callbag-share

callbag-share

Callbag operator that broadcasts a single source to multiple sinks. Does reference counting on sinks and starts the source when the first sink gets connected, similar to RxJS .share(). Works on either pullable or listenable sources.

npm install callbag-share

example

Share a listenable source to two listeners:

const interval = require('callbag-interval');
const observe = require('callbag-observe');
const share = require('callbag-share');

const source = share(interval(1000));

observe(x => console.log(x))(source); // 0
                                      // 1
                                      // 2
                                      // 3
                                      // ...

setTimeout(() => {
  observe(x => console.log(x))(source); // 3
                                        // 4
                                        // 5
                                        // ...
}, 3500);

Share a pullable source to two pullers:

const fromIter = require('callbag-from-iter');
const share = require('callbag-share');

const source = share(fromIter([10,20,30,40,50]));

let talkback;
source(0, (type, data) => {
  if (type === 0) talkback = data;
  else console.log('a' + data);
});

source(0, (type, data) => {
  if (type === 1) console.log('b' + data);
});

talkback(1); // a10
             // b10
talkback(1); // a20
             // b20