function
stable
Attaches a timestamp to each item emitted by an observable indicating when it was emitted
timestamp<T>(scheduler: SchedulerLike = async): OperatorFunction<T, Timestamp<T>>
scheduler | Optional. Default is Type: |
OperatorFunction<T, Timestamp<T>>
:
The timestamp
operator maps the source observable stream to an object of type {value: T, timestamp: R}
. The properties are generically typed. The value
property contains the value and type of the source observable. The timestamp
is generated by the schedulers now
function. By default it uses the async scheduler which simply returns Date.now()
(milliseconds since 1970/01/01 00:00:00:000) and therefore is of type number
.
In this example there is a timestamp attached to the documents click event.
import { fromEvent } from 'rxjs'; import { timestamp } from 'rxjs/operators'; const clickWithTimestamp = fromEvent(document, 'click').pipe( timestamp() ); // Emits data of type {value: MouseEvent, timestamp: number} clickWithTimestamp.subscribe(data => { console.log(data); });
© 2015–2018 Google, Inc., Netflix, Inc., Microsoft Corp. and contributors.
Code licensed under an Apache-2.0 License. Documentation licensed under CC BY 4.0.
https://rxjs.dev/api/operators/timestamp