Going forward, we'll start dealing with user-generated content within our application and therefore require a minimal setup that allows us to deal with users correctly. We're creating a model to represent users as well as a simple user service that will tell us about the currently logged in user. Our service will just act as a mock user service and concerns like registration, login, and authentication are not within the scope of this book.

Let's stick to the practice we've established within this book and start by introducing the model for our users. Let's open the src/app/model.ts file and add the following interface at the end of the file:

export interface User {
  readonly id?: number;
  readonly name: string;
  readonly pictureUrl: string;
}

Let's keep this as minimal as possible. Our users will consist of only an ID, name, and...