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bufferWhen

signature: bufferWhen(closingSelector: function): Observable

Collect all values until closing selector emits, emit buffered values.

Examples

Example 1: Emit buffer based on interval
// RxJS v6+
import { interval } from 'rxjs';
import { bufferWhen } from 'rxjs/operators';
//emit value every 1 second
const oneSecondInterval = interval(1000);
//return an observable that emits value every 5 seconds
const fiveSecondInterval = () => interval(5000);
//every five seconds, emit buffered values
const bufferWhenExample = oneSecondInterval.pipe(
bufferWhen(fiveSecondInterval)
);
//log values
//ex. output: [0,1,2,3]...[4,5,6,7,8]
const subscribe = bufferWhenExample.subscribe(val =>
console.log('Emitted Buffer: ', val)
);

Additional Resources