Observable

An observable is:

A pushable collection of multiple values
Is a stream of data or a source that can arrive over time
Observables are mostly created from events - e. g. mouse actions, clicks, text input

Usually, we have a Data Provider. Then we have an Observable on this Data Provider.
The Observable pushes to our subscribers / observers.

Observables should be created with an $at the end to highlight it.

Observables only

Creating Observables:

of is an operator to create an Observable
fromEvent

Example

import { Observable } from 'rxjs';

const observable = new Observable(subscriber => {
  subscriber.next('Hello');
  subscriber.next('World');
  subscriber.complete();
});

observable.subscribe({
  next(x) { console.log(x); },
  complete() { console.log('Done'); }
});

This will log "Hello" and then "World".
After this, completewill close the observable. any other calls of nextwould not push a notification.

Creating observables

Mostly created using functions like of , fromand interval.

When creating an observable, it takes in the subscribe function as the only parameter.

Observable

Example

Creating observables

Oberservers