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- import { Observable } from '../Observable';
- import { ObservedValueOf, ObservableInput } from '../types';
- /**
- * Creates an Observable that, on subscribe, calls an Observable factory to
- * make an Observable for each new Observer.
- *
- * <span class="informal">Creates the Observable lazily, that is, only when it
- * is subscribed.
- * </span>
- *
- * 
- *
- * `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 declare function defer<R extends ObservableInput<any>>(observableFactory: () => R): Observable<ObservedValueOf<R>>;
- //# sourceMappingURL=defer.d.ts.map
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