https://github.com/franciscotln/callbag-take-until

Callbag that emits the source values until a notifier Callbag emits a value
https://github.com/franciscotln/callbag-take-until

Last synced: 3 months ago
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Callbag that emits the source values until a notifier Callbag emits a value

• Host: GitHub
• URL: https://github.com/franciscotln/callbag-take-until
• Owner: franciscotln
• License: mit
• Created: 2018-03-20T17:21:15.000Z (almost 7 years ago)
• Default Branch: master
• Last Pushed: 2023-03-04T02:36:35.000Z (almost 2 years ago)
• Last Synced: 2024-09-15T10:40:39.427Z (4 months ago)
• Language: JavaScript
• Size: 44.9 KB
• Stars: 6
• Watchers: 2
• Forks: 1
• Open Issues: 1
• Metadata Files:
  • Readme: readme.md
  • License: LICENSE

Awesome Lists containing this project

• awesome-callbags - take-until

README

        
# callbag-take-until

- Emits the values emitted by the source Callbag until a notifier Callbag emits a value.

- Works on either pullable or listenable sources.

- NOTE: if the notifier immediately completes without emitting any data (i.e.: callbag-empty) the source callbag will NOT be terminated.

`npm install callbag-take-until`

## Examples

### Listenables

Drag and drop:

[Demo Here](https://codesandbox.io/s/zwjnjnn25p)

```js

import forEach from 'callbag-for-each';

import fromEvent from 'callbag-from-event';

import map from 'callbag-map';

import pipe from 'callbag-pipe';

import switchMap from 'callbag-switch-map';

import takeUntil from 'callbag-take-until';

const getCoords = downEvt => moveEvt => {

  moveEvt.preventDefault();

  return {

    left: moveEvt.clientX - downEvt.offsetX,

    top: moveEvt.clientY - downEvt.offsetY

  };

};

const ball = document.querySelector('.drag-ball');

const mouseDown$ = fromEvent(ball, 'mousedown');

const mouseUp$ = fromEvent(ball, 'mouseup');

const mouseMove$ = fromEvent(document, 'mousemove');

pipe(

  mouseDown$,

  switchMap(downEvt =>

    pipe(

      mouseMove$,

      map(getCoords(downEvt)),

      takeUntil(mouseUp$)

    )

  ),

  forEach(({ left, top }) => {

    ball.style.left = `${left}px`;

    ball.style.top = `${top}px`;

  })

);

```

## Listenable source that will not be terminated

```js

const empty = require('callbag-empty');

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

const pipe = require('callbag-pipe');

const subscribe = require('callbag-subscribe');

const takeUntil = require('callbag-take-until');

pipe(

  interval(500),

  takeUntil(empty()),

  subscribe({

    next(v) {

      console.log('value', v);

    },

    complete() {

      console.log('done'); // won't ever be called

    }

  })

);

```

### Pullables

Immediatelly "unsubscribe" from the source:

```js

const forEach = require('callbag-for-each');

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

const pipe = require('callbag-pipe');

const takeUntil = require('callbag-take-until');

pipe(

  fromIter([1, 2, 3]),

  takeUntil(fromIter('a')),

  forEach((x) => {

    console.log(x); // void (immediately stops pulling)

  })

);

```