From e4fa1e69e7ebfb627c7198fd1a9881e9327ec4d4 Mon Sep 17 00:00:00 2001 From: Pinapelz Date: Sat, 28 Jun 2025 17:26:46 -0700 Subject: initial commit: scaffolding --- node_modules/rxjs/src/internal/observable/defer.ts | 56 ++++++++++++++++++++++ 1 file changed, 56 insertions(+) create mode 100644 node_modules/rxjs/src/internal/observable/defer.ts (limited to 'node_modules/rxjs/src/internal/observable/defer.ts') diff --git a/node_modules/rxjs/src/internal/observable/defer.ts b/node_modules/rxjs/src/internal/observable/defer.ts new file mode 100644 index 0000000..2bd3db9 --- /dev/null +++ b/node_modules/rxjs/src/internal/observable/defer.ts @@ -0,0 +1,56 @@ +import { Observable } from '../Observable'; +import { ObservedValueOf, ObservableInput } from '../types'; +import { innerFrom } from './innerFrom'; + +/** + * Creates an Observable that, on subscribe, calls an Observable factory to + * make an Observable for each new Observer. + * + * Creates the Observable lazily, that is, only when it + * is subscribed. + * + * + * ![](defer.png) + * + * `defer` allows you to create an Observable only when the Observer + * subscribes. It waits until an Observer subscribes to it, calls the given + * factory function to get an Observable -- where a factory function typically + * generates a new Observable -- and subscribes the Observer to this Observable. + * In case the factory function returns a falsy value, then EMPTY is used as + * Observable instead. Last but not least, an exception during the factory + * function call is transferred to the Observer by calling `error`. + * + * ## Example + * + * Subscribe to either an Observable of clicks or an Observable of interval, at random + * + * ```ts + * import { defer, fromEvent, interval } from 'rxjs'; + * + * const clicksOrInterval = defer(() => { + * return Math.random() > 0.5 + * ? fromEvent(document, 'click') + * : interval(1000); + * }); + * clicksOrInterval.subscribe(x => console.log(x)); + * + * // Results in the following behavior: + * // If the result of Math.random() is greater than 0.5 it will listen + * // for clicks anywhere on the "document"; when document is clicked it + * // will log a MouseEvent object to the console. If the result is less + * // than 0.5 it will emit ascending numbers, one every second(1000ms). + * ``` + * + * @see {@link Observable} + * + * @param observableFactory The Observable factory function to invoke for each + * Observer that subscribes to the output Observable. May also return any + * `ObservableInput`, which will be converted on the fly to an Observable. + * @return An Observable whose Observers' subscriptions trigger an invocation of the + * given Observable factory function. + */ +export function defer>(observableFactory: () => R): Observable> { + return new Observable>((subscriber) => { + innerFrom(observableFactory()).subscribe(subscriber); + }); +} -- cgit v1.2.3