import { OperatorFunction, ObservableInput, ObservedValueOf, SubjectLike } from '../types'; import { Observable } from '../Observable'; export interface ConnectConfig { /** * A factory function used to create the Subject through which the source * is multicast. By default this creates a {@link Subject}. */ connector: () => SubjectLike; } /** * Creates an observable by multicasting the source within a function that * allows the developer to define the usage of the multicast prior to connection. * * This is particularly useful if the observable source you wish to multicast could * be synchronous or asynchronous. This sets it apart from {@link share}, which, in the * case of totally synchronous sources will fail to share a single subscription with * multiple consumers, as by the time the subscription to the result of {@link share} * has returned, if the source is synchronous its internal reference count will jump from * 0 to 1 back to 0 and reset. * * To use `connect`, you provide a `selector` function that will give you * a multicast observable that is not yet connected. You then use that multicast observable * to create a resulting observable that, when subscribed, will set up your multicast. This is * generally, but not always, accomplished with {@link merge}. * * Note that using a {@link takeUntil} inside of `connect`'s `selector` _might_ mean you were looking * to use the {@link takeWhile} operator instead. * * When you subscribe to the result of `connect`, the `selector` function will be called. After * the `selector` function returns, the observable it returns will be subscribed to, _then_ the * multicast will be connected to the source. * * ### Example * * Sharing a totally synchronous observable * * ```ts * import { defer, merge, of } from 'rxjs'; * import { tap, connect, filter, map } from 'rxjs/operators'; * * const source$ = defer(() => { * console.log('subscription started'); * return of(1, 2, 3, 4, 5).pipe( * tap(n => console.log(`source emitted ${n}`)) * ); * }); * * source$.pipe( * // Notice in here we're merging 3 subscriptions to `shared$`. * connect((shared$) => merge( * shared$.pipe(map(n => `all ${n}`)), * shared$.pipe(filter(n => n % 2 === 0), map(n => `even ${n}`)), * shared$.pipe(filter(n => n % 2 === 1), map(n => `odd ${n}`)), * )) * ) * .subscribe(console.log); * * // Expected output: (notice only one subscription) * "subscription started" * "source emitted 1" * "all 1" * "odd 1" * "source emitted 2" * "all 2" * "even 2" * "source emitted 3" * "all 3" * "odd 3" * "source emitted 4" * "all 4" * "even 4" * "source emitted 5" * "all 5" * "odd 5" * ``` * * @param selector A function used to set up the multicast. Gives you a multicast observable * that is not yet connected. With that, you're expected to create and return * and Observable, that when subscribed to, will utilize the multicast observable. * After this function is executed -- and its return value subscribed to -- the * the operator will subscribe to the source, and the connection will be made. * @param config The configuration object for `connect`. */ export declare function connect>(selector: (shared: Observable) => O, config?: ConnectConfig): OperatorFunction>; //# sourceMappingURL=connect.d.ts.map