buffertoggle.md

bufferToggle

signature: bufferToggle(openings: Observable, closingSelector: Function): Observable

Toggle on to catch emitted values from source, toggle off to emit buffered values as array.

Examples

Example 1: Toggle buffer on and off at interval

( StackBlitz | jsBin | jsFiddle )

// RxJS v6+
import { interval } from 'rxjs';
import { bufferToggle } from 'rxjs/operators';

//emit value every second
const sourceInterval = interval(1000);
//start first buffer after 5s, and every 5s after
const startInterval = interval(5000);
//emit value after 3s, closing corresponding buffer
const closingInterval = val => {
  console.log(`Value ${val} emitted, starting buffer! Closing in 3s!`);
  return interval(3000);
};
//every 5s a new buffer will start, collecting emitted values for 3s then emitting buffered values
const bufferToggleInterval = sourceInterval.pipe(
  bufferToggle(startInterval, closingInterval)
);
//log to console
//ex. emitted buffers [4,5,6]...[9,10,11]
const subscribe = bufferToggleInterval.subscribe(val =>
  console.log('Emitted Buffer:', val)
);

Example 2: Toggle buffer on and off on mouse down/up

( StackBlitz )

import { fromEvent } from 'rxjs';
import { bufferToggle } from 'rxjs/operators';

fromEvent(document, 'mousemove')
  .pipe(
    bufferToggle(fromEvent(document, 'mousedown'), _ =>
      fromEvent(document, 'mouseup')
    )
  )
  .subscribe(console.log);

Additional Resources

• bufferToggle 📰 - Official docs

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📁 Source Code: https://github.com/ReactiveX/rxjs/blob/master/src/internal/operators/bufferToggle.ts