A quick tutorial on how to create an observable in Angular 9

The concept of Observables in Angular is extremely useful. Observables provide support for passing messages between publishers and subscribers inside an angular application.

Observables offer significant benefits for event handling, asynchronous programming, and handling multiple values.

Think of Observables as declarative. In other words you define a function for publishing values, but it is not executed until a consumer subscribes to it. The subscribed consumer then receives notifications until the function completes, or until they unsubscribe.

You can think of the concept of Observables using the following analogy:

An author on the Medium platform is considered a publisher. Authors publish stories for readers to enjoy. Members on the medium platform can choose to follow authors/publishers. As soon as members choose to follow they will start receiving notifications of new articles upon publishing. This act of notification will only occur if the member is subscribed to the author. Member can choose to stop notifications by unsubscribing to the author (or perhaps stopping notification via the medium settings).

Create Observables

To create an observable example we need to create a shell angular project so that we can utilize to implement this exercise. To create a new angular project using the CLI please follow the steps is the section below.