In Chapter 7, Introduction to Angular, we mentioned the http client as a means of communication between the Angular 2 application and your backend API. Since the REST architecture is well structured, it would be quite easy to implement a service for our Angular module, which we'll provide to our components with an API in order to communicate with the server. To do that, the Angular http client utilizes the Observable pattern to deal with its asynchronous nature, so before we continue, it would be best to quickly review this powerful pattern.
In programming, we mostly expect things to run in a serial way, where all of our instructions occur in an order. Alas, from its beginning, web application development suffered from a lack of synchronicity. This is especially a problem when dealing with data and, more specifically in our case, data that is retrieved from the server. To solve this issue, various different patterns were created, from...