We now have a cart application. To make it work as a real-world app, we need it to get data from a server. However, this book is focused on how to develop a project using KnockoutJS, not on how to configure and run a server.

Fortunately, this situation occurs in every project. Frontend developers begin to work just with the data specification and without any backend servers.

In this chapter, we are going to build a fully-functional frontend communication layer without a server at the backend. To succeed in this task, we are going to mock our data layer with fake objects. When we remove the mock layer, our application will be able to work with real data. This will help us to develop our applications faster and safer: faster because we don't need to wait for a real server response, and safer, because our data manipulation doesn't affect the real server.