JavaScript Web Applications

Chapter 12. The Backbone Library

Backbone is an excellent library for building JavaScript applications. Its beauty is in its simplicity; the library is very lightweight, giving you a great deal of flexibility while covering all the basics. As with the rest of this book, MVC is the name of the game, and that pattern runs right through the core of Backbone. The library gives you models, controllers, and views—the building blocks for your application.

How is Backbone different from other frameworks, such as SproutCore or Cappuccino? Well, the main difference is Backbone’s lightweight nature. SproutCore and Cappuccino provide rich UI widgets and vast core libraries, and they determine the structure of your HTML for you. Both frameworks measure in the hundreds of kilobytes when packed and gzipped, as well as many megabytes of JavaScript, CSS, and images when loaded in the browser. By comparison, Backbone measures just 4 KB, providing purely the core concepts of models, events, collections, views, controllers, and persistence.

Backbone’s only hard dependency is underscore.js, a library full of useful utilities and general-purpose JavaScript functions. Underscore provides more than 60 functions that deal with—among other things—array manipulation, function binding, JavaScript templating, and deep-equality testing. It’s definitely worth checking out Underscore’s API, especially if you’re doing a lot of work with arrays. Other than Underscore, you can safely use jQuery or Zepto.js to help ...