clerx 💁

A Timely Suite of RxJS Operators and Observables

Install

npm install clerx

Try out the example

Operators

As defined in the RxJS docs:

Operators are the essential pieces that allow complex asynchronous code to be easily composed in a declarative manner. Operators are functions.

rateLimiter(count, slidingWindowTime)

Defer sending events if count events occur within slidingWindowTime (milliseconds). Optionally, stop deferring if the wait time goes past timeoutDue. Returns an Observable.

Examples

Only send two events within three seconds

In this example, only 2 (count) events are sent during a 3 second (3000 ms slidingWindowTime) sliding window. As displayed in the marble diagram, additional events beyond 2 events in the sliding window will be deferred.

abcdef--g---

> rateLimiter(2, 3000)

ab-cd-ef-g--

Only one event within five seconds

Similarly, this example limits events to one (count) event in a five second (5000 ms slidingWindowTime) window. The marble diagram shows how the events are distributed over time.

-(abc)def

> rateLimiter(1, 5000)

-a----b----c----d----e----f----

Observables

As defined in the RxJS docs:

Observables are lazy Push collections of multiple values.

postDelay(event: T, dueTime): Observable<T>

Creates an observable that emits the event then waits dueTime (milliseconds) before closing the observable, like so:

event--{ dueTime }--|

Example: Delay 5 seconds after emitting an event

> postDelay("a", 5000)

a----|

intervalBackoff(backoff: number): Observable<number>

Creates an Observable that emits sequential numbers in an exponentially increasing interval of time. backoff is the starting time interval, in milliseconds, and will exponentially increase with each event.

Example: Exponentially increase delay starting at a one second interval

The marble diagram illustrates the exponentially growing duration between events.

> intervalBackoff(1000)

01-2---3-------4---------------5