Reactive programming and the NgRx library
Angular, the leader of a new generation of web frameworks

Angular integrates the principles of the reactive programming paradigm through the use of the RxJs library. Initiated from the "observer" design pattern, reactive programming, as implemented in this library, enables data streams (observables) to be scanned, and each time a piece of data is received in a stream, a processing operation to be invoked.

Let's return to the TypeScript class that manages the Products component contained in the produits.component.ts file. We saw that the constructor of this class created a variable named produitsService of type ProduitsService :