buffer
signature: buffer(closingNotifier: Observable): Observable
Collect output values until provided observable emits, emit as array.
Examples
Example 1: Buffer until document click
( StackBlitz | jsBin | jsFiddle )
// RxJS v6+
import { interval, fromEvent } from 'rxjs';
import { buffer } from 'rxjs/operators';
//Create an observable that emits a value every second
const myInterval = interval(1000);
//Create an observable that emits every time document is clicked
const bufferBy = fromEvent(document, 'click');
/*
Collect all values emitted by our interval observable until we click document. This will cause the bufferBy Observable to emit a value, satisfying the buffer. Pass us all collected values since last buffer as an array.
*/
const myBufferedInterval = myInterval.pipe(buffer(bufferBy));
//Print values to console
//ex. output: [1,2,3] ... [4,5,6,7,8]
const subscribe = myBufferedInterval.subscribe(val =>
console.log(' Buffered Values:', val)
);
Related Recipes
Additional Resources
- buffer - Official docs
- Transformation operator: buffer - André Staltz
Source Code: https://github.com/ReactiveX/rxjs/blob/master/src/internal/operators/buffer.ts