@benev/slate/x/tools/pubsub.js

frontend web stuff

import { deferPromise } from "./defer-promise.js";
/**
 * simple pub-sub mechanism.
 *
 *     // create pubsub function
 *     const onCount = pubsub<[string, number]>()
 *
 *     // subscribe
 *     const stop = onCount((a, b) => console.log(a, b))
 *
 *     // publish
 *     onWhatever.publish("count", 123)
 *
 *     // unsubscribe
 *     stop()
 *
 */
export function pubsub() {
    const set = new Set();
    function subscribe(fn) {
        set.add(fn);
        return () => { set.delete(fn); };
    }
    subscribe.publish = async (...a) => {
        await Promise.all([...set].map(fn => fn(...a)));
    };
    subscribe.clear = () => set.clear();
    subscribe.once = async () => {
        const { promise, resolve } = deferPromise();
        const unsubscribe = subscribe((...a) => {
            resolve(a);
            unsubscribe();
        });
        return promise;
    };
    return subscribe;
}
//# sourceMappingURL=pubsub.js.map