O'Reilly logo

Web App Testing Using Knockout.JS by Roberto Messora

Stay ahead with the world's most comprehensive technology and business learning platform.

With Safari, you learn the way you learn best. Get unlimited access to videos, live online training, learning paths, books, tutorials, and more.

Start Free Trial

No credit card required

The ViewModel in detail

A ViewModel is a pure-code representation of the View. We saw in the previous sections that it contains data to show and commands that handle events triggered by the user.

It's important to remember that a ViewModel shouldn't have any knowledge about the View and the UI. Pure-code representation means that a ViewModel shouldn't contain any reference to HTML markup elements (buttons, text-boxes, and so on.) but only pure JavaScript properties and methods.

Knockout.JS is a JavaScript implementation of the Model-View-ViewModel presentation design pattern whose objective is to promote a clear separation between the View and ViewModel. This principle is called Separation of Concerns.

Why is this so important? The answer is quite ...

With Safari, you learn the way you learn best. Get unlimited access to videos, live online training, learning paths, books, interactive tutorials, and more.

Start Free Trial

No credit card required