62 lines
2.0 KiB
TypeScript
62 lines
2.0 KiB
TypeScript
|
import { Observable, ObservableInput } from '../Observable';
|
||
|
|
/**
|
||
|
|
* Catches errors on the observable to be handled by returning a new observable or throwing an error.
|
||
|
|
*
|
||
|
|
* <img src="./img/catch.png" width="100%">
|
||
|
|
*
|
||
|
|
* @example <caption>Continues with a different Observable when there's an error</caption>
|
||
|
|
*
|
||
|
|
* Observable.of(1, 2, 3, 4, 5)
|
||
|
|
* .map(n => {
|
||
|
|
* if (n == 4) {
|
||
|
|
* throw 'four!';
|
||
|
|
* }
|
||
|
|
* return n;
|
||
|
|
* })
|
||
|
|
* .catch(err => Observable.of('I', 'II', 'III', 'IV', 'V'))
|
||
|
|
* .subscribe(x => console.log(x));
|
||
|
|
* // 1, 2, 3, I, II, III, IV, V
|
||
|
|
*
|
||
|
|
* @example <caption>Retries the caught source Observable again in case of error, similar to retry() operator</caption>
|
||
|
|
*
|
||
|
|
* Observable.of(1, 2, 3, 4, 5)
|
||
|
|
* .map(n => {
|
||
|
|
* if (n === 4) {
|
||
|
|
* throw 'four!';
|
||
|
|
* }
|
||
|
|
* return n;
|
||
|
|
* })
|
||
|
|
* .catch((err, caught) => caught)
|
||
|
|
* .take(30)
|
||
|
|
* .subscribe(x => console.log(x));
|
||
|
|
* // 1, 2, 3, 1, 2, 3, ...
|
||
|
|
*
|
||
|
|
* @example <caption>Throws a new error when the source Observable throws an error</caption>
|
||
|
|
*
|
||
|
|
* Observable.of(1, 2, 3, 4, 5)
|
||
|
|
* .map(n => {
|
||
|
|
* if (n == 4) {
|
||
|
|
* throw 'four!';
|
||
|
|
* }
|
||
|
|
* return n;
|
||
|
|
* })
|
||
|
|
* .catch(err => {
|
||
|
|
* throw 'error in source. Details: ' + err;
|
||
|
|
* })
|
||
|
|
* .subscribe(
|
||
|
|
* x => console.log(x),
|
||
|
|
* err => console.log(err)
|
||
|
|
* );
|
||
|
|
* // 1, 2, 3, error in source. Details: four!
|
||
|
|
*
|
||
|
|
* @param {function} selector a function that takes as arguments `err`, which is the error, and `caught`, which
|
||
|
|
* is the source observable, in case you'd like to "retry" that observable by returning it again. Whatever observable
|
||
|
|
* is returned by the `selector` will be used to continue the observable chain.
|
||
|
|
* @return {Observable} An observable that originates from either the source or the observable returned by the
|
||
|
|
* catch `selector` function.
|
||
|
|
* @method catch
|
||
|
|
* @name catch
|
||
|
|
* @owner Observable
|
||
|
|
*/
|
||
|
|
export declare function _catch<T, R>(this: Observable<T>, selector: (err: any, caught: Observable<T>) => ObservableInput<R>): Observable<T | R>;
|