KnockoutJS is a framework that implements a lot of the principles found in MVVM and makes it easier to apply. In this chapter, we're going to use the following two features of KnockoutJS, and it's therefore important to understand what they are and what significance they have:
Observables: In order for a view to be able to know when state change in a ViewModel occurs, KnockoutJS has something called an observable for single objects or values and an observable array for arrays.
BindingHandlers: In the view, the counterparts that are able to recognize the observables and know how to deal with its content are known as BindingHandlers. We create binding expression in the view that instructs the view to get its content from the properties found in the binding context. The default binding context will be the ViewModel, but there are more advanced scenarios where this changes. In fact, there is a BindingHandler that enables you to specify the context at any given time...