https://github.com/staltz/callbag-from-obs

👜 Convert an observable to a callbag listenable source
https://github.com/staltz/callbag-from-obs

Last synced: 5 days ago
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👜 Convert an observable to a callbag listenable source

• Host: GitHub
• URL: https://github.com/staltz/callbag-from-obs
• Owner: staltz
• License: mit
• Created: 2018-01-23T21:17:26.000Z (almost 7 years ago)
• Default Branch: master
• Last Pushed: 2023-04-20T05:39:54.000Z (over 1 year ago)
• Last Synced: 2024-12-24T20:38:16.501Z (20 days ago)
• Language: JavaScript
• Homepage:
• Size: 22.5 KB
• Stars: 3
• Watchers: 3
• Forks: 5
• Open Issues: 3
• Metadata Files:
  • Readme: readme.js
  • License: LICENSE

Awesome Lists containing this project

• awesome-callbags - from-obs

README

        
/**

 * callbag-from-obs

 * --------------

 *

 * Convert an observable (or subscribable) to a callbag listenable source.

 *

 * `npm install callbag-from-obs`

 *

 * Example:

 *

 * Convert an RxJS Observable:

 *

 *     const Rx = require('rxjs');

 *     const fromObs = require('callbag-from-obs');

 *     const observe = require('callbag-observe');

 *

 *     const source = fromObs(Rx.Observable.interval(1000).take(4));

 *

 *     observe(x => console.log(x))(source); // 0

 *                                           // 1

 *                                           // 2

 *                                           // 3

 *

 * Convert anything that has the `.subscribe` method:

 *

 *     const fromObs = require('callbag-from-obs');

 *     const observe = require('callbag-observe');

 *

 *     const subscribable = {

 *       subscribe: (observer) => {

 *         let i = 0;

 *         setInterval(() => observer.next(i++), 1000);

 *       }

 *     };

 *

 *     const source = fromObs(subscribable);

 *

 *     observe(x => console.log(x))(source); // 0

 *                                           // 1

 *                                           // 2

 *                                           // 3

 *                                           // ...

 */

const $$observable = require('symbol-observable').default;

const fromObs = observable => (start, sink) => {

  if (start !== 0) return;

  let dispose;

  sink(0, t => {

    if (t === 2 && dispose) {

      if (dispose.unsubscribe) dispose.unsubscribe();

      else dispose();

    }

  });

  observable = observable[$$observable] ? observable[$$observable]() : observable;

  dispose = observable.subscribe({

    next: x => sink(1, x),

    error: e => sink(2, e),

    complete: () => sink(2)

  });

};

module.exports = fromObs;