group should
- * exist.
- * @return {Observable<GroupedObservable<K,R>>} An Observable that emits
- * GroupedObservables, each of which corresponds to a unique key value and each
- * of which emits those items from the source Observable that share that key
- * value.
- * @method groupBy
- * @owner Observable
- */
- export function groupBy(keySelector, elementSelector, durationSelector, subjectSelector) {
- return higherOrder(keySelector, elementSelector, durationSelector, subjectSelector)(this);
- }
- //# sourceMappingURL=groupBy.js.map
|