Although this book assumes a comfortable level of familiarity with Backbone.js, Underscore.js, and jQuery, we will briefly touch upon the basics of Backbone.js application development.
Backbone.js provides abstractions and useful functionality for architecting and developing JavaScript web applications. Backbone.js brings order to the chaotic interactions between program and display logic, DOM events, and backend communication. This is achieved via what could loosely be considered a Model-View-Controller (MVC) paradigm that separates application code into the following topics:
Data modeling and retrieval
Display rendering and user interactivity
Brokering data and display logic to appropriately bind and manipulate data models and user interfaces
Note
Backbone.js does not completely follow a traditional MVC approach, causing some observers to call it an MV* framework. An MV* application has a model and a view but has something other than a controller connecting the model and the view. For a much more detailed discussion on MVC and the various MV* approaches, see Developing Backbone.js Applications by Addy Osmani, and the article, Journey Through The JavaScript MVC Jungle (http://coding.smashingmagazine.com/2012/07/27/journey-through-the-javascript-mvc-jungle/).
To this end, Backbone.js provides a set of core library components:
Events: The Backbone.Events module gives JavaScript objects the ability to emit and respond to events, including built-in Backbone.js class events as well as custom application events.
Models: The Backbone.Model class provides a data wrapper that can synchronize with a backend, validate data changes, and emit events to other parts of a Backbone.js application. A model is the fundamental unit of data in a Backbone.js application.
Collections: The Backbone.Collection class wraps a set of models in an ordered list. Collections provide events, backend synchronization, and many helper methods for manipulating and mutating the set of underlying models.
Views: A Backbone.View object is the glue that binds models, collections, and templates together with the browser environment and DOM. Backbone.js is deliberately agnostic as to what a view must do, but a typical view references a collection or a model, couples data to the user interface via a template, and mediates user interaction and backend server events. To clarify potentially confusing terminologies, Backbone.View is much more analogous to a traditional MVC controller, and a Backbone.js template acts like an MVC view.
Routers: Backbone.js programs are commonly developed as single-page applications in which the entire HTML page source and JavaScript libraries are downloaded in a single page load. Backbone.Router maintains the internal state of the application and manages the browser history. Routers provide client-side routing via URL hash fragments (#app-page) to allow different views to be linked to, bookmarked, and navigated like traditional web pages.
In the chapters that follow, we will test these components separately and together, so it is important to ensure a solid grasp of the fundamentals. The core documentation at http://backbonejs.org is a good starting point for the concepts, API, and pointers and tips on application development. For a deeper dive into Backbone.js topics, there are many great online and print resources, including:
Developing Backbone.js Applications by Addy Osmani, which is a Creative-Commons-licensed book developed with the help of the open source community on GitHub. This book discusses the theory, architecture, and fundamentals of creating Backbone.js applications (https://github.com/addyosmani/backbone-fundamentals).